We've many times documented that Coal can be gasified; that is, partially combusted or partially oxidized; and, that the resulting mix of gases, primarily Carbon Monoxide and Hydrogen, known as synthesis gas, or "syngas", can then be catalytically, chemically condensed into, depending in part upon the mix of catalysts used, virtually any and all types of liquid and gaseous hydrocarbon fuels.
As seen for just one example in our report of:
Eastman Chemical Coal Gasification Overview | Research & Development | News; concerning: "Eastman Gasification Services Company: Eastman Gasification Overview; March 22, 2005; Gasification 101: Just the Basics: C + O2 + H2O = CO + H2; The partial oxidation of carbon to produce a 'synthesis gas'. ... What Is Gasification? Coal + Water + Oxygen = Carbon Monoxide + Hydrogen";
the basic chemistry of Coal gasification is well-known and pretty straightforward. And, as seen in:
Texaco Clean Methane from High-Sulfur Coal | Research & Development | News; concerning: "United States Patent 3,928,000 - Clean Methane ... from High-Sulfur Containing Hydrocarbonaceous Materials; 1975; Inventors: Edward Child, et. al., NY and CA; Assignee: Texaco Incorporated, NYC, NY; Abstract: This is an improved process for converting low-cost high-sulfur containing hydrocarbonaceous materials into a clean methane-rich gas stream which may be burned as a fuel without contaminating the atmosphere. A high-sulfur hydrocarbonaceous fuel is gasified by partial oxidation to produce a process gas stream which is cooled, cleaned and subjected to catalytic methanation over a sulfur-resistant catalyst comprising 0.8 to 10 atoms of an element selected from the group comprising Co, Cr, W or mixtures thereof per atom of an element selected from the group Mo, Ni, or mixtures thereof. The catalyst may be supported on a structure formed from Group III and IV elements e.g. alumina, silica stabilized alumina, zeolite. A distinct advantage of the subject process, is that the sulfur in the process gas stream is not removed prior to the methanation step. Rather, the sulfur is permitted to remain in the process gas stream in order to moderate the highly exothermic methanation reaction. After cooling and purification ... the resulting methane-rich gas stream comprises (up to) 95% CH4";
the complete process of converting Coal into hydrocarbon synthesis gas, and then producing an essentially pure, "95%", stream of synthetic natural gas Methane, "CH4", from that syngas has been established for quite some time. Further, the process of Coal gasification, since it involves partial combustion, partial oxidation, to be conducted efficiently, does result in the co-production of some Carbon Dioxide, along with the more reactive and more desired Carbon Monoxide. And, as seen in our report of:
Phillips 66 Converts 100% of CO2 to Methane | Research & Development | News; concerning: "United States Patent 8,754,137 - Methanation Reaction Methods Utilizing Enhanced Catalyst Formulations and Methods of Preparing Enhanced Methanation Catalysts; 2014; Inventors: Scott Scholten, et. al., Texas and Oklahoma; Assignee: Phillips 66 Company, Houston; Abstract: Enhanced mixed metal catalysts are provided which allow high conversions of carbon dioxide to methane, in some cases up to about 100% conversion";
with proper catalysis and sufficient Hydrogen, fully "100%" of any Carbon Dioxide in the product of the initial Coal gasification can, as well, be directly converted into substitute natural gas Methane.
