Purdue University Explains Basics of Coal-To-Liquid Fuels

http://www.purdue.edu/discoverypark/energy/assets/pdfs/cctr/outreach/Basics1-CoalGasification-Jun07.pdf

Purdue University, actually, with regards to the headline, is explaining herein the "Basics" only of "indirect" Coal-to-Liquid Fuels technology, wherein Coal, usually combined with water, either in a liquid slurry or with applied steam, is first "gasified" - that is,partially combusted or oxidized - to produce a blend of, primarily, Carbon Monoxide and Hydrogen, that is, hydrocarbon synthesis gas. And, which "syngas" is then chemically, catalytically condensed into hydrocarbons.

 

Both liquid and gaseous hydrocarbon fuels can be generated from Coal in such processes, although Purdue focuses only on the production of liquid hydrocarbons via an initial Coal gasification. And, they focus as well, in their presentation, only on the nearly-ancient "Fischer-Tropsch"-type of technology for synthesizing liquid hydrocarbons from Coal-derived synthesis gas.

The Fischer-Tropsch method of converting Coal-derived syngas into liquid hydrocarbons, as we explained for only one example in:

Bayer Improves Fischer-Tropsch Hydrocarbon Synthesis | Research & Development | News; concerning: "United States Patent 8,557,880 - Multi-stage Adiabatic Method for Performing the Fischer-Tropsch Synthesis; 2013; Assignee: Bayer Intellectual Property GmbH, Germany; Abstract: The present invention relates to a multistage adiabatic process for performing the Fischer-Tropsch synthesis at low temperatures, in which the synthesis is performed in 5 to 40 series-connected reaction zones under adiabatic conditions. Claims: Process for preparing liquid hydrocarbons from the process gases carbon monoxide and hydrogen, comprising a Fischer-Tropsch synthesis in the presence of heterogeneous catalysts, which is performed in 5 to 40 series-connected reaction zone";

was developed in Germany in the period between WWI and WWII. And, although it has been around for a long time, and is, as seen for just one example in our report of:

US EPA Recommends Coal Liquefaction as a Clean Alternative | Research & Development | News; concerning: "Clean Alternative Fuels: Fischer-Tropsch; United States Environmental Protection Agency; Transportation and Air Quality Transportation and Regional Programs Division; EPA420-F-00-036; March 2002; A Success Story (!) For the past 50 years, Fischer-Tropsch fuels have powered all of South Africa’s vehicles, from buses to trucks to taxicabs. The fuel is primarily supplied by Sasol, a world leader in Fischer-Tropsch technologies. Sasol’s South African facility produces more than 150,000 barrels of high quality fuel from domestic low-grade coal daily";

being currently practiced on a large-scale industrial basis in other parts of the world, it is also, as in Bayer's above "United States Patent 8,557,880", being further developed and improved by various corporate and government interests in the United States and internationally. .

As far as generating the Coal-derived blend of, primarily, Carbon Monoxide and Hydrogen "syngas" is concerned, we've seen in, for just a few examples, our reports of:

Texaco Coal Conversion Recycles Carbon & Disposes of Waste | Research & Development | News; concerning: "United States Patent 4,983,296 - Partial Oxidation of Sewage Sludge; 1991; Assignee: Texaco Inc., NY; Abstract: Municipal sanitary sewage sludge is disposed of by an improved partial oxidation process without polluting the environment. Aqueous slurries of sewage sludge are upgraded by hydrothermal treatment, preferably while being sheared, concentrated, and then mixed with a supplemental fuel, preferably coal. ...  A process for the partial oxidation of sewage sludge (by) heating a concentrated aqueous slurry of sewage sludge obtained from sewage and ... mixing the pumpable aqueous slurry of sewage sludge produced ... with a supplemental solid fuel comprising particles of coal  (and) reacting said pumpable aqueous sewage sludge-coal (slurry) in the reaction zone of a partial oxidation gas generator at (specified conditions of temperature and pressure) in the presence of a free-oxygen containing gas, thereby producing a hot raw effluent stream of synthesis gas"; and:

