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"Researchers engineer bacteria to turn carbon dioxide into liquid fuel
In a new approach, researchers from the UCLA Henry Samueli School of Engineering and Applied Science have genetically modified a cyanobacterium to consume carbon dioxide and produce the liquid fuel isobutanol, which holds great potential as a gasoline alternative. The reaction is powered directly by energy from sunlight, through photosynthesis.
This new method has two advantages for the long-term, global-scale goal of achieving a cleaner and greener energy economy, the researchers say. First, it recycles carbon dioxide, reducing greenhouse gas emissions resulting from the burning of fossil fuels. Second, it uses solar energy to convert the carbon dioxide into a liquid fuel that can be used in the existing energy structure, including in most automobiles.
While other alternatives to gasoline include deriving biofuels from plants or from algae, both of these processes require several intermediate steps before refinement into usable fuels.
Using the cyanobacterium Synechoccus elongatus, researchers ... engineer(ed) a strain that intakes carbon dioxide and sunlight and produces isobutyraldehyde gas (which is) easily be stripped from the system.
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First of all, the gas can be readily converted into the liquid alcohol, isobutanol, which, like methanol, can itself be used as a liquid fuel, or, again like methanol, be further converted into gasoline. Some web references indicate, we submit without citation, that commercial gasoline, which is a blend of hydrocarbons, typically contains a lot of petroleum-based isobutanol, in any case.
Second, unlike ethanol, isobutanol, without or without converting or blending into gasoline, "can be used in the existing energy structure, including in most automobiles". Not to mention the fact that the production of ethanol, from food crops and agricultural wastes, generates a lot of CO2 in the initial fermentation required by the process.
Third, we can make this useful liquid fuel, and make it directly "next to existing power plants that emit carbon dioxide".
Carbon Dioxide is a resource, and a renewable one; a valuable co-product of our coal-use industries.
We should set our sights, like these UCLA researchers, on figuring out how to use it more profitably, rather than on how to, at great and unrecoverable expense, stuff it all down leaky geologic storage rat holes.
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333 Ravenswood
Menlo Park, CA 94025
D. Ross
U.S. Geological Survey, Bldg 15 MS 999
345 Middlefield Rd.
Menlo Park, CA 94025
The United States currently meets 80% of its energy needs by burning fossil fuels to form CO2. The combustion-based production of CO2 has evolved into a major environmental challenge that extends beyond national borders and the issue has become as politically charged as it is technologically demanding.
Because of the fundamental nature of the study, the results should also serve as a significant contribution to the chemical literature.
reduction to formate. Band gaps and photoefficiencies of several minerals for reduction of CO2 will be measured as a function of particle size and the results used to optimize a photoreactor design with practical value.
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The production of syngas and the synthesis of methanol
CO + 2 H2 –> CH3OH
CO2 + 3 H2 –> CH3OH + H2O
CO + H2O –> CO2 + H2
The methanol synthesis variant developed by Lurgi works at pressures of 50 - 100 bar and at temperatures between 220°C and 280°C with a Cu-Zn-Al2O3 catalyst.
(We submit that "a Cu-Zn-Al2O3 catalyst" would be a zeolite-type mineral similar to the zeolite used by ExxonMobil in their own "MTG"(R), Methanol-to-Gasoline, technology.)
The production of olefin
2 CH3OH –> DME + H2O
and then into hydrocarbons e.g. to
DME –> 2/3 C3H6 + H2O
4 C3H6 –> C12H24
This reaction occurs at temperatures between 150°C and 350°C and at pressures between 35 and 85 bar, using a zeolitic catalyser. The oligomerised products in the area of C10+ are separated by distillation from the product mixture and hydrogenated. The resulting flow directly represents the diesel product of the MtSynfuels® process. Apart from that, during the distillation, a low-molecular gasoline product containing paraffin and aromatics is separated. For the two main products diesel and gasoline a total yield of > 90% (relating to carbon) is specified, whereby the ratio of diesel to gasoline can vary over a wide range. LPG (C3/C4) and light ends (C1/C2) are produced as by-products and water is also produced from the methanol conversion process.
Lurgi gives the energy efficiency of the process chain of 67% as an advantage over the FT path (< 63%). The overall efficiency, including all operating materials, is however about the same for both paths. The gasoline product from the MtSynfuels(R) process has a significantly better quality than the gasoline-like by-product of an FT systhesis."
We're glad they improved the efficiency of the process, relative to "the FT path".
But, either way, you get gasoline from syngas; and, you get syngas from ... Coal.
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Department of Energy and Geo-Environmental Engineering, Pennsylvania State University, 206 Hosler Building, University Park, PA 16802, USA
December 1999.
We have found that adding a proper amount of water can dramatically improve conversion of a sub-bituminous coal in solvent-free liquefaction under at 350C using ammonium tetrathiomolybdate (ATTM) as precursor to dispersed MoS2 catalyst H2 pressure. However, adding water to catalytic reactions at 400C decreased coal conversion, although water addition to the non-catalytic runs was slightly beneficial at this temperature. We further examined the effect of water in solvent-mediated runs in addition to “dry” tests and explored a temperature-programmed liquefaction (TPL) procedure to take advantage of the synergetic effect between water and dispersed Mo catalyst precursor at low temperatures for more efficient coal conversion. The TPL using ATTM with added water at 350C, followed by water removal and subsequent reaction at 400C gave good coal conversion and oil yield. Model reactions of dinaphthyl ether (DNE) were also carried out to clarify the effect of water. Addition of water to ATTM substantially enhanced DNE conversion at 350C. The combination of data from one-step and two-step tests of DNE and coal at 350–400C revealed that water results in highly active MoS2 catalyst in situ generated at 350C, but water does not promote the catalytic function or reaction once an active catalyst is generated. Using ATTM coupled with water addition and removal and temperature-programming may be an effective strategy for developing a better coal conversion process using dispersed catalysts."
We have cited Dr. Song, and others at Penn State, in a few of our previous dispatches. And, we have referenced for you other work indicating that plain old water, for various reasons, could enhance the efficiency and productivity of coal liquefaction processes. We've submitted this piece, like others recently, to help demonstrate that, unlike what some would have us believe, the science and technology to convert our abundant coal into liquid fuels doesn't just exist, but, it is, in some circles, well-known, well-understood and undergoing continuous improvement.
Our question: Just how good does it, coal-to-liquid conversion technology, have to be before we stop allowing ourselves to be extorted for overseas oil? Before we stop allowing our domestic economy to be further weakened and crippled? Before we put all of our people to work? Before we establish a self-sufficient US domestic energy economy based on coal; and, on the recycling of coal-use by-products, including CO2?
It's now obvious the technology to accomplish all of that is available. But, why we aren't now using that technology sure ain't so obvious.
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"Preparation of urethane from polyamine and carbon dioxide
Patent number: 5371183
Filing date: Nov 16, 1992
Issue date: Dec 6, 1994
Assignee: Monsanto Company"
