CO2 Recycling - Univ. of Illinois


 

Herein we introduce the work of Professor James Economy, and his research group, at the University of Illinois, Urbana-Champaign.
 
The title of the link might be a little misleading, as it seems to focus attention on fuel cells as the end use of recycled Carbon Dioxide. As it happens, they are but one possibility.
 
Some excerpts:
 
"The underlying goal behind UIUC CO2 Sequestration and Utilization Project is to capture CO2 in an efficient manner from the effluent of a power plant and convert it into a useful fuel source using the power plant's own waste heat.
 
Our unique approach employs microelectrochemical cells which utilize the waste heat of the power plant to reduce the energy of conversion. The captured Carbon Dioxide from the waste stream is first converted to formic acid which could be further converted to methanol for utilization in a fuel cell or storage and retail in the commercial markets."
 
We have previously cited references attesting to the potential for converting CO2 into formic acid, which, according to some of those other sources, can itself be used in fuel cell applications. It can also, as noted by the intriguingly and appropriately-named Dr. Economy, be converted into the versatile liquid fuel, and gasoline and plastics synthesis raw material, Methanol.
 
The good doctor lives up to his name by indicating something that should be, or should have been, obvious to everyone whose driven past a coal-fired power plant - all of us, in other words: Those plants make a lot of "waste" heat; that's why they have cooling towers. So, why not make use of that extra thermal energy by employing it to capture the emitted Carbon Dioxide, and to drive it's catalysis into formic acid and then into Methanol liquid fuel?
 
Is that something that just makes too much sense, or is it too obvious to have been thought of by those of us raised in coal country, who have spent lifetimes driving by coal plant cooling towers with huge plumes of wasted energy billowing out of them?
 
We can, in other words, use waste products, i.e. CO2, and otherwise wasted energy arising from our coal use to manufacture liquid fuel.
 
Doesn't that make one heck of a lot more sense than trying, through Cap & Trade and sequestration schemes, to bury a potentially-valuable raw material and tax the producers of it out of existence?

China Coal to Gas and Oil


There has been some misinformation recently published that China is having second thoughts about proceeding with their extensive Coal Conversion, to liquid and gas fuels and chemicals, industrialization.
 
Like much negative press about Coal Conversion in general, those reports are false; and, we would contend, deliberately false, as this very recent release, from China, might help to attest.
 
An excerpt:
 
"BEIJING, Aug 28 (Reuters) - China Datang International Power Generation Co has won government approval to build a 25.7 billion yuan ($3.76 billion) plant in Inner Mongolia to convert coal to gas, the China Mining News reported.
 
The plant, which would also produce liquid oil including naphtha, would be linked to a new 359-kilometre gas pipeline to Beijing, the report said."
 
"Naptha" is a term which might carry inaccurate connotations to non-technical readers. In the context of this news release, it conveys the following meaning, distilled from several web-based references:
 
"Naphtha normally refers to a number of different flammable liquid mixtures of hydrocarbons. Naphtha is used primarily as feedstock for producing a high-octane gasoline component."
 
As we have, from other sources, reported: It is feasible, on a practical basis, to produce replacements for both liquid petroleum and natural gas, from coal, at the same facility, in the same industrial process stream.

Coal's Triple Play

Herein we submit two reports from collaborative researchers, in Israel and Switzerland, documenting in even further detail the validity of proposals we earlier reported, that urge the actual capture and recycling, into liquid fuels and useful chemicals, from industrial exhaust, of Carbon Dioxide.
 
The article links and excerpts, with comments inserted and appended:
 
 
"Thermoneutral tri-reforming of flue gases from coal- and gas-fired power stations  
 
M. Halmann and A. Steinfeld

Weizmann Institute of Science, Department of Environmental Sciences and Energy Research, Rehovot 76100, Israel

ETH-Swiss Federal Institute of Technology Zurich, Department of Mechanical and Process Engineering, 8092 Zurich, Switzerland

Solar Technology Laboratory, Paul Scherrer Institute, 5232 Villigen, Switzerland

Abstract

The treatment of flue gases from fossil fuel fired power stations by tri-reforming with natural gas or by coal gasification (In other words, you don't need natural gas for this process. Syngas derived from coal gasification will work as well.) could become an attractive approach for converting the CO2, H2O, O2, and N2 contained in these flue gases via syngas processing into useful products, such as methanol, hydrogen, ammonia, or urea. (So, we can get both fuel and fertilizer by treating CO2-containing flue gas with syngas derived from coal gasification.) The present study determines the constraints for achieving such thermochemical reactions under conditions of thermoneutrality, by reacting the flue gases with water, air, and natural gas or coal at 1000–1200 K. (The overall process of reacting CO2 flue gas with coal-derived syngas and water is "thermoneutral" because some of the included reaction steps are exothermic and provide the heat energy needed to drive the rest of the process, as other research we've documented for you confirms.) The implications of such reactions are examined in terms of CO2without the addition of much, if any, of energy from external sources. The process is nearly self-sustaining.) emission avoidance, fuel saving, economic viability, and exergy efficiency.(Again, by "exergy efficiency" we presume them to mean that some steps of the reaction process produce enough heat energy to drive the entire system


