Electrodialysis of amino acids for the production of biochemicals
Promotion date: March 22.
Promotor: Prof. dr. ir. Kitty Nijmeijer
| An interesting feedstock for the production of biobased chemicals, are amino acids that can be obtained from cheap protein sources (e.g. side streams from the production of biotransportation fuels form rapeseed oil), as amino acids already have the functionalities (-N and –O) required for the production of chemicals. However, amino acids from biomass are present as a mixture and need to be separated for further processing. In this thesis project electrodialysis (ED),an electro-membrane process that uses an electrical potential difference over the membrane as driving force for the selective extraction of ions from a solution, is studied for the isolation of amino acids. Amino acids are zwitterionic molecules whose charge is determined by the surrounding pH. Due to similar charge behavior among different amino acid groups, enzymatic modification is applied to achieve separation within basic, acidic and neutral amino acid groups. At the same time these reaction products form intermediate building blocks for the production of chemicals. |
Was your work application oriented?
Yes, very much so. The technology is a generic one, very useful for treating biomass side streams. Especially interesting is, for example, the isolation of glutamic acid, the amino acid present in higher amounts in most of available biomass sources. This amino acid is non-essential, what means that it does not compete with feed or food applications and it’s modification product, γ-aminobutyric acid (GABA) is an important precursor in the production of industrial chemicals.
Being part of a STW-project, various partners of industry were involved. Twice a year we had meetings scheduled with them to monitor the results obtained and steer the direction of research. This took place in an open-minded, two-way directional manner, in which industry had their say and the scientists always felt free to carry on with the questions of interest to them.
Integrating enzyme modification with electrodialysis is very interesting for industrial applications, I believe. In about ten years the first applications could be running. By then important factors of commercially available membranes – carrying the enzymes themselves – the acid flux/throughput and the up scaling techniques are mature.
Was there a special moment that you recall during your thesis project?
After the first year, my research planning and process performances progressed very nicely, in a straightforward way.
I remember the oral presentations I was glad to perform and also won first prizes at the ICOM 2011 conference in Amsterdam as well as the NPS11 conference in Arnhem. Winning these prizes made me feel even more confident about the importance of the research itself and about the obtained results so far.
Did you manage to have some nice publications?
Two times the Journal of Membrane Sciences had an article published, as well as one article in Industrial Engineering Chemical Research Journal. Two articles have been submitted, one to the Journal of Membrane Science and one to the Journal of Chemical Technology and Biotechnology. One manuscript is still in preparation for publication.
In what way did you develop personally as a researcher and scientist?
In the experimental work I developed rapidly, right from the start. The membrane field was completely new to me when I came here four years ago. I attended the weekly meetings at the membrane group and valued them greatly, learning a lot from them. Also I developed a broad, worldwide view on biomass technologies and on membrane technology in combination with industry.
I had the opportunity to attend several conferences inside and outside The Netherlands. I learned to interact with researchers from various fields and visited their labs. For example in our research group we have a profound vision on safety, always taking precaution as to the chemicals and reactions at hand. By having the chance to be part of this group, I developed a mature and conscious view on safety.
I also developed my presentation skills and training skills along the way. Especially working with students taught me to use psychology and management skills.
Also I had the opportunity to be part of the Organising Committee of ICOM 2011, the world’s largest conference on membranes and membrane science. I learned to handle stress situations in all phases of this process. As an organization team we succeeded very well. Our guests were impressed with the quality of the organization and the conference in general. At the same time, we were able to enjoy the conference as it actually took place.
What are your future plans?
The next one and a half year I keep working for the membrane group, in a different type of research involving gas separation. I like research, be it in academics or in industry. I hope to develop my skills even further and after that gain more experience abroad, preferably in Singapore, Australia or the US.
What, in your opinion, is important for Mesa+ to stay successful in future?
I became part of the Mesa+ institute quite recently. I appreciated the working atmosphere and scientific exchange right away. However, it was too late to actually start new collaborations. I would very much recommend collaboration and strengthen it by advertising its benefits more intensely. Looking for expertise within Mesa+ could have brought me collaboration partners, for example on enzyme modification, I’m sure.