Investigation on Detrimental Aspects of Pitch Types and Their Biological Control Alternatives in Pulp and Paper Industries

Nowadays، annual consumption of paper in the world and also in Iran is growing. To provide the present need، finding new ways for optimum usage of lignocellulosic resources and improved production methods are required. One of the common problems in the papermaking industry is existence of undesirable compounds and by-products such as pitch، stickies and external contamination in papermaking process that each of these materials may arise from various sources. Wood، as a raw material for pulping، because of having hydrophobic materials such as waxes، lipids، fatty acids، resin acids، hydrocarbons، etc، can be the origin of such contaminants. The pitch can cause significant problems in papermaking equipment. For example، it can block drainage felt or attach to wire or drying cylinders and cause holes in the paper. Up to now، various methods have been proposed to control and eliminate these problems. Enzymes due to having various applications such as pitch control، reducing the refining time، helping in pulp dewatering، improving bleaching efficiency and increasing pulp yield، have gained a lot of popularity in pulp and paper industry. Enzymes cause hydrolysis of triglycerides and prevent their formation. Furthermore، enzymatic treatments is the basis of pitch and stickies control which can be used to reduce the size of these materials. In this paper، efforts are done to investigate utilization of enzymes as a new and environment friendly method based on biotechnology to control pitch in papermaking process.