Effect of pre- extraction liquid reuse on and soda-AQ pulp properties made up of wheat straw

In this study، the effect of recycle liquor resulted from alkaline pre- extraction step and its reuse on next pre- extraction step was investigated to produce soda-AQ pulp from wheat straw. This pre-extraction was done at a temperature of 140°c and 90 minute to get its weight decrease about 8-10 percent. Under alkaline pre-extraction، liquor of this step was used as pre extracted liquor of wheat straw in next step (first recycle liquor step)، and liquor from first recycle liquor step was used as pre-extracted liquor of wheat straw in next step (second recycle liquor step). According to produced pulp from alkaline pre-extracted straw and recycled liquor compared with un pre-extracted one and in order to gain kappa number 12، results have shown that total yield based on primary weight of straw particles in pre extracted cook was equal to un pre- extracted straw. The pre-extracted soda-AQ pulp had weaker reactions to refine than un the pre-extracted control pulp. Pre-extracted Straw pulp had equal tearing strength، and lower bursting and tensile strengths than the control pulp.