Thermochemical conversion involves either the gasification of biomass or coal followed by synthesis to liquid fuels (indirect liquefaction) or the direct conversion of coal to liquid fuels (direct liquefaction) with high-pressure hydrogen (H2), as shown in Figure 4.1. Those thermochemical conversion processes are considered to be ready for deployment between now and 2020. Because of its chemical complexity, biomass can also be converted to liquid fuels by pyrolysis or liquefaction. Those routes are not as well developed.
For each of the technologies, the panel has considered the technological readiness, costs, environmental impacts, characteristics of the finished products, and barriers to deployment. The panel also projected the potential commercial contribution that thermochemical conversion could make in the period 2020–2035 and beyond 2035.