Carbon Sciences to produce first samples of diesel fuel from methane and CO2 using catalytic dry reforming process
06 June 2011
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Overview of Carbon Sciences’ process. Click to enlarge. |
Carbon Sciences, Inc., a technology developer focusing on the conversion of carbon dioxide and methane to fuels, plans to produce samples of diesel fuel in an end-to-end process demonstration.
In December 2010, Carbon Sciences announced a worldwide exclusive license agreement with the University of Saskatchewan (UOS), Canada, for catalyst technology for the dry reforming of methane with CO2. (Earlier post.) Dry reforming of methane, which produces a syngas that can then be transformed into fuels and chemicals using a conventional Fischer-Tropsch (FT) process, offers lower projected capital and operating costs than other methods for converting methane to syngas—i.e., steam reforming, partial oxidation, or autothermal reforming—according to the company. However, there currently is no commercial catalyst robust enough to sustain dry reforming reactions on an industrial scale. Carbon Sciences says it has solved this problem.
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Catalyst performance. Click to enlarge. |
The UOS catalyst technology, developed over the past decade by Dr. Hui Wang, professor of Chemical Engineering, has demonstrated high performance and reliability. The UOS catalyst achieved 92% conversion into essentially 1:1 H2/CO syngas with no detectable sintering, no significant carbon deposition, and thus no catalyst deactivation. Dr. Wang’s research team has successfully tested the catalyst for 2,000 hours of continuous operation in a bench top reactor.
The catalyst has also undergone 600 hours of commercial testing without regeneration. The company claims that its second-generation catalyst has achieved performance levels close to its theoretical limits.
After achieving very positive commercial test results for our catalyst, we are moving ahead aggressively to accelerate the production of larger quantities of the catalyst, as well as completing the technical and economic analyses in preparation for discussions with strategic partners. Working with the GTL experts at our engineering firm, Emerging Fuels Technology, we also plan to demonstrate an end-to-end process that will produce samples of diesel fuel that can be used by existing diesel vehicles.
—Byron Elton, Carbon Sciences’ CEO
Broadly, the methane dry reforming reaction is:
Since the CH4 and CO2 reaction consumes CO2, the company says, syngas from dry reforming can be carbon neutral or carbon negative, depending upon the carbon balance of the energy source. For example, if reaction heat was provided by geothermal or solar thermal energy, then the resulting sygnas would be carbon negative. In countries where carbon credits are available, a carbon negative balance may offset a majority of the cost of producing syngas, offering a major cost advantage over other methane reforming processes.
Carbon Sciences’ claims that using its catalyst can achieve a 20% to 30% capital cost advantage over the alternatives because dry reforming is a simpler process, does not require an oxygen plant, uses small amounts of steam and has high conversion efficiency. Additionally, the feedstock cost of dry reforming syngas may be lowered by as much as 25% because CO2 is a zero cost feedstock (and often negative value) that occurs naturally in methane gas fields.
Resources
Haijun Sun Jian Huang, Hui Wang, and Jianguo Zhang (2007) CO2 Reforming of CH4 over Xerogel Ni-Ti and Ni-Ti-Al Catalysts. Ind. Eng. Chem. Res., 46 (13), pp 4444–4450 doi: 10.1021/ie070049e
Jianguo Zhang, Hui Wang and Ajay K. Dalai (2009) Kinetic Studies of Carbon Dioxide Reforming of Methane over Ni-Co/Al-Mg-O Bimetallic Catalyst. Ind. Eng. Chem. Res., 48 (2), pp 677–684 doi: 10.1021/ie801078p
US Patent # 2009/0314993 A1. Catalyst for Production of Synthesis Gas (24 Dec 2009)
I figure that there will be a valuable use for CO2. Natural gas used to be seen as a waste product and flared, then they decided to build pipelines and now it is a major source of energy.
We can make methane from coal and biomass, we have more coal reserves and biomass is more sustainable, it is just that the price of natural gas is so low now, it is not worth it. Once we have good prices for bio derived methane, we can use the CO2 from ethanol plants to make whatever fuels we want.
I suspect that we will not have the capital available to do any of this however. Financial collapses take more of a toll than many people think.
Posted by: SJC | 06 June 2011 at 08:46 AM
This is no carbon-neutral panacea. Hydrocarbons have the rough formula of (CH2)n, so the required H2:CO ratio is about 2:1, not the 1:1 generated by this process.
This means that roughly 1/3 of the CO has to be converted to H2 with the water-gas shift to get the correct mixture for F-T synthesis of long-chain hydrocarbons. This creates most of the CO2 required for the reforming process; in other words, there is little external CO2 required if the product is to be a hydrocarbon. Therefore, the process cannot usefully recycle much CO2 from other sources, and the only way to make the process carbon-neutral is to start with bio-methane.
On the other hand, per the patent the process reaches its claimed conversion efficiency at about 800 C. This temperature is within the reach of molten-salt reactors (and conversion is reasonable even at 600 C).
Posted by: Engineer-Poet | 06 June 2011 at 12:43 PM
Another way to hit the 2:1 ratio is siphon off half of the CO and burn it to provide some of the process heat.
From a strategic standpoint, an economical process that uses coal and natural gas (and negligible amounts of water) at high efficiencies would be huge for the U.S.
Posted by: GreenPlease | 06 June 2011 at 01:25 PM
Gads, you have to use an awful lot of methane to get a gallon of liquid fuel. If it prevents the methane from being flared, that's goodness. I generally prefer to see methane used in cogeneration or fuel cell plants, as they're much more efficient than ICE engines, AND you don't have to pay the conversion cost of making them into a liquid.
Posted by: HealthyBreeze | 06 June 2011 at 03:22 PM
@HealthyBreeze
One of the great hopes for GTL technologies is to create a portable and modular system to collect what would otherwise be "stranded" natural gas the reserves of which amounts to 1,000s of TCF globally.
Posted by: GreenPlease | 07 June 2011 at 06:45 AM
There is enough stranded gas flared in the world to provide half the natural gas in the U.S. If that represents a 50% production increase, I do not mind a therm of natural gas turned into a gallon of methanol.
We could say that we would like fuel cells and cogeneration because they are more efficient, but the gas is stranded and there are NO transmission lines. So making that gas into liquid fuels at that location has a real positive benefit NOW.
Posted by: SJC | 11 June 2011 at 09:54 AM