METHOD FOR PRODUCING A LIQUID BIOFUEL OR AT LEAST ONE OF ITS PRIMARY COMPONENTS

Abstract

closes a method for producing a liquid fuel or at least one of its primary components from carbonaceous material, wherein a concatenation of individual processes, which make up the entire method, are employed. The concatenation of processes employed in said novel method has the potential to provide an exothermic operation during the production of the liquid fuel, or the at least one primary component, thereby producing a portion of its own raw material, supplying the majority of its energy requirements and consuming the majority of its byproducts, which in turn reduces feedstock reactant requirements for said method.

Description

BACKGROUND OF THE INVENTION

[0001]1. Field of Invention

[0002]The present invention relates to a method for producing a liquid motor fuel or at least one its primary components, which is industrially applicable in the fields of biological fuel technology and energy. More particularly, it relates to a method of producing a liquid biological fuel (i.e., "biofuel") or at least one its primary components from a carbonaceous material, wherein said method is versatile to adapt to different production line arrangements and at least one of said mentioned production line arrangements offers the potential for an exothermic output which provides a majority of the energy required by said method for that at least one production line arrangement, and the mentioned method provides at least part of the raw material requirements.

[0003]2. Description of the Prior Art

[0004]The production of motor fuels from biomass is known in the prior art. Particular fuels that are produced include methanol, ethanol, biodiesel or synthetic hydrocarbons obtained through the Fisher-Tropsch process, which focuses on a single line production process to produce a single application fuel product, usually either being a substitute for gasoline or diesel fuel for internal combustion engines.

[0005]The inventors know the following patents in the prior art. In regards to patents related to biomass and synthesis gas, there are patents that disclose methods related to the use of photo-bioreactor systems using the biomass coming there from as the feedstock to feed a combustion unit to produce liquid fuels. However, none produce a highly oxygenated fuel component or integrating individual production fuel components production lines, in a way that each line is independent from the other, and when both are implemented simultaneously, complement each other and produce a versatile highly oxygenated liquid fuel that may substitute fossil fuels.

[0006]U.S. Pat. No. 7,214,720 to Bayle et al. discloses a method for producing a liquid fuel from biomass using high temperature pyrolysis and then the Fisher-Tropsch process, followed by a fractioning of the resulting products.

[0007]U.S. Pat. No. 6,824,682 to Branson discloses a method for producing methanol by generating synthesis gas from an anaerobic digestion of agricultural waste, and then reforming the aforementioned gas and producing the methanol there from.

[0008]U.S. Pat. No. 6,685,754 to Kindig et al. discloses a method for converting carbonaceous material into synthesis gas, which is then converted to methane or methanol. This invention focuses on the transformation of coal and provides processes for the control of the hydrogen to carbon monoxide ratio towards the production of methane or methanol.

[0009]U.S. Pat. No. 5,344,848 to Steinberg et al. discloses a process for the production of methanol from synthesis gas, which is obtained from a condensed carbonaceous feedstock in a hydro-gasification process. The aforementioned gas is treated in a steam pyrolysis system with additional natural gas to produce a synthesis gas having fixed hydrogen to carbon monoxide ratio for producing a resultant methanol.

[0010]Also known in the prior art are processes that synergistically produce some biomass in photo-bioreactors, which is then used as a raw material. In some cases, these prior art processes propose the use of the synthesis gas for the generation of electricity.

[0011]US Patent Application Publication No. 2008/0009055 to Lewnard discloses a process for using a photo-bioreactor system to remove pollutants from a gaseous stream produced by an oil sands facility. The biomass produced in the photo-bioreactor system is used as fuel source and for cutting stock.

[0012]US Patent Application Publication No. 2005/0260553 to Berzin discloses a photo-bioreactor process in which micro-algae may be grown and then integrated with a combustion system, wherein photosynthetic organisms from the photo-bioreactor are a fuel source for the combustion device. The process includes synergetic features like using the heat from the flue gas coming from the combustion device to dry the photosynthetic organisms. Also, water recovered from the process is used for the photosynthetic organisms growing medium. Furthermore, the photo-bioreactor functions as a gas treatment to remove pollutants of the gaseous stream coming from the combustion device. However, it does not include a method to obtain a liquid fuel for conventional engines.

[0013]US Patent Application Publication No. 2005/0239182 also to Berzin discloses a process that employs a photo-bioreactor, which is part of a production process for producing an organic molecule-containing product from biomass produced in the photo-bioreactor apparatus. The photo-bioreactor functions as a CO₂ and NO_x pollutant remover and the biomass produced therein is harvested and utilized as a source for generating polymers and/or organic molecule-containing products and/or as a fuel source for a combustion device.

[0014]US Patent Application Publication No. 2005/0064577 again to Berzin discloses a process employing a photo-bioreactor system, wherein photosynthesis is carried out or hydrogen may be directly produced from the microorganisms through alternative metabolism paths. The photo-bioreactor system is part of a production process for producing hydrogen from biomass in the photo-bioreactor apparatus. The photo-bioreactor functions as a CO₂ and NO_x pollutant remover.

[0015]US Patent Application Publication No. 2008/0052987 to Busch et al. discloses systems and methods for growing microorganisms in enclosed units, which are used to obtain and process and distribute molecules useful for bio-fuels.

[0016]Further known to Applicants is prior art related to the utilization of synthesis gas in energy or fuels generation processes that decompose, into simpler elements, the tar oil that is obtained on a first pyrolysis or gasification stage. However, the separation of the tar oil is problematic and the conversion into simpler gaseous compounds requires very high temperatures and therefore considerable amounts of energy. The use of plasma chambers to carry out the tar oil conversion represents a valuable option, as it also may work as a steam reformer, a char converter and ash separator. There are patents related to the use of plasma to reform fuel gases.

[0017]US Patent Application Publication No. 2007/0261303 to Surma et al. discloses a system that employs a plasma unit, which converts char and products of incomplete combustion, coming from a previous gasification unit, into a hydrogen-rich gaseous stream. The gasification unit is fed with organic materials and the output there from is sent to a joule heated vitrification unit to convert the ash coming from the gasification unit into glass like material.

[0018]Applicants are also aware of prior art relating to a dimethyl carbonate single production line. Many fuel components, added in proportions over 5% v/v, are known in the industry and many of them are currently applied to fossil fuels for improving the performance of diesel or gasoline engines. Some of these additives have limited application due to their high cost or environmental and/or health implications. Further, not all of these fuels are sufficiently versatile so as to have a measurable positive impact on the performance on both diesel and gasoline engine fuel mixtures. Dimethyl carbonate is a low toxicity biodegradable fuel component, which has unique chemical properties that it can improve the octane number for gasoline engine fuel mixtures and improve the cetane number for diesel engine fuel mixtures. Dimethyl carbonate represents a good option to substitute environmentally threatening methyl tert-butyl ether as an octane or cetane improver. A traditional path to produce dimethyl carbonate is from methanol, oxygen and carbon monoxide.

[0019]However, no one hereto before has disclosed or taught, let alone employed, a synergetic production method wherein a dimethyl carbonate production line is integrated with a photo-bioreactor system and other highly oxygenated fuel components production line, which generates biomass and oxygen as a byproduct, such that the biomass can be used to generate a synthesis gas, which contains carbon monoxide, and at least part of the synthesis gas is then used to produce methanol.

[0020]What Applicants know relates to conventional path processes that produce dimethyl carbonate from methanol, oxygen and carbon monoxide, independently of how these components are produced. For example, U.S. Pat. No. 5,523,452 to Kricsfalussy et al. discloses a system for the production of dimethyl carbonate, in the presence of molten copper salts based catalysts, from carbon monoxide, methanol and oxygen in a distillation reactive column, which allows the withdrawal of water from the reaction system.

[0021]Applicants have processes related to dimethoxymethane and higher polyoxymethylene dimethyl ethers which have structures represented by the formula:

CH₃O(CH₂O)_n CH₃

where n is a whole number representing an example of fuel additives that are capable of being added to diesel and gasoline engine fuel mixtures to improve the performance. However, none of the prior art can employ this product into a production line, starting from biomass when the production path involves the reaction of methanol and formaldehyde.

[0022]U.S. Pat. No. 6,437,195 to Hagen et al. discloses a process to produce dimethoxymethane and polyoxymethylene dimethyl ethers from a feed stream containing methanol and formaldehyde, wherein the later is produced from the first. The reaction is carried out in a reactive distillation column packed with an acidic catalyst activated by an organic acid.

