Catalytic pyrolysis of lignocellulosic bio-packaging (jute) waste – kinetics using lumped and DAE (distributed activation energy) models and pyro-oil characterization

Abstract

The present study concentrates on the catalytic pyrolysis of a waste bio-packaging material, namely, jute, under iso-thermal and non-isothermal conditions using a 50 mm diameter and 164 mm long semi-batch pyrolyzer and a TGA set-up, respectively. The temperature range of pyrolysis is 673 K to 1173 K. Alumina, zinc oxide, sodium chloride, potassium chloride, and sodium aluminosilicate have been used as the catalysts. The patterns of the yields of all products of non-catalytic and catalytic pyrolysis under isothermal conditions have been compared. Lumped kinetics have been determined using the data of iso-thermal experiments. Alumina has been selected as the best performing catalyst showing the highest pyro-oil yield and lowest activation energy. The pyro-oil of catalytic pyrolysis has higher and lower contents of carbon and oxygen, respectively, and a more acidic pH in comparison to the non-catalytic counterpart. The kinetics of non-isothermal pyrolysis with and without alumina have been determined using a distributed activation energy (DAE) model. While the activation energies of non-catalytic pyrolysis follow a Gaussian distribution over a wide conversion range (0.2 to 0.8), no such pattern is obtained for catalytic (alumina) pyrolysis. The pyro-oils of both catalytic and non-catalytic pyrolysis have been analyzed using GC/MS and many components of industrial applications have been identified.