MMaterialsgateNEWS 2018/05/16

Lignin – a super green fuel for fuel cells

Credit: Linköping University

Researchers from the Laboratory of Organic Electronics at LiU have developed a fuel cell that uses lignin, a cheap by-product from paper manufacture and one of the most common biopolymers.

Approximately 25% of a tree is lignin – a biopolymer that glues the cellulose fibres together to form strong and durable wood. During the chemical manufacture of paper pulp this lignin is dissolved in either the sulphate or sulphite process, since the cellulose is the desired component for making paper.

Lignin is cheap and readily available. It is a biopolymer that consists of a large number of hydrocarbon chains woven together, which can be broken down in an industrial process to its energy-rich constituent parts, benzenediols. One of these, catechol makes up 7% of lignin. Researchers at the Organic Energy Materials group at LiU, led by Professor Xavier Crispin, have discovered that this type of molecule is an excellent fuel for use in fuel cells.

Benzenediols

The fuel most often used in tradition fuel cells is hydrogen gas, which reacts with oxygen from the air. The chemical energy is converted in the fuel cell to electricity, water and heat. However, 96% of the hydrogen produced worldwide is from non-sustainable sources, and is accompanied by carbon dioxide emission.

Other fuels used in fuel cells are ethanol and methanol, but these produce also carbon dioxide as a by-product. The electrodes necessary to attract the fleeing electrons are usually made from platinum, which is both expensive and scarce.

Benzenediols, however, are aromatic molecules, and metal electrodes cannot be used in fuel cells based on benzenediols since the reactions are slightly more complex. The researchers instead use electrodes made from the popular conducting polymer PEDOT:PSS. This polymer has the interesting property of conducting electricity, while at the same time having a surplus of protons. This means that it functions as both electrode and proton conductor.

“PEDOT:PSS is a perfect catalyst for the reaction with a benzenediol such as catechol,” says Xavier Crispin

Super green fuel

The chemical energy of the fuel is converted to electricity without carbon dioxide being formed.

“When a fuel such as ethanol is used in a fuel cell, people usually claim that it has zero impact on the climate, since the carbon dioxide is a component of a circulation. This means that ethanol is considered to be a green fuel. We can now manufacture electricity without any emission of carbon dioxide at all, which makes our fuel supergreen. The technology also both cheap and scalable,” says Xavier Crispin.

Only a few research groups have investigated PEDOT:PSS as a possible material for both electrodes and catalyst.

“There is a fundamental lack of knowledge about PEDOT:PSS within electrochemistry,” concludes Xavier Crispin, as he proudly introduces doctoral student Canyan Che and principal research engineer Mikhail Vagin, who make up the group that has worked with the fuel cell.

The researchers have calculated that the amount of electricity produced by the new fuel cell is approximately the same as the current ethanol-based and methanol-based fuel cells.

First in the world

“An efficient method to produce catechol from lignin is already available, and we are first in the world to demonstrate a fuel cell that uses fuel from this forestry raw material,” concludes Xavier Crispin.

It remains to improve and optimise the function.

The results have been published in the scientific journal Advanced Sustainable Systems.

Source: Linköping University – 14.05.2018.

Investigated and edited by:

Dr.-Ing. Christoph Konetschny, Inhaber und Gründer von Materialsgate
Büro für Material- und Technologieberatung
The investigation and editing of this document was performed with best care and attention.
For the accuracy, validity, availability and applicability of the given information, we take no liability.
Please discuss the suitability concerning your specific application with the experts of the named company or organization.

You want additional material or technology investigations concerning this subject?

Materialsgate is leading in material consulting and material investigation.
Feel free to use our established consulting services

MMore on this topic

Researchers at the KU Leuven Centre for Surface Chemistry and Catalysis have found a more eco-friendly way to derive lignin – a paper industry waste product – from wood and convert it into chemical building blocks.

The resulting chemicals can be used in paint, insulation foam, and several other products. The researchers published their findings in the journal Energy & Environmental Science. Lignin is a substance in the cell walls of plants that strengthens their structure. When wood is processed into paper pulp, lignin is produced as a waste product. Researchers have long been trying to valorise this lignin waste stream, says Professor Bert Sels. “The traditional method to remove lignin from the pulp requires heavy chemistry and has side-effects: you end up with lignin that is unsuitable for further processing.” Therefore, the paper industry usually burns the lignin, even though it is a rather... more read more

MaterialsgateNEWSLETTER

Partner of the Week

Search in MaterialsgateNEWS

MaterialsgateFAIR:
LET YOURSELF BE INSPIRED