[0023]None of the above-mentioned prior art fulfills the need for a synergetic process or sequence of processes for producing a liquid fuel, wherein byproducts and energy of one process can be used by the other processes so as to provide all of the required caloric energy and at least part of the raw material. Such process is clearly needed.

SUMMARY OF THE INVENTION

[0024]There is need for a process or sequence of processes for producing a liquid fuel through an overall process that enhances synergy for which certain operation arrangements provide an exothermic process, for providing a thermal energy integration, which eliminates the need for external hot services, while byproducts of one process within the sequence are used by other processes, thus decreasing reactant input for a given production volume; and at least part of the raw material for the entire process is provided internally.

[0025]The present invention fulfills these aforementioned needs by employing a concatenation of processes that has the potential to lower the overall external energy and raw material requirements. Our novel method provides a synergy to produce an exothermic process, which harvests at least part of its own raw material thereby enhancing synergy and reducing the "outsource feedstock to end product volume ratio". Our novel method also uses two independent, but complementary, production lines for providing an unknown hereto before level of synergy in regards to mass and energy, as compared to any known individual fuel component production lines of the prior art. Our novel method is capable of providing a concatenation of unit operations and/or equipments that result in an exothermic operation and generates biomass and oxygen as byproducts that are simultaneously consumed by its own processes within the overall system.

[0026]The primary steps of the method include producing at least part of the carbonaceous material used as feedstock, from photosynthetic organisms, in at least one photo-bioreactor: [0027]a) producing a primary synthesis gas, from the carbonaceous material; [0028]b) reformulating the primary synthesis gas to produce a reformulated synthesis gas stream having a fixed hydrogen to carbon monoxide ratio; [0029]c) producing at least one alcohol from the reformulated synthesis gas; [0030]d) producing at least one aldehyde, from at least one alcohol; [0031]e) producing a first individual liquid fuel primary component and by making said at least one alcohol react with oxygen and some of the carbon monoxide from the reformulated synthesis gas; and/or [0032]f) producing a second liquid fuel primary component from the at least one alcohol and the at least one aldehyde;and then producing the liquid fuel by mixing the first and second liquid fuel primary components, in a multitude of varying proportions, during or after both liquid fuel primary components are produced.

[0033]With more particularity, the present novel invention relates to a concatenation of processes (hereinafter "COP"), for the production of a liquid fuel, or at least one of the liquid fuel primary components, made from a carbonaceous material. The innovation provides a synergy, which generates a process that is exothermic and providing to the entire process, all hot service requirements, and produces at least part of its raw material, all the while reducing "outsource feedstock to end product volume ratio" by consuming the majority of its byproducts.

[0034]The COP comprises at least six steps. The first is the generation of at least part of the carbonaceous material, which is used as feedstock or raw material, in at least one photo-bioreactor, where at least one species of photosynthetic organisms is grown and harvested, and at least one of the species of said photosynthetic organisms is a species of micro-algae. The at least one photo-bioreactor has access to a light source, artificial or natural, capable of driving photosynthesis therein, with the advantage that byproduct oxygen is recovered and purified in order to function as a reactant in later steps of mentioned concatenation of processes.

[0035]In an alternative embodiment of this invention, the generation of feedstock from photosynthetic organisms may utilize a system of two or more photo-bioreactors operating in parallel, each of them containing at least one species of photosynthetic organisms, allowing to have different organisms in separate units, thus providing the option for driving different metabolism paths and, therefore, producing different byproducts. For example, one photo-bioreactor may contain the species chlorella carrying out photosynthesis which releases oxygen as a byproduct and another unit may contain dunaliella salina which under given feeding conditions drives a metabolism path that produces hydrogen as a byproduct, thus hydrogen and oxygen may be simultaneously obtained from the photo-bioreactor system.

[0036]If the feedstock requirements for the COP is not fulfilled with said at least one species of harvested photosynthetic organisms, it is completed with carbonaceous material coming from an outsource and may comprise, but is not limited to, vegetal biomass coming from fast growing non-food crops such as wild cane and e-grass or agricultural waste. One advantage of the present invention, which enhances its synergy, is that the photo-bioreactor system that produces at least part of the raw material is fed with carbon dioxide, which is a byproduct on a downstream step of COP, as is explained below.

[0037]The second step involves a pre treatment of the total feedstock, which starts by sizing down the particles until they are circa 5 cms, and reducing water content by preheating so as to eliminate part of its water content until about 20%, preferably 10 to 15%. The treated feedstock is then taken to a gasification/pyrolysis unit, using specific flows of water vapor and/or oxygen, where at least part of the oxygen is a byproduct coming from the photosynthesis of the at least one species of photosynthetic organisms mentioned in the first step. Said water vapor and/or oxygen flows have two functions, the first is to assure the generation of a primary synthesis gas, as rich as possible in carbon monoxide and hydrogen; the second one is facilitating endothermic and exothermic reactions, wherein the exothermic ones release more heat than the heat required for the endothermic ones, which makes this unit operation thermally self sustained once it reaches steady state, given that the heat surplus is used to heat the raw material, water vapor, and/or oxygen up to the reaction temperature. The primary synthesis gas contains other compounds, besides the compounds mentioned above, and they are carbon dioxide, alkanes, and tar oil which is a mixture of heavy condensable organic chemical compounds of dissimilar chemical nature.

[0038]A third step of the COP comprises reformulating the above mentioned primary synthesis gas to obtain a stream of reformulated primary synthesis gas, which implies that the composition of the primary synthesis gas is changed to desirable standards given by the chemical processes that lead towards the production of the liquid fuel or at least one of the liquid fuel primary components. In order to carry out the mentioned chemical processes, water and/or oxygen are also required in specific flows and at least part of this oxygen is a byproduct coming from the photosynthesis of the at least one species of photosynthetic organisms mentioned in the first step.

[0039]The reformulation step involves at least one unit, where mentioned chemical processes take place at mild to high temperatures involving water and/or oxygen. This unit or units may include, not being limited to, a steam reformer reactor and/or a water gas shift reactor and/or a plasma reactor and/or a mild to high temperature reactor capable of producing a change in the composition of the primary synthesis gas. The reformulation of the primary synthesis gas transforms the alkanes and tar oil, into carbon monoxide, hydrogen and carbon dioxide.

[0040]The reformulation step also comprises two separation processes, the first is a carbon dioxide separation following mentioned reformulation unit or units, which operate at mild to high temperatures. As mentioned above, said separated carbon dioxide, is used to feed the at least one photo-bioreactor containing at least one species of photosynthetic organisms. The separated carbon dioxide is also used as anti-detonator in the production of the first liquid fuel primary component. However, this represents no more than 1% of the total separated carbon dioxide. The production of carbonaceous material from the at least one photo-bioreactor which is used as feedstock for the gasification/pyrolysis step, is limited by the amount of carbon dioxide herein recovered.

[0041]The second is a carbon monoxide separation, for only the amount that is required as reactant in the production of the first liquid fuel primary component, the rest of the carbon monoxide not removed herein, remains in the reformulated primary synthesis gas stream in the required ratio of hydrogen to carbon monoxide, as given per downstream requirements.

[0042]The fourth step of the at least six steps that comprise the COP is related to the production of an alcohol, which is an intermediate product towards the production of the first and the second liquid fuel primary components. Mentioned alcohol may be methanol or ethanol, preferably methanol.

[0043]Methanol is produced from a feed stream mainly composed of the reformulated primary synthesis gas and contains carbon monoxide, hydrogen and a small amount of carbon dioxide, which molar quantities are determined by a mathematical equation to assure efficient operation. The reaction is carried out using pressure of 40 to 110 bars and temperatures of 200 to 300° C.

[0044]Ethanol is produced in a bio-reactor using micro-organisms that consume carbon monoxide and hydrogen simultaneously and yield the alcohol by fermentation, which is carried out at atmospheric pressure and temperature of 25 to 40° C. Ethanol may also be produced directly from biomass fermentation, providing the disadvantage in relation to the synthesis gas fermentation, that only certain types of biomass and/or certain compounds in the biomass are useful.

[0045]The at least one alcohol mentioned may follow two paths, each of them aiming to the production of one of the two liquid fuel primary components.

