Jun 14 2016
Today’s chemical industry is based on oil, because many chemical products originate from oil and its components. Products ranging from solvents to medication, plastics to detergents and crop protection products are all based on oil. Due to the limitations in the number of oil reserves, scientists are now searching for new techniques to produce these products from sustainable materials.
The timber industry generates waste. This can be put to use in the future. (Symbolic photograph: Colourbox)
A team of international researchers, comprising of scientists from EPFL and the Chalmers University of Technology in Gothenburg, have now developed an alternative method to manufacture a basic yet significant chemical product, succinic acid. The study was headed by Konrad Hungerbühler, Professor of Safety and Environmental Protection Technology in Chemistry at ETH Zurich.
As part of a detained ecological assessment, the research team showed that bacteria can be used to manufacture succinic acid in a safe, economical, and eco-friendly way. The researchers selected cellulose waste or wood from the forestry and paper industries as their preferred source of material.
More sustainable or more cost-effective
Simulation procedures were used by the scientists to draw a comparison between various bacteria and manufacturing processes. The latter were optimized at EPFL laboratories for biotechnological manufacture of succinic acid. The findings revealed that based on the type of processes and bacteria used, the biotechnological manufacturing process employing wood waste is either more environmentally friendly or cheaper than that of other oil-based conventional methods.
The researchers accounted for the total energy needed to manufacture, such as grey energy, which spans the indirect energy needed for manufacturing primary products, waste management and infrastructure, as a measure of the environmental effect.
When a particular biotechnological manufacturing technique is used, 20% more succinic acid can be manufactured in a cost-effective way with a similar effect on the environment. In a second method, where different bacteria were used to manufacture succinic acid, the environmental impact can be decreased by as much as 28%, with similar costs to the conventional oil-based techniques.
Innovation for the paper industry
Glucose (grape sugar) is used as a raw material to manufacture succinic acid using bacteria. Sugar beet or sugar cane can be utilized to extract glucose, but wood can also be considered as an option.
Cellulose, found in wood, can be converted to glucose by adding acid.
Merten Morales, Ph.D. Student, ETH Zurich
A comparison was made between the manufacturing process of succinic acid from sugar beet and the manufacturing process from wood waste. It was observed that in terms of safety, environmental impact, and cost effectiveness, the variations were negligible. "If it is possible to use wood waste - in other words, waste from the forestry industry - that is what we should do," says Morales. "Then there is no competition with the food supply chain."
This new method holds potential for the paper industry, because an alkaline solution consisting of cellulose is also generated as waste in this industry. Currently, this waste is not recycled, but can be used as a suitable source of glucose.
The European paper industry could once again hope to compete with strong competition overseas if it succeeded in recycling waste products and selling them with added value.
Merten Morales, Ph.D. Student, ETH Zurich
Nevertheless, the development of a biotechnological production plant remains a matter of consideration for the chemical engineer and is considered to be a long-term investment project. Hence, before a company follows this route it is important to understand whether it is beneficial in the long run. "We have now been able to answer this question in the affirmative thanks to our work."