Anellotech’s catalytic pyrolysis technology: Is it viable for biofuels production?
Start-up Anellotech is developing a catalytic pyrolysis technology to convert wood waste, sugarcane bagassee, and corn stover to aromatic hydrocarbons, to be used as raw materials for the chemicals industry and as fuel additives for gasoline producers[1, 2]. Anellotech has also indicated on its website that its technology can be applied to produce unspecified transportation fuels, and it has previously indicated that gasoline and diesel are possibilities.
The inherent complexity of Anellotech’s technology and the vast number of associated chemical reactions and purification steps strongly suggest that application of this technology to transportation fuel production is at least a decade from commercialization and carries serious technical risk. As a result, technical hurdles, including scale-up, are likely to hamstring Anellotech and other first generation developers of catalytic pyrolysis for biofuels production such as Khosla-backed start-up Kior. In this context, Anellotech’s plan to initially target the more tractable aromatic hydrocarbons is a good strategy, and may allow it to survive long enough to improve and apply the technology to gasoline or diesel production. Alternatively, it’s possible that Anellotech has already experienced technical challenges and low yields for gasoline or diesel, and is pursuing, by default, the only feasible near-term products.
Anellotech’s technology comes from the laboratory of George Huber at University of Massachusetts Amherst, and the aromatic hydrocarbons the company currently intends to produce include toluene, benzene, and xylenes. Huber claims that the laboratory-scale process yields 50 gallons of product per metric tons of biomass, where the product is evidently a mix of these three aromatic hydrocarbons (we are assuming this value is for dry tons of wood, given that Anellotech has used wood sawdust as feedstock in early tests).
The laboratory-scale yield of 50 gallons per ton of aromatic hydrocarbons is unimpressive when used as a benchmark for the potential yield of a transportation fuel like gasoline using the Anellotech process. For Anellotech to make transportation fuel production commercially viable, major process improvements will be needed, as yields will only decrease as finished fuel products are generated and scale increases.
At the core of Anellotech’s technology is a chemical catalyst related to zeolite ZSM-5 and comprised of a porous structure. According to US patent application 2009/0227823, which is listed on Anellotech’s website, useful materials include cellulose, hemicellulose, and lignin, as well as associated pyrolysis-derived components and their combinations[1, 4]. Although reference 2 indicates the catalyst structure is made up of silicon and aluminum, it’s clear from US2009/0227823 that, more precisely, the elements silicon and aluminum are present with oxygen, in the form of silica and alumina.
For additional information, note that Forisk Consulting and the Schiamberg Group have conducted a multi-client study to assess the wood-based liquid transportation fuel sector in the continental United States. This research evaluates projects based on technology risk, with profiles of firms, wood markets and technologies. For more about the study, “Transportation Fuels from Wood: Investment and Market Implications of Current Projects and Technologies,” or to purchase it, click here.
Copyright © Bruce A. Schiamberg 2011. All rights reserved.
1. Anellotech company website.
2. Katherine Bourzac, “From Biomass to Chemicals in One Step,” Technology Review (2010).
3. “UMass Amherst, Anellotech pioneer conversion of bio-oil to chemical intermediates”, Renewable Chemicals Digest (2010).
4. US2009/0227823, “Catalytic Pyrolysis of Solid Biomass and Related Biofuels, Aromatic, and Olefin Compounds.”