[0046]The first fuel primary component comprises dimethyl carbonate, which is produced from methanol, carbon monoxide and oxygen; and/or diethyl carbonate, which is produced from ethanol, carbon monoxide and oxygen. Preferably, the first fuel primary component contains mostly dimethyl carbonate. The carbon monoxide used herein comes from the carbon monoxide partial separation carried out as part of the reformulation step mentioned above, and at least part of the oxygen required comes from the photosynthesis carried out in at least one of the units that the photo-bioreactor system involves. Carbon dioxide is used as anti-detonator to avoid explosion threat and most of it is recycled back to the reaction unit along with non-converted reactants; however, a small amount is constantly fed to replace losses, and it comes from the separated carbon dioxide during the reformulation step.

[0047]The second path that the intermediate alcohol (or alcohols) comprises is the generation of the at least one aldehyde mentioned on step five. The preferred aldehyde is formaldehyde, produced by dehydrogenation of methanol, at mild pressures and temperatures of 300 to 700° C. The methanol conversion in this reaction unit allows an outlet stream containing the formaldehyde only or both, methanol and formaldehyde.

[0048]The second preferred aldehyde is acetaldehyde produced by dehydrogenation of ethanol, at reaction conditions similar to those required for the dehydrogenation of the preferred alcohol methanol. The ethanol conversion in this reaction unit, also provides an outlet stream containing only acetaldehyde, or both, ethanol and acetaldehyde. In an alternative embodiment, both ethanol and methanol may go through a dehydrogenation process, to respectively produce formaldehyde and acetaldehyde, in order to provide a feed stream for the next reaction step to produce the second liquid fuel primary component containing formaldehyde and/or acetaldehyde and methanol and/or ethanol, in any proportion.

[0049]Step five involves a chemical reaction to produce the second liquid fuel primary component. The feed stream to produce mentioned fuel primary component comprises at least one aldehyde produced from methanol or ethanol and at least one alcohol, either methanol or ethanol, taken from the amount of the at least one alcohol not used in the production of the first fuel component and not sent to or not converted in the at least one aldehyde reaction unit.

[0050]The second fuel primary component contains a mixture including dimethoxymethane and/or diethoxymethane and/or diethoxyethane and/or acetal oligoethers. The preferred components to be present in the second fuel primary component are the ones derived from methanol and formaldehyde such as dimethoxymethane, or polyoxymethylene dimethyl ethers, or a mixture of both in any proportion. The second preferred are the ones derived from ethanol and formaldehyde such as diethoxymethane and/or polyoxymethylene diethyl ethers, or a mixture of both in any proportion. Less preferred components present in the second liquid fuel primary component, include other than those mentioned above, which are derived from the reaction in any possible reactant combination between methanol and/or ethanol with formaldehyde and/or acetaldehyde.

[0051]The chain length of the acetal oligoethers, depends on the ratio of alcohol to aldehyde on the feed stream. The higher the proportion of aldehyde on the feed stream, the longer is the chain and the higher is the boiling point of the acetal oligoethers. The reaction is carried out at temperatures between 150 to 250° C. and mild pressures.

[0052]When both the first and second liquid fuel primary components are simultaneously produced, a final step of the COP comprises the mixing of both components in specific proportions, according to the kind of application the fuel will have. The proportion of the first and second liquid fuel primary components on the end product, it is defined by the proportion of alcohol sent to the production path to produce said components, as mentioned above.

[0053]An important feature of this invention is the synergy among processes that is set by using byproducts of one step, as feedstock on other steps.

[0054]Also, water is produced as a byproduct in the catalytic production of the intermediate alcohol, as well as the first and second liquid fuel primary components. Mentioned water byproduct is separated from the outlet stream using membrane technology or preferably using a system based on temperature swing adsorption principles, then the water is treated and utilized in the photo-bioreactor system and/or to obtain steam for the generation of the primary synthesis gas and/or its reformulation step and/or to replace water in at least one of the photo-bioreactors.

[0055]One more novel feature of this invention related to its synergy, is given by the generation of hydrogen as a byproduct in the production of the at least one aldehyde, which joins the reformulated primary synthesis gas; and also, if desired, to the hydrogen coming from the photo-bioreactor system, in order to make the proper feed stream components molar ratio for the production of the alcohol.

[0056]The oxygen produced in at least one photo-bioreactor system unit is purified using membrane technology, filters or preferably by using a pressure swing adsorption system. The oxygen there from recovered is used in the production of the primary synthesis gas and/or the reformulation of mentioned gas and/or the production of the first liquid fuel primary component. If the COP oxygen requirements cannot be satisfied by mentioned oxygen source, an air pressure swing adsorption is used as a preferred system, to fulfill the requirements.

[0057]In an alternative embodiment of the invention, those streams rich in hydrogen that require mild to high pressure in the reformulation step or alcohol production of the COP, may use a compression system that comprises a temperature swing adsorption process. Also, a turbo charger like system may be utilized, as a pressure recovery system, which provides at least part of the pressure, required by certain gaseous streams.

[0058]One advantage of the present invention is that the overall concatenation of processes has the potential to provide an exothermic operation, regardless of the relative proportions of the first and second liquid fuel primary components that is obtained or the fact that only one of mentioned components may be produced. Through a specific heat exchanger network design for a given production arrangement, heat is recovered from the process energy sources, in a way that no external hot services are required for an exothermic operation of the COP, or at least the majority of the thermal heat COP requirements are provided internally by other COP energy sources, given that this invention presents a concatenation of processes containing at least six steps, each step offering different options to approach its objective, and the combination of different approaches provide a different performance from an energy perspective. In the case of the preferred embodiment, if the electricity supplied to generate plasma comes from an electric generator powered by some of the fuel being produced in the COP, the COP becomes not only exothermic but also energetically self-sustained.

[0059]Yet one more advantage of the novel present invention is that liquid fuel of this invention, consisting of the mix of the first and second primary fuel components, is that it can improve its performance when blended with minor fuel component or additive consisting of dibutyl ether diluted in normal butanol. If more lubricity is required to the liquid fuel of this invention, an oil, such as canola or refined palm oil, can be added to said minor fuel component or additive, and if more explosiveness is required to the liquid fuel of this invention, any cetane improver can be added to said minor fuel component or additive.

BRIEF DESCRIPTION OF THE DRAWINGS

[0060]The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description when considered in conjunction with the accompanying drawings in which:

[0061]FIG. 1 illustrates a novel method for producing a liquid biofuel or at least one of its primary components of the present invention in a preferred embodiment for a production arrangement; and

[0062]FIG. 2 illustrates by means of a graph the exothermic and endothermic characteristics of the novel method of the present invention according to a preferred embodiment for a production arrangement, which includes a plasma chamber as the main primary synthesis gas reformulating unit, wherein thermal heat is indirectly provided by electricity and it is not shown on the diagram.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0063]The present invention relates to a concatenation of processes, hereafter COP, for the synergetic production of a liquid fuel or at least one of the liquid fuel primary components, from a carbonaceous material. This synergy has the potential to provide an overall exothermic operation, which provides at least part of its own raw material, and reduces "outsource feedstock to end product volume ratio" requirements by consuming its own main byproducts.

[0064]The COP comprises the following steps: [0065]a) producing at least part of the carbonaceous material used as feedstock, from photosynthetic organisms in a photo-bioreactor system; [0066]b) producing a primary synthesis gas rich in hydrogen and carbon monoxide, from the feedstock mentioned in step a, and if required, from a carbonaceous material outsource; [0067]c) reformulating the primary synthesis gas mentioned in b; [0068]d) producing at least one alcohol from the reformulated primary synthesis gas from c, and [0069]e) producing a first individual fuel primary component using at least part of the at least one alcohol mentioned in step d; and/or [0070]f) producing at least one aldehyde from at least one alcohol mentioned in d, and producing a second individual fuel primary component from at least part of the at least one alcohol mentioned in step d and the at least one aldehyde; [0071]g) producing the liquid fuel, which is a blend in any proportion, of the first and second liquid fuel primary components mentioned in steps e and f, using the fuel as they are produced and/or from storing supplies.

[0072]The term "step" as used herein refers to a stage of the COP that involves one or more equipments and/or unit operations that define an interaction in the overall production system that leads to a determined common objective.

[0073]The term "unit" as used herein refers to individual equipment capable of performing a specific unit operation or causing a physical or chemical change to an inlet stream in a continuous process.