And, herein, we see that the process of converting Coal into synthetic natural gas, "SNG", has been even further developed and refined by a major multinational energy company headquartered in Europe and with operations in the US, who have appeared in our reports previously. Comment follows excerpts from the initial link in this dispatch to:
"Coal to SNG - - The Methanation Process
Christian Wix, et. al., Haldor Topsoe A/S (and) Inc., Denmark (and) Houston, TX
(We've previously reported on Haldor Topsoe's established technologies and expertise in Coal and Carbon Oxide conversion processes, as in, for one example:
West Virginia Coal Association | Denmark Converts CO2 to Methane and Carbon Monoxide | Research & Development; concerning: "United States Patent 5,496,530 - Process for the Preparation of Carbon Monoxide Rich Gas; 1996; Inventors: Rickard Vannby and Charlotte Nielsen; Assignee: Haldor Topsoe, Denmark; ("Haldor Topsoe is a Danish catalyst company ... founded in 1940. The company ... develops process technology for petroleum refining, ammonia production, methanol production, and other industries. Haldor Topsoe specialises in the production of heterogeneous catalysts and the design of process plants based on catalytic processes. Focus areas include the fertiliser industry, chemical and petrochemical industries, and the energy sector (refineries and power plants.) Abstract: Process for the preparation of carbon monoxide rich gas comprising reacting a mixed gas of hydrogen and carbon dioxide in the presence of a conversion catalyst to carbon monoxide rich gas, which process further comprises reacting part of the carbon dioxide and hydrogen in the gas feed exothermically to methane simultaneously with the carbon monoxide producing reaction and carrying out both reactions under adiabatic conditions, so that the exothermical methane producing reaction provides necessary heat for the endothermic carbon monoxide producing reaction".
Their technologies and processes, especially for such conversions of both Carbon Monoxide and Carbon Dioxide are extensive and sophisticated, and we perhaps should have been more diligent in our reportage of their achievements. More reports concerning them, and especially their technologies for the productive use and consumption of Carbon Dioxide in the synthesis of hydrocarbons, will follow in the hopefully near future.
Presented at the Twenty-fourth Annual International Pittsburgh Coal Conference
September 10-14, 2007, Johannesburg, South Africa
(We've noted previously that the 24th Annual Pittsburgh, PA, Coal Conference was actually held, not in Pittsburgh, but, in Johannesburg, South Africa, where, as can be learned for one example in our report of:
USDOE Assesses South Africa Coal Liquefaction | Research & Development | News; concerning: "Foreign Coal Liquefaction Technology Survey and Assessment: SASOL - The Commercial Experience; Prepared for Chemical Technology Division of Oak Ridge National Laboratory; Subcontract Number 62b-1383C; 1980; OSTI ID: 12195973; Report Number: ORNL/Sub--79/13837/4; DOE Contract: W-7405-ENG-26; Sponsoring Organization: United States Department of Energy";
South Africa Synthetic Oil Limited, "SASOL", have been converting Coal into synthetic petroleum fuels and other related products since, basically, the 1940's, and now make virtually every type of petroleum-based fuel and chemical on a large scale industrial basis out of Coal.)
Introduction: Conversion of coal or similar feedstock (petcoke, biomass, etc.) to Substitute Natural Gas (SNG) is becoming an attractive option in the energy landscape due to high and fluctuating natural gas prices as well as to political issues. In general, environmental concerns and security of energy supply are high on the political agenda. Alternative energy sources and flexibility in the conversion and distribution network are important to reduce the dependency on oil and natural gas.
Oil and natural gas reserves are limited and mainly concentrated at relatively few locations, often far from the main markets, and often ecologically or politically sensitive. In contrast, coal is abundantly available, also locally in important energy markets such as China, India, and the USA. Therefore, coal is now back as an important feedstock with gasification for production of synthesis gas (a mixture of mainly hydrogen and carbon monoxide) as a key technology.
(We'll note in passing that the much ballyhooed shale gas "miracle" is most likely a flash in the pan. Shale gas wells and fields exhibit high production decline rates, and initial gas production from new wells and new fields cannot it seems be maintained at competitive prices. New wells and repeated fracking operations are constantly needed, and the capital expense of maintaining established production in a given area quickly and steadily rises. Further, even at the height of the shale gas mania, the United States of America remains a net importer of natural gas, with most of it coming in via pipeline from Canada and Mexico. For some additional info, have a look at:
Shale gas: ‘The dotcom bubble of our times’ | Peak Oil News and Message Boards; "Shale gas: ‘The dotcom bubble of our times’; Comment: output from shale wells declines so quickly that they will never be profitable - when investors realise this, the industry will collapse".)
