UK-based TMO Renewables (TMO) and Usina Santa Maria Ltda have entered into an agreement to form a joint venture to build the first commercial production plant in Brazil to convert sugar cane waste (bagasse) to cellulosic bioethanol.
TMO signed a binding Memorandum of Understanding (MOU) with Usina Santa Maria Ltda to build Brazil’s first cellulosic bioethanol production facility in São Paulo state. Under the MOU, TMO in joint venture with Usina Santa Maria Ltda will first build, own and operate a 10-million liter (2.6-million gallon US) second-generation ethanol pilot plant to convert bagasse to cellulosic bioethanol.
This will be followed by the construction of a full-scale industrial plant. The plant will be located alongside a sugar mill owned by Usina Santa Maria at Cerquilho (São Paulo state). The plant is scheduled to go into production in 2014. The bioethanol will primarily be used to power Flex-Fuel vehicles in the Brazilian market.
TMO has developed a fully integrated pre-treatment, high-solids enzyme hydrolysis and fermentation process for the production of cellulosic ethanol from biomass. This process has been designed around engineered strains of the thermophilic Geobacillus bacteria.
Among their reported work, TMO scientists engineered strains of Geobacillus thermoglucosidasius to divert the fermentative carbon flux from a mixed acid pathway to one in which ethanol becomes the major product. This involved up-regulation of the native pyruvate dehydrogenase gene and inactivation of the native pyruvate formate lyase and lactate dehydrogenase genes.
Steps in the TMO cellulosic ethanol process include:
Pre-treatment. ADeptt (Anaerobic Digestion enhanced pre-treatment technology) prepares the feedstock for the best possible enzyme hydrolysis using steam with mild conditions which are specific to the feedstock.
Feedstock is pre-treated with steam within an enclosed reactor for a hold period. The contents of the reactor is then released to atmospheric conditions resulting in rapid decompression which aids in mechanical shearing of the macro molecular structure of the organic material. Following this cell rupture, the material is further treated in an enzymatic treatment stage to further break down complex molecules into simpler forms, making them readily available for rapid acidogenesis, acetogenesis and methanogenesis.
High-solids enzyme hydrolysis. The pretreated material at high-solids concentration is treated with to a feedstock-specific enzyme cocktail at temperatures between 50-60°C to further break down the cellulose. An optimum cellulose sugar stream is transferred to the fermentation system.
Fermentation. The TMO organism uses its inherent enzymes to break down the shorter cellulose and hemicelluloses chains in the hydrolyzed material into simple sugars to generate alcohol. Fermentation is usually between 55-65°C. Finally, the fermentation broth is sent to a separation and dehydration system where ethanol is distilled and recovered.
TMO worked with the support of BB2E, a British company that assists the development and commercialization of British technology, who have helped to build what has become a strong relationship between TMO and the owners of Usina Santa Maria.
TMO entered into negotiation with Usina Santa Maria in September 2012 when it formed part of a UK business delegation to Brazil led by the UK Prime Minister David Cameron.
Brazil is the second-largest producing nation of first generation ethanol with a rapidly-developing demand for ethanol to replace hydrocarbon fuels. In September 2012, TMO signed a Letter of Intent to secure long-term supply of feedstock. The new MOU guarantees a 20-year supply of feedstock as part of the joint venture to build the pilot plant.
Cripps RE, Eley K, Leak DJ, Rudd B, Taylor M, Todd M, Boakes S, Martin S, Atkinson T. (2009) Metabolic engineering of Geobacillus thermoglucosidasius for high yield ethanol production. Metab Eng. 11(6):398-408. doi: 10.1016/j.ymben.2009.08.005.
US Patent Nº 8143038: Thermophilic micro-organisms for ethanol production