[0074]The term "acetal oligoether" as used herein refers to a group of organic compounds which molecular structure comprises a chain that contains at least 3 carbon atoms and at least two oxygen atoms having the following general molecular form:

CH₃--(CH₂)_n--O--(R--O)--(CH₂)_n--CH₃

Wherein:

[0075]the total chain containing up to about 10 carbon atoms;

[0076]the portion R of the molecule may have the form CH₂ or CH₂--CH₂;

[0077]n can take values of 0 or 1, and does not necessarily have to take the same value for both portions of the molecule form that involve the sub index n.

[0078]The COP that this invention is related to includes aspects and processes that are selected to enhance the synergy between them, while producing a valuable environmental friendly product. This is achieved by establishing interaction among steps and/or units, in which certain byproducts have application in other steps and/or units, thus decreasing operation costs and potentially increasing the production volume of the liquid fuel or at least one of the liquid fuel primary components.

[0079]The phrase "liquid fuel" herein refers to a liquid fuel which main components are oxygenated liquid compounds mixed in any proportion, which are obtained as product from the COP that this invention comprises, and which chemical nature and production reaction path are described in detail below; mentioned liquid fuel can be used in conventional motors and/or the individual fuel primary components may be utilized as components for other motor fuels of biological or fossil nature to enhance the performance.

[0080]The raw material for the COP is carbonaceous material which may comprise, but is not limited to, vegetal biomass preferably coming from agricultural wastes or any sort of fast growing photosynthetic organisms such us, but not limited to, fast growing non food-crops like wild cane, e-grass and miscanthus; more preferably the raw material comes from at least one species of photosynthetic organisms grown in enclosed units, where mentioned photosynthetic organisms comprise at least one species of micro-algae.

[0081]As mentioned in step a, at least part of the total raw material requirement for the COP comes from a photo-bioreactor system, wherein at least one species of photosynthetic organism is grown in the mentioned system, which includes at least one species of micro-algae. A "photo-bioreactor", as used herein, refers to an enclosed apparatus containing, or designed to contain, a liquid medium comprising at least one species of photosynthetic organism and having either a source of light capable of driving photosynthesis associated therewith, or having at least one surface, at least part of which is capable of letting light into the volume containing the at least one species of photosynthetic organism for them to carry out photosynthesis; the design of the photo-bioreactor includes a system within it to harvest at least part of the photo-synthetic organisms growing in it.

[0082]A "photo-bioreactor system" herein refers to one or more photo-bioreactor units, wherein at least one species of photosynthetic organisms is grown and if the photo-bioreactor system comprises two or more units these are set on parallel arrangement.

[0083]Part of the synergetic functionality of the photo-bioreactor system in the COP is that the oxygen produced, as a result of photosynthesis, in at least one of the photo-bioreactor unit or units that comprises mentioned system is, as will be explained in detail below, used in the generation of the primary synthesis gas as in step b and/or its subsequent reformulation as in step c and/or in the production of one of the liquid fuel primary components as in step e. The oxygen produced as a result of the photosynthesis that is driven in at least one of the enclosed units that comprise the photo-bioreactor system is recovered as an oxygen rich gaseous stream and sent to a purification unit, which preferably comprises, but is not limited to, a pressure swing adsorption unit.

[0084]In an alternative embodiment of this invention, when the photo-bioreactor system includes two or more units operating in parallel, each particular unit may have different photosynthetic organisms and/or different feeding conditions, thus driving different metabolism paths and therefore producing different byproducts, as a result of different feeding conditions on each unit. The advantage of this is the flexibility through which two valuable compounds, like hydrogen and oxygen, may be simultaneously produced if, in at least one unit, regular photosynthesis having oxygen as a byproduct is driven by a species like, for example, chlorella; and in at least one unit, a species like, for example dunaliella salina, is kept at feeding conditions that include poor amounts of carbon dioxide and sulfur, which makes this species follow an alternative metabolism path through which the organisms consume its own energy reserves, stops producing oxygen and the enzyme hydorgenase is activated releasing hydrogen in the process.

[0085]If the feedstock requirements for the COP are not fulfilled with the at least one species of harvested photosynthetic organisms from the photo-bioreactor system, the feedstock requirement is completed with carbonaceous material coming from an outsource, which may comprise, but is not limited to, vegetal biomass preferably coming from agricultural waste or from any sort of fast growing non-food crops photosynthetic organisms.

[0086]The second step of the COP, as in b, is related to the production of a primary synthesis gas from the carbonaceous material. The production of mentioned gaseous stream involves steps of:

[0087]i) raw material size reduction, wherein the size of the carbonaceous material, which may comprise a mixture of different sources of carbonaceous material and at least part of which comes from the photo-bioreactor system, is reduced in its size to circa 5 cm, preferably 80% of the mass of the raw material has a size of less than 5 cm. This operation may involve grinding, breaking and cutting in one or more units;

[0088]ii) raw material water content reduction, to circa 20%, preferably between 10 to 15%, depending on the initial water content of the raw material, one or more units are required; between 50 to 80% of the total water content to be eliminated is removed using mechanical mediums which involves, but is not limited to, squeezing or centrifugation; the rest of the water to be removed involves thermal evaporation, which requires one or more drying units with a design determined according to the amount of water to be removed and the solid initial properties, this step may comprise, but is not limited to, units like rotary dryers, fluidized bed dryers and screw dryers;

[0089]iii) gasification and/or pyrolysis of the raw material, which is carried out at mild temperatures, preferably between 600 to 900° C., more preferably between 650 to 700° C., in one or more units, which may involve, but are not limited to, fluidized or fixed bed gasifiers or any other conventional design or adaptation of conventional designs of gasification and/or pyrolysis units. Water vapor and oxygen, are fed in very specific quantities, individually and from 10 to 40% mass of the raw material, to at least one of the units where the gasification and/or pyrolysis takes place, in order to make the overall gasification and/or pyrolysis operation thermally neutral and increasing the relative amounts of hydrogen and carbon monoxide.

[0090]"Primary synthesis gas" as used herein refers to the gas stream which is rich in carbon monoxide and hydrogen, but also contains amounts of other compounds which limit its direct application in a subsequent reaction process, the primary synthesis gas is obtained from a primary thermal treatment of a solid carbonaceous material, which may involve gasification and/or pyrolysis, The primary synthesis gas, besides the mentioned compounds, contains carbon dioxide, alkanes and tar oil, which is a mixture of heavy condensable organic chemical compounds of dissimilar chemical nature.

[0091]On step c, the COP comprises reformulating the above mentioned primary synthesis gas; which implies that the composition of the primary synthesis gas is changed to desirable standards given by the chemical processes that lead towards the production of the liquid fuel or at least one of the liquid fuel primary components. These processes require a maximum amount of carbon monoxide and hydrogen from the feedstock in order to maximize the production volume of the liquid fuel or at least one of the liquid fuel primary components; the maximum proportion of carbon monoxide and hydrogen is achieved by facilitating specific chemical reactions for the alkanes and tar oil contained in the primary synthesis gas with stoichiometric amounts of oxygen and/or water vapor. These reactions are carried out in at least one unit that operates at mild to high temperatures, which may comprise, but is not limited to, a reformer and/or a water gas shift reactor and/or a plasma reactor and/or any other reactor capable of causing a change to the composition of the primary synthesis gas. The units to be used are of conventional design and/or adaptations of conventional designs and the outlet stream from mentioned unit or units contains mainly carbon monoxide, hydrogen and carbon dioxide.

[0092]"Reformulation" is used herein to refer to a COP step that involves more than one unit, which function as a whole is to change the composition of an inlet gaseous stream to desired standards. "Reformulated primary synthesis gas" as used herein, refers to the outlet stream of the reformulation step that has the higher mass flow and contains mainly hydrogen and carbon monoxide, and carbon dioxide in a proportion that is as low as possible and is definitely lower than the content of carbon monoxide.

[0093]The step c for reformulating the primary synthesis gas comprises, as was mentioned above, one or more units to facilitate the chemical reactions that increase the amounts of carbon monoxide and hydrogen according to a specific ratio. Once the chemical conversion stage of the reformulation step is done, most of the carbon dioxide is removed from the output stream, only a small quantity is left with the other gaseous components; thus at this point of the reformulation step, there are two outlet streams, one of them is carbon dioxide and the other contains carbon dioxide, hydrogen and carbon monoxide. The carbon dioxide separation may be carried out using operations that involve, but is not limited to, membranes, pressure swing adsorption or temperature swing adsorption, with liquids or solids, of conventional design or adaptations of conventional designs.

