Isobutene—one of the main petroleum derivatives—is a platform molecule. In the fuel sector, it is presently used to manufacture isooctane, ETBE and MTBE which are valuable compounds used in gasoline mixes. (Global Bioenergies is partnering with Audi, earlier post.) It can also be converted into isododecane, a compound found in jet fuel. Isobutene is also used to manufacture a wide variety of materials and chemicals such as rubbers, plastics, organic glass, paints and cosmetics.

Micro-organisms do not naturally produce isobutene. Global Bioenergies developed an artificial metabolic pathway—a series of enzymatic reactions—which, when implanted into a host micro-organism, allows the microbe to convert sugars into isobutene in a several-stage process.

The demo plant will be ramped up in the first half of 2017, with the goal of reaching performances close to commercial levels by the end of the year. The delivery of the first tons to Global Bioenergies’ numerous industrial partners will enable the validation of downstream processes for the conversion of this green isobutene in a range of industries, including cosmetics, rubber and fuels, the goal being to continue discussions on commercial exploitation in tens of thousands of tons of product.

While Global Bioenergies continues with the demonstration phase of the technology, it will now amplify its strategy aimed at diversifying the resources compatible with its isobutene fermentation process.

The process currently uses first-generation sugar as feedstock, an approach facilitated by the existence of the well-established sugar beet, sugar cane and corn processing industries.

The company will now expand its focus to other second- and third-generation carbon feedstocks, which are associated with even higher reductions in greenhouse gas emissions. Second-generation feedstock consists of agricultural residues (wood, straw, miscanthus, etc.), while third generation feedstock is based on the use of gaseous carbon (CO₂, syngas, etc.) directly.

The successful production of isobutene from second-generation carbon resources has already demonstrated the adaptability of the company's gaseous fermentation technology. These tests were based on wheat straw extracts supplied by Clariant.

Global Bioenergies has also been selected by a consortium led by large Swedish industrialists, Preem and Sveaskog, to study the potential for converting forestry waste into renewable fuel. Global Bioenergies will intensify its efforts to maximize the use of currently un-valorized or under-valorized waste streams in an environmental and economic objective.

Third-generation feedstock is also a priority for Global Bioenergies’ research and development because it has the highest environmental potential and also because of the low cost of the carbon sources considered. The principle of gaseous fermentation promoted by the company will also apply here, allowing a continuous, more efficient and more cost-effective production.

Global Bioenergies expects that the exploitation of the process based on first-generation feedstock will be facilitated by the gradual recovery in oil prices and a softening in sugar prices (as the quota system comes to an end in Europe and sugar consumption is reduced in the United States).

By broadening the technology’s potential even further, Global Bioenergies is setting ambitious economic and environmental targets, based on the use of carbon from a variety of sources and lower costs.