Semi-bleached paper and fermentation products from a larch biorefinery

This study was focused on the products from a larch biorefinery, specifically bleached paper and different fermentation products. Siberian larch (Larix sibirica Lebed.) wood chips were treated with water in a pre-extraction (PE) stage. The larch extract was removed by drainage and fermented into different products. Eight different bacteria strains were tested. The extracted wood chips were mildly washed before kraft pulping with polysulfide (PS) and anthraquinone (AQ). The PE-PSAQ pulps were bleached to about 80% brightness. Laboratory paper sheets were made and tested for different paper properties, and a conventional larch kraft pulp was also prepared as reference. The larch PE-PSAQ paper and the larch kraft paper had similar properties. The removal of a significant amount of hemicelluloses from the wood chips before pulping was not a detriment to the paper properties.