Bioethanol production processes

Figure 8.1 Bioethanol production processes (reproduced from J. Bigorra and R. Hofer, Comunicaciones, 38 Jornadas CED, Barcelona, 2008, pp. 179-200).

Alvarado-Morales, M., Hamid, M.K.A., Sin, G., Gernaey, K.V., Woodley, J.M., Gani, R., 2010. A model-based methodology for simultaneous design and control of a bioethanol production process. Comput. Chem. Eng. 34, 2043-2061. 

Alvira P, Tomas-Pejo E, Ballesteros M, Negro MJ. (2010). Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis a review. Bioresour Technol, 101,4851 861. 

Figure 6.1 Schematic diagram of a typical first generation bioethanol production process.

In summary, currently there is no method that could meet all the requirements for the pre-treatment of lignocellulosic raw materials. Table 6.2 compares the advantages and disadvantages of various methods that are commonly used in the advanced generation bioethanol production process. 

As cellulose only represents 30-40% of the lignocellulosic biomass, the utilization of only glueose in the fermentation would undeniably have an effect on the overall biomass to ethanol conversion yield. Therefore, it is necessary to eonsider the utilization of the hemicellulose hydrolysate in the development of the advanced generation bioethanol production process. ... 

Figure 2.11 Bioethanol production processes. (Reproduced from Ref. 172.)...

Dias, M., A. Ensinas, S. Nebra, R. Maciel, C. Rossell and M. Wolf (2009a). Production of bioethanol and other bio-based materials from sugarcane bagasse Integration to conventional bioethanol production process. Chemical Engineering Research and Design 87 1206-1216. 

Figure 4.5 Overview of bioethanol production process from Ugnocellulosic feedstock. Data included shows the process parameters used for process simulation (Stenberg et af, 1998 Wooley et ah, 7 999 Aden et ai, 2002 Cal be Zacchi, 2002 Soderstrom et ak, 2003 National Renewable Energy Laboratory, 2004 Soderstrom et ai, 2004 Sassner et ai, 2008 Fornell Berntsson, 2009)...

Harun, R. Danquah, M. K. Influence of acid pre-treatment on microalgal biomass for bioethanol production. Process Biochem. 2011b, 46, 304—309. 

Similarly to biobutanol, biopropanol is another bioalcohol with high heating value. Isopropanol can be dehydrated to produce propylene, a product that can be used to esterify fats and oils for the production of biodiesel. Isopropanol can be produced by Clostridium or genetically modihed E. coli. Commercial isopropanol production from biomass-derived glucose is highly desired (Ismaiel et ah, 1993). However, the highest concentration of biopropanol observed from fermentation experiments was 4.9 g/L (Atsumi and Liao, 2008), which is still much lower than the titer of the bioethanol production process. More research would be expected to increase the efficiency and yield of the process before sizable application. 

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