info:eu-repo/semantics/article
Estimating Pure Diffusion Contributions in Alkaline Pulping Processes
Fecha
2002-12Registro en:
Costanza, Vicente; Costanza, Pedro; Estimating Pure Diffusion Contributions in Alkaline Pulping Processes; Planta Piloto de Ingeniería Química; Latin American Applied Research; 32; 12-2002; 151-159
0327-0793
1851-8796
CONICET Digital
CONICET
Autor
Costanza, Vicente
Costanza, Pedro
Resumen
A model that predicts isothermal alkali diffusion and reaction with acetyl groups in moist wood chips was derived and approximated. System parameters were estimated from unsteady-state experimental data. Simulation results reinforce the idea that the diffusion effect is not fully exploited in pulping processes. Traditionally, digestion is conducted at high temperature, where delignification reaction kinetics is enhanced and the reaction effect is predominant. This approach is being reviewed by modern industry since energy and environmental savings associated with low temperature operation might compensate for high-yield productivity. The concentration of alkali at the center of the chip is a measure of the completeness of wood deacetylation, which translates into the aptitude of the final product for pulping purposes. This concentration is predicted here from the solution to a pair of coupled ODE’s. Since alternatives combining both low and high-temperature processes are being studied, the results in this paper provide basic data for optimization analysis.