Patent application title: Process for Maximization and Optimization of Coal Energy
Jayant Chandulal Mehta (Nagpur, IN)
IPC8 Class: AF01K1300FI
Class name: Motive fluid energized by externally applied heat process of power production or system operation including production of withdrawable product or steam for external use
Publication date: 2013-03-14
Patent application number: 20130061592
A process for maximization and optimization of coal energy comprising the
steps of Selection of old coal mine or coal bearing areas; surveying of
the mine or coal bearing areas for preparing of the panels;
hydro-geological survey and Geo-Mechanical survey of the panels of
Step-II above; sub paneling and slicing of the survey panels of the
step-II and III above; preparing of the surface of the panel of step-IV
above for development for at least boring of the panels;
underground/Channeling of the boreholes at the floor level of the coal;
burning of the coal in said channel of step-vi; extraction of the heat
from the prepared boreholes seam & simultaneously filling of the voids
created by extraction; use of the extraction heat for conversion into
steam energy; use of the steam energy for generation of electricity or
any other alternate use.
1. A process for maximization and optimization of coal energy comprising
the steps of: i) selecting old coal mine or coal bearing areas; ii)
surveying the mine or coal bearing areas for preparing of survey panels;
iii) conducting a hydro-geological survey and a geo-mechanical survey of
the panels of step ii above; iv) sub paneling and slicing of the survey
panels of steps ii) and iii) above; v) preparing the surface of the panel
of step iv) above for development for at least boring of the panels; vi)
underground/channeling of the boreholes at the floor level of the coal;
vii) burning of the coal in said channel of step-vi; viii) extraction of
the heat from the prepared boreholes seam and simultaneously filling of
the voids created by extraction; ix) use of the extraction heat for
conversion into steam energy; and x) use of the steam energy for
generation of electricity or any other alternate use.
2. The process as claimed in claim 1, wherein, the compaction and strength shall be of the coal removed from the slices.
FIELD OF INVENTION
 The present invention relates to a process for maximization and optimization of Coal Energy, more particularly the present invention relates to a process which optimizes the coal energy utilization.
BACKGROUND OF THE PRESENT INVENTION
 Coal is one of the most rich and abundantly available energy resources in the world. The need for the conservation and optimization of all the carbon generating energy resources are attracting the center stages at all international forums. The need for the optimum utilization of the available energy with minimal green house gas production is of utmost necessity.
 The latest technology used worldwide cause huge losses of the coal energy. The presently known and utilized coal winning process results into generation of only 1/45 of available coal energy. The said figure is very and low and there was necessity to have a mechanism wherein the loss of energy can be saved and maximum utilization of energy is made possible.
 The present mechanism for coal winning needs a complete revamp.
DRAWBACKS OF THE PRIOR ART
 Winning in underground mines is hazardous process as working is against nature. Different hazards associated with underground mines are inundation, explosions (coal dust and methane); mine coal fires, roof and side falls, hazards due to machineries and electricity etc.
 Maximum possible percentage of extraction with advance coal winning technology is 1/6 of commercial reserves. The disadvantages of opencast mines are degradation of coal, environmental pollution, degradation of fertile land, socio-economical problems, etc.
 Disadvantages of U/G Coal gasification are uncontrolled coal fire poor coal gas quality.
OBJECTS OF THE PRESENT INVENTION
 Object of the present invention aims at developing a process for maximization and optimization of coal energy.
 Object of the present invention is to develop a process, wherein the loss of coal energy during the course of the coal winning can be saved.
 Another objective of the main invention is to maximize the production of coal generation and use the same for generation of power.
 Yet another objective of the present invention is to maximize the power generation from coal which can result into reduction of cost for power generation.
STATEMENT OF THE INVENTION
 According to this invention, therefore, a process for maximization and optimization of coal energy comprising the steps of
 i) Selection of old coal mine or coal bearing areas;
 ii) Surveying of the mine or coal bearing areas for preparing of the panels;
 iii) Hydro-geological survey and Geo-Mechanical survey of the panels of Step-II above;
 iv) Sub paneling and slicing of the survey panels of the step-II and III above;
 v) Preparing of the surface of the panel of step-IV above for development for at least boring of the panels;
 vi) Underground channeling of the boreholes at the floor level of the coal seam. vii) Burning of the coal in said channel of step-vi;
 viii) extraction of the heat from the prepared boreholes & simultaneously filling of the voids created by extraction;
 ix) use of the extraction heat for conversion into steam energy;
 x) use of the steam energy for generation of electricity or any other alternate use.
