Lignocellulosic biomass pyrolysis mechanism: A state-of-the-art review

Determination of pyrolysis characteristics and kinetics of palm kernel shell using TGA–FTIR and model-free integral methods

Valorization of biomass waste to engineered activated biochar by microwave pyrolysis: Progress, challenges, and future directions

Co-pyrolysis of biomass and waste plastics as a thermochemical conversion technology for high-grade biofuel production: Recent progress and future directions elsewhere worldwide

Biomass pyrolysis: A review of the process development and challenges from initial researches up to the commercialisation stage

Microwave assisted co-pyrolysis of biomasses with polypropylene and polystyrene for high quality bio-oil production

Resource recovery from synthetic polymers via microwave pyrolysis using different susceptors

Microwave pyrolysis is an efficient technique to valorize the abundantly available Prosopis juliflora (PJF) biomass into fuel intermediates. In this study, the effects of microwave power, susceptor...

Bio-Oil Production from Prosopis juliflora via Microwave Pyrolysis

The present research work focuses on understanding the kinetics and mechanism of co-pyrolysis of cellulose, a major constituent of biomass, and polypropylene (PP) that is abundantly present in waste plastics. Co-pyrolysis of cellulose and PP of different compositions, viz., 100:0, 80:20, 60:40, 40:60, 20:80, and 0:100 (mass%/mass%), was carried out in a thermogravimetric analyzer at various heating rates from 5 to 180 K min−1. The kinetics of slow to medium heating rate pyrolysis was analyzed using first Kissinger and Kissinger–Akahira–Sunose techniques. Cellulose and PP decomposition occurred in two distinct temperature regimes, viz., 575–650 and 675–775 K, respectively. However, apparent activation energies of thermal decomposition of the mixtures clearly indicated the presence of interaction between cellulose and PP. The presence of cellulose in the mixture decreased the apparent activation energy of PP decomposition from 210 to 120 kJ mol−1, while the presence of PP did not affect the apparent activation energy of cellulose decomposition (E
 a = 158 ± 3 kJ mol−1). A significant decrease in apparent activation energy was observed in the conversion regime corresponding to the completion of cellulose pyrolysis and beginning of PP pyrolysis. Differential scanning calorimetry data clearly showed the shift of exothermic char formation to higher temperatures with PP incorporation in the mixture. The presence of PP also resulted in reduction of final char content. Based on the above analyses, a new interaction step that involves a bimolecular reaction of activated PP with volatiles from cellulose pyrolysis to form interaction products and char is proposed, and the rate limiting steps for char formation are clearly identified.

Kinetic analysis of co-pyrolysis of cellulose and polypropylene

In this study, microwave assisted co-pyrolysis of mixtures of cellulose, paraffin oil, kitchen waste and garden waste that closely mimic municipal solid wastes (MSW) is conducted at different reaction conditions. Experiments were conducted in a multimode microwave reactor using ten different microwave absorbing materials (or susceptors) such as aluminium, activated carbon, garnet, iron, silica beads, cement, SiC, TiO2, fly ash and graphite. Pyrolysis was conducted up to 600 °C, and the effects of feed to susceptor ratio and composition of the model MSW mixture on (i) overall bio-oil, gas and char yields, (ii) heating value of the bio-oil, and (iii) composition of the bio-oil and gases, were evaluated. Besides greatly affecting the yields of bio-oil, gases and char, the susceptors played a catalytic role in altering the selectivity of the various components in bio-oil. The bio-oil contained oxygenated compounds (furans, phenolics, cyclo-oxygenates), aliphatic and aromatic hydrocarbons (mono and polycyclics). Aromatic hydrocarbons were the key products of interaction among the model components. Highest bio-oil yield of 53 wt% was achieved with an equal composition mixture at 1 : 1 wt/wt of MSW : graphite. This corresponded to nearly 95% energy recovery and 85% deoxygenation in bio-oil. High selectivities of monoaromatics such as benzene, toluene, xylene and styrene, and C8–C20 aliphatic hydrocarbons, and low selectivity of polycyclic aromatics were obtained with a majority of the susceptor–MSW combinations. Methane, ethylene, propylene, isobutylene and hydrogen were the major gaseous products, whose selectivities varied with MSW composition. This study shows that microwave assisted pyrolysis is a promising strategy to derive value added organics from MSWs.

Dadi V. Suriapparao

Papers

Microwave assisted co-pyrolysis of biomasses with polypropylene and polystyrene for high quality bio-oil production

Resource recovery from synthetic polymers via microwave pyrolysis using different susceptors

Bio-Oil Production from Prosopis juliflora via Microwave Pyrolysis

Kinetic analysis of co-pyrolysis of cellulose and polypropylene

Bio-oil production via catalytic microwave pyrolysis of model municipal solid waste component mixtures