 
Fuel saving, carbon dioxide emission avoidance, and syngas production by tri-reforming of flue gases from coal- and gas-fired power stations, and by the carbothermic reduction of iron oxide  

M. Halmann and A. Steinfeld

Weizmann Institute of Science, Department of Environmental Sciences and Energy Research, Rehovot 76100, Israel

ETH—Zurich, Department of Mechanical and Process Engineering, 8092 Zurich, Switzerland

Solar Technology Laboratory, Paul Scherrer Institute, 5232 Villigen, Switzerland

Abstract

Flue gases from coal, gas, or oil-fired power stations, as well as from several heavy industries, such as the production of iron, lime and cement, are major anthropogenic sources of global CO2 emissions. The newly proposed process for syngas production based on the tri-reforming of such flue gases with natural gas (As noted above, syngas derived from coal will work as well as natural gas. - JtM) could be an important route for CO2 emission avoidance. In addition, by combining the carbothermic reduction of iron oxide with the partial oxidation of the carbon source, an overall thermoneutral process can be designed for the co-production of iron and syngas rich in CO. (In other words: This process could, as well as producing fuels from Carbon Dioxide by using syngas derived from coal, refine iron from iron ore. Talk about your useful by-products. - JtM) Water-gas shift (WGS) of CO to H2 enables the production of useful syngas. The reaction process heat, or the conditions for thermoneutrality, are derived by thermochemical equilibrium calculations. The thermodynamic constraints are determined for the production of syngas suitable for methanol, hydrogen, or ammonia synthesis. The environmental and economic consequences are assessed for large-scale commercial production of these chemical commodities. Preliminary evaluations with natural gas, coke, or coal as carbon source indicate that such combined processes should be economically competitive, as well as promising significant fuel saving and CO2 emission avoidance. The production of ammonia in the above processes seems particularly attractive, as it consumes the nitrogen in the flue gases."

We'll attempt to summarize the gist of all this, as we understand it:  We can, without the addition of much external energy, use Syngas, derived from coal, to convert Carbon Dioxide into liquid fuels and useful chemicals, and, at the same time, refine iron ore, the use of which helps to both chemically reduce the Carbon Dioxide and provide heat energy to drive the entire process, and, by involving the excess Nitrogen contained in the CO2-containing flue gases, we can make some fertilizer, as well. 

How much more complete, how much more sensible and profitable, does all of this have to be before we stop whining about liquid fuel shortages and global warming, and just get to work solving the problems - with coal?

Yes, Coal can do that. Coal can do all of that. Heck, it ain't a triple play. It's a Grand Slam home run.

 

 

"Coal" and "A Cleaner Future"

 
Amidst all this enclosed article's dreary, non-productive blather about the wasteful concept of Carbon Capture and Storage - i.e., CCS, the costly collection of the potentially-valuable coal-use by-product, Carbon Dioxide, and the expensive pumping of it down geologic storage rat holes, sometimes to the benefit of Big Oil in their pot scraping efforts - are a few "enlightening" facts.
 
Some excerpts:
 
"CCS is broken down into four stages: capture (about 50% of the cost), which separates CO2 from other exhaust gases..."
 
and 
 
"South Africa’s Sasol, and PetroSA synfuels plants are said to be in a prime position for CO2 capture, as they already produce a stream of almost 95% concentrated CO2 through coal-to-liquids processes, bringing down capture costs."
 
So, coal-to-liquid conversion facilities produce nearly pure, "95% concentrated" Carbon Dioxide as their waste gas stream, thus drastically reducing capture costs - which represent "about 50% of the cost" of "CCS".
 
Wouldn't it make sense to then send that nearly-pure CO2 to a Sabatier processor, and convert it into Methane, for further processing into valuable Methanol, and thus pay at least for the cost of capturing it in the first place, and obviating the need to spend even more money burying it?
 
Carbon Capture and Storage, and Cap & Trade, just haven't been thought out, or examined in the true light of Coal-to-Liquid conversion, and Carnol and Sabatier CO2 conversion, technologies.
 
