Novel biorefinery concept for efficient use of wood residue materials

Research Project, 2018 –

Many of the novel bioproduct concepts that are currently being developed are based on nano-structures (cellulose based) and/or biopolymers from wood. For this type of product, it is not necessary to use expensive stem wood feedstock, since the target components can be obtained from much less costly and underutilized wood residue raw materials (branches, tops etc.). The ultimate goal of this project is to develop a biorefinery concept based on wood residue feedstock. During recent years, it has become obvious that investment costs for bio-refineries could be very high and concepts that are attractive from an economical point of view must deliver high-value material streams as well as high-value energy carrier streams to achieve high material utilization and meet investors’ financial requirements. Furthermore, the processes itself must be very energy efficient. For these reasons, integration with exiting processes is of high interest. The concept proposed here will have several different product streams, both material streams, including dissolving cellulose, and energy carriers, including bio-oil from lignin. An important feature of the proposed process is that the feedstock component with a low heating value (cellulose) is used to produce a material stream and the component with a higher heating value (lignin) is used to produce an energy carrier. Some key aspects of the proposed process concept have been investigated in two recent MSc thesis projects at Chalmers and a primary economic analysis has been made (GROT som råvara till kemikalier och flytande bränsle, förstudie. The results show that the process has a large techno-economical potential and the value of products is high compared to the cost of the raw materials (3-4 times). Furthermore, it is also obvious that the energy efficiency of the process will be of high importance. The aim of this project is to further develop the first critical steps in the process to evaluate the quality of the dissolving cellulose compared to industrial standards (at this point we have a much better knowledge regarding the bio-oil). Furthermore, we will do a pre-investigation of the possibility to heat integrate the proposed biorefinery with a modern kraft pulp process.