[0094]In an alternative embodiment related to the reformulation step c, of the primary synthesis gas; when the first liquid fuel primary component of step e is produced, a partial carbon monoxide separation is carried out following the carbon dioxide separation mentioned on the previous paragraph. The percentage of the carbon monoxide that is separated is determined by the amount of mentioned first liquid fuel primary component to be produced, which is simultaneously dependent on the amounts available of the other compounds that are reactants in the production of mentioned component, which comprise methanol and oxygen. The availability of mentioned compounds is determined by the operation conditions of other steps and/or units in the COP, as per the synergistic overall operation that is explained in more detail below. The separation of the specific amount of carbon monoxide may be carried out using conventional or adaptation of conventional designs involving, but not limited to, membranes, pressure swing adsorption or temperature swing adsorption in liquids or solids.

[0095]The step d of the COP is related to the production of at least one alcohol; wherein the preferred alcohol is methanol, which is produced in a reaction unit having a feed stream mainly composed of the reformulated primary synthesis gas joined with recycled unconverted reactants from the at least one alcohol production unit and streams from other units of the COP containing one or more of the same components of the reformulated primary synthesis gas, in a way that the molar relation between mentioned components in the total feed stream is given by the following mathematical equation:

X=([H₂]--[CO₂])/([CO₂]+[CO])

[0096]where,

X≧2

[0097][H₂] is the concentration of hydrogen on the feed stream;

[0098][CO₂] is the concentration of carbon dioxide on the feed stream; and

[0099][CO] is the concentration of carbon monoxide on the feed stream.

[0100]In a preferred embodiment, the feed stream has a hydrogen concentration level of between 53% to 66%, a carbon dioxide concentration level of between 8% to 12% and a carbon monoxide concentration level of between 8% to 12%. Further, in the preferred embodiment, the at least one alcohol is chosen from the group of simple organic acyclic alcohols containing from 1 to 4 carbon atoms, preferably from the group of methanol and ethanol, and more preferably methanol.

[0101]The reaction for the production of methanol is preferably carried out in an isothermal reactor at pressures of 50 to 100 bar and temperatures of 200 to 300° C., in the presence of a zinc oxide and/or chromium oxide and/or copper oxide based catalyst.

[0102]A second preferred alcohol is ethanol, which production is carried out in a bioreactor using ethanol-producing bacterium through anaerobic fermentation of synthesis gas. The preferred temperature is around 37° C., normal pressure and a pH comprised between 3 and 6.

[0103]The at least one alcohol is an intermediate product towards the production of the first and the second liquid fuel primary components, therefore the at least one alcohol produced on step d. may follow two paths, each of them aiming for the production of the first and/or the second liquid fuel component. The amount of the at least one alcohol sent in each direction determines the proportion of the components in the final product, which determines whether the final product is more suitable to be used in diesel or gasoline motors. In an alternative embodiment, the proportion of the liquid fuel primary components on the final product liquid fuel may be fixed independently of the flows of the liquid fuel primary components coming from the COP individually, if there are storing tanks containing the liquid fuel primary components from which product is extracted and blended as the formulation requires.

[0104]On step e, the first liquid fuel primary component is produced from the at least one alcohol, carbon monoxide and oxygen. The carbon monoxide that is used herein is the one that is separated (in the carbon monoxide separation) on the reformulation step c; the amount of recovered carbon monoxide therein is determined by the amount of the at least one alcohol sent to the step e and the reaction stoichiometry for the production of the first liquid fuel primary component, which is predetermined according to the fuel components composition required for the final product and/or the individual flows of the liquid fuel components coming out of the COP.

[0105]The molar relation between the reactants on the feed stream to the first liquid fuel primary component production unit containing at least part of the at least one alcohol/carbon monoxide/oxygen is 0.9/1.6/1.0, respectively. The reaction takes place in the presence of a copper chloride and/or potassium chloride based catalyst, at temperatures from 120 to 150° C., preferably 130° C., and pressures from 15 to 25 bar, preferably 20 bar. Since the feed stream is explosive, carbon dioxide is used as anti-detonator, in order to maintain the concentration of oxygen below 22%. Most of the carbon dioxide herein used is recycled back to the reactor along with other unconverted gaseous reactants; however, a small amount is constantly fed to replace losses, which comes from the output carbon dioxide separation of step c and corresponds to no more than 1% of the carbon dioxide therein recovered. The first fuel component herein produced depends on the alcohol from which it is produced, methanol and/or ethanol, yielding respectively, dimethyl carbonate and/or diethyl carbonate; water is produced as byproduct.

[0106]The output mixture from step f that comprises dimethyl carbonate and/or diethyl carbonate, water byproduct and unconverted reactants, is sent to one or more units to achieve the separation of water and dimethyl carbonate and/or diethyl carbonate, from the other compounds, which may comprise, but is not limited to, flash distillation units, packed bed or plates distillation units, pressure or temperature swing adsorption units and/or any other sort of separation system and/or process of conventional designs and/or adaptation of conventional designs.

[0107]On step f, the amount of the at least one alcohol produced on step d not sent to the production of the first liquid fuel component on step e, is then sent on a path towards the production of the second liquid fuel component. The at least one alcohol sent on this path is sent to a reaction unit, according to step f, where at least part of the at least one alcohol, or at least part of one of the alcohols if more than one alcohol is produced, goes through a dehydrogenation reaction to produce the at least one aldehyde, preferably formaldehyde, and hydrogen as a by product.

[0108]In step f, byproduct hydrogen from the dehydrogenation reaction is separated from the other output compounds and joins the reformulated primary synthesis gas stream and the recycled unconverted products from the at least one alcohol production unit and possibly streams from other units of the COP containing one or more of the same components of the reformulated primary synthesis gas, which makes the total feed stream to the step d for the at least one alcohol production unit. The separation of the hydrogen from the other reaction products of the aldehyde reaction unit outlet stream is carried out using a separation system which may involve, but is not limited to, conventional designs and/or equipments and/or adaptation of conventional designs and/or equipments which perform operations of cooling, depressurizing and adsorbing, in packed beds and/or plate columns.

[0109]The reaction to produce the at least one aldehyde in step f takes place at temperatures from 450 to 750° C., preferably 500 to 650° C., and pressures from 1 to 8 bars, preferably 5 bar, in the presence of an iron oxide and/or molybdenum oxide and/or chromium oxide and/or zinc oxide and/or selenium oxide and/or tellurium oxide based catalyst.

[0110]The step f is also related to the production of the second fuel primary component, which is defined by a mixture in any proportions of dimethoxymethane and/or diethoxymethane and/or diethoxyethane and/or polyoxymethylene dimethyl ethers and/or polyoxymethylene diethyl ethers and/or other acetal oligoethers obtained from reactions that comprise methanol and/or ethanol with formaldehyde and/or acetaldehyde as reactants.

[0111]The reaction that originates the second liquid fuel primary component takes place when the outlet stream from the step f where dehydrogenation reaction occurs, where at least one aldehyde is produced, and where also the at least one alcohol with no more than 5% weight of water, is contacted with an acidic catalyst, preferably in a distillation reaction column of a design such that provides a gaseous outlet stream and at least two liquid side streams, one of them containing mainly water and the other, withdrawn near the bottom of the column, is an essentially water-free stream containing a mixture of acetal oligoethers. In order to produce an acid free product, the distillation reaction column comprises an anion exchange resin for at least part of the liquid effluent to get in contact with.

[0112]The reaction for the production of the second fuel primary component is carried out at pressures from 1 to 5 bars and temperatures comprised between 90 to 220° C. The acidic catalyst is a cation exchange resin; it preferably comprises at least one cation exchange resin of the group consisting of styrene-divinylbenzene copolymers, acrylic acid-divinylbenzene copolymers, methacrylic acid-divinylbenzene copolymers or cation exchange resins having sulfonate groups. The acidic catalyst is activated by the presence of a soluble condensation promoting component, which is added to the feed stream and is preferably an organic compound of low boiling point, more preferably a monobasic organic acid like, but not limited to, acetic acid or formic acid.

[0113]Dimethoxymethane and/or diethoxymethane are recovered from the top of the reaction distillation column and are afterwards condensed and mixed together with the less volatile acetal oligoethers. The proportion between Dimethoxymethane and/or diethoxymethane and the less volatile acetal oligoethers that make the second fuel primary component, depends on the proportion of aldehyde to alcohol in the feed stream, the higher the content of aldehyde, the higher the average molecular weight of the acetal oligoethers.

