SusChEM: Defining a Disruptive Biorefinery Concept

University Of California-Davis, Davis CA

Investigators

Abstract

PI: Mascal, Mark Proposal Number: 1335646 Institution: University of California-Davis Title: SusChEM: Defining a Disruptive Biorefinery Concept This proposal describes the concept of a fully chemical-catalytic biorefinery, involving at no point either fermentative or thermal biomass processing methods. The outcome will be an exceptionally efficient, versatile system for converting biomass into renewable, drop-in automotive fuels, chemicals, and combustible solids for power generation. The first part of the project examines operationally simple, irreversible C-C coupling reactions that lead to extended carbon backbones in sugars. The electrochemical coupling of biomass-derived pentoses and hexoses to give C10-12 glycitols is proposed; an industrially relevant reaction that uses the cheapest possible reagent-the electron. The PI will also investigate the anodic decarboxylation of the C6 acid gluconate, which can lead to a C10 macrosugar, as well as the products of the Kolbe electrolysis of corresponding diacid salt (glucarate). These molecules, when submitted to the hydrodeoxygenation protocol described below, will give linear C10+ hydrocarbons, which are the main constituents of diesel fuel and feedstocks for a plethora of petroleum-based chemicals. A head-start advantage here is that the target coupling products, both reductive and oxidative, have previously been observed as side products of other reactions. The second part of the project catalytically reduces extended glycitols to linear alkanes under gentle conditions which do not lead to C-C bond cleavage. This becomes a possibility due to the powerful tendency of sugar alcohols to form cyclic ethers under acidic conditions, and the relative ease with which cyclic ethers can be reductively cleaved by hydrogenation in the presence of a strong acid. The broader impacts in terms of research infrastructure and diversity lie in the program?s interdisciplinary nature, encompassing at various points organic electrochemistry, catalysis, biphasic reaction dynamics, and interactions with power systems engineers. The educational goals of the proposal are closely linked to the PI?s research as well as his interests in pedagogical innovations.