A High-Yield Biomass Alternative to Petroleum for Industrial Chemicals

University of Massachusetts Amherst chemical engineers report in Science that they have developed a way to produce high-volume platform chemicals including benzene, toluene, xylenes and olefins from cheap oils produced via pyrolysis of renewable biomass. These chemicals are used in a variety of applications such as solvents, dyes and plastics, and at present are usually produced from petrochemicals.

Associate Professor of Chemical Engineering at UMass Amherst, George Huber:
"Thanks to this breakthrough, we can meet the need to make commodity chemical feedstocks entirely through processing pyrolysis oils. We are making the same molecules from biomass that are currently being produced from petroleum, with no infrastructure changes required. We think this technology will provide a big boost to the economy because pyrolysis oils are commercially available now. The major difference between our approach and the current method is the feedstock; our process uses a renewable feedstock, that is, plant biomass. Rather than purchasing petroleum to make these chemicals, we use pyrolysis oils made from non-food agricultural crops and woody biomass grown domestically. This will also provide United States farmers and landowners a large additional revenue stream. But here we show how to achieve three times higher yields of chemicals from pyrolysis oil than ever achieved before. We've essentially provided a roadmap for converting low-value pyrolysis oils into products with a higher value than transportation fuels."

The research represents an innovation in the processing of bio-oils; this is already possible for these applications however this development reduces the cost involved to make the process more commercially attractive. While production of the bio-oil feedstock is cheap, an extra processing step is needed to convert the bio-oils into a usable form; the oxygen content of these oils is high making them acidic and corrosive, this oxygen must be removed. This step has been the cause of the extra cost, until now.

A hydrogenation step removes excess oxygen from the oils. This enhances the stability of the oils in preparation for conversion into the starting chemicals for production of toluene, benzene, xylene, ethylene and propylene using a zeolite catalyst. The process can be varied to direct the reaction toward particular products. These five chemicals are some of the major starting chemicals used in the $400 billion US chemicals industry. The economics of the process and its variations are also considered in detail.

A pilot plant at the University is running this process a liter scale, and Huber has also created a start-up company named Anellotech Corp. to commercialize the process.