I read the attached report (PRENFLO gasification), and have the following comments:

1. While this process addresses the desirability of substituting domestic fuel resources (i.e. coal) for imported oil, any process using coal is NOT going to be carbon-neutral. Hence we will have to be careful, to say the least, to maximize benefits (i.e. electricity + useful products) in proportion to carbon dioxide discharged into our atmosphere.

2. Coal ash contains small amounts of mercury and other toxic heavy metals. That will have to be taken into consideration in designing the overall system.

2a. In China (and we will most likely find this out with our own coal as well), coal ash piles are being studied as a source of uranium for their nuclear power effort. We should recover uranium (and thorium, if present) from ash and slag, not only to keep it out of the air, soil and water but also to provide a source of fuel for nuclear power plants.

3. We note that dimethyl ether (DME) is a product of the synthesis process. DME is a good fuel in its own right, and we should consider using it directly instead of converting it to gasoline.

3a. Methanol is useful too, as fuel and as a chemical building block. We may be better off using it directly, instead of converting it to something else.

Finally, 4: General Motors, before they ran into their most recent financial difficulties, invested its own money in a process devised by Coskata for converting synthesis gas into ethanol. Since ethanol is a good automotive fuel (octane rating well over 100), we should consider integrating the Coskata process into the TransGas system.

@Mathew

I don't think so either; however, it won't be astronomical for prolonged periods of time in this given timeframe and probably well after this date; the price will fluctuate around some median value that constantly gets higher as the oil supplies dwindle.
But that's not the main problem. The problem is that coal-to-liquids is probably 5 times as CO2-intensive than oil.
Biofuels must be the highest priority. They will supplant oil-derived fuels until we get the storage system for the electrical car.

You guys aren't doing the math right. It's 6.5 M barrels of GASOLINE...refined & ready to go into cars. 1 barrel is what, roughly 40 gallons (US)? So 260 million gallons of gas per year... times $2 per gallon avg. equals $520 million dollars in revenue per year, equals plant paid for 6 years with revenue alone. Realistically maybe 10 to 15 years to pay back investors with operating expenses or something like that, but it will be a cash cow eventually. ...ejj...

I think this is great. Lets do it again 10 more times! An excellent use for coal, an excellent source of income for Americans--in all aspects. Caterpillar wins, hotels in the area win, people working their keep their houses, spend money. And none of it goes to people who hate our guts.

Nate H.
Dover, Ohio

OTOH if the process can use biomass and Obama genuinely brings in carbon taxes or cap-and-trade then the coal input fraction could decline over time. The technology would already be up and running as the carbon taxes got tougher. I suspect the trend to alcohol as opposed to traditional petrofuels (alkanes, aromatics etc) is due the use of fermentation. Maybe some optimised blend of alcohols and thermo-BTL can be worked out. The fly ash should be back loaded and spread on the fields or forests. The slag could be used in green cement.

The story says that you need hydrogen rich syn gas, coal does not make hydrogen rich syn gas, it makes carbon rich syn gas, so you end up dumping a large amount of CO2 to get the ratio right. This is true of any xTL scheme.

So Alain has it right, you need to build a nuclear powered hydrogen plant that produces H2 and O2 using a thermal cycle. You feed this to the xTL plant, you turn every carbon atom into fuel and you get a huge increase in the volume produced. And most of the energy that goes into your gas tank is clean green nuclear power.

It is the same as a PHEV but you don't need to make electicity and you don't need an advanced battery and a yet to be produced concept car. And better yet, if a succesful PHEV becomes available, we would be two steps ahead instead of one.

The Fischer-Tropsch process was originally developed in Germany in the 1920s, and provided much of the fuel for Germany during the Second World War. It then became the basis for much oil production in South Africa by Sasol, which now supplies about 30% of that country's gasoline and diesel fuel. However, it is a significant user of hydrogen, catalyzing a reaction with carbon monoxide. The hydrogen is now produced with the CO by coal gasification, part of the gas stream undergoing the water shift reaction. A nuclear source of hydrogen coupled with nuclear process heat would more than double the amount of liquid hydrocarbons from the coal and eliminate most CO2 emissions from the process.
Using simply black coal, 14,600 tonnes produces 25,000 barrels of synfuel "oil" (with 25,000 tonnes of CO2).

The hybrid system uses nuclear electricity to electrolyse water for the hydrogen. Some 4400 tonnes of coal is gasified using oxygen from the electrolysis to produce carbon monoxide which is fed to the Fischer-Tropsch plant with the hydrogen to produce 25,000 barrels of synfuel "oil". Very little CO2 results, and this is recycled to the gasifier.

Axil,

Why gasify coal at all? If you have got a lot of cheap nuclear hydrogen, use CO2 from power plant stack gases etc. Then water-gas shift the mixture to the required composition which is usually 1:2 CO-H2 ratio.
This is possible because water gas shift works the other way around too, i.e. CO2 + H2 = CO + H2O, only this happens at high temperatures because it is endothermic.
Cheers,

Well to Tank Report 2006 says for syn-diesel:

conventional diesel: 0,6 kgCO2/kg
diesel CTL (CCS): 1,68 kgCO2/kg
diesel CTL: 5,56 kgCO2/kg

+ combustion: 3.17 kgCO2/kg

...and add to these 32 kg CO2 per gal the emissions from the power plant to make electricity for making oxygen, compressors etc. They most likely did not include this in their calculations. The total would probably be around 50 kg/gal.

Good point Aussie!
Of all possible solutions the most practical wins!
I think that red-ox batteries will never get so practical as to beat naturally available HC's, and even synthetic HC's.

Don't bother, use micronised slurry coal in stationary diesel engines (50% thermal efficiency) to generate electricity and district heating and / of fish farming.

Use this to to charge electric vehicles or free up natural gas to use as a transport fuel.

Alternatively use solar assist on existing coal plants to reduce the volume of coal burn.