A greener route for ethylene

Polyethylene balls  (From Wikipedia - Lluis tgn) From plastic bags to nylon to fuels, ethylene is a key ingredient in a vast variety of production processes. This widespread use has made ethylene the most produced organic compound in the world.

The chemical industry needs ethylene, and this demand is currently being kept at bay by its production from fossil fuels. Fossil fuels are finite. Moreover, the process plays a role in climate change; taking carbon that’s locked underground and releasing some into the atmosphere. Ethylene production represents the largest CO2-emitting process in the chemical industry.

The case is clear. We need a renewable route to produce ethylene- to meet the ever growing global demand and reduce the significant environmental impact.

Ethylene is produced naturally by plants and some microbes that live with plants. Bioethylene could supplement or replace fossil fuels as a base in chemical industry, using renewable sources of carbon such as waste biomass (plant matter) and CO2. A review published in Biotechnology for Biofuels this month discusses the potential and challenges associated with the microbial-based route of bioethylene production. The researchers from National Renewable Energy Laboratory, University of Louisiana Lafayette, and University of Colorado boulder (USA) provide the first literature review on ethylene-forming enzyme and its potential for bioethylene production.Cyanobacteria

There are great prospects for this technology, for example algae. Algae draw CO2 out of the atmosphere to feed into photosynthesis. Progress has been made recently at NREL, where a cyanobacterium (blue-green alga) has been engineered with the ethylene-forming enzyme to produce ethylene continuously from CO2. This could mean comparatively saving of six tons of CO2 emissions for every ton of bioethylene produced.

There are still many questions that loom over this technology, the most obvious being how does ethylene-forming enzyme work? We need to develop specialized microbes that efficiently produce ethylene and customized systems for cultivation and harvest. On future prospects, Eckert and colleagues believe that “synthetic biology tools will speed up the progress toward higher productivity and lower cost in bioethylene development.”

This technology is still in its infancy, though its potential is undoubtedly great.

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