Two-stage ex-situ catalytic pyrolysis of lignocellulose for the production of gasoline-range chemicals

Abstract

The appropriate system is needed to produce a scalable and economically viable renewable energy from biomass. The objective of this study is to improve the quality of bio-oil, in terms of Organic Liquid Product (OLP), water content, acidity, favourable fractions, as well as gasoline-range chemicals. The influence of a staged layered catalyst system consists of a mesoporous catalyst, Al-MCM-41, and a microporous catalyst, HZSM-5, on the biooil quality was investigated. Additionally, the effect of reaction temperatures in the range of 400-600°C with the optimum staged catalyst system on the catalytic pyrolysis product was analysed. The experiments of lignocellulosic biomass pyrolysis and catalytic pyrolysis were performed using a fixed bed reactor equipped with oil condensers and a gas collection sample bag. The quality of bio-oil produced from the thermal pyrolysis of lignocellulosic biomass, catalytic pyrolysis with single catalysts, catalytic pyrolysis with the staged catalyst system, as well as catalytic pyrolysis with mixed catalyst system was studied. The results show that Al-MCM-41 with HZSM-5 in the staged catalyst system enhanced the production of favourable compounds: hydrocarbons, phenols, furans, and alcohols. The favourable compounds yield that boosted 5.25-6.43% of that with single HZSM-5 catalyst was produced with HZSM-5:Al-MCM-41 mass ratio of 3:1 and 7:1. The pyrolysis and catalysis temperature of 500°C with HZSM-5:Al-MCM-41 ratio of 3:1 obtained the optimum quality of bio-oil with 11.08 wt.% of OLP, 76.20% of favourable fractions, 41.97 wt.% of water content, low TAN of 43.01 mg-KOH/g, high deoxygenation, as well as high gasoline-range production of 97.89%.

Kinetic Study of an H-ZSM-5/Al–MCM-41 Catalyst Mixture and Its Application in Lignocellulose Biomass Pyrolysis

“…The area percentage of the other compounds are presented elsewhere. 21 The results in this study agree with the earlier results by Melligan et al, 65 namely that the temperature influenced the product selectivity toward BTX. They observed an increase of the benzene and toluene levels during catalytic pyrolysis of biomass using Ni−MCM-41 as the temperature rose from 300 to 450°C.…”

“…A previous study by the authors 21 has primarily concentrated on the investigation of catalyst mixtures for favorable compound production, which include hydrocarbons, phenols, furan, and alcohols. In the present work, the pyrolysis kinetic behaviors, such as the activation energy (E a ), will be determined for TGA-pyrolyzed samples using the Coats− Redfern integral method.…”

Effect of H-ZSM-5 and Al-MCM-41 Proportions in Catalyst Mixtures on the Composition of Bio-Oil in Ex-Situ Catalytic Pyrolysis of Lignocellulose Biomass

“…A physical mixture of mesoporous catalyst, Al-MCM-41, and microporous catalyst, H-ZSM-5 was used to produce bio-oil with a low content of oxygen and a high amount of desirable compounds from the catalytic pyrolysis of lignocellulose biomass. In the previous work, Ratnasari et al [32] studied the effect of two-stage catalyst bed on the bio-oil quality. Although more product is formed when using two-stage catalyst bed, due to increased reactant/catalyst contact [32][33][34][35], the catalyst is difficult to replace [34] as the entire reactor has to be dismantled for the replacement of catalyst [35] and the unit may be difficult to service and clean [36].…”

“…Moreover, the authors performed experimental investigations on the effect of catalyst mixtures on the lignocellulose biomass pyrolysis using a bench-scale fixed bed reactor [32]. The Al-MCM-41 with H-ZSM-5 in the staged catalyst method has been shown to facilitate the synthesis of desirable compounds, such as hydrocarbons, phenols, furans, and alcohols.…”

“…The Al-MCM-41 with H-ZSM-5 in the staged catalyst method has been shown to facilitate the synthesis of desirable compounds, such as hydrocarbons, phenols, furans, and alcohols. Ex-situ catalytic pyrolysis of beech wood at a temperature of 500 • C with H-ZSM-5:Al-MCM-41 ratio of 3:1 resulted in a bio-oil containing 11.08 wt.% of organic liquid products and 76.20 wt.% of desirable fractions [32].…”