Fig. 1 shows the main process steps in the conversion of coal or similar feedstock via gasification to products such as hydrogen, ammonia, methanol, di-methyl-ether (DME), liquid fuels (via Fischer-Tropsch technology or Topsoe’s TIGAS technology), electric power with carbon dioxide sequestering, or SNG.
(Concerning the above "Topsoe's TIGAS technology", see:
http://www.topsoe.com/subprocess/gasoline-synthesis-tigas; "TIGAS (TM) (Topsoe Improved Gasoline Synthesis) makes it possible to produce high-quality, high-value gasoline from ... coal".
"DME", we remind, without linking to any of our past reports concerning it, is a versatile hydrocarbon that can, with relatively minor mechanical modifications, serve as a direct, clean-burning substitute for both Diesel fuel and LPG.)
The main process steps are gasification of the feedstock with oxygen by one of several available technologies, adjustment of synthesis gas properties as required by the final synthesis process (mainly the H2/CO ratio) by carbon monoxide conversion, ... and finally conversion of the synthesis gas to the desired product.
When SNG is the product, only partial conversion of carbon monoxide and partial removal of carbon dioxide is required, since both are reactants in the methanation process.
However, complete removal of sulphur is essential, since it is a poison to the methanation catalysts.
SNG will normally be exported as a product via a natural gas pipeline grid, and it must therefore comply with relevant gas specifications. However, there is no general pipeline gas or SNG specification available, and the conditions in the SNG production process must therefore be adjusted on a case to case basis to fit not only feedstock properties, but also the relevant product specification.
The Topsoe Recycle Methanation Process (TREMPTM) as described in the following is a cost competitive process featuring the required flexibility to fit any realistic specification. The TREMPTM technology for manufacture of SNG by high temperature methanation was studied extensively in the 1970’s. The technology is today being further developed and optimized due to the present energy situation.
The hydrogenation of carbon oxides to methane takes place over nickel catalysts according to the following, exothermic reactions:
CO + 3H2 = CH4 + H2O (and) CO2 + 4H2 = CH4 + 2H2O
The high heat of reaction results in a large potential adiabatic temperature rise. A key challenge is therefore to manage the high heat of reaction by having a catalyst that has high activity at low temperature after long exposure to high temperatures.
(As we've seen for one example in our report of:
NASA Converts 97% of CO2 to Substitute Natural Gas Methane | Research & Development | News; concerning: "United States Patent Application 20140178270 - Sabatier Process and Apparatus for Controlling Exothermic Reaction; 2014; Inventors: Christian Junaedi, et. al., CT; Assignee: Precision Combustion, Inc., Hartford, CT; Abstract: A Sabatier process involving contacting carbon dioxide and hydrogen in a first reaction zone with a first catalyst bed at a temperature greater than a first designated temperature; feeding the effluent from the first reaction zone into a second reaction zone, and contacting the effluent with a second catalyst bed at a temperature equal to or less than a second designated temperature, so as to produce a product stream comprising water and methane. The first and second catalyst beds each individually comprise an ultra-short-channel-length metal substrate. An apparatus for controlling temperature in an exothermic reaction, such as the Sabatier reaction, is disclosed. Government Interests: This invention was made with support from the U.S. government under U.S. Contract No. NNX10CF25P sponsored by the National Aeronautics and Space Administration. The U.S. Government holds certain rights in this invention";
designs and technologies have been developed to harvest, and perhaps utilize, the heat energy generated by the Carbon Oxide-to-Methane reaction. And, the potentials of using that heat are emphasized by Topsoe.)
The exit gas from the first methanation reactor is cooled by generation of superheated high pressure steam.
After cooling recycle gas is extracted, and the remaining, partly methanated synthesis gas passes through one or two intermediate methanation reactors in series, before it is passed to the “clean-up” reactor for complete conversion of the carbon oxides into methane. The process stream leaving the last methanation reactor is cooled, dried and compressed to meet the relevant pipeline specification.