BRIEF DESCRIPTION OF THE DRAWINGS
 The invention is described with reference to the accompanying drawings wherein:
 FIG. 1 shows the Panel preparation
 FIG. 2 shows Plan of Mine
 FIG. 3 shows Panels divided into slices
 FIG. 4 shows Developed Mine Plan
 FIG. 5 shows Borehole pattern
 FIG. 6 shows Slice extraction
 FIG. 7 shows Extraction of Virgin seam
 FIG. 8 shows 3 D view showing ascending extraction of slices
DETAILED DESCRIPTION OF THE INVENTION
 The technology derived is the outcome of the experience gained in coal winning methods during my experience of 30 years and from following process that need to be studied in detail such as:
 Coal winning methods
 Working of Thermal Power Plant
 Experience gained from different technologies such as underground coal gasification
 Technologies used to tackle Zaria coal fire
 Advanced drilling technologies used in oil industry
 Dewatering technique used in lignite mining of Naivelly to produce coal at mean sea level
 Methane drainage technique, heat collecting pumps used in geothermal power plants
 Underground coal winning technologies
 Long-wall & B&P (board and pillars) depillaring with caving and stowing
 Isolation of fire area from surface technology
 Roof and floor rock mass of coal
 Transportation of steam
 Shaft sinking in difficult conditions
 Water infusions &pulse infLisions
 Ventilation of long headings.
The Outcome of all the Above Experiences and Studies Shows That:--
 We are using only 1/45 part of coal energy
 All the studies are carried out only to control fire. i.e fire is taken as liability besides only way to use coal energy is by combustion.
 Uncontrolled fire in coal seam is only problem to use coal energy insitu.
 The technology developed make it absolutely possible to keep coal fire under total control and exploit coal energy left in abandoned mines, deep seated coal seams, thin coal seams (less than 1.2 meters) in maximum percentage.
Stages of Technology:--
 Preparation of panels, sub panels and slices
 Development for extraction of panels
 Extraction of coal energy and using the extracted coal energy for power generation and other industrial usages.
 Partial filling while extraction progress and complete airtight fillings of voids created by extraction
 Abundance of boreholes shifting equipment's to next slices
 Restoring the surface visual impact and using the same surface for prior use
Preparation of Panels and Sub Panels:--
 The working will be kept in isolated panel from other workings by airtight isolation. The panel preparation will facilitate sub-surface dewatering and uninterrupted working of panel due to water problem especially in case where aquifers are present.
 The extraction of panels in line of extraction will reduce the isolation work in companion panels. Extraction of number of panels at time is possible. Panel size is such that preparation cost is least and extraction is economical. The presence of geological disturbances faults, folds, also need to considered.
 Technological experiences used in preparation of panels. Technologies used in shaft sinking in difficult condition, preparation of blocks, freezing or cementation will be applied which is given in detail below.
 Isolation of panel from other workings by remote isolation method used in remote sealing of fire by constructing leak proof (air tight) isolation. Dewatering of blocks, sub ground water drainage used in Naivelly lignite
 Advantages of paneling
 1) Number of panels worked at a time
 2) Dewatering water available in panel block used for power generation superheated steam produced etc. will make needful water for process and need not necessary to arrange external water supply
 1.1.1. Need for Preparation of Sub-Panel & Slices
 Subpanel is divided into number of slices for extraction of coal energy at a time
 Slice area is kept in such a way that the area of slice exposed to roof is kept in such a way that the roof will not fall and facilitate complete extraction of slice. Number of slices in a panel of different subpanel will be worked at a time as shown in fig no 3 extraction of slice and sequence of extraction of the same
 The number of panels (slices) worked at a time will decide the capacity of generation unit. To ensure uninterrupted supply of superheated steam is . achieved fixing the relation for above maximum capacity of generation is possible
 If complete extraction of heat up to cooling of roof rock to certain decided temperature is achieved it will facilitate uncontrolled spreading of fire
 Filling of extracted slices with stowing material that is having strength of solid coal will facilitate keep fire in control and controlling roof movement to achieve complete extraction of coal energy
 Barrier left in slice extraction will be extracted while working adjoining slices after complete extraction of heat in the slice (complete process and exhausted).
3. Different Stages of Technology
 3.1.1. Preparation of Sub Panels and Slices
 1) Size of panel-geo mechanical property of roof rock will decide the size of the slices.
 2) Factors controlling preparation work
 Abandoned mines
 Developed and standing on pillars
 Virgin coal seam
 Type of mining method used for extraction
 Seam density
 Geo hydrological survey report
 Accuracy of plans
 3) Capacity of drilling equipment's and accuracy of drilling holes are the major factors controlling the panel preparation.
 Once the size of panel is decided preparation of the slice extraction can be started. Further in developed working the slice is isolated by remote isolation technique. In virgin seam the isolation procedure need not be followed.
 The development work is as shown in the FIG. 5 & FIG. 8
 3.1.2. Development Work for Extraction of the Slices
 After completing the panels, sub panels and slices isolation work development work for extraction of slices starts. The seam is approached by set of boreholes for coal energy extraction and boreholes for filling of voids.
