Isobutene process

Global Bioenergies was founded in 2008 with a unique goal – to develop a process converting renewable resources (sugar, crops, agricultural and forestry waste) into isobutene, one of the main petroleum derivatives.

A simple and robust technology in two steps

 

General diagram of the process
 

This new approach based on gas fermentation has two major advantages and will bring down operating costs:

  • The main drawback of conventional fermentation processes – the liquid product that builds up in the reactor is toxic to the micro-organism – has been overcome since the product evaporates spontaneously. The process can even be implemented almost continuously.
  • The purification stage is simpler – the isobutene merely has to be extracted from the air, CO2 and steam, rather than having to separate a liquid compound from a complex and varying cultured broth. Conventional methods, tried and tested over many decades, can achieve this.

fermenteur-industriel-global-bioenergies

 

Why use this process?

Because isobutene, one of the major building blocks of the petrochemicals industry, represents a market worth $25 billion and may one day address an additional market worth $400 billion. 15 million tonnes are produced every year and are turned into plastics, rubbers and fuels.

 

Tree - Product isobutene
 

Why was it a scientific challenge ?

Because micro-organisms do not naturally produce isobutene. And it’s easy to understand why. A micro-organism converting its nutrients into isobutene, a volatile compound, would soon lose its carbon stores and be discarded by evolution. We had to “recode the software” in micro-organisms in our laboratory to make them produce the compound.

For the first time, an artificial metabolic pathway – a series of enzymatic reactions – was created from scratch. When implanted into a host micro-organism, it can convert sugars into isobutene in a several-stage process.

“Microbial plant”

 

Bacteria modified to produce isobutene
 

This ground-breaking achievement has opened up the entirely new domain of synthetic biology.

Modified micro-organisms have been used in fermenters on an ever-increasing scale, initially in a laboratory and now in an industrial pilot. They are intended for use in plants in rural areas where they can produce fuel, plastics and rubbers using this alternative technology.

Industrial fermenter