The XTL Diet: New Paths to Feasible, Domestic Low-Carb Fuels
by Jim Lane (Biofuels Digest) Can synthetic biology capture and utilize CO2 to such an extent that it not only can make money – but can mitigate the carbon intensity of no-no feedstocks like coal, gas and oil, opening up new paths towards low-cost domestic energy security?
…The trouble with CTL, GTL and technologies like them? They produce high amounts of CO2 as a byproduct, and generally run afoul of the principle that alternative fuels should be, at least, no worse on greenhouse gas emissions than conventional fossil fuels.
…Projects that are using algae or other micro-organisms to capture CO2 – and convert the resultant gas stream either to biomass (which can then be converted into fuels, food, feed, or fertilizer), or directly into fuels and high-value chemicals.
In the case of waste CO2 from industrial processes, it’s a value-add, and a talking point for sustainability that, say, an ethanol or cement plant or steel mill is getting a second bite of the cherry with its waste CO2. It’s not reducing the CO2 footprint of the industrial process itself (unless the CO2 is converted to, for example, an algae fertilizer that is stored in the soil). But the combined process is generating a second use of the CO2 – which certainly reduces the overall carbon intensity of both the industrial complex, and the resulting fuel.
In the case of XTL (CTL, GTL) fuels, the possibility is that biomass capture will mitigate the carbon intensity of the XTL fuels, so that they can qualify under Section 526 for military use, or otherwise be used by customers who would otherwise show little interest in high-carb fuels. …