Dr. Ciara Beausang:

I would not see much competition between various energy applications with regard to the feedstocks we are speaking about for grass silage or food waste. It does indeed look to be the optimum application from an energy perspective. Where there is potential for more conflict is among the various products that can be produced, particularly with regard to producing grass silage from the land and the various applications it can be used for. It goes back to promoting a cascading approach in the bioeconomy. The value of biological materials in the first instance is as feed. Next is extracting various chemicals and proteins from them. Going down the order, anaerobic digestion is on a lower tier. In this regard the prospect of biorefining is a very good option. The technology means that grass can be crushed using an extruder to produce two different products. There is a juice and fibre. The fibre can be ensiled and fed directly to cows. The juice can be heated to create a protein concentrate that also can be used to feed animals. The residual grass whey left over can be used for anaerobic digestion. This type of approach is good to avoid the conflicts we have seen in feed and fuel debates. It is one that needs to be implemented when considering anaerobic digestion in the bioeconomy.