More efficient use of biomass for chemicals and fuel

From the standpoint of energy efficiency, it would be better to put biomass to use in the production of nitrogen-rich chemicals than in the generation of electricity, or the production of biofuels.

With several partners, Wageningen UR is working on a project which uses yeast and fungus from biomass to extract cyanophycin, an important raw material for bulk chemicals. At the same time, ethanol is produced. This is a unique form of process integration.

The production of nitrogen-rich bulk chemicals which serve as a basis for plastics and nylon, for example, requires a great deal of energy. In addition to the raw material naphtha, a variety of other chemicals are also necessary such as chlorine and ammonia. The production of these chemicals requires a tremendous amount of electricity and natural gas.

From the standpoint of energy savings, it would be much better to use biomass or biomass fractions in the production of nitrogen-rich chemicals since these substances already resemble the chemicals in terms of their structure. By using biomass this way, an energy efficiency level may be achieved that is two to four times higher than that achieved using biomass for the production of electricity or transport fuel.


The N-ergy project focuses on finding out which technology is suitable for this biorefinery route, and which may be applied on a large and profitable scale. The project concentrates on a fermentation process in which a yeast or fungal strain is developed which is capable of storing an accumulation of an insoluble biopolymer (“bioplastic”) while simultaneously producing ethanol. In this case, cyanophycin is involved, a substance which is extracted via biorefinery from grass, potatoes or mangolds for example.


Cyanophycin, the primary components of which are polyaspartate and arginine, can be used as a raw material in the production of bulk chemicals such as butanediamine, ureum and acrylonitril. Polyaspartate is possibly suitable as a replacement for polyacrylate. In order to extract the arginine from the polymer, various steps are necessary, after which the enzymes must be converted to further modify these components. The researchers are studying how and in which sequence these enzymes may be applied in a cost-efficient manner in industrial processes. They are also examining which steps must be taken in combination with one another, and which must be carried out consecutively, and how the end products may be made pure enough for inclusion in the current petrochemical route.

Transformation system

In Münster, they have now succeeded in producing cyanophycin in baking yeast. At present, production is being optimised, and attempts are being made to produce cyanophycins using various formulations. A transformation system for the fungus has also been set up, however the production of cyanophycin in fungus has not been successful to date.

The first steps towards converting cyanophycin into bulk chemicals have now also been taken.Two enzymes have been successfully immobilised and tested in order to be able to carry out the first steps in the total transformation into bulk chemicals. The focus now is on the hydrolysis of cyanophycin with the aid of a heterogeneous catalyst.


Four partners are working together on the N-ergy project. The group at Fungal Genomics (Wageningen UR) is working on the production of cyanophycin using a fungus. In Germany, the Institute for Molecular Microbiology and Biotechnology of the Westphalian Wilhelms University in Münster is working on the production of this polymer in baking yeast. The other two partners are working on converting cyanophycin into nitrogen-rich bulk chemicals. These partners are the Value Conversion of Plant Production Chains chair group and the Organic Chemistry Laboratory at Wageningen UR. The Netherlands Energy Research Centre (ECN) is helping shape the industrial process, and Easthouse Business Solutions BV is marketing the system. The Agrotechnology & Food Sciences group is testing the possibility of converting agrarian residual flows into cyanophycin and ethanol.