Pulping reactions delignification

The kinetics of the delignification are of importance especially when considering the control of the pulping process. Since kraft pulping follows simpler kinetics than the sulfite processes, more applications have been adopted for this case. Because of the heterogenity of the system, however, pulping reactions are complicated and can therefore not be treated in the same fashion as homogeneous reactions in solution. 

Miksche, G. E. Lignin reactions in alkaline pulping processes (rate processes in soda pulping). In Chemistry of Delignification with Oxygen, Ozone, and Peroxides Nakano, J. Singh, R. P.,Eds. Uni Publishers Co Tokyo, Japan, 1980 pp. 107-120. 

In pulp and paper processing, anthraquinone (AQ) accelerates the delignification of wood and improves liquor selectivity. The kinetics of the liquid-phase oxidation of anthracene (AN) to AQ with NO2 in acetic acid as solvent has been studied by Rodriguez and Tijero (1989) in a semibatch reactor (batch with respect to the liquid phase), under conditions such that the kinetics of the overall gas-liquid process is controlled by the rate of the liquid-phase reaction. This reaction proceeds through the formation of the intermediate compound anthrone (ANT) ... 

Carbonates are widely used as buffers in organic redox reactions, and the formation of COj should be taken into account in interpretation of their mechanisms. There are promising reports on CO3 as a potential oxidant for the environmental-friendly delignification of pulp (Stenman et al. 2003, Carlsson et al. 2006). 

Chen, C. L., Capanema, E. A., and Gracz, H. S., Reaction mechanisms in delignification of pine Kraft-AQ pulp with hydrogen peroxide using Mn(IV)-Me4DTNE as catalyst. J Agricultural Food Chem 2003, 51 (7), 1932-1941. 

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