ChBE Seminar Series–Dr. George Huber
In addition to its annual lectures, ChBE hosts a weekly seminar throughout the year with invited lecturers who are prominent in their fields. Unless otherwise noted, all seminars are held on Wednesdays in the Molecular Science and Engineering Building ("M" Building) in G011 (Cherry Logan Emerson Lecture Theater) at 4:00 p.m. Refreshments are served at 3:30 p.m. in the Emerson-Lewis Reception Salon.
Design of New Catalytic Processes for the Production of Renewable Fuels and Chemicals
The objective of the Huber research group is to develop new catalytic processes for the production of renewable fuels and chemicals from renewable resources. We use a wide range of modern chemical engineering tools to design and optimize these clean technologies including: heterogeneous catalysis, kinetic modeling, reaction engineering, spectroscopy, analytical chemistry, nanotechnology, catalyst synthesis, conceptual process design, and theoretical chemistry. In this presentation we will discuss three approaches for the production of renewable fuels and chemicals that we are developing.
Renewable aromatics and olefins can be produced from biomass by a technology catalytic fast pyrolysis (CFP). The aromatics can be used as a feedstock to make renewable polymers including polycarbonates, polyurethanes, polystyrenes, and polyethylene terephthalates. CFP involves the direct production of aromatics from biomass in a single catalytic step. Solid biomass is fed into a fluidized bed reactor where the solid biomass thermally decomposes. The biomass vapors enter a zeolite catalyst where a series of dehydration, decarbonylation and oligomerization reactions occur to form aromatics, olefins, CO, CO2, coke and water. Coke is formed from homogeneous decomposition reactions or catalytic reactions inside the zeolite. Fundamental catalytic studies with model compounds combined with in-situ and temperature programmed techniques have aided in the design of improved zeolite catalysts for CFP. The catalytic properties and reaction conditions can be adjusted to produce targeted aromatics (p-xylene vs. benzene. vs. toluene) in economically viable yields
Working with other researchers at UC-Riverside and Wisconsin, we have also developed catalytic technology for the production of renewable diesel and jet fuel blendstocks from lignocellulosic biomass. This process involves first separating the biomass into an aqueous hemicellulose stream and a cellulose/lignin stream by a hydrothermal treatment. The hemicellulose streams undergo an acid catalyzed dehydration step to produce furfural and acetic acid. In the dehydration reactions, undesired humins are formed through reactions between the furfural and carbohydrates and self polymerization of the furfural. We have designed a continuous biphasic reactor where a solvent is able to selectively remove the furfural before it reacts further to form undesired humins. An economic analysis shows that this continuous biphasic process can produce furfural at costs of 25% the market value of furfural with energy savings of 75% compared to current industrial processes for furfural production. Solid acid catalysts can potentially be incorporated into this process offering additional cost benefits. The furfural then undergoes a C-C bond forming step followed by hydrogenation and hydrodeoxygenation to make diesel and jet fuel compounds. The cellulose/lignin feedstock is converted into levulinic acid and formic acid, which is then further processed to make jet fuel range alkanes through a series of other reaction steps.
Aqueous phase hydrodeoxygenation (HDO) is a platform technology used to convert water soluble biomass derived feedstocks (including aqueous carbohydrates, pyrolysis oils, and aqueous enzymatic products) into alkanes, alcohols and polyols. In this process, the biomass feed reacts with hydrogen to produce water and a deoxygenated product using a bifunctional catalyst that contains both metal and acid sites. The challenge with HDO is to selectively produce targeted products that can be used as fuel blendstocks or chemicals and to decrease the hydrogen consumption. Understanding the catalytic chemistry involved in HDO allows us to design improved catalysts and processes for the production of targeted feedstocks.