Catalysis and Synthetic Biology - novel pathways to produce hydrocarbon biofuels
A number of novel pathways are being developed for producing advanced biofuels, via catalysis and synthetic biology. The common aim is to produce petrochemical replacements - synthetic fuels that can be used in conventional engines.
Catalysis
In March 2010, Virent and Shell announced the world's first biogasoline demonstration plant based on Virent’s BioForming® process. The demonstration plant in Madison, WI can produce up to 38,000 litres (10,000 U.S. gallons) per year, which will be used for engine and fleet testing. In June 2010, Virent announced that it has secured $46.4m from Cargill and Shell to accelerate biofuel scale-up.
Virent’s BioForming® process can convert a wide range of feedstocks, including non-food and home grown energy sources, into the variety of fuels and chemicals now made from fossil fuels. The BioForming® process, is based on the novel combination of Virent’s core APR technology with conventional catalytic processing technologies such as catalytic hydrotreating and catalytic condensation processes, including ZSM-5 acid condensation, base catalyzed condensation, acid catalyzed dehydration, and alkylation. Like a conventional petroleum refinery, each of these process steps in the BioForming platform can be optimized and modified to produce a particular slate of desired hydrocarbon products. For example, a gasoline product can be produced using a zeolite (ZSM-5) based process, jet fuel and diesel can be produced using a base catalyzed condensation route, and a high octane fuel can be produced using a dehydration/oligomerization route.
(Source: www.virent.com)
Virent
Technology Whitepaper (August 2008, 869 kb)
In the Netherlands, Avantium Furanics are developing processes that use catalytic dehydration/esterification of carbohydrates (e.g. cellulose, hemi-cellulose, starch and sucrose) to produce furan derivatives that can substitute hydrocarbons deived from petroluem. These can be used to create biofuels, biopolymers and other products. The process also yields heat and power.
The 50M Euro CatchBio project (Catalysis for Sustainable Chemicals from Biomass) involves public-private partnership R&D on use of chemical catalysis on biomass feedstocks (2008-2015) to produce advanced biofuels and novel biochemicals.
GVL gamma-valerolactone
Researchers at the University of Wisconsin, Madison, have been researching the conversion of cellulosic materials to 5-hydroxymethylfurfural (HMF), which can then be converted to alkenes (building blocks for synthetic fuels). The process requires expensive ketones and also produces levulinic acid and formic acid. Less costly catalysts can be used to convert these acids into gamma-valerolactone (GVL). GVL can be catalysed into butene, which is readily converted into transport fuels, with an overall efficiency of 95% (GVL -> fuel). Research is now focused on finding a highly efficient route from cellulose to GVL.
Researchers at the University of Science and Technology of China have developed a new catalytic route for the conversion of biomass carbohydrates into gamma-valerolactone (GVL) without using an external H2 supply. A model experiment with glucose provided gamma-valerolactone in 48% yield. [Source: Angewandte Chemie International Edition Vol 48, Iss 35, 6529-6532, 23/07/09]
Shell has also reportedly tested blends of ethyl valerate (EV) derived via hydrogenation of gamma-valerolactone (GVL) into valeric acid followed by esterification. "Petrol blended with 10-20% EV would largely meet European petrol specificiations (EN 228). EV also leads to an increase in octane rate (RON and MON) of the fuel, without affecting other characteristics, such as corrosion and plaque formation. The fuel density and oxygen levels also increase. EV also reduces the volatility and levels of aromates, olefines and sulphur." [Source GAVE]
See also Jean-Paul Lange et al (2010) Valeric Biofuels: A Platform of Cellulosic Transportation Fuels. Angewandte Chemie International Edition, and a summary at Green Car Congress.
Since 2007 Maine Bioproducts has operated a pilot plant in Gorham, Maine to demonstrate the Biofine process, which involves high-temperature dilute-acid-catalyzed hydrolytic breakdown of cellulose to form levulinic acid.
Synthetic Biology
Amyris Inc is developing technology based on synthetic biology to produce added value biofuels (renewable biodiesel and jet fuel) from sugar cane, and has established 'joint undertakings' for production facilities in Brazil.
"On 30 November 2011, Total and Amyris announced an agreement to expand their ongoing research and development collaboration to accelerate the deployment of Biofene® and develop renewable diesel based on this molecule produced from plant sugars. The ambitious R&D programme, launched in 2010 and managed jointly by researchers from both companies, aims to develop the necessary stages to bring the next generation renewable fuels to market at commercial scale. Total has committed to contribute $105 million in funding for an existing $180 million program. In addition, Total and Amyris have agreed to form a 50-50 joint venture company that will have exclusive rights to produce and market renewable diesel and jet fuel worldwide, as well as non-exclusive rights to other renewable products such as drilling fluids, solvents, polymers and specific biolubricants. The venture aims to begin operations in the first quarter of 2012" [Source: Amyris Press Release].
In July 2011 Amyris Brasil S.A., a subsidiary of Amyris, Inc., announced it will begin supplying up to 160 city buses in the Brazilian city of São Paulo with Amyris renewable diesel derived from sugarcane (Diesel de Cana™). Vehicle manufacturers in Brazil have issued warranties for the use of 10% Amyris renewable diesel blends in Brazil. The renewable diesel derived from plant-based sugars does not require engine or infrastructure modifications.
LS9 is engineering a wide range of DesignerMicrobes™ that are used in a proprietary 1-step fermentation process to produce renewable fuels and sustainable chemicals. The technology enables the rapid and widespread adoption of renewable transportation fuels. Patent-pending UltraClean™ fuels are custom engineered to have higher energetic content than ethanol or butanol; to have fuel properties that are essentially indistinguishable from those of gasoline, diesel, and jet fuel; and to be distributed in existing pipeline infrastructure and run in any vehicle. [Source: LS9].
See also Gevo (biobutanol) and Synthetic Genomics (algae).
In the Netherlands, the 120M Euro Public/Private BE-Basic project is developing advanced genomics technologies and bioprocess engineering for bioproducts, including advanced biofuels.
In the US, the Joint BioEnergy Institute (JBEI) has identified a three-gene cluster in Micrococcus luteus that encodes enymes that catalyze key steps in the conversion of plant sugars into hydrocarbons. When intrdouced into Escherichia coli, the genes enabled synthesis of long-chain alkene hydrocarbons from glucose.