We earlier suggested that some types of biomass, specifically cellulose derived from various botanical sources, such as pulpwood, and the cell walls of algae, which have been proposed to be grown in "bioreactors", attached to the exhaust flues of coal power plants to take advantage of the more concentrated Carbon Dioxide content, could be liquefied along with coal to provide hydrogen to help with the "hydrogenation" of primarily carbonaceous coal into liquid hydrocarbon fuels.
Researchers in India have now proposed that biomass, which naturally recycles Carbon Dioxide in any case, but which is Hydrogen-rich, can be gasified, combined with additional Carbon Dioxide to enrich the synthesis gas, and then catalyzed into liquid hydrocarbons, i.e. liquid fuels.
"Title: Fischer-Tropsch synthesis using bio-syngas and CO2
Authors: Srinivas, S.; Malik, Ranjan Kumar; Mahajani, Sanjay; Indian Institute of Technology - Bombay
Citation: Energy For Sustainable Development; Elsevier, 2007
Abstract:
While Fischer-Tropsch synthesis (FTS) using coal and natural gas in conventional reactors is an almost well-established technology, the production of liquid hydrocarbons from syngas obtained from biomass is in its preliminary stages of commercialization in countries like Germany. With concerns about global warming and ways of disposing of CO2 being searched for, CO2 hydrogenation using FTS to liquid hydrocarbons can act as a CO2 sink. A brief review of FTS using CO2-rich syngas is given in this paper, looking at FTS as a technology that can help reduce global warming and as a process integration alternative. The reverse water gas shift (r-WGS) reaction is vital for CO2 hydrogenation. We have studied the effect of this using an FT kinetic model and have proposed a new flow sheet alternative for FTS using CO2-rich syngas. Simulations suggested that this new process gives better conversion of CO2. The product selectivity and yields from an FT plant are vital to make the process viable economically."
The key excerpt here might be: "CO2 hydrogenation using FTS (Fischer-Tropsch Synthesis - JtM) to liquid hydrocarbons can act as a CO2 sink. A brief review of FTS using CO2-rich syngas is given in this paper, looking at FTS as a technology that can help reduce global warming."
So, a technology developed to convert coal into liquid hydrocarbon fuels can be used, as we have earlier suggested, and documented to be feasible, for "CO2 hydrogenation" to create "liquid hydrocarbons" that serve as a "CO2 sink", or channel of CO2 recycling, and can thereby "help reduce global warming".
It is yet another coal-based solution to both the problem of liquid fuel shortages, and the possible hazard of greenhouse gas emissions, and it bears repetition:
Coal-to-Liquid conversion technology can "help reduce global warming".
And, another thing: These Indian researchers refer to Fischer-Tropsch coal conversion as being "an almost well-established technology".
Not, sadly, in Coal Country, where it should long ago have been.