The Property C₂N₂H₆-KOH Pulping And Bleaching For Rice Straw

In China, grass fiber raw material was one of main raw material for pulping. But alkali from spent liquor was difficult to be recycled, which caused resource wasted and environment polluted. To enrich the application of raw material and offset the fertilizer lacking element of K in our country, Ethylene diamine-potassium hydroxide pulping was adopted, which producing valid compound fertilizer. At the same time the pulp provided medium for laccase pretreatment, and realized the purpose in circulativeeconomy, such as process of agriculture produces-rice straw using-pulping-fertilizer-agriculture.Optimum synthesis condition was obtained : ethylene diamine charge was 16%, KOH charge was 9%( KOH account), AQ charge was 0.05%, time at temperature was 20min, liquids ratio was 1:6, maximum temperature was 150℃. Concluded from the research that pulp's kappa number was 17.2, yield was 37.20%, brightness was 24.7% (SBD).From the research on EP- P cooking of the straw, the result was as follows: delignification of cotton seed can be divided into two stages: the bulk stage from beginning temperature of cooking to 110℃, and the supply stage from 110℃ to the cooking end. It was concluded by kinetics reaction that activation energy of delignification in the bulk stage was 31.643 kJ/ mol, which belonging to one stage reaction.In spent liquid of EP- P cooking of straw: The total nitrogen content was 13.48g/1, the ammonium content was 0.16g/l. During oxidize reaction, ammonium content was increasing with time prolonged.laccase pretreatment can get the same result without ABTS which acting as medium, and 5IU/ g of laccase dosage was the best for pulp of EP- P. It can be Studied from IR of the EP- P pulp that these were two nitrogenous compounds, because —NH⁺₂— and —N⁺=C^- were absorbed at 2374 cm^-1 and 2136 cm^-1. It can proved that EP- P cooking provided element of N for laccase pretreatment.Advantages of C₂N₂H₆-KOH pulping were studied and prospects of nitrogenous-spent-liquor utilization for agricultural resources were forecasted.