Technology Advances in Cellulosic Ethanol

The jury is still out on cellulosic ethanol, which is made out of grass, wood and non-edible parts of plants, as to how green and even viable it is.

One of the main challenges is to find the right enzyme that breaks down the cellulosic wall that lodges the sugar that can be converted to alcohol.

There is a lot of research in the field and one of the latest breakthroughs was announced by scientists at the University of York in the UK, wrote Biofuels Daily. Professor Paul Walton and Professor Gideon Davies, of the University’s Department of Chemistry identified the molecular mechanism behind an enzyme found in fungi, which can degrade the cellulose chains of plant cell walls to release shorter sugars for biofuels.

The scientists were part of an international team that has found a method to overcome the chemical intractability of cellulose, thus allowing it to be converted efficiently into bioethanol. They were working with scientists in Novozymes laboratories at Davis, California, and Bagsvaerd, Denmark, as well as researchers at the University of Copenhagen and the University of Cambridge.

The researchers found a way of initiating effective oxidative degeneration of cellulose using the copper-dependent TaGH61 enzyme to overcome the chemical inertness of the material, a major obstacle to make use of it for biofuels. They have published their findings in the Proceedings of the National Academy of Sciences (PNAS). They said the research removes the major constraint on the production of bioethanol from cellulose.

Earlier this week, Renmatix, a producer of cellulosic sugars, unveiled its PlantroseTM process, which takes a different approach to producing sugars more cost-effectively.

The company said that at its demonstration facility in Kennesaw, Georgia, it has already scaled its process to convert three dry tons of woody biomass to sugars daily. To further support the company’s growth plans, Renmatix is commencing technical and business operations in King of Prussia, Pennsylvania.

PlantroseTM process is the first to break down cellulose at industrial scale through supercritical hydrolysis, which utilizes water at elevated temperatures and pressures to quickly solubilize cellulose. The supercritical state of matter has long been utilized in industrial processes including coffee decaffeination and pharmaceutical applications.

Up to this point, supercritical water had never successfully yielded sugar from biomass at significant scale. The process breaks down a wide range of non-food biomass in seconds, uses no significant consumables and produces much of its own process energy, the company said.

It added that with its water-based approach, it is possible to provide cellulosic sugar affordably and on large-scale with no need of expensive enzymes or harsh chemicals.

“Sugar has game-changing potential for the bio-based fuels and chemicals market,” said John Doerr, a partner at Kleiner Perkins Caufield & Byers and Renmatix board member. “The Renmatix breakthrough enables access to affordable non-food based sugar on an industrial scale.”

Article by Antonio Pasolini, a Brazilian writer and video art curator based in London, UK. He holds a BA in journalism and an MA in film and television.