Miscanthus May Double Danish Biomass Production20 February 2012
Scientists at Aarhus University believe that they will be able to double the amount of bioenergy produced from the biomass production areas by including more C4-plants such as miscanthus. They have now been put in charge of a research project on the subject.
Miscanthus together with willow and poplar can be the key to solving one of the future’s largest challenges of securing sufficient renewable energy that is sustainable in relation to the environment, the climate and the food supply.
This is the background for a new research project at Aarhus University which has just received financial support from The Danish Council for Strategic Research.
"We have high hopes for the project where we first and foremost have to reduce the cost of production and increase the productivity of biomass by growing miscanthus, willow and poplar which will be used for biorefining, and where we in addition to energy such as bioethanol will also gain a feed product in the form of molasses. miscanthus, and also maize, belongs to the group of plants with C4-photosynthesis, which is about 30% more efficient at converting solar energy to production than the other agricultural crops with C3-photosynthesis," explains Uffe Jørgensen, senior scientist at Aarhus University, about the project.
"At the same time we intend to break the link between productivity and environmental impact. A doubling of the productivity is actually expected to be linked with at least a halving of the environmental impact in terms of nitrate leaching, pesticide use and greenhouse gas emissions compared to a normal cereal production. The long growing season and the absence of annual soil tillage are some of the explanations for the improved environmental profile."
Crop with a future
The project involves one of the world’s leading scientists within the development of C4 photosynthesis, namely Stephen P. Long, Deputy Director of the Energy Biosciences Institute in the United States. His research will help to identify clones of miscanthus that have the potential to increase the amount of biomass per unit area.
"Wheat gives a yield of 9 t dry matter per hectare, when you include both straw and grain. Maize gives 12 t dry matter, but we believe we can develop systems that will give up to 15-20 t dry matter per hectare in Denmark. Willow is the energy crops of today, while miscanthus is the energy crop of tomorrow, because it has the potential to yield more than willow," explains Uffe Jørgensen.
In the United States, Stephen P. Long has succeeded in producing a yield from miscanthus of 30 t dry matter per hectare, of course under ideal conditions.
High yields are precisely the ambition of the project, where the right clones of C4 plants can help to increase the energy fixation of photosynthesis. At the same time the energy loss during biomass production should be minimised along with an improvement in the conversion to energy and feed. In this way it will be possible to double the energy yield and the CO2 displacement per hectare.
"In the project we will, among other things, be looking at the cold tolerance of miscanthus, which unlike maize has a defence mechanism that ensures that the grass continues to grow when the temperature goes below 15 degrees. We also have to develop some practical cropping systems that provide a cheap and sustainable production. The plants will for example also be grown on marginal soils not suited to the production of food crops," explains Uffe Jørgensen.
Another part of the project deals with the storage of the harvested biomass and subsequent conversion or biorefining, whereby the biomass is converted to ethanol that can be used as a liquid fuel in transport, and lignin that can be used as a solid fuel. The biorefining process also produces an animal feed in the form of molasses. The refining process itself will be carried out at the DONG/Inbicon plant.