The invention discloses a TCE (Total
Chlorine-Free) bleaching technology for
sulfate pulp of growing poplar by biological chemical method. The technology comprises the following steps: (1), cooking: getting fast-growing polar pieces; putting the fast-growing polar pieces into a distilling pan for cooking, so as to obtain primary pulp, and then washing and screening the primary pulp to obtain paper pulp; (2), pre-treating the paper pulp with
xylanase; (3), TCE bleaching: bleaching the paper pulp pre-treated with the
xylanase, wherein the bleaching process is one of OP-Q-P, O1-O2P-Q-P or O1P-O2P-Q-P. According to the TCE (Total
Chlorine-Free) bleaching technology for
sulfate pulp of growing poplar by biological chemical method, the
xylanase is adopted to pre-treat the paper pulp, then one of the bleaching processes OP-Q-P, O1-O2P-Q-P or O1P-O2P-Q-P is adopted for bleaching, so that the paper pulp with higher whiteness and
viscosity is obtained; compared with the paper pulp obtained through directly bleaching without xylanase pre-treatment, the paper pulp provided by the invention has the advantages that the loss value of whiteness is lesser, the folding strength is higher 45 times averagely, the
bursting index is higher 0.45 N*m*g <-1> averagely, the breaking length is higher 0.35 KM, and the tearing index is quite. The beating revolution number is lesser when the paper pulp reaches the same or similar beating degree, and the 20% of beating
energy consumption can be saved approximately.