Renewable fuels from biomass: Technical hurdles and economic assessment of biological routes

Abstract

Lignocellulosic biomass is an abundant, renewable source of polysaccharides that could be available in amounts sufficient to provide a source of sugars for carbon neutral biofuel production. We review the background to biofuels production in the US from corn sugars and subsequent R and D efforts to saccharify plant biomass to provide an alternative sugar source. Research efforts and programs have generally not addressed the key technical hurdles in providing a commodity-scale supply of biomass and in developing biological routes to saccharify it at high yields. Techno-economic analyses of proposed processes highlight the importance of biomass cost and the role of pretreatment on both inhibitor generation and the contribution of enzyme costs to saccharification. Alternatives, such as the production of fatty acids by microalgae, have comparable technical hurdles. Although there is a regulatory framework for biofuels, which is discussed, a credible biological process for large-scale, cost-effective production of lignocellulosic biofuels remains elusive.

Evaluation of Brown Midrib Sorghum Mutants as a Potential Biomass Feedstock for 2,3-Butanediol Biosynthesis

“…In 2013, 23.4 billion gallons of bioethanol was produced globally from maize, sugarcane, and other food materials [1]. USA alone produced 13.3 billion gallons ethanol, which consumed 30% of US maize [2]. The US Renewable Fuels Standards (RFS2) set a goal of producing 36 billion gallons of transportation fuel per year from renewable resources by 2022 [3].…”

Optimization and kinetic modeling of an enhanced bio-hydrogen fermentation with the addition of synergistic biochar and nickel nanoparticle

“…5 Apart from the direct water splitting via the semi-conductive photocatalyst that has attracted many interests in the past, 6 the bio-hydrogen process still remains competitive because of its many appealing advantages, ie, cost-effectiveness, simplicity in operations, independence of solar radiation, and highly efficient utilization of renewable lignocellulose. [7][8][9][10] Although efforts of investigating dark hydrogen fermentation have been made for a few decades, there are still quite many spaces left for the optimization of the entire process in the aspect of maximizing the hydrogen yield, minimizing the secondary metabolites inhabitations, and maintaining the stability of the microbes during fermentation. 11,12 In order to enhance the hydrogen yield, different efforts have been trialed by many scholars.…”

Progress Towards Engineering Microbial Surfaces to Degrade Biomass

“…At present, microbe-based CBP of lignocellulose is not being performed industrially, and ongoing research is primarily focused on constructing and identifying microorganisms with optimal cellulolytic and biocommodity production capabilities. Furthermore, detailed cost analyses of CBP versus conventional pretreatment and saccharification approaches have not been reported [36]. This is because the specific costs associated with CBP will vary based on the biocommodity produced, and the microbe and biomass source that is employed.…”