Will second‐generation ethanol be able to compete with first‐generation ethanol? Opportunities for cost reduction

Abstract

The production costs of a lignocellulosic ethanol process, both currently and projected for 2020, were compared to a corn ethanol process, to determine its economic competitiveness. A techno‐economic model was used to estimate the current production costs for a base‐case, 50 ML yr‐1 softwood facility, as well as providing a basis for cost‐reduction test cases assessing different feedstock, scaling, enzyme, and coproduct options. The progress ratio indicated that lignocellulosic ethanol could be competitive with corn ethanol by 2020, based on volumes mandated by 2007 EISA. However, cost reductions must occur across all components of the production process. The ambitious cellulase enzyme cost reductions that have been projected were shown to be challenging as cellulase costs still need to be significantly lower than those of amylase enzymes on a unit‐of‐protein basis. Opportunities for capital cost reduction relative to first‐generation plants were primarily restricted to the pre‐treatment/hydrolysis unit operations, with operational conditions such as the severity of pre‐treatment and hydrolysis residence times, significantly influencing operating costs. Alternative operating strategies, such as maximizing hydrolysis rate with shorter residence times rather than maximizing ethanol yield and using the unhydrolyzed residue for heat and power production, showed some promise. Increasing the size of the facility to 1 BL yr‐1 output substantially reduced the per unit capital costs, but not to a level competitive with an average (150 ML yr‐1) corn ethanol facility. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd

Combined production of biogas and ethanol at high solids loading from wheat straw impregnated with acetic acid: experimental study and techno-economic evaluation

“…A variety of raw materials, which require different process configurations, have been examined, including bagasse and sugar cane [21,22], switch grass [23,24], wood [25][26][27], and corn and corn stover [28][29][30]. However, to the best of the authors' knowledge, there are few reports on the technical and economic aspects of wheat straw biorefineries.…”

Second-generation bioethanol from industrial wood waste of South American species

“…The performance of different pretreatments at varied LSR was studied in several works (Saska and Ozer, 1995 The production of multiple products is key to have competitive production cost against the first-generation biofuels and that depends on the pretreatment processes. Several high-value products can be produced through the secondgeneration biorefineries to reduce the overall processing cost of biofuels (Stephen et al, 2012;Balan, 2014). Lignin is an aromatic polymer usually used in the pulp and paper industry to generate energy (heat and power).…”

Optimizing ethanol and bioelectricity production in sugarcane biorefineries in Brazil

“…Recently, Furlan et al (2013) and Dias et al (2013) have investigated the economic advantages of a flexible (able to switch between 2G ethanol and bioelectricity production) sugarcane biorefinery [30,31]. Some authors claim that lignocellulosic ethanol may require policy support for implementation [32]. In addition, have simulated stand-alone and integrated second generation ethanol production from sugarcane biomass considering different technological scenarios [28].…”