Abstract: A pulping method using alkaline K₂SO₃-AQ system as cooking liquor to digest rice straw was studied in this paper. The optimal cooking conditions were 10% of total alkali, 0.8 of alkali ratio, 0.2% of AQ, 160℃ of maximum temperature and 120 min of cooking time.Pulp yield reached 53.8%, screened pulp yield reached 42.5%, and Kappa number was 14.5. It looks promising to use effluents of cooking into fertilizer because it contains rich nutrition such as potassium and lignin. A new ecological cycling maybe set up between paper industry and farming.

Key words: alkaline K₂SO₃-AQ system, rice straw, cooking