Patent ID: 7807021

Claim:
A process for cooking wood in a cooking liquor medium comprising: providing wood to a treatment vessel; contacting said wood with a composition comprising an alkaline mixture, a surface active agent, and at least one polymer, the alkaline mixture comprising sodium sulfide and having a pH from 12 to 14, the at least one polymer comprising a carbon linear backbone segment having two ends or a carbon and phosphorus linear backbone segment having two ends, the at least one polymer further comprising at least one phosphorus component, said phosphorus component comprising a phosphorus atom that is either directly chemically linked to said linear backbone segment of said polymer, forms part of the linear backbone segment of the polymer, or any combination thereof, said phosphorus component comprising a phosphonate, phosphinate, or any combination thereof that can be stable at temperatures above 250° C., and two end components, each said end components chemically linked to each end, respectively, of said linear backbone segment of said polymer, wherein the two end components do not include a phosphorus component, and wherein when said polymer comprises a phosphinate at least one end component comprises nitrogen, sulfur or any combination thereof; and cooking said wood that has been contacted with said composition to produce a pulp, wherein said process provides a simultaneous reduction in pulp rejects, an increase in pulp yield, and a reduction in scaling.