A new concept for optimizing chemical additions in deinking processes

For quite a number of paper grades, recycled fibres have proven an economically viable alternative to primary fibres. Waste paper recycling is generally considered to make a valuable contribution to the protection of natural resources and the environment The newly developed Cell'link process provides for optimum utilization of the deinking chemicals peroxide, sodium hydroxide and sodium silicate. The chemical savings thus obtained help to improve process economics whilst enhancing the ecological compatibility of the deinking process. Apart from offering a number of side effects, the Cell'link concept inhibits the catalase enzyme which is formed by aerobic bacteria and usually enters the circuit together with the waste paper. Catalase, very effectively splits up peroxide into water and oxygen. Controlled inhibition of catalase in process water loops and relevant system sections prevents peroxide from being enzymatically decomposed, which substantially increases the available peroxide amount in the deinking process. As peroxide dosages are accordingly reduced, additions of sodium hydroxide and/or sodium silicate have to be correspondingly diminished if pH settings are to be optimized.