Global Bioenergies announced the production of ETBE—Ethyl tert-butyl ether, an oxygenate additive for gasoline—purely from renewable resources. ETBE features very different and advantageous physical and chemical characteristics, compared to ethanol, when blended into gasoline. These include significantly lower blending volatility; no significant distortion of the distillation curve; better tolerance of wet distribution systems; double the octane increase per “barrel” at equivalent ethanol content and narrower octane sensitivity; and better material compatibility. (ETBE RON = 119, MON = 103, AKI = 111)
ETBE also provides a series of environmental benefits compared to ethanol used alone, such as lower VOCs emission, lower permeation losses in the vehicle, and additional CO2 emissions reduction due to less severe refinery operations.
Conventionally, partially renewable ETBE is obtained by combining a molecule of renewable ethanol with a molecule of fossil isobutene using a simple and proven process. It is used as an additive in vehicle fuel, up to a maximum of 23%. The global market for the product is currently valued at more than €2 billion, or more than 3 million tonnes annually.
Global Bioenergies has now used this same process to combine renewable ethanol with renewable isobutene obtained using Global Bioenergies’ technology. This purely renewable ETBE holds the potential for incorporating 2.7 times more renewable energy in gasoline than with traditional biofuels. It will also help to cut greenhouse gas emissions even further.
Current standards limit the inclusion of traditional biofuels because of their physical and chemical properties. For example, the French standard caps ethanol content at 5% in 95-octane and 98-octane unleaded gasoline, and at 10% in unleaded 95-E10 gasoline.
The majority of countries in the world impose this type of limit – commonly known as the “blend wall”, but if biofuels are to become more widely used in the future, this limit will have to be addressed. Global Bioenergies’ fully renewable ETBE thus offers a new method for getting beyond the blend wall.
We have used commercial fermentative ethanol and renewable isobutene produced by Global Bioenergies, which is a perfect match for the specifications required for this reaction. We are proud to have been selected to produce this first batch of 100% renewable ETBE, which could be a game changer in fuel additives.—Daniela Pufky-Heinrich, Project Manager at the Fraunhofer Center for Chemical-Biotechnological Processes
This first production of entirely renewable ETBE was supported by a grant of the German Ministry of Education and Research (BMBF).
The conversion into purely renewable ETBE adds to our previous successes converting renewable isobutene to chemical products, materials and iso-octane fuel. The increasing number of applications underscores the value of our strategy to give priority to isobutene as a target from the company’s earliest beginnings and strengthens it in its innovative approach to reforming the global energy model.—Philippe Marlière, co-founder and partner of Global Bioenergies