Furfural residues from straw become complex fertilizer by addition method

The additives such as phosphoric acid, calcium phosphate,calcium super phosphate, calcium over-super phosphate, calcium carbonate, sodium hydrosulphite, etc. were used to produce furfural from the straw by hydrolysis with sulfuric acid. The effect of amount of the additives, the content of the added substance and the conditions of distillation on the acidity of the residues were studied. The experiment results showed that the all residues become neutral complex fertilizer, and the productivity of furfural increases under the following conditions: sulfuric acid concentration is 20% (by weight), the ratio of liquid to solid is 3:1--4:1 (by weight), the ratio of the additives to straw is suitable.