According to a study reported in the Biofuels, Bioproducts & Biorefining journal, the cost and efficiency of producing ethanol using materials having high lignocellulose content such as waste paper, wood residues, straw and utilized cardboard is not as competitive as with corn starch. It may take years to achieve the same efficiency, probably by 2020.
The study analyzes the options to increase return and decrease expenditures in the lignocellulose-to-ethanol production technique and provides information about the priority areas need to be handled in the future.
Jamie Stephen’s study emphasizes on the fact that the expenditure of developing industrial scale ethanol-manufacturing facilities for second generation ethanol technologies is expected to be more than that of first generation technologies. One reason is that lignocellulose sources may need expensive pre-treatment process. Stephen stated that manufacturers and scientists will focus on decreasing the pre-treatment expenditures and improving the digester yield to facilitate cost reduction of the lignocellulose-to-ethanol production process.
The second reason for higher costs is that pre-treated lignocellulose needs a mix of cellulase enzymes, as it is made of several types of sugar. To produce the same quantity of ethanol, the amount of cellulase needed is 12 folds more than the amount of amylase protein used for ethanol production utilizing corn starch or sugarcane. The cost of cellulase enzyme consumption must be decreased significantly if lignocellulose has to be used in place of sugarcane and corn, said Stephen.
The final reason is that the input to the lignocellulose process is inconsistent, as wood produced by various species of plants will be different, and agricultural waste and paper waste feedstocks will have different materials. In order to obtain optimal efficiency, each woody biomass must be treated in a range of conditions, which is an added challenge to manufacturers striving to produce ethanol using these materials. Altogether, a number of issues need to be addressed prior to the commercialization of second-generation technologies for ethanol production, Stephen concluded.
Source: http://onlinelibrary.wiley.com