Texaco Coal to Synthetic Fuels and Electrical Power | Research & Development | News; concerning: "United States Patent 4,099,383 - Partial Oxidation Process; 1978; Assignee: Texaco, Inc., NY; Abstract: Sensible heat in the hot effluent gas stream leaving a partial oxidation gas generator for the production of gaseous mixtures comprising H2 +CO, i.e. synthesis gas, reducing gas, or fuel gas, is used at maximum temperature to heat a stream of heat transfer fluid preferably comprising a portion of the product gas circulating in a substantially closed loop. The heat transfer fluid serves as the working fluid in a turbine that produces mechanical work, electrical energy, or both. Further, the heat transfer fluid leaving the turbine may be used to preheat hydrocarbonaceous feed and free-oxygen containing gas which is then introduced into the gas generator. Optionally, by-product superheated steam may be produced at high temperature levels for use in the gas generator and as the working fluid in an expansion turbine";

that the technologies for manufacturing such syngas have been developed to such a degree that they enable the use and consumption of organic wastes, with Coal, as raw materials for the sygas - - as well as making it possible to generate some amount of electricity as a byproduct of the gasification, that is, the syngas production process.

And, as seen for just one more example, in our report of;

General Electric Co-Gasifies Coal and Biomass for USDOE | Research & Development | News; concerning: "Product Characterization for Entrained Flow Coal/Biomass Co-Gasification; DOE Award No. DE-NT0006305; Final Technical Report; December 11, 2011; Shawn Maghzi, et. al.; GE Global Research; Abstract: The U.S. Department of Energy‘s National Energy Technology Laboratory (DOE NETL) is exploring affordable technologies and processes to convert domestic coal and biomass resources to high-quality liquid hydrocarbon fuels. ... In this project, GE Global Research performed a complete characterization of the gas, liquid and solid products that result from the co-gasification of coal/biomass mixtures. ... Results ...provide guidance ... to develop and commercialize gasification technologies. ... Experiments were performed on mixtures of the three major types of coal (bituminous, sub-bituminous, and lignite) with three types of biomass (cornstover, wood, and grass). ... (Barriers) to biomass utilization at scales large enough to make a noticeable contribution to global energy production include biomass variability, availability, seasonality, and low energy density (and those barriers) can be substantially mitigated if biomass is used synergistically with the most abundant fossil fuel resource - - coal";

such technology for co-gasifying Biomass and Coal offers such promise that it continues, like the, generically-labeled, Fischer-Tropsch hydrocarbon synthesis technologies, to be a focus of development by our United States Department of Energy.

We won't be able to provide you with many excerpts from the document we bring to you herein, which provides us with graphic illustration of a representative Coal gasification - and subsequent liquid hydrocarbon fuel synthesis - process.

We're providing it now so that when we discuss additional indirect Coal-to-Hydrocarbon conversion technologies in reports to follow, our readers not that familiar with the terminology, or with related industrial processes in general, might have some better understanding of the issues involved. For the sake of illustration and explanation, we will likely refer back to this document in future reports concerning indirect Coal conversion technical developments and practices.

That said, comment follows rather limited, due both to it's graphic format and to technical problems on our end, excerpts from the initial link in this dispatch to:

"Coal-To-Liquids (CTL) & Fischer-Tropsch Processing (FT)

CCTR Basics Facts File #1

The Energy Center at Discovery Park; Purdue University; West Lafayette, Indiana

June, 2007

CTL Technology: There are two main processes: Coal to Syngas (and) Syngas to FT Fuels; With two major equipment needs: Coal Gasifier; (for) Coal to SynGas; (and) FT Reactor (for) SynGas to FT Products

(There is included a presentation concerning various Ranks of Coal and their their relative Carbon and volatile matter contents. A segment headlined "Gasification Basics" illustrates the key steps in preparing and gasifying a Coal-water "slurry", with clear illustration of the fact that "steam" can be a byproduct, with the "SynGas" of Coal gasification. That can be one source of Electricity, which is headlined further on as one of the co-products of an indirect, "FT"-type "CTL" process.)

Beginnings of the FT Process: (The Fischer-Tropsch process) was used by Germany and Japan during WWII to produce alternative fuels.

FT Process Basics; The Fischer-Tropsch process uses hydrogen (H2) and carbon monoxide (CO) to make different types of hydrocarbons with various H2-CO ratios (and, in) a CTL facility the H2 and CO can be supplied from the coal gasifier.

FT + Catalysis: The FT Process is a catalyzed chemical reaction in which carbon monoxide and hydrogen are converted into liquid hydrocarbons of various forms. Catalysts ... quicken the speed of the reaction.

(Various catalysts also influence the types and ranges of products generated by the FT Process.)