 Number of exhaust and inlet service borehOles for providing air to working area and extraction of heat.
 The number of boreholes, diameter of boreholes and positioning of boreholes depends upon certain determining factors such as
 Finding of geo mechanical studies. i.e. roof rock strength
 Permitted maximum exposure
 Thickness of seam
 The pattern depends on extraction of developed working or virgin seam
 Seam density, if seam density is more it needs close spacing to achieve complete filling of voids so as to make complete extraction of coal energy possible
 Design capacity of heat extraction
 Capacity of heat extraction pumps
 Area needed for installation of pumps
 Position of heat extraction pumps i.e vertical or horizontal
 Number of units of heat extraction pumps
 Quantity of coal on fire to generate desired quantity of heat
 Quantity of air to achieve desired quantity of coal on fire
 Size and number of stowing boreholes depends on certain factors such as
 Size of stowing material
 Type of material used
 Technique used to flush stowing material either by hydraulic or pneumatic or by simple dropping system
 Thickness of coal seam
 Gradient of coal seam
 Density of coal seam
 Rate of stowing for filling voids
 Tightness & strength of filling material to be achieved
 Need of cement slurry or foam injection to complete compactness and air tightness of voids
 By taking into consideration above factors the designing of the borehole pattern will be done and accordingly the seam will be approached After the seam is approached by boreholes, the next step of development will be Driving channels--for connection between boreholes (i.e. inlet and outlet) channels at floor portion of seam has to be driven Fitting of burners attached to coil tubing in the channels
 Technologies, experience used in preparation of subpanel and slices
 Remote isolation of fire area with complete airtight seal
 Geothermal energy based power plant units
 Experience in heat extraction pumps, its design and capacity, installation and its efficiency used in geothermal power plants
 Ventilation of fire area while tackling underground coal fires
 Different mechanical ventilators used for mine ventilation as used for ventilation of long drive up to 1000 meter or more single entry particularly used in long wall
 Design of mine ventilation
 Experience gained in different stowing practices such as hydraulic, mechanical or pneumatic
 Technology used in gasification of coal seam to create channel in coal seam using special drilling technique
 Technology used in underground gasification of use of a burner attached to the coil tubing. The burner is used to burn through boreholes casing and ignite coal. The ignition system can be moved to any desired location in injection well. Thus `control reaction ignition point` (CRIP) technique enables a new reactor to be installed at any chosen upstream location, after the decline reactor has been abandoned
 3.1.3. Stage 3:
 3.1.4. Extraction Method for Extracting Coal Energy from Slices
 After completing development work extraction of panel will be started.
Manner of Extraction of Coal Energy
 The coal seams, panels, slices are extracted in ascending manner as shown in FIG. 7
 Panel, slices are extracted in designed line of extraction (the line of extraction may change according to condition)
Procedure for Coal Energy Extraction:
 By `Control Reaction of ignition Point` (CRIP) coal is ignited at bottom most portion of slice. Ventilation of working area beside buoyancy (hot gases in exhaust, content of moisture, etc.) is necessary by mechanical means as to control the quantity of coal on fire & quantity of heat generated and also to carry out heat generated to heat extraction pumps.
 The slice will be extracted by different compartments to facilitate complete extraction of coal energy within the permitted area of exposure. As shown in FIG. 6 the sequences of extraction of slice in compartment.
 Air shall be kept blowing in inlet & heat extracted in exhaust bore holes to produce superheated steam directly used for driving turbine. Further steam produced can be used to flash power plant that needs 6000 kgs-9000 kgs of steam each hour to produce each MW of electrical power. This is for maximum possible use of heat produced.
 3.1.6. Stage 4:
 3.1.7. Partial filling while extraction progress and complete airtight fillings of voids created by extraction
 As the bottom coal is extracted the exposure of top coal is available for oxidation, as ash falls down and gets a dome shape.
 As coal combustion at work place reaches to stowing boreholes, forming certain voids, partial filling of voids by stowing material should be started. The Pneumatic stowing is suitable as complete filling of void is possible within slice.
 The extraction height is kept within limit as less as possible by continuous partial filling of voids (as low as 1.5 meters or less). It will facilitate more area of exposure as height of extraction has direct effect on roof fall
 After completion of slice extraction the heat generation will fall
 Continue the heat extraction till the roof rock temperature reduces to certain designed temperature.
 The voids should be complete filled even inlet and exhaust holes can be used for the purpose.
 Injection of cement slurry, foaming material to make air tight to facilitate compaction along roof.
 Achieve the strength of filling to facilitate working of seams above uninterrupted
 The FIG. 5 will show the extraction of slices in compartment.
 Simultaneous extraction of 1st & 2nd compartment and after extraction & complete filling working of 3rd compartment will be started.
