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Maryam M Kabir i labbet

2015-10-01 08:00

More biogas from forest waste, straw and wool with new technology


Forest waste, straw and wool are quite difficult materials for bacteria to break down. However, it is possible to treat them so they become easier to break down and can then be used more efficiently to produce biogas. This is shown by Maryam M Kabir in her doctoral thesis at the University of Borås.

“I have found away to pre-treat forest waste, straw and wool so it can be digested and it can then produce up to twenty times more biogas”, says Maryam M Kabir. “Therefore, within the same length of time and using the same amount of waste, we can produce a lot more biogas. I'm happy with my results and I now want to transfer them so they can be used on an industrial scale”.

In her research, she used forest waste and straw from the area around Borås, where her research is being conducted. She ground down the waste and pre-treated it by saturating it with a liquid in which an environmentally-friendly chemical (a solvent for cellulose, NMMO) makes the waste easier to break down.

She carried out experiments at different temperatures and using different quantities of the chemical.

“I analysed how the structure of waste was altered and tried to find the best point in the process for the biogas bacteria to then break it down efficiently”, she says. 

Forest waste is a cheap raw material

Maryam M Kabir has had a keen interest in the environment for a long time and that is what underpins the research. In her native Iran, she studied chemistry and electricity production, among other things. She began to study in Sweden after hearing about the opportunities to study in more detail and learn more about renewable energy sources and new technologies at the University of Borås.

“There is so much forest and forest waste in Sweden, so it's quite a cheap raw material that's very suitable for this purpose”, says Maryam M Kabir. “I would love to find ways to be able to produce renewable biofuels at a low price on an industrial scale. When it works, we can eliminate our dependence on fossil fuels and reduce the greenhouse effect and enjoy a better environment”.

She has also studied how wool can be pre-treated to make it more easily biodegradable for biogas production. She got the wool from waste at a local textile company and she calculates that textile waste consisting of wool is also a raw material that can be obtained for a relatively low price.

The start of something big

Biogas is a very useful type of energy that is produced by the anaerobic decomposition of organic matter. It is used for electricity and heating in many countries and also on a small scale with tiny production plants for one family or a few families at a time. However, in Sweden biogas is mostly used as fuel for vehicles.

She says that she has chosen pre-treatment processes that will also be economically sustainable so that her methods will be profitable and will work in industrial production in the long term. However, there is much that needs to be included in the calculations and perfected before her results can be used on such a large scale.

“My research is a start and the method can benefit us economically, environmentally and socially. We produce waste every single day. If we use it for something good, it can make our environment better, help create new jobs and be profitable”.

Facts

Thesis title: Bioprocessing of Recalcitrant Substrates for Biogas Production
Main supervisor: Assistant Professor Ilona Sárvári Horváth, University of Borås
Public defence of the thesis: 9 October, University of Borås