Forest residues such as stumps, bark and twigs are now proving of great benefit in a new test facility for the production of high-quality synthesis gas intended for transport fuels. The results which are unique in Scandinavia, are based on close cooperation between Luleå University of Technology, the Energy Technology Centre (ETC) and industry.
By applying known gasification technology, valuable synthesis gas has been obtained from waste materials from the forest.
"We chose to take the shortest route and make use of, for example, tree stumps and the tops of trees from the forest and use them as they are in our facility.Primarily, we use make use of low-quality forest residues which the wood and paper industry cannot use.People often talk of the need to pre-treat these kinds of raw materials or to use it with charcoal to produce synthesis gas effectively.What we have done is to show how to use forest residues directly – and this is an important aspect of our success," says CEO Magnus Marklund, at ETC in Piteå.
The 8 metre high IVAB-manufactured gasifier stands in the robust gasification laboratory at the ETC in Piteå. It has succeeded with that which many scientists have tried to achieve for several years; to produce high-quality synthesis gas from forest residues.The gasification project at ETC is based on simplicity, with the direct input of untreated pulverised forest residues, but with intricate technical challenges, which scientists and engineers at ETC, LTU, IVAB (commercial partner) have worked with for three years via a project financed by the Swedish Energy Agency, IVAB, Sveaskog and Smurfit kappa.
"The actual input of the raw materials in the gasifying apparatus is a challenge.It is a pressurized process and the powder that is fed into the gasifier is composed of fibres and particles, which vary in characteristics depending on the origin of the material, for example whether it comes from birch or pine forests.It places great demands on the design in order to achieve a smooth and stable feed into the gasifier," says Fredrik Weiland, research engineer at ETC and also a PhD student at Energy Engineering at Luleå University of Technology.
To minimize unwanted nitrogen when the synthesis gas is produced, pure oxygen and carbon dioxide is used when the raw material is transformed into synthesis gas in the gasifier.
"Our synthesis gas has very low levels of hydrocarbons which is good when you want to produce fuels from gas.A possible final product could be methanol, hydrogen and even synthetic benzine," says Magnus Marklund.