Screening Pathways for the Production of Next Generation Biofuels

Abstract

A large number of alternative fuel molecules based on lignocellulosic biomass have been proposed recently, but a reliable evaluation of their economic potential is challenging due to the limited data available. A rapid screening methodology, Reaction Network Flux Analysis (RNFA), has been suggested to screen a large number of future reaction pathways. The RNFA is extended in this work by a comprehensive sensitivity analysis to account for inevitable uncertainty in the underlying data and hence in the ranking of biofuel candidates with respect to cost and environmental impact. The extended RNFA is then used to assess and rank candidate reaction pathways and associated processes for the production of a variety of proposed future pure-component biofuels from lignocellulosic biomass. Ethyllevulinate and 2-methyltetrahydrofuran have been identified as promising alternatives to bioethanol, while lignin-based biofuels can be excluded from further consideration. Methane is found to be attractive economically but shows significant environmental impact.

Minimal viable sugar yield of biomass pretreatment

“…In conclusion, a low lignin content of the feedstock biomass is clearly beneficial for a low carbon loss and low fuel costs. This is in line with earlier studies showing that the production of biofuels derived from lignin is economically not feasible . A low lignin content not only implies an increased fraction of carbohydrates that can be converted effectively to biofuels, but also diminishes the inhibition potential of enzymes during hydrolysis …”

“…This is in line with earlier studies showing that the production of biofuels derived from lignin is economically not feasible. 56 A low lignin content not only implies an increased fraction of carbohydrates that can be converted effectively to biofuels, but also diminishes the inhibition potential of enzymes during hydrolysis. 55 Figure 5(b) shows the screening results for a variation of c/hc ratio at a fixed average lignin content with average pretreatment and hydrolysis yields.…”

Advanced Biofuels and Beyond: Chemistry Solutions for Propulsion and Production

“…[354] 2-n-Butyltetrahydrofuran (2-BTHF) 2-BTHF is aC 8 molecule bearing the THF moiety (boiling point = 160 8 8C; density = 0.86 gcm À3 )and represents apotential fuel additive. [69,317] Thesynthesis of 2-BTHF starting from the platform chemical furfural has been previously reported. In the course of the preparation of n-octane through the dehydration/hydrogenation of furfuralacetone (FFA; see Scheme 6), 2-BTHF was detected as aside product.…”

“…Thei nteresting properties of this bio-derived molecule,c omparable to gasoline, [241,316] have motivated numerous investigations of its sustainable production. [69,317] 2,5-DMF is generally obtained by hydrogenation/dehydration( or hydrogenolysis) of the platform chemical HMF (Scheme 5). In general, the transformation of C 6 sugars to 2,5-DMF is at wo-step process involving acid-catalyzed isomerization and dehydration of monosaccharides to HMF,f ollowed by hydrogenation/dehydration of the resultant HMF by using av ariety of heterogeneous catalysts.…”

Catalytic One‐Pot Conversion of Renewable Platform Chemicals to Hydrocarbon and Ether Biofuels through Tandem Hf(OTf)4+Pd/C Catalysis

“…[2] Recent studies have shown that, based on current production technologies, 6-pentylundecane, 2-methyltetrahydrofuran, and ethyl levulinate are promising next-generation biofuels that could exceed the performance of bioethanol in both cost and environmentali mpact. [3] Furthermore, efficient and precise new ways to produce hydrocarbon, cyclic ether,a nd levulinate biofuels from simple biomass platformc hemicalsm ay drive breakthroughst on ext-generation biofuels. Upgrading strategies to convert platform chemicals into higher molecular weightf uels typicallyc onsist of two or three independent steps:( 1) acid-or base-catalyzed condensation of simple fuelp recursors into carbon-chain-extended complex fuel precursors, (2) hydrogena-tion to cyclic ethers, and/or (3) hydrodeoxygenation (HDO) of ethers to alkanes( Scheme 1a).…”