Solmaz Aslanzadeh

An Overview of Existing Individual Unit Operations

Abstract This chapter presents an overview of the different unit operations of biochemical platforms used in biorefineries producing ethanol and butanol. Biochemical platforms primarily convert lignocellulosic biomass into mixed sugars and then liquid fuels. Biochemical conversion processes rely on biocatalysts, such as enzymes and microorganisms, in combination with heat, chemical catalysts, and solvents, to convert the carbohydrate fraction of lignocellulosic biomass (hemicellulose and cellulose) into an intermediate sugar stream, which serves as the substrate for ethanol and butanol fermentation. Future biorefineries can benefit from the various combinations of diverse raw materials, conversion processes, technologies, and product portfolios associated with these platforms. Biochemical conversion routes apply biocatalysts, such as enzymes and microbial cells, plus heat and chemicals, to convert biomass into an intermediate sugar mix stream and then to ethanol or butanol. Thermochemical conversion technologies use heat and/or physical catalysts to convert biomass into a gaseous intermediate that primarily consists of H2 and CO, and a subsequent chemical or biological step converts the intermediate into biofuels. Fully understanding these processes requires knowledge of each step. Therefore, this chapter offers a summary of the individual unit operations involved in these processes.