Gluconic Acid from Biomass Fast Pyrolysis Oils: Specialty Chemicals from the Thermochemical Conversion of Biomass

Abstract

Fast pyrolysis of biomass to produce a bio-oil followed by catalytic upgrading is a widely studied approach for the potential production of fuels from biomass. Because of the complexity of the bio-oil, most upgrading strategies focus on removing oxygen from the entire mixture to produce fuels. Here we report a novel method for the production of the specialty chemical, gluconic acid, from the pyrolysis of biomass. Through a combination of sequential condensation of pyrolysis vapors and water extraction, a solution rich in levoglucosan is obtained that accounts for over 30% of the carbon in the bio-oil produced from red oak. A simple filtration step yields a stream of high-purity levoglucosan. This stream of levoglucosan is then hydrolyzed and partially oxidized to yield gluconic acid with high purity and selectivity. This combination of cost-effective pyrolysis coupled with simple separation and upgrading could enable a variety of new product markets for chemicals from biomass.

Implementation of concepts derived from model compound studies in the separation and conversion of bio-oil to fuel

“…Recent results from our group in collaboration with researchers from Iowa State University demonstrate that high concentrations of levoglucosan could be produced after sequential condensation of the biomass vapors and washing to produce a sugar stream, see Fig. 13 [ 135 ]. After some mild filtering to remove the suspended solid particles and furanics, the levoglucosan was hydrolyzed produce glucose with 100% selectivity, followed by partial oxidation to produce gluconic acid, a reaction that is also 100% selective.…”

Microbial conversion of pyrolytic products to biofuels: a novel and sustainable approach toward second-generation biofuels

“…Hydrolysis with 0. [163] fermented to ethanol by S. cerevisiae T2, using high yeast inoculum (1 g/l in flask) under micro-aerophilic conditions. The ethanol yield (0.46 g ethanol/g glucose) in this study was very near to the theoretically calculated yield for pure glucose (0.51 g ethanol/g glucose), suggesting that ethanol production from pyrolysis oil is as efficient as producing ethanol from pure glucose (Table 4).…”

A Systems‐Level Roadmap for Biomass Thermal Fractionation and Catalytic Upgrading Strategies

“…Oxidation is typically performed over Pt and Pd catalysts. The hydrolysis of levoglucosan with the solid acid Amberlyst‐15, followed by oxidation in air to gluconic acid has been demonstrated over Pd/C . One noteworthy disadvantage of oxidation is that it increases the oxygen content, which must subsequently be removed to form hydrocarbon products.…”

“…Furthermore, one may also incorporate additional separations within the upgrading process. In the above example, one may attempt to isolate levoglucosan from the stream to upgrade the isolated component.…”