Brazil’s Granbio is the producer of second generation ethanol from sugarcane straw on a commercial scale (Click here to know more about third and fourth generation biofuels). Founded in 2011, this biotech company is controlled by Gran Investimentos S.A. Headquartered in Sao Paulo, Brazil, the company also has an office in San Francisco, CA, USA. Granbio owns a synthetic biology research center and an experimental station to develop new sources of biomass.The Company uses Beta Renewables’ pretreatment technology Proesa®.
Granbio makes use of cane straw both left out and burnt in the cane fields. The company maintains alliances with first-generation factories for supplying its feedstock. Apart from this, sugarcane straw is collected from local fields too.
Some other giants in the field of cellulosic ethanol production are Beta renewables and Du Pont utilizing variety of agricultural residues, POET-DSM and Abengoa Bioenergy utilizing mainly corn crop residues and INEOS Bio utilizing organic part of municipal solid waste, industrial wastes and other lignocellulosic waste.
Granbio applies multiple technologies for pre-treatment, enzymatic hydrolysis and fermentation through which its feedstock undergoes transformation.
Pre Treatment Phase: The biomass is sent to the reactor where it is broken down to cellulose and hemi-cellulose fibres.
Enzymatic Hydrolysis: In the presence of enzymes which act as catalyst, the components are again broken down to easily fermented C5 and C6 sugars.
Fermentation: With the help of genetically modified microorganisms (Yeast), the sugars are fermented into ethanol.
Distillation-The fermented beer is finally distilled to produce near pure ethanol at the top of the column, and vinasse at the distillation bottoms.
Granbio’s Bioflex1 Plant
Granbio opened the southern hemisphere’s first cellulosic ethanol plant Bioflex 1 in Alagoas in 2014. The plant produces cellulosic ethanol from sugarcane bagasse and straw residues to produce 82 million liters (22 million gallons) of ethanol per year. The plant is located next to a first generation (1G) sugar mill and utilizes its sugarcane straw as a feedstock for production. For Bioflex 1, GranBio developed a system to harvest, store and process 400,000 metric tons of straw per year.
As per the company, the plant has the capacity to increase Brazilian ethanol production capacity per acre by 50% through the use of agricultural waste without meddling with the cane fields. For Proesa Technology, the company has partnership with Beta Renewables. The Dutch company DSM, and the Danish company Novozymes provide the plant with industrial yeast and enzymes consecutively. The lignin byproduct is combusted on-site along with additional bagasse from the neighboring sugar refinery to provide all of the steam and electricity needs of both the BioFlex cellulosic ethanol plant and the 1G ethanol/sugar refinery. Excess power is exported to the local electricity grid. Vinasse and boiler ash are applied to the sugarcane fields, reducing fertilizer consumption. The American agency Air Research Board has approved carbon footprint of ethanol produced by Granbio and labeled it as the most environment friendly fuel ever produced.