A full article on the subject can be found at Energy Bulletin . It is quite interesting, at least to me. I don't have problems with the "MEGO" ("my eyes glaze over" ) effect that is mentioned.

So, there are three critical things that this has the possibility of doing:

Removing CO2 From The Air (rather than simply preventing the addition of new CO2, which is what coal-based CO2 sequestration will do). I'm sure we are all aware of the climate change/global warming situation. What we all think of it, actually know about it, or say about it before actually knowing about it is a different story.

This correlates with what NASA climatologist James Hansen recommended - coupling carbon sequestration with biomass fuel rather than with fossil fuels in order to produce a net reduction in atmospheric CO2 concentrations. Instead of simply bringing fossil carbon to the surface, taking the energy, and sending it back underground, we would be taking carbon from the atmosphere, taking its energy (put there through photosynthesis) and then sending that carbon underground.

Produces electrical and/or thermal energy. We all had better be aware of the world's energy situation. We all seem to demand limitless amounts of cheap energy, though few people really know how it all works or what it takes to make that possible. A by-product of charcoal making is the volatile component of the biomass which can be used for energy production.

Naturally and safely enriches the soil for agriculture. We all had better be (though I know we're not) aware of the condition of the world's food producing soils and how industrial agriculture really works (by applying petroleum-derived chemicals to a dead soil "sponge" to grow food.)

Now, there obviously must be some engineering that goes into this if all three outcomes are to be accomplished in a clean and safe manner. All bickering over money and politics aside, I've described below a possible "Biochar Cogeneration Facility" for the production of energy and charcoal as a soil amendment as well as the possibility of producing feedstock for chemical manufacture. Versions of this are also discussed in that article linked above (On Energy Bulletin).

Wood, Husk, Shells, Straw and other biomass materials are shredded and homogenized. Unlike highly criticized corn alcohol, the ENTIRE biomass is utilized - not just a little sac of starch inside a kernel. Forestry and agriculture wastes would work quite well. Even municipal solid waste (paper, cardboard) could be used, but these have the possibility of being contaminated with heavy metals.

The resulting biomass is then dried, using waste heat from the generator engine block and/or exhaust and/or possibly solar energy.

The dry, homogenized biomass is fed into a kiln, heated to above 1000 K and kept under reducing conditions (very little air is allowed). In the kiln, the volatile components of the biomass are converted into flammable gases (methane, hydrogen, various other organic compounds) while the fixed carbon remains in its original state. The flammable gases can be passed through a bed of hot charcoal and converted to hydrogen and carbon monoxide. Steam may be added to facilitate the production of hydrogen.

The process could be tweaked to optimize either energy production or charcoal production/sequestration. Leaving more carbon in the reactor and producing the maximum level of charcoal would result in less energy production, but more carbon going to the soil and less to the atmosphere. Charcoal could also be gasified and used for energy production. Charcoal produced by the plant could be used as a form of energy storage, gasifying some of it during times of high energy demand.

The H₂/CO mixture (called "syngas" ) is siphoned off and is used either directly for energy production or is used in further chemical synthesis. With H₂ and CO, virtually every organic compound currently produced by humans in chemical facilities can be synthesized. It can also be converted to liquid fuels capable of being used in diesel engines (through Fischer-Tropsch synthesis).

The hydrogen in the gas stream may be used in the Haber-Bosch synthesis process (ammonia making), and the resulting ammonia used on the charcoal to add nitrogenous value as well. Adding the Haber process, though, would require a larger-scale operation rather than a village- or town-scale operation.

The carbon (charcoal, or biochar) left in the kiln after gasification is collected and used as a soil amendment, with the capability of sequestering large amounts of carbon dioxide in the soil for long periods of time while increasing the fertility, moisture, and nutrient holding ability of the soil. The nutrients (potassium, phosphorus) that were in the biomass before gasification are returned to the soil.

Adding charcoal to the soil produces the "terra preta" previously described. Sequestering carbon in the soil using the terra preta method is probably more technically feasible than using proposed "geosequestration" systems which store the CO2 from coal-fired power stations in a compressed state deep underground in rock strata. It is also much simpler to build the plant (a very good possibility for the developing world), and the use of biomass as fuel instead of coal means that CO2 will be actively removed from the atmosphere while producing energy and enriching the quality of soils. Coal-Fired systems produce energy, but do not remove CO2 from the air or enrich the soil.

Facilities for combustion of the syngas for energy production would consist of a diesel engine, gas turbine, and/or steam-based Rankine cycle turbine. These engines would drive a generator for electricity production, and the waste heat they produce would be collected for use as well. Part of this waste heat may be used to operate the plant itself (drying the biomass).

The waste heat may be used to heat adjacent greenhouses, while the flue gases from the syngas combustion, rich in humidity and carbon dioxide, may be funneled into the greenhouses to encourage plant growth.

This all seems to be much easier, cheaper, and more effective than coal-based geosequestration, and with available technology. There are not too many things we do which act to reverse ecological damage; most things tend to simply halt or slow further damage. This actually REVERSES damage.