Sustainability of Systems Producing Ethanol, Power, and Lignosulfonates or Lignin from Corn Stover: A Comparative Assessment

Bad economics and low environmental performance are considered to be typical of ethanol production systems deriving from lignocellulosic material such as agricultural wastes. Integrated ethanol production systems where various byproducts are also exploited have been proposed as a solution to the above-mentioned problems. The main contribution of this study is the development of a model for the examination of the sustainability of five ethanol production systems so as to discern and eventually chose the most attractive ones. This model can be used as a managerial tool for assessing biofuel production systems in general. Interdisciplinary methods and tools from engineering, economics, and operational research have been employed for the systems’ evaluation. More specifically, mass balances were used for the systems’ inventory determination, while their environmental performance is calculated by means of a life cycle impact assessment method and a relevant tool (SimaPro software). Economic analysis is used to access the alternatives’ economics. Moreover, in order to determine the combined performance of each system against certain environmental, economic, and societal criteria, both objective and subjective, the analytic hierarchy process has been employed. The systems’ overall performances are compared with each other, and the systems are ranked in order of preference. Sensitivity analysis has also been used for testing the results’ robustness. For the particular criteria selected and assumptions made, the study claims that the performance of the system producing ethanol and electricity is equal to that of the system producing ethanol, electricity, and lignin as geomaterial, while both outdistance the systems producing ethanol, electricity, and lignosulfonates. Thus, the former systems are more appealing to extensive research and further development