[0114]On step g the liquid fuel is produced by mixing together the first and second liquid fuel primary components directly as obtained from the steps e and f, or if there is storing tanks containing those, the liquid fuel proportions may be defined as required, using stored material and/or the one being produced.

[0115]An important feature of this invention is the synergy among steps and/or units that is set by using byproducts of one-step and/or unit as a commodity on others. This includes the use of the separated carbon dioxide in the reformulation step c, which is used in the photo-bioreactor system for driving photosynthesis and also as anti-detonator in the production of the first liquid fuel component according to step e.

[0116]Also, water is produced as a byproduct in the production of the at least one alcohol on step d as well as the first and second liquid fuel primary components on steps e and f, as mentioned above this water is separated from the output streams, then treated and utilized in the photo-bioreactor system and/or to obtain steam for the generation of the primary synthesis gas and/or its reformulation step.

[0117]One more feature of this invention related to its synergistic functioning is given by the generation of hydrogen as a byproduct in the step f when dehydrogenation occurs from the of at least one alcohol, which joins the reformulated primary synthesis gas and potentially the hydrogen coming from the photo-bioreactor system to make the feed stream for the production of the at least one alcohol.

[0118]Also synergistically, the oxygen produced through photosynthesis in at least one unit of the photo-bioreactor system is purified and used in the production of the primary synthesis gas and/or the reformulation of mentioned gas and/or the production of the first liquid fuel primary component. If the COP oxygen requirements can not be satisfied by mentioned oxygen source, an air separation system is used to fulfill the requirements which may comprise, but is not limited to, conventional designs involving operations of pressure swing adsorption and/or temperature swing adsorption and/or centrifugation and/or variations of conventional designs.

[0119]The following describes the preferred embodiment for the production of the liquid fuel or at least one the liquid fuel primary components in order to better express the individual unit operations that are part of the COP and the interaction between them that defines the synergy of present invention; it is with reference to the attached drawing corresponding to FIG. 1, where not all units are shown in the detail of their design or are not included, e.g. pumps, heat exchangers, compressors, valves, for simplicity purposes. In this explanation, the alcohol is methanol and the aldehyde is formaldehyde; therefore, the first liquid fuel primary component is dimethyl carbonate and the second is a mixture of polyoxymethylene dimethyl ethers with dimethoxymethane in a multitude of various proportions.

[0120]A photo-bioreactor system including at least one enclosed photo-bioreactor unit as in 1, contains at least one species of micro-algae and produces at least part of the feedstock that the COP requires; each unit or units that the photo-bioreactor system 1 comprise has a controlled harvesting system to remove specific amounts of micro-algae according to their growing rate, which is a function of the nutrients feed and light. Besides carbon dioxide, the nutrients include nitrogen, phosphorus, calcium, iron, magnesium, potassium and zinc.

[0121]If the biomass produced in the photo-bioreactor system 1 does not fulfill the feed stock requirements, then biomass coming from an out source is used. Mentioned biomass is grinded and dried, in equipment not shown on the diagram, with design according to the biomass particular properties and output conditions required; 15% humidity and 80% of the total mass with size of 5 cm or less. The feed stock requirements are the same for any sort of biomass going to the gasifier 5.

[0122]The harvested biomass from the photo-bioreactor system 1 is sent to a grinder 2 and dryer system 3, which involves squeezing and thermal evaporation carried out by a counter-current fluidized bed system with a hot gas.

[0123]If the process requires raw material from both, the photo-bioreactor system and an outsource, then the dried material coming from both sources is mixed in a solid mixer unit 19 and fed through a screw 4 to the gasifier 5, where the biomass pyrolysis and partial combustion take place. Thus, water and oxygen are oxidizing agents that are fed in specific amounts, 15 to 25% mass of each in relation to the total raw material feed, to the gasifier 5 to promote chemical reactions and producing energy so as to have a thermal neutral operation in the gasifier 5 at 650-700° C., when steady state is achieved. Preferred biomass outsources are fast growing non food-crops like wild cane (also known as "Arundo donox L." or "Giant Reed"), elephant grass and miscanthus, microalgae and corn stem. However, other outsources include vegetal biomass from agricultural waste.

[0124]Since there is at least one unit in the photo-bioreactor system 1, which micro-algae is driving photosynthesis and therefore producing oxygen, a gaseous stream is withdrawn from mentioned unit or units running photosynthesis towards unit 7, which provides at least part of the COP oxygen requirements, and uses a zeolite bed pressure swing adsorption system to purify the oxygen from the other gaseous components being recovered from the photo-bioreactor system 1.

[0125]If the oxygen recovered on 7 from the photo-bioreactor system 1 does not fulfill the COP requirements, then extra oxygen is supplied by an air zeolite pressure swing adsorption unit, not shown on the diagram, which is fed with air and separates oxygen thereof. There is an oxygen tank connected to the outputs of both oxygen sources, not shown on the diagram, which stores oxygen and serves the COP requirements as of node 28.

[0126]The outlet gaseous stream from gasifier 5, which comprises a fuel gas rich in carbon monoxide, hydrogen, carbon dioxide, water vapor, a mixture of heavy condensable organic compounds known as tar oil and also char and ashes, is sent directly to a plasma chamber 6, where oxygen and water vapor is fed to produce an outlet stream rich in carbon monoxide, hydrogen and carbon dioxide. The molar ratio of hydrogen to carbon monoxide on the plasma output is circa 2, and the amount in mole of carbon dioxide is definitely less than that of carbon monoxide.

[0127]The plasma produced in the plasma chamber 6 generates enough thermal energy to convert, along with the specific amounts of water vapor and oxygen in the chamber, the remaining charcoal and tar oil into hydrogen, carbon monoxide and carbon dioxide. The plasma generated does not necessarily have physical contact with the gaseous stream, but it reaches very high temperatures and produces radiation that provides energy for endothermic reactions to take place. The outlet gaseous stream temperature is circa 1200° C. The plasma is produced through the electrical excitement of the molecules of an inert gas, such as nitrogen or argon. The ash melts inside the chamber because of high temperatures and it is continuously tapped off; when it cools down it is separated as a granite-like glassy slag.

[0128]The output from the plasma chamber 6 is cooled down and the water that remains unconverted is separated on a condenser 34. The gas is cooled to at least normal temperature and brought together in node 20 with another stream, rich in hydrogen and carbon dioxide, coming from a water gas shift reactor 35.

[0129]The water gas shift reactor 35 functions as a reformulation unit since it converts part of the carbon monoxide produced in the gasifier 5 and the plasma chamber 6 to produce hydrogen and fix the hydrogen to carbon monoxide ratio according to downstream requirements. The output form the water gas shift reactor 35 is sent to a condenser before node 22 to recover the excess water, not shown on the diagram, and is recycled to the water gas shift reactor 35.

[0130]The outlet stream from node 20 is directed to a carbon dioxide separation unit 9, which comprises a pressure swing adsorption system, wherein cold methanol, not shown on the diagram for simplification purposes, at a temperature under 0° C. and pressures above 15 bar, is contacted with the gaseous stream to adsorb carbon dioxide, which is recovered by depressurizing the saturated liquid solvent. The outlet stream from separation unit 9 that reaches node 21 is a carbon dioxide free gaseous stream, the top stream from 9 contains circa 99% carbon dioxide.

[0131]The feed stream to the methanol reactor 11 requires carbon monoxide, carbon dioxide and hydrogen in a molar relation determined by the following mathematical equation:

X=([H₂]--[CO₂])/([CO₂]+[CO])

[0132]where,

X≧2

[0133][H₂] is the concentration of hydrogen on the feed stream;

[0134][CO₂] is the concentration of carbon dioxide on the feed stream; and

[0135][CO] is the concentration of carbon monoxide on the feed stream.

[0136]According to that equation, a branch from node 22 is sent to node 25 containing the required amount of carbon dioxide in the methanol reactor 11. The other branch joins the stream coming from the plasma chamber 6 on node 20 before going to the carbon dioxide separation 9.

