ABSTRACT
Biofuels are fuels produced from contemporary biological resources such as plants or plant-derived materials or other biomasses such as agricultural, domestic, and other industrial wastes. Currently, worldwide biofuel production is increasing to mitigate the global energy demands and reduce the greenhouse gas emissions. To reduce the dependence on petroleum and coal, many countries already have mandated blending of biofuels with gasoline and are developing new policies to increase the biofuel usage in the future. However, so far biofuels comprise of only 3 percent of the total world fuels. Various social, economic, environmental, and technical issues limit the practical viability of biofuel production technologies. Scaling up of biofuel can be broadly classified into four stages: (1) cell scale that deals with microbiological aspects (such as growth kinetics, temperature, and nutrients), (2) process scale which includes fermentation engineering (such as reactor design, mass transfer, and process control), (3) gene scale which includes molecular engineering (such as gene manipulation and protein engineering) and (4) metabolism scale, which includes system biology (such as metabolomics and transcriptomics). In this chapter, different technical obstacles that challenge the scaling up of biofuel production are discussed. In addition, certain case studies relating to industrial biofuel production are emphasized.
