PULPING AND PAPERMAKING POTENTIAL OF BREWERY SPENT GRAIN

摘要

The potential of brewery's spent grain(BSG)for pulp and paper production was evaluated.Chemical analyses have shown that this sub-product of the brewing process has the following composition;35.9% hemicelluloses,22.7% protein,17.7% cellulose,10.1% lignin,9.1% extractives in ethanol/toluene and 4.5% ashes.The raw material was pulped by kraft,soda and neutral sulphite semichemical(NSSC)processes.The corresponding pulping yields are close to 17% for kraft and soda processes and to 64.6%,respectively,for the NSSC process.The pulp fibers are short(around 0.4 mm),the pulps having quite a high fines content(close to 20%).The chemical compositions of kraft and soda pulps are the following;4.3% and 4% ashes,1.6% and 1.1% protein,55.9% and 60.2% cellulose,35.7% and 32.4% hemicelluloses,respectively.The structural strength properties of the laboratory papers are relatively poor,but the performance of the material as a corrugating medium,measured by both corrugated crush test and concora medium test,is similar to that of the reference materials,which reveals the potential of BSG to produce this paper material.