[0137]The gaseous stream that reaches node 21 derives in two branches, one of them goes to node 23, which also provides two more branches, and one of them comprises the feed stream to the water gas shift reactor 35 and the other goes to unit 10, which is a normal temperature carbon monoxide separation comprising a pressure swing adsorption system with a packed bed, preferably containing an inorganic copper salt, like copper chloride, on alumina. The adsorption stage is carried out at pressures above 15 bar. The carbon monoxide is desorbed from the alumina based packing by using vacuum and the quantity of carbon monoxide separated, which is directed to node 37, corresponds to the requirements of this compound on the first liquid fuel primary component reactor 12. The gaseous carbon monoxide free stream, containing pure hydrogen, is sent directly to node 25 prior to the methanol reactor 11. The other branch from node 21 is sent to node 24 to finally become part of the methanol reactor 11 feed stream coming out of node 25.

[0138]The output from node 25 is the feed stream to the methanol reactor 11, which components come from different units enhancing the COP synergy and as mentioned above, contains carbon monoxide, carbon dioxide and hydrogen in a specific molar relation.

[0139]The output from node 25 comprises controlled molar flows coming from node 22 there from 35, the highly pure hydrogen from 10, the output from node 24; which results from the joint of one branch from node 21 from the carbon dioxide separation 9 and the recycled unconverted gases from separation unit 38 coming from the methanol reactor 11; and finally hydrogen coming from separation unit 17.

[0140]On the methanol reactor 11 the reaction is carried out preferably on an isothermal reactor at temperatures of 250 to 300° C. and pressures above 70 bar. The output stream that contains methanol and water, which is a byproduct, besides unconverted carbon monoxide, carbon dioxide and hydrogen is sent there from to 38 which is a separation packed or plate column, wherein the top stream contains non converted gases that are recycled to the methanol reactor through nodes 24 and 25. The bottom stream contains condensed methanol and water.

[0141]Since methanol is an intermediate product for the production of the first and/or second liquid fuel primary components, node 26 determines the relative proportions of mentioned components at the end of the COP.

[0142]The first liquid fuel primary component corresponds to dimethyl carbonate and it is produced on reactor 12 from methanol coming from node 26, oxygen from node 28 and carbon monoxide, together with carbon dioxide, from node 37, all getting together on node 27 before being compressed up to 20 bar and heat up to 130° C. The reactants are fed in a methanol/carbon monoxide/oxygen molar relation of 0.9/1.6/1.0, respectively, while carbon dioxide functions as an anti-detonator.

[0143]The output from unit 12 contains unconverted reactants, carbon dioxide, dimethyl carbonate, dimethoxymethane and water; of which the two later are reaction byproducts. The gaseous outlet stream from 12 is directed to a flash separation unit 39; wherein a bottom stream containing condensed dimethyl carbonate, dimethoxymethane and water is there from removed, and a top stream containing unconverted carbon monoxide, oxygen and carbon dioxide is recycled back to first liquid fuel primary component reactor 12, through node 27.

[0144]The bottom stream from 39 is sent to separation unit 15, which comprises a temperature swing adsorption system, wherein the liquid stream is pressurized by means of a pump and water is adsorbed on an calcium inorganic salt packed bed, while producing a water free liquid stream containing dimethyl carbonate and dimethoxymethane. The water is desorbed from the packed bed by hot air flowing through it, not shown on the diagram for simplicity purposes. The hot saturated air flow is sent to a condenser, not shown either, wherein water is recovered and the air is recycled to a heat exchanging unit to maintain the desorption cycle.

[0145]The branch from node 26 sent to unit 13 is closely related to the production of the second fuel primary component, which is a mixture in any proportion containing dimethoxymethane and polyoxymethylene dimethyl ethers. Unit 13 corresponds to a reactor where methanol experiences dehydrogenation to produce formaldehyde; the reaction is carried out at 5 bar and 550° C. The conversion of methanol is 50%, thus producing an outlet stream containing methanol, formaldehyde and hydrogen, which is a byproduct and is removed on unit 17, to produce a hydrogen free liquid stream, most of which is sent to unit 18. Mentioned hydrogen separation 18 is carried out at atmospheric pressure on a packed or plate column, wherein the top stream contains highly pure hydrogen, which becomes part of the methanol reactor 11 feed stream through node 25, therefore, increasing the methanol production and thus the liquid fuel production as well. On node 29 a design determined proportion of the bottom stream is recycled to maintain appropriate separation conditions.

[0146]The methanol conversion on unit 13 determines the amount of hydrogen produced, but also, as explained below, the proportions of dimethoxymethane to polyoxymethylene dimethyl ethers, as well as the average chain length for the later, produced on the second fuel primary component reaction unit 14.

[0147]On unit 18 a water separation is carried out in order to maintain the water content on the feed stream to 14 below 5%. This separation comprises a temperature swing adsorption system, wherein the liquid stream is pressurized by means of a pump and water is adsorbed on a calcium inorganic salt packed bed, while producing a water free liquid stream containing methanol and formaldehyde therein. Water is desorbed from the packed bed by hot air flowing through the packed bed, not shown on the diagram for simplicity purposes. The hot saturated air flow is sent to a condenser, not shown either, wherein water is recovered and the air is recycled to a heat exchanging unit to maintain the desorption cycle.

[0148]The water free liquid stream from 18 is sent to a reactive distillation column 14 wherein methanol and formaldehyde react to produce dimethoxymethane that remains gaseous and is withdrawn as the top stream, while polyoxymethylene dimethyl ethers flow to the bottom along with water, which is produced as a byproduct. In a rectification zone on the lower part of column 14, heavier polyoxymethylene dimethyl ethers are withdrawn near the bottom, while water is removed just above. The top dimethoxymethane stream from 14 is condensed on 32 and mixed with the bottoms from 14 and the first liquid fuel component coming from 15 on a regular liquid agitated tank 16.

[0149]In an alternative embodiment, the outlet stream from 15, and the output from node 30 may be sent to storing tanks and thereafter, the liquid fuel component is prepared by mixing the liquid fuel components in any given proportions, which may be different from the proportions in which the liquid fuel primary components are being obtained from unit 15 and node 30.

[0150]One aspect related to the synergy of this invention's COP, is that water produced as a byproduct on units 14, 15, 18 and 36, is recovered and treated on a unit not shown on the diagram for simplicity purposes before node 31, where the treated process water gets together with fresh treated water to supply boiler 8, which produces steam for all COP units that require it.

[0151]FIG. 2 fully shows from above example and for a production arrangement wherein 15% of the methanol input to node 26 is sent to unit 13 for the production of the second liquid fuel primary component, wherein a total production of 210 gal/h is obtained from a 1 ton/h dry biomass feed, how the energy balance is positive in 1084 Kilowatts, this does not include the energy sink that the plasma chamber represents, which is provided by electricity. If this electricity provided to the plasma unit comes from an electric generator powered by the fuel of this invention, the COP becomes self-sustained. The exothermic processes are in red color bars and the endothermic ones are in blue color bars. In the diagram, POX means polyoxymethylene dimethyl ethers, DMC means dimethyl carbonate and RXN means reaction. More particularly, the bars of FIG. 2, represent energy sinks and sources for the above example that may be involved in the COP thermal energy integration in order to minimize hot and cold service requirements, which for this particular example and production arrangement results in not requiring external hot services.

[0152]Other steps can be employed in the novel method of the present invention to achieve the same result in the same way and in the same manner.

Claims

1. A method of producing a liquid fuel or at least one of two liquid fuel primary components for said liquid fuel from carbonaceous materials, the steps of the method comprising:a) providing at least one photo-bioreactor for producing at least a first portion of a total feedstock needed for said method;b) providing a feedstock outsource containing a second portion of a total feedstock needed for said method;c) producing the total feedstock needed by combining the first and second portions of the total feedstock;d) producing a primary synthesis gas from the total feedstock needed, the primary synthesis gas having a formulation rich in hydrogen and carbon monoxide;e) reformulating the primary synthesis gas for producing a synthesis gas stream having a specific hydrogen to carbon monoxide ratio and a source of carbon monoxide not used in producing the synthesis gas stream stored for later use in said method;f) producing at least one alcohol from the synthesis gas stream; andh) producing a first liquid fuel primary component by reacting a provided source of oxygen and a portion of the stored source of carbon monoxide with the at least one alcohol, the first liquid fuel primary component being one of the at least one of two liquid fuel primary components.

2. The method of claim 1, further comprising the steps of:a) producing at least one aldehyde from the at least one alcohol; andb) producing a second liquid fuel primary component from the at least one alcohol and the at least one aldehyde, the second liquid fuel primary component being another one of the at least one of two liquid fuel primary components.

