Achieving the near-term economic competitiveness target with gasoline and starch-based ethanol outlined above for biomass gasification — mixed-alcohol synthesis — requires im­provements in catalytic tar and light hydrocarbon reforming to increase conversion effi­ciencies and reduce the capital costs of syngas cleanup and conditioning. However, as is the case for biochemical conversion, significant technological advances beyond this state of technology will be required to realize the ultimate potential of thermochemical conver­sion approaches for biofuels production. A strategy for accomplishing this involves moving forward with two complementary approaches:

• Pursue scientific achievements to improve yields and efficiencies and maximize process integration opportunities in existing thermochemical processes

• Implement a rigorous research program to investigate fundamental biomass thermo­chemical conversion to enable alternative processes that will help erase the lines between gasification and pyrolysis as separate technology options.

R&D efforts for breakthrough thermochemical technology should focus on the front-end processes, while the downstream unit operations continue to be optimized. Significant im­provements in catalytic gasification will be needed to increase carbon conversion efficiencies to syngas and decrease tar formation. An example of a breakthrough technology would be converting 50% of the methane produced to syngas while simultaneously increasing the throughput of the gasifier by 25%. This improved technology would reduce thermochemi­cal conversion cost by an estimated 38% over the technology listed above (46).

t

• Chemical fractionation • Thermochemical/catalytic/chemical

• Thermochemical pretreatment transformation with high yields and

• Catalytic modification (hetero/homogeneous) controllable selectivity

-Acid/base

— Solid acid catalytst

— Transition metals

— Organometallics

• Biomass deconstruction

• De-polymerization

Figure 2.12 Selective thermochemical processing.

Process consolidation is needed to continue lowering capital and operating costs. The block flow diagram in Figure 2.12 illustrates the R&D required to advance thermochemical conversion technology to meet the long-term goals of the biorefinery and biofuels. The following sections describe the research needed to accomplish advanced state of technology for thermochemical conversion shown in Figure 2.12.