 The completion of slice in lower coal seam and for extraction of upper seam, same set of boreholes will be used for extraction of upper seam and same procedure will be adopted as in case of lower coal seam.
 3.1.8. In certain cases the fire in coal seam is difficult to achieve so it is necessary to prepare coal for easy fire. The preparation is needed in bottom most coal where coal to enlighten needs to develop cracks in coal seam. These cracks in coal seam can be developed by advance water infusion under pressure to open the cracks and fast advancement of fire with aid of pressure air difference between Inlet and outlet boreholes.
 The fig will give the sequence of extraction of adjoining slices and slices in upper seam.
 Number of slices in one panel in different seams or within panels will be worked simultaneously in keeping certain sequence as shown in FIG. 3 & 8.
 Number of slices simultaneously work depends on following factors:
 Infrastructure available for drilling
 Funds available
 Size of generator and requirement of superheated steam
 The provision of simultaneous extraction of slices will facilitate
 Uninterrupted supply of steam
 Planning of high generation capacity plants
 Methane (CH4) formed as emission or distillation of coal burnt below heat extraction pump by installing activated platinum wire gauze and heat generated will be used for stem generation.
 Different Technologies and Experiences Used in Extraction of Coal Energy
 Methane drainage system
 Methane explosibility
 Ventilation of mine
 Interpretation of samples of air in different stages of coal fire
 Development workings in coal seam effect of height of gallery on roof control
 Experience in Zaire coal fire to reduce rate of fire travel particularly by circulation of liquid Nitrogen through bore holes for cooling down the roof rock.
 Checking packing of galleries and making airtight seal in remote sealing of fire area.
 Extraction of coal in ascending method with stowing
 Extraction of coal in multi seam mines
 Technologies used in detection of CH4 in M.S.A methanometer.
 Boundary ventilation system used in metal underground mines
 Product of coal combustion and exhaust treatment in thermal power stations.
 Infusion of coal by pressure water, shock or pulse infusion of coal seam
 Directional drilling technique
 Continuous sampling of mine air technique
 Fire in coal stock
 Abundance of boreholes shifting equipment's to next slices
 After completing the extraction procedure of slices subpanels and panels to the topmost seam the boreholes are left abundant.
 3.1.10. Stage 6:
 3.1.11. Restoring the Surface Visual Impact and Using the Same Surface for Prior Use
 3.1.12. Restoring the surface visual impact will be done as per the EMP-Environmental Management Plan.
SUMMARY OF THE PRESENT INVENTION
 A coal mine is initially divided into number of panels preferably of 200/200 meters and the said panels are divided further in to sub panels of 45/200 meters. The said panels are thereafter converted into the dewatered compartments. The said compartments are thereafter provided with the boreholes of diameter of 24''. The stowing is done by bore of small 8'' diameter.
 Thereafter fire is enlightened in the coal seam by using the advance torch technology. The controlled and predetermined air is infused in sub panel during the combustion of coal to keep the fire in control. The extraction of heat is also done in controlled manner in order to maintain the combustion in the advanced stage, thereby reducing the emission of green house gases like Carbon Monoxide or Hydrogen. The same is further achieved by filing the voids formed by the combustion of coal. The panels are selected in such a manner that the roof of the panels shall not fall at any point of time during the process.
 Thereafter the heat generated from the combustion can be utilized for generation of power by using the state of art technology.
ADVANTAGES OF THE PRESENT INVENTION
 1. The process is capable to bring down the cost of electricity 40-50 paisa/unit.
 2. There is no need of vigorous R & D it can be conceptualized by unification and modification of available technologies used in Thermal Power Station (hereinafter called as T.P.S.) and mining.
 3. This process is capable of using coal energy from already abandoned mines, unworkable coal seams and even for coal seams, which are 1.2 meters thick, hence, exploitation of larger reserves of coal is possible.
 4. Maximum % utilization of coal energy is possible as compared to other technologies possible in the arena of electricity generation.
 5. It is also safer and intuitively more efficient because of lowers emission fugitive dust, noise and visual impact of the surface, lower water consumption, no dirt handling and disposal at mine sites, no coal washing and fines disposal at mine sites, no ash handling and disposal at power station sites, no coal stocking and transport, no mine water recovery and significant surface hazard liabilities on abandonment.
 6. The process is free from degradation of land and has comparatively less environmental impact with potential of lowering the overall capital and operation cost.
 7. The process will revolutionize the generation or power both cost wise and technology wise and will be able to meet the need of 3,00,000 MW/Day persistently for 3500 years.
 8. The process will not lead to emission of the green house gases.
 9. It will prove to be best alternative to nuclear energy, which cost about (6.50 Rs/unit) and ensure health & security.
Patent applications in class Including production of withdrawable product or steam for external use
Patent applications in all subclasses Including production of withdrawable product or steam for external use