ABSTRACT
This chapter overviews the technical and economic results of alternative approaches taken to integrate various unit operations into processes for converting biomass to ethanol. Process integration for biomass-to-ethanol conversion is a bioprocess that synthesizes individually evaluated unit operations into a unified or integrated continuously operating development model of a full-size process. The chapter highlights recycle technology that looks at whole process integration, some with a view toward the "biomass refinery". Bench-scale integration has many advantages for the study of alternative process scenarios, particularly for new processes involving new operations that have not been integrated previously. Bench scale permits an economical modular process in which well-understood unit operations can be interchanged and alternative recycle options evaluated within the whole integrated process. The improvements in starch hydrolysis have, coupled with price subsidies, enabled bioethanol, largely from corn wet milling and dry milling operations, to add several billion liters to the total ethanol capacity and flip-flop the once dominant "ethanol from ethylene" process.