Catalysts and Products:

Iron - - Linear Alkenes and Oxygenates

(Alkene - Wikipedia, the free encyclopedia; Ethylene, etc.;

Oxygenate - Wikipedia, the free encyclopedia; Methanol, Ethanol and "Gasoline-grade t-Butanol", among many others.)  

Cobalt - - Alkanes

(Alkane - Wikipedia, the free encyclopedia; "Alkanes" would include Methane, Ethane, Butane, Propane, and many other hydrocarbons.)

Nickel - - Methane (i.e., substitute Natural Gas)

Ruthenium - - High Molecular Weight Hydrocarbons

Rhodium - - Large Amounts of Hydrocarbons + Little Oxygenates

What can be Produced from a CTL Facility?

- - Ammonia Fertilizer

- - Methanol/DME/Propylene

- - Electricity

- - Diesel Fuel; Kerosene; Jet Fuel

- - Gasoline

- - Waxes; Lubricants; Detergents

- - Electricity

- - Synthetic Natural Gas

- - Carbon Dioxide"

----------------------------------------------- 

Note that "Electricity" is specified twice as being a product of Coal Gasification and Fischer-Tropsch hydrocarbon synthesis processes, as in our above citation of our earlier report concerning Texaco's "United States Patent 4,099,383 - Partial Oxidation Process".

As we've documented in several other reports, although we won't include additional links, heat is generated by both the Coal gasification and the hydrocarbon synthesis processes; and, heat can be recovered from both and then used to generate byproduct electricity.

Something we did want to emphasize, though, is Purdue's mention of "Carbon Dioxide" as something that can be "Produced", as well, from the sort of indirect Coal-to-hydrocarbon technology illustrated herein by them. As seen for only one out of now many examples in our report of: 

USDOE Reforms Coal Syngas CO2 for Hydrocarbon Synthesis | Research & Development | News; concerning: "United States Patent 8,366,902 - Methods and Systems for Producing Syngas; 2013; Assignee: Battelle Energy Alliance, LLC, Idaho Falls; Abstract: Methods and systems are provided for producing syngas utilizing heat from thermochemical conversion of a carbonaceous fuel to support decomposition of at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells. Simultaneous decomposition of carbon dioxide and water or steam by one or more solid-oxide electrolysis cells may be employed to produce hydrogen and carbon monoxide. A portion of oxygen produced from at least one of water and carbon dioxide using one or more solid-oxide electrolysis cells is fed at a controlled flow rate in a gasifier or combustor to oxidize the carbonaceous fuel to control the carbon dioxide to carbon monoxide ratio produced. Government Interests: This invention was made with government support under Contract Number DE-AC07-05ID14517 awarded by the United States Department of Energy. The government has certain rights in the invention. ...  The method ... wherein producing heat and a mixed gas comprising carbon dioxide, carbon monoxide, water and hydrogen by gasifying a carbonaceous fuel comprises gasifying the carbonaceous fuel in the presence of a portion of the oxygen formed by electrolyzing carbon dioxide and steam to control a ratio of carbon monoxide and hydrogen produced by electrolyzing the carbon dioxide and the steam";

 - - wherein our own United States Government clearly states that "Carbon dioxide gas (CO2)" as produced  by a Coal "gasifier" like that discussed in part herein by Purdue University, "may be converted into liquid fuels such as ... gasoline ... through multi-step reactions" - -

Carbon Dioxide can, indeed, be thought of as a "product", or byproduct, of a Coal conversion process like that illuminated herein, rather than as something that is just a wasteful, unwanted pollutant. And, maybe it would be a profitable change in thinking if the majority of us came to be able to see it and think of it that way. 

In any case, again, our intent with this dispatch is to provide a graphic illustration of Fischer-Tropsch type, indirect Coal-to-Hydrocarbon processes, like those now practiced on a large industrial scale in the nation of South Africa. Should the link to Purdue's exposition of it fail, we will be forwarding the file to the West Virginia Coal Association. We will be making reference to it in reports to follow.

And, we'll close with a quote that we've used before, and which, as time goes on, becomes ever more meaningful, as it relates to many things - - like the fact that our domestic Coal can, cleanly and efficiently and profitably, be converted into anything and everything we're now selling ourselves, our nation, out to keep buying from OPEC without a substantive voice of protest being raised - - to us:

"A time comes when silence is betrayal." - Martin Luther King, Jr.; April 4, 1967; Riverside Church, NYC.