3. The method of claim 2, further comprising the step of:a) producing the liquid fuel by combining the first and second liquid fuel primary components.

4. The method of claim 1, wherein the total feedstock is microalgae.

5. The method of claim 1, wherein the step of producing the primary synthesis gas is a process chosen from the group consisting of gasification and pyrolysis.

6. The method of claim 1, wherein the step of reformulating the primary synthesis gas for producing the synthesis gas stream comprises the step of:a) performing at least one chemical reaction in a unit operating at a temperature sufficient for said at least one chemical reaction to occur for producing an increase in hydrogen and carbon monoxide content to the primary synthesis gas within said unit and thereby forming the synthesis gas stream.

7. The method of claim 6, further comprising the step of:a) providing a source of water or oxygen or a source of water and oxygen to the unit operating at a temperature sufficient for at least one other chemical reaction to occur between the source of water or oxygen or the source of water and oxygen and components of the primary synthesis gas, other than hydrogen, carbon monoxide and carbon dioxide.

8. The method of claim 6, wherein the unit operating at a temperature sufficient for at least one chemical reaction to occur employed in the step of reformulating the primary synthesis gas for producing the synthesis gas stream is chosen from the group consisting of a plasma chamber, a reformer reactor and a water gas shift reactor.

9. The method of claim 6, wherein the unit operating at a temperature sufficient for at least one chemical reaction to occur employed in the step of reformulating the primary synthesis gas for producing the synthesis gas stream comprises a plurality of sub-units used in coincidence, wherein at least two of the plurality of sub-units are employed, the plurality of sub-units chosen from the group consisting of a plasma chamber, a reformer reactor and a water gas shift reactor.

10. The method of claim 1, wherein the at least one alcohol is chosen from the group consisting of methanol and ethanol.

11. The method of claim 1, wherein the first liquid fuel primary component is chosen from the group consisting of dimethyl carbonate and diethyl carbonate.

12. The method of claim 2, wherein the at least one aldehyde is chosen from the group consisting of formaldehyde and acetaldehyde.

13. The method of claim 12, wherein the formaldehyde is produced from methanol and the acetaldehyde is produced from ethanol.

14. The method of claim 2, wherein the second liquid fuel primary component is chosen from the group consisting of dimethoxymethane, diethoxymethane, diethoxyethane and a mixture of acetal oligoethers.

15. The method of claim 1, wherein the step of producing the total feedstock needed by combining the first and second portions of the total feedstock further comprises the steps of:a) grinding at least one of the first and second portions of the total feedstock in a grinding unit;b) drying at least one of the first and second portions of the total feedstock in a dryer unit; andc) mixing together the at least one ground and the at least one dried first and second portions of the total feedstock.

16. The method of claim 1, further comprising the step of:a) removing water from the synthesis gas stream in a condenser unit.

17. The method of claim 16, further comprising the step of:a) separating a portion of carbon dioxide from the synthesis gas stream after it has been cooled by the condenser unit.

18. The method of claim 4, further comprising the step of:a) producing hydrogen byproduct from the microalgae in the at least one photo-bioreactor.

19. The method of claim 1, wherein the at least one photo-bioreactor comprises at least two photo-bioreactors disposed in parallel in said method, each of said at least two photo-bioreactors growing a different species of photosynthetic organisms, or each of said at least two photo-bioreactors growing the same species of photosynthetic organisms, or each of said at least two photo-bioreactors growing a combination of species of photosynthetic organisms.

20. The method of claim 19, further comprising the steps of:a) producing and storing hydrogen byproduct from a first of the different species of photosynthetic organisms in a first of the at least two photo-bioreactors; andb) producing and storing oxygen byproduct from a second of the different species of photosynthetic organisms in a second of the at least two photo-bioreactors.

21. The method of claim 19, further comprising the step of:a) producing and storing, separately, hydrogen and oxygen from the same species or combination of photosynthetic organisms in the at least two photo-bioreactors, wherein each of the at least two different photo-bioreactors comprises a different feedstream.

22. The method of claim 20, further comprising the step of:a) adding the hydrogen byproduct to the synthesis gas stream.

23. The method of claim 1, wherein the step of producing at least one alcohol from the synthesis gas stream further comprises the step of:a) extracting thermal energy from the step of producing at least one alcohol for use in any unit of said method requiring thermal energy.

24. The method of claim 2, wherein the step of producing at least one aldehyde from the at least one alcohol is affected through an endothermic reaction path of said method, the method further comprising the steps of:a) producing heat from at least one thermal energy-releasing unit of said method,b) providing at least a portion of said heat to the endothermic reaction path of said method used in the step of producing at least one aldehyde from the at least one alcohol; andc) producing a hydrogen byproduct.

25. The method of claim 24, further comprising the step of:a) adding the hydrogen byproduct to the synthesis gas stream.

26. The method of claim 2, further comprising the steps of:a) producing a hydrogen byproduct from the at least one photo-bioreactor or from the step of producing at least one aldehyde from the at least one alcohol or from the at least one photo-bioreactor and from the step of producing at least one aldehyde from the at least one alcohol;b) feeding said hydrogen byproduct to the synthesis gas stream for producing an intermediate alcohol producing feed stream; andc) producing an intermediate alcohol product from said intermediate alcohol producing feed stream.

27. The method of claim 26, wherein the intermediate alcohol producing feed stream comprises hydrogen, carbon monoxide and carbon dioxide in a molar relation wherein X is determined by the equation:X=([H₂]--[CO₂])/([CO₂]+[CO])wherein,X≧2,H.- sub.2 is a concentration level of hydrogen in the intermediate alcohol producing feed stream,CO₂ is a concentration level of carbon dioxide in the intermediate alcohol producing feed stream, andCO is a concentration level of carbon monoxide in the intermediate alcohol producing feed stream.

28. The method of claim 2, further comprising the steps of:a) producing a first water byproduct from the step of producing at least one alcohol from the synthesis gas stream;b) producing a second water byproduct from the step of producing a second liquid fuel primary component from the at least one alcohol and the at least one aldehyde;c) producing a third water byproduct from the step of producing a first liquid fuel primary component; andd) providing at least a portion of the first, second and third water byproducts to a boiler unit of said method for producing steam needed by at least the at least one photo-bioreactor or a unit used in the step of producing a primary synthesis gas or a unit used in the step of reformulating the primary synthesis gas for producing a synthesis gas stream.

29. The method of claim 2, wherein the step of producing a second liquid fuel primary component from the at least one alcohol and the at least one aldehyde is an endothermic process, the method further comprising the steps of:a) providing at least one heat-releasing unit of said method;b) extracting thermal energy from said at least one heat-releasing unit; andc) providing said extracted thermal energy to a reaction path for the endothermic process for producing a second liquid fuel primary component.

30. The method of claim 1, further comprising the step of:a) separating carbon dioxide from the primary synthesis gas during the step of reformulating the primary synthesis gas for producing a synthesis gas stream having a specific hydrogen to carbon monoxide ratio.

31. The method of claim 30, wherein the separated carbon dioxide is used as an anti-detonator in the step of producing a first liquid fuel primary component and as a feed source to the at least one photo-bioreactor.

32. The method of claim 20, further comprising the step of:a) directing the oxygen byproduct to at least one unit of said method, the at least one unit used in the steps chosen from producing a primary synthesis gas from the total feedstock needed, reformulating the primary synthesis gas for producing a synthesis gas stream and producing a first liquid fuel primary component.

33. The method of claim 32, further comprising the step of:a) providing an air separation system for satisfying an oxygen demand of said method that is not fulfilled by the oxygen byproduct.

34. The method of claim 1, wherein the feedstock outsource is chosen from the group consisting of vegetal biomass from agricultural waste, cassava, and fast growing non-food crops, such as Arundo donax L., elephant grass, microalgae and corn stem.

35. The method of claim 15, wherein the step of drying the at least one of the first and second portions of the total feedstock in a dryer unit provides a dried at least one of the first and second portions of the total feedstock having a water content below 25%.

36. The method of claim 1 having a plurality of exothermic and endothermic processes and a total thermal energy requirement, the method further comprising the steps of:a) harnessing thermal energy from the plurality of exothermic processes of said method; andb) providing a heat exchanger network for fulfilling the total thermal energy requirements of the plurality of endothermic processes of said method by using the harnessed thermal energy.

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