Carbon Dioxide is a valuable by-product of our coal-use industries. We can make more liquid fuels and other useful chemicals with CO2, and we shouldn't be trying to "landfill" all of it, especially to subsidize Big Oil's squeezing of last drops, or trying to tax the producers of it out of existence.
 

Black to Green


 
We've cited quite a number of references documenting the technology that exists, and which is being developed and practiced, especially in China, to convert coal into the valuable liquid fuel, and gasoline and plastics raw material, Methanol. 
 
Herein is additional information on the subject of Methanol manufacture, which will, we hope, serve as even more illustration and confirmation that coal, and the CO2 that arises from our coal use, can, on a practical and environmentally-beneficial basis, be converted into valuable products we urgently need, such as liquid fuel.
 
An excerpt:  

"The typical feedstock used in the production of methanol is natural gas. Methanol can also be made from renewable resources such as wood, municipal solid wastes and sewage. The production of methanol also offers an important market for the use of flared natural gas.

(And, to beat the horse to death: Methanol can be manufactured from syngas derived from both coal and hydro-treated Carbon Dioxide, as well as materials noted in this report.) 

In a typical plant, methanol production is carried out in two steps. The first step is to convert the feedstock natural gas into a synthesis gas stream consisting of CO, CO2, H2O and hydrogen. (Synthesis gas should by now be familiar to all our readers.) This is usually accomplished by the catalytic reforming of feed gas and steam. (Here, again, is another process wherein water, in the form of steam, supplies the needed Hydrogen to hydrogenate, to convert into hydrocarbons, the essentially carbonaceous raw material as would be derived from coal, or, by extension, Carbon Dioxide.) Partial oxidation is another possible route. The second step is the catalytic synthesis of methanol from the synthesis gas. Each of these steps can be carried out in a number of ways, and various technologies offer a spectrum of possibilities to suit most any desired application(s).

(The last statement bears emphasis, with a rephrasing, since it confirms what much of the earlier research we've reported to you indicates: There are multiple ways through which Methanol, liquid fuel, can be derived from synthesis gas, which itself can be extracted from coal, or made from Carbon Dioxide, in multiple ways.)

Conventional steam reforming is the simplest and most widely practiced route to synthesis gas production:

2 CH4 + 3 H2O -> CO + CO2 + 7 H2 (Synthesis Gas)

CO + CO2 + 7 H2 -> 2 CH3OH + 2 H2 + H2O

This process results in a considerable hydrogen surplus, as can be seen in the formula above."

(The Hydrogen surplus results from the use of pure methane, as the original Carbon source, combined with water (as steam). Synthesis gas, syngas, derived solely from coal might exhibit a Hydrogen deficit, which could be easily resolved through more H2O in the form of additional reactive steam, and/or the collateral conversion of coal with other, Hydrogen-rich, raw materials, such as saw dust, crop wastes and scrapped auto tires.)

"If an external source of CO2 is available, the excess hydrogen can be consumed and converted to additional methanol. (In other words, if additional Carbon Dioxide can be obtained, such as from a coal power plant's flue gas, more Methanol can be made. That's a switch: More CO2 is actually wanted.) 

The most favorable gasification processes are those in which the surplus hydrogen is “burnt” to water, during which steam reforming is accomplished through the following partial oxidation reaction:

CH4 + _O2 -> CO + 2 H2 -> CH3OH

CH4 + O2 -> CO2 + 2 H2

The carbon dioxide and hydrogen produced in the last equation would then react with an additional hydrogen from the top set of reactions to produce additional methanol. This gives the highest efficiency, but may be at additional capital cost.

Unlike the reforming process, the synthesis of methanol is highly exothermic, taking place over a catalyst bed at moderate temperatures. Most plant designs make use of this extra energy to generate electricity needed in the process. By employing even its by-products, methanol production proves its efficiency over other fossil fuels used in the world today."

As we've earlier referenced, some components of the Methanol synthesis procedure are exothermic, as affirmed above, and can themselves provide a portion of the energy needed to drive the complete process of converting carbonaceous feed stocks, including coal and some renewable materials, such as Carbon Dioxide and Cellulose (waste wood, Intelligencers and News-Registers, sewage plant sludge, etc.) into liquid fuel.

In conclusion, we'll note once more that Methanol is itself a liquid fuel of high worth. However, it can also be converted into the gasoline we all know and love, and serve as the raw material for manufacturing some other very useful things, such as certain plastics.

Methanol production, as the basis for manufacturing fuels and plastics out of renewable resources, such as cellulose, municipal waste and CO2, is well-understood and viable. Coal is the raw material for methanol manufacture, aside from natural gas, which actually enables the scale of such an industry that would allow the economically meaningful inclusion of those environmentally beneficial resources.