This article is an initiative of the Hbo Key Technologies Theme Table. The aim of this national partnership is to make the impact of practice-oriented research by universities of applied sciences in the field of key technologies more visible.

The challenge: creating added value from green waste

In the search for alternatives to fossil oil, the green waste that people produce is an important and extensive source of raw materials. In nature, dead organic material is processed by specific microorganisms. As humans, we have recently started making grateful use of the natural processing process to ferment large flows of organic waste in a controlled environment. This creates compost and produces methane, the so-called biogas.

Biogas is currently mainly used as a source of energy. At the same time, there are many waste locations where fermentation does not take place in a controlled manner and the methane that is produced disappears into the air (approximately 20% of man-made emissions). This is a problem as methane is a potent greenhouse gas that contributes significantly to global warming.

Rudi van Hedel, projectmanager Sweco Netherlands:
''Methane to Materials' is a topic of social importance. It really is learning together and doing together. We strive to really put it into practice together with HAN, where bio(process) technology knowledge is an indispensable link.”

The conversion of organic material to methane and from methane to bioplastics.

Results

In the 'Genomics for more Biogas' project, the researchers have been able to take a first step in mapping the composition of the microbial population. The acquired knowledge is used for further process optimization. So-called metagenome sequence data were collected at various points in the fermentation process. Specific software has been developed for effective analysis and interpretation.

Based on an analysis of the types of methane-forming organisms present, an indication could be given of the type of methane-forming process in the digesters. In addition, the specific bacterial composition appeared to be related to the nature and phase of the fermentation and the fungal composition was related to the nature of the green starting material. A KIEM-VANG grant from Regieorgaan SIA was received for this research.

In addition, research has been conducted into landfill gas with a relatively low methane content, such as that released from waste dumps such as the Bavelse Berg. In the 'Methane to Materials' project, the researchers examined whether landfill gas can be used for the production of bioplastics, specifically polyhydroxybutyrate (PHB). They used fermentation by methanotrophic bacteria to convert methane into a biopolymer.

It has been shown on a laboratory scale that the methanotrophs can grow on landfill gas and that they can also produce PHB. This makes it possible to recycle carbon and reduce methane emissions, thus contributing to a circular 'waste to value' system. A KIEM GoChem subsidy from SIA was awarded for this project.

A lot of methane is released at the Bavelse Berg waste site.

Next steps

The researchers still have a number of bottlenecks to overcome. For example, they will have to scale up production for economic profitability. The reactor system also needs to be further developed to achieve a good biofilter design. In addition, they must set up new analytical methods for purity determination and characterization of bioplastics.

Through the project work, the researchers hope to build knowledge together with market parties for the raw materials transition, which is necessary to actually tackle the climate crisis.

An important principle is to intensively involve students from the HAN Academy of Applied Biosciences and Chemistry in the research. In addition to collaboration, further development of the various key technologies is essential for knowledge building. The research group hopes to be able to contribute to this.

Nardy Kip, lecturer-researcher HAN Biobased Innovations professorship:
''Finding something out, testing it, what works and what doesn't work. Actually solving the puzzle, that's what I like about this job. And of course the result in this study. With this I can make a concrete contribution to solving an environmental problem."

Projectpartners

• HAN, lectoraat Biobased Innovations en Centre of Expertise (CoE) HAN BioCentre, where the research is carried out by associate lecturers Richèle Wind (Biobased Technology) and Christof Francke (Bioinformatics | Data Science) and researchers Nardy Kip and Bram Visscher, with support from numerous students.
• Wageningen Food & Biobased Research (part of WUR), depattment BBP Biorefinery & Sustainable Value Chains.
• ENKI Energy, producer of small-scale digesters for biogas production.
• Excellent Biogas, builder of biogas plants.
• Afvalzorg Holding ARN, GFT waste processing center for the Nijmegen region.
• Sweco Netherlands, part of international architectural and engineering consultancy firm Sweco.

Together with various partners, HAN researchers conduct long-term research with the aim of creating added value from green waste by:

• optimizing methane production
• converting naturally produced methane into sustainable products

In concrete terms, they work on this by:

• determining the relationship between the composition of the microorganism population and methane production, in order to optimize the
• controlled fermentation process
• looking for ways to convert methane into higher quality materials, such as bioplastics using the methane that is created in our waste mountains ('landfills').

They use key technologies in the field of Chemical Technology (bioprocess, separation and analytical technology), Digital and Information Technology (data science, data analytics, bioinformatics) and Life Science & Biotechnology (biomolecular and cell technology, biomanufacturing and bioprocessing). .