Steam Explosion Pretreatment and Ethanol Extraction of Wheat Straw

It has been increasing the interest in the study of alternative pulping processes that conciliate high performance and protection to the environment. In the same way, the use of agricultural residues has been more and more reminded as promising raw material for production of bioethanol and chemical products. The wheat straw is a very abundant agricultural residue and it has been used in many countries for the production of cellulosic pulps. This work describes the effect of the pretreatment by steam explosion on the ethanol-water extraction of wheat straw. The samples of wheat straw were treated by steam explosion at 190°C and 210 °C for 4 minutes and later transferred to the treatment with ethanol-water (1:1, v:v) at different temperatures (140, 160 and 200 °C) and 60 minutes as reaction times. The pretreatment led to an increase in the amount of extracted lignin in the ethanol pulping. This effect was more pronounced in the pulping performed at lower temperatures. The use of higher temperatures in the treatment by steam explosion was more significant as shown by lower pulp yield and higher extractive extent.