Patent application number | Description | Published |
20100168473 | PROCESS FOR THE PREPARATION OF UREA - Process for the preparation of urea from ammonia and carbon dioxide in a urea production process comprising, in a high-pressure synthesis section: a. a reactor, wherein ammonia and carbon dioxide react to form a urea-comprising synthesis solution; b. a stripper, wherein the urea-comprising synthesis solution is heated and stripped, optionally in counter-current with a stripping agent; c. a submerged condenser, wherein the gas leaving the top of the stripper is, at least partially, condensed to form a condensate solution and d. an ejector, in the line connecting the submerged condenser and the reactor, supporting the transport of the condensate solution from the submerged condenser to the reactor, wherein a gas stream leaving the top of the submerged condenser is controlled by one or more controlling elements. | 07-01-2010 |
20110110826 | PROCESS FOR INCREASING THE CAPACITY OF AN EXISTING UREA PLANT - Process for increasing the capacity of an existing urea plant comprising a high-pressure urea synthesis section and one or more recovery sections, wherein next to the existing urea plant a urea production unit, comprising a high-pressure urea synthesis section and a medium-pressure recovery section, is installed, wherein a urea-containing stream is produced from ammonia and carbon dioxide and the urea-containing stream is sent to the existing urea plant where the urea-containing stream is further purified in the low-pressure recovery section. | 05-12-2011 |
20110118506 | PROCESS FOR THE PRODUCTION OF UREA FROM AMMONIA AND CARBON DIOXIDE - Process for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section comprising at least one reactor section, a stripper and a condenser wherein all the high-pressure equipment is placed in a low position, wherein the height of the high-pressure section is less than 35 m from ground level and at least one of the reactor sections comprises means for the separate distribution of ammonia in the bottom of the reactor section. | 05-19-2011 |
20110160486 | PROCESS FOR THE PRODUCTION OF UREA FROM AMMONIA AND CARBON DIOXIDE - Process for the production of urea from ammonia and carbon dioxide in a urea plant containing a high-pressure synthesis section comprising two reactor sections, a stripper and a condenser, and a recovery section, wherein in the first reactor section a first synthesis solution is formed that is fed to the second reactor section; fresh carbon dioxide is fed to the second reactor section and in the second reactor section a second synthesis solution is formed that is fed to the stripper, wherein the second synthesis solution is stripped with the use of carbon dioxide as stripping gas and the mixed gas stream obtained in the stripper is sent to the condenser together with fresh ammonia and a carbamate stream, whereafter the condensate that is formed in the condenser is fed to the first reactor section and the urea stream that is obtained in the stripper is further purified in the recovery section, wherein the flow of the first synthesis solution from the first reactor section to the second reactor section, the flow of the second synthesis solution from the second reactor section to the stripper, the flow of the mixed gas stream from the stripper to the condenser and of the condensate from the condenser to the first reactor section is a gravity flow. | 06-30-2011 |
20120282149 | APPARATUS FOR THE DECOMPOSITION OF NON-CONVERTED AMMONIUM CARBAMATE IN UREA SOLUTIONS IN A UREA SYNTHESIS PROCESS - An apparatus used for the decomposition of non-converted ammonium carbamate in a supplied urea solution in a urea stripping synthesis section. The apparatus comprises a number of heat exchanger tubes between a top chamber and a bottom chamber, a liquid distributor mounted on each heat exchanger tube and a gas/liquid separator together with a perforated basket at the centre of the top chamber. | 11-08-2012 |
20120302789 | UREA STRIPPING PROCESS FOR THE PRODUCTION OF UREA - The invention relates to a process for producing urea wherein an aqueous urea solution, leaving a urea reaction zone is fed to a stripper, where a part of the non-converted ammonia and carbon dioxide is separated from the aqueous urea solution, which solution leaves the stripper to a first recovery section of one or more serial recovery sections and is subsequently fed to one or more urea concentration sections, wherein the urea solution leaving the stripper is subjected to an adiabatic expansion, thus creating a vapor and a liquid, which are separated before the liquid enters a first recovery section and the vapor is condensed. The invention further relates to a urea plant comprising a stripper and a first recovery section, wherein an adiabatic expansion valve and a liquid/gas separator is provided between the stripper and the first recovery section. | 11-29-2012 |
20140046094 | ZERO EMISSION UREA PROCESS AND PLANT - Disclosed is a method for the production of urea allowing a substantial reduction, even down to zero, of the continuous emission of ammonia conventionally resulting from such a process. According to a preferred embodiment of the invention, the urea-forming reaction from carbon dioxide and ammonia is conducted in a synthesis section that does not require passivation by oxygen. As a result of the absence of oxygen, a hydrogen-rich gas stream results from the synthesis section, that can be used as a fuel in an incinerator. In the incinerator, ammonia-comprising gas streams from the urea production process are combusted. | 02-13-2014 |
Patent application number | Description | Published |
20140206902 | UREA PRODUCTION PROCESS CHARACTERIZED BY SHORT UREA MELT TRANSPORTATION TIME BETWEEN LAST CONCENTRATOR AND PRILLING TOWER - The invention relates to a method for urea production and to a urea production plant wherein ammonia emission in the final step of forming urea prills is reduced. In the method, the concentration of a urea solution is performed in at least three consecutive concentration steps and the residence time of urea melt leaving a last concentrator to the prilling tower is minimised. This can be achieved by placing the last concentrator in adjacency with a urea melt inlet of the prilling tower, such as above the prilling tower. In this way, the ammonia emission in the prilling tower can be reduced by as much as 50% compared to the conventional urea production plants. The invention further relates to a method for reducing ammonia emission in the prilling tower of an existing urea production plant. | 07-24-2014 |
20150026943 | UREA FINISHING METHOD - Disclosed is a method for urea finishing. A urea solution is subjected to crystallization and, other than in conventional processes, the urea crystals are shaped by exerting mechanical force onto them. Thus, the conventional prilling or granulation finishing steps can be avoided, and so are the corresponding emissions of ammonia and/or dust. The crystallization comprises a flash crystallization. The invention also pertains to the urea particles obtainable by the process, to a urea plant, and to a method of modifying an existing urea plant. | 01-29-2015 |
20150133690 | UREA PRODUCTION PLANT - Disclosed is a plant for the production of urea. The plant comprises conventional sections for synthesis and recovery, for evaporation and condensation, for urea finishing, and for dust scrubbing. According to the invention, an additional evaporation and condensation loop is introduced from and to the dust scrubbing section. This loop results in a more favorable energy consumption of the plant. | 05-14-2015 |