An interesting project!

@SJC

It is definitely possible to improve the total yield of BtL by using external heat and hydrogen. You can do the calculations yourself. Assuming biomass consists of 49% C, 44% O, and 6% H (wt%, 1% ash), then 100 g of biomass conains 49 g carbon, 44 g oxygen, and 6 g hydrogen. From this it is possible to obtain, purely stoichiometrically, 4.1 mol CO and 4.3 mol H2 (I added 1.3 moles of water to convert all of carbon). These gases upon combustion release 530 kcal. 100 g biomass contain about 450 kcal. This way you need about 80 kcal external heat energy to convert 100 g biomass to CO and H2. Now if 3.9 mol of H2 is added from an external source, you would get 4.1 mol of CO and 8.2 mol of H2, which would yield after FT reaction 4.1 mol of (CH2)n hydrocarbons. That's about 57 g of hydrocarbons from 100 g of biomass, or 570 kg per ton! No biomass C is released as CO2 during the production process.
However, considerable external heat energy (about 1/5th of the biomass feed energy), and a lot of additional hydrogen are required. Another problem is that the heat energy has to be supplied at very high temperatures, at least 1200 degC, through heat conducting wall of the gasification reactor. The heat energy could be solar thermal or even nuclear. The extra hydrogen is harder to come by, electrolysis of water is probably the most feasible option.
However, these guys as well as CHOREN guys are using oxygen for gasification. This is gasification by internal heating, which inherently meens that part of the feed carbon has to be combusted to supply the energy for the endothermic gasification, and this way inevitably some of biomass carbon will end up as CO2.
Internal gasification with oxygen is technologically simpler, but I personally believe that external gasification is the way to go if we want to convert as much of biomass carbon to fuel as possible.

"the ratio of hydrogen to carbon monoxide generated during the synthesis stage of the fuel will be greatly enhanced by the external input of hydrogen."

The French Atomic Energy Agency using idle off-peak nuclear power to provide hydrogen to increase BTL yields fits in well with the energy profile of France.

http://www.eoearth.org/article/Energy_profile_of_France

"According to Oil and Gas Journal (OGJ), France had 159 million barrels of proven oil reserves in January 2006. Including refinery gain, the country produced 73,500 barrels per day (bbl/d) of oil in 2005. Despite the lack of significant domestic production, France is the tenth-largest consumer of oil in the world, consuming 1.97 million bbl/d in 2005. To meet this demand, France had net crude oil imports of 1.89 million bbl/d in 2005, the largest sources of these imports being Norway, Saudi Arabia, Russia, and the United Kingdom. Due to the lack of domestic oil sources, the French government has encouraged the use of nuclear power as an alternative energy source to oil where possible, and the proportion of France's total energy consumption derived from oil decreased from 71 percent in 1973 to 39 percent in 2003.

France has the second-largest electricity sector in the EU, behind Germany. In 2003, France produced 536.9 billion kilowatt-hours (Bkwh) of electricity and consumed 433.3 Bkwh. The country depends upon nuclear energy for 78 percent of its electricity generation. Electricite de France (EdF), owned by the French government, controls almost the entire market for electricity generation and distribution in the country. Gestionnaire du Reseau de Transport d'Electricite (RTE), a company nominally separate from but controlled by EdF, operates the national electricity grid.

Going against the trend in most other European countries, France has plans to further grow its nuclear power industry. A report released by the French government in November 2003 called for a significant expansion of the industry, including the construction of a third-generation of nuclear reactors and the upgrading of existing plants. France has partnered with Germany to develop the European Pressurized Reactor (EPR). The EPR is a third-generation reactor, designed to be safer, more efficient, and less susceptible to a terrorist attack. Each EPR reactor should produce around 1,600 megawatts (MW) of electricity, versus 900 MW for most second-generation reactors. EdF announced in November 2004 that it would build the world's first EPR at a site near Flamaville; EdF plans to complete the project by 2012, at a cost of $3.8 billion."

France imports most of it's crude oil consumption and has vast idle off-peak nuclear electricity generating capacity.

The capital cost of building a nuclear power station is high, but the marginal cost of generating additional off-peak electricity is very low.

Hence France can use off-peak idle nuclear power capacity to maximise the yield from BTL to displace imported crude oil.

France can import much natural gas from the north sea fields in exchange for nuclear electricity. It can also build massive lakes of calcium hydroxide to collect CO2. It can then use nuclear energy to free CO2 from Calcium carbonate and it can use nuclear energy to free hydrogen from water. The oxygen produced can be sold where chemically pure oxygen is needed or used to make CO and hydrogen from natural gas. Nuclear heat should be provided to all the required chemical processes for producing liquid fuels.

Some of the French Speaking Canadians should persuade France to build a few CANDU 600 reactors, and this would allow the French to use free nuclear fuel from its reprocessing plants. France could buy used fuel rods from the US power reactors for less than nothing, and just remove the fission products to make a fuel that has far more energy than the fuel normaly used by the Canadians.

Just repackaging the used US fuel can also be done for a very good fuel, but removing the fission products allows more power to be produced from the fuel rods and also allows the unused mixture of plutonium isotopes and other transuranic elements from used MOX fuel to be used and eliminated. France would have then no need to plan for the long term storage of any large amounts of plutonium or tranuranic elements. The mix of plutonium isotopes from used MOX fuel cannot be used to make explosive weapons and can be mixed with weapons plutonium to make it also useless for weapons.

Present CANDU fuel cartriges are safe for people to handle directly, and the reprocessed ones are not, but automatic machines can make and handle them. The negative fuel price will make up for the extra handling.

People must at this point be reminded or told that all food, plants and animals have always been radio-active for all of the billions of years of earth existance and the cells of all life forms including humans know how to survive their own internal radio-activity and many times more. If cuts can be repaired naturaly by the body, the repair of the damage done by more than 3000 internal nuclear explosions every second must have also been developed over the millenia.

The widespread use and knowledge of uranium centrifuges makes natural uranium the preferred source of nuclear weapons material anyway.

The use of nuclear energy to produce liquid fuels is very economic at this point of time, and whilst the production of hydrogen from nuclear electricity is expensive the cost can be reduced by using high temperature steam from nuclear reactors for high temperature electrolysis. High temperature steam can also be used to provide much of the energy needed to produce hydrogen from carbon containing materials and water. Coal can be imported from Australia for very cheap carbon instead of crude oil from the world markets.

If there is any unused nuclear capacity in France it should be devoted to making hydrogen until it is needed. The hydrogen can be used to make methanol from the CO2 produced by fermentation. Or it can be used to make ethanol by fermentation.

Nuclear fuel is very cheap, but it is the nuclear reactor and the boilers and turbine generators that are expensive. Earth and water source heatpumps are a very good use of nuclear electricity to heat houses and water. The natural gas saved can be used for automobiles, directly or indirectly. Ice can also be made with off peak power. ..HG..