The optimal recovery of the substantial heat of reaction from the methanation reactors is important for an optimized operating economy. The ability of the MCR-2X methanation catalyst to operate at high reactor exit temperatures makes the production of valuable, superheated high pressure steam possible. Such steam may be used in steam turbines for driving compressors and pumps or for production of electric power.
(We've previously documented in a number of reports the potentials for, through various means and at various stages in the process, recovering heat energy from multiple stages within a Coal gasification and conversion operation, and then using that excess heat to generate byproduct electric power. See, for example:
Germany Coal to Methanol and Electric Power | Research & Development | News; concerning: "United States Patent 4,590,760 - Medium-load Power Generating Station With An Integrated Coal Gasification Plant; 1986; Inventors: Konrad Goebel, Ranier Muller and Ulrich Schiffers, Germany; Assignee: Kraftwerk Union, AG, Mulheim; Abstract: Medium-load power generating station with an integrated coal gasification plant, a gas turbine power generating station part connected to the coal gasification plant, a steam power generating station part connected to the raw gas heat exchanger plant of the coal gasification plant, a methanol synthesis plant having a plurality of modules connected in parallel to each other, and a purified gas distribution system which connects the methanol synthesis plant to the gas turbine power generating station part and which includes a purified gas continuous flow interim storage plant and is connected on the gas side to the raw gas heat exchanger plant. The methanol synthesis plant is associated, for hydrogen enrichment, to a "cooler-saturator loop" which is connected to the raw gas heat exchanger plant and consists of the saturator, a converting plant, cooler and following gas purification plant. In one mode of operation, a water electrolysis plant is associated with the methanol synthesis plant and its hydrogen line is connected to the methanol synthesis plant, and its oxygen line is connected to the coal gasifier".)
The methanation reaction is favored by high pressure and works well with synthesis gas from all types of coal gasifiers. ... Most of the carbon dioxide will be converted to methane.
Production (and) consumption figures will vary and depend on the type of coal gasifier used as well as other design conditions of each specific plant.
An example based on synthesis gas from a GE coal gasifier (provided).
(For some discussion of "GE", General Electric, expertise in Coal gasification/conversion, see for one example our report:
The TREMP(TM) high temperature methanation process is a robust, simple, and economically competitive process allowing production of SNG meeting pipeline specifications from synthesis gas with varying composition. The process is based on the use of the (specified Topsoe propietary) catalyst ... which allows a large temperature increase over the first methanation reactor. This minimizes equipment size and cost, reduces power consumption for recycle and facilitates production of superheated high pressure steam. The process is flexible, and layout and operating conditions may be adjusted on a case to case based to obtain the optimal result".
The full presentation is much more complete and, since it includes illustrations we can't present in our excerpts, much more understandable than the above might make it seem.
In sum, though, Haldor Topsoe's "economically competitive process" for making Substitute Natural Gas via the gasification of Coal, in which process nearly all of the byproduct "carbon dioxide will", as well, "be converted to methane", also allows for the concurrent "production of electric power", thus maximizing the value of the entire operation, and of the Coal.
And, as can be learned via the complete and lengthy dissertation accessible via:
Coal might very well need to come to the rescue, via the production of synthetic natural gas in a process like that described herein by Haldor Topsoe, of companies and individuals who, deceived by the hype, committed to providing themselves with heat, electricity and raw materials derived from natural gas, only to find themselves confronted with short supplies and tall prices.
Coal can be efficiently converted, via an initial process of gasification, into Synthetic Natural Gas suitable for pipeline distribution and for all current uses of natural gas. And, some amount of electric power can be generated as a byproduct of the overall Coal-to-SNG conversion.
Further: Such use of our abundant Coal would, unlike the current situation, no doubt employ a significant number of actual Coal Country citizens.
Isn't it time we all woke up and recognized just how much value Coal could actually bring to our game?