Catalytic fast pyrolysis of durian rind using silica-alumina catalyst: Effects of pyrolysis parameters

Thermo-catalytic pyrolysis of sewage sludge and techno-economic analysis: The effect of synthetic zeolites and natural sourced catalysts

This work focuses to the value added utilization of animal sewage sludge into gases, bio-oil and char using synthetic zeolite (ZSM-5 and Y-zeolite) and natural sourced (diatomite, kaolin, perlite) materials as catalysts. Pyrolysis was performed in a one-stage bench-scale reactor at temperatures of 400 and 600 °C. The catalyst was mixed with the raw material before the pyrolysis. Catalysts had a significant effect on the yield of products, because the amount of volatile products was higher in their presence, than without them. In case of kaolin, due to the structural transformation occurring between 500-600 °C, a significant increase in activity was observed in terms of pyrolysis reactions resulting in volatiles. The hydrogen content of the gas products increased significantly at a temperature of 600 °C and in thermo-catalysts pyrolysis. In the presence of catalysts, bio-oil had more favourable properties.

Catalytic pyrolysis of lignocellulosic biomass for bio-oil production: A review

Catalytic pyrolysis has been widely explored for bio-oil production from lignocellulosic biomass owing to its high feasibility and large-scale production potential. The aim of this review was to summarize recent findings on bio-oil production through catalytic pyrolysis using lignocellulosic biomass as feedstock. Lignocellulosic biomass, structural components and fundamentals of biomass catalytic pyrolysis were explored and summarized. The current status of bio-oil yield and quality from catalytic fast pyrolysis was reviewed and presented in the current review. The potential effects of pyrolysis process parameters, including catalysts, pyrolysis conditions, reactor types and reaction modes on bio-oil production are also presented. Techno-economic analysis of full-scale commercialization of bio-oil production through the catalytic pyrolysis pathway was reviewed. Further, limitations associated with current practices and future prospects of catalytic pyrolysis for production of high-quality bio-oils were summarized. This review summarizes the process of bio-oil production from catalytic pyrolysis and provides a general scientific reference for further studies.

Microwave assisted carbonization and activation of biochar for energy-environment nexus: A review

Conventional thermochemical conversion techniques for biofuel production from lignocellulosic biomass is often non-selective and energy inefficient. Microwave assisted pyrolysis (MAP) is cost and energy-efficient technology aimed for value-added bioproducts recovery from biomass with less environmental impacts. The present review emphasizes the performance of MAP in terms of product yield, characteristics and energy consumption and further it compares it with conventional pyrolysis. The significant role of biochar as catalyst in microwave pyrolysis for enhancing the product selectivity and quality, and the influence of microwave activation on product composition identified through sophisticated techniques has been highlighted. Besides, the application of MAP based biochar as soil conditioner and heavy metal immobilization has been illustrated. MAP accomplished at low temperature creates uniform thermal gradient than conventional mode, thereby producing engineered char with hotspots that could be used as catalysts for gasification, energy storage, etc. The stability, nutrient content, surface properties and adsorption capacity of biochar was enhanced by microwave activation, thus facilitating its use as soil conditioner. Many reviews until now on MAP mostly dealt with operational conditions and product yield with limited focus on comparative energy consumption with conventional mode, analytical techniques for product characterization and end application especially concerning agriculture. Thus, the present review adds on to the current state of art on microwave assisted pyrolysis covering all-round aspects of production followed by characterization and applications as soil amendment for increasing crop productivity in addition to the production of value-added chemicals, thus promoting process sustainability in energy and environment nexus.

Combustion parameters, evolved gases, reaction mechanisms, and ash mineral behaviors of durian shells: A comprehensive characterization and joint-optimization

In this work, the characteristic parameters, evolved gases, reaction mechanisms, and ash conversions of the durian shell (DS) combustion were quantified coupling thermogravimetry, mass spectroscopy, Fourier transform infrared spectroscopy, and X-ray fluorescence spectra analyses. The main stage of the DS combustion occurred between 130.2 and 481.9 °C. Its activation energy value estimated by the three model-free methods ranged from 192.82 to 213.24 kJ/mol. The average enthalpy, entropy and Gibbs free energy changes were in the ranges of 177.74-178.47 kJ/mol, 32.00-34.25 J/(mol·K), and 200.79-207.74 kJ/mol, respectively. The third-order (F3) model best described its most likely reaction mechanism. The main evolved gas was CO₂, with no SO₂ emission. The ash from the DS combustion belonged to K-type ash. 618 °C and 8 K/min were determined as the optimal operation conditions to jointly optimize the multiple targets of the combustion responses.

Fast corn stalk pyrolysis and the influence of catalysts on product distribution

Fast pyrolysis of corn stalk (CS) was performed by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and the product distribution was measured as a function of temperature, time, and catalyst. The types and yields of product compounds were influenced dramatically by temperature, while the duration of the reaction had little effect on the type of compound. Three primary components in the biomass interacted during pyrolysis. The maximum proportions of aldehydes (27.26%), furans (5.93%), and olefins (6.46%), and the minimum proportions of alcohols (0%) and carbohydrates (0.74%) were obtained over MCM-41. HZSM-5 improved the selectivity of aromatic hydrocarbons while inhibiting acid formation. The proportion of N-compounds was maximal (23.39%) over ZrO₂. ZnCl₂ tended to generate the least amounts of ketones (2.02%), phenols (9.08%), and esters (2.16%), but the greatest amount of carbohydrates (37.31%). K₂SO₄ promoted the formation of acids, ketones, alcohols, and phenols, while reducing the production of N-compounds and aldehydes.

Deoxygenation of pyrolysis vapour derived from durian shell using catalysts prepared from industrial wastes rich in Ca, Fe, Si and Al

Catalysts prepared from industrial wastes rich in Fe, Ca, Si, and Al were used in catalytic upgrading of pyrolysis vapour derived from durian shell and their effect on product yield and properties were compared. With same silica-to-alumina ratio, catalyst prepared from oil palm ash (AS-OPA) with lower Fe and Ca contents gave higher liquid yield (8.32 wt%) with alcohols (28.90%), hydrocarbons (46.00%), and nitrogen-containing compounds (21.46%) while catalyst prepared from electric arc furnace slag (AS-EAF) with higher Fe and Ca contents produced lower liquid yield (50.21 wt%) with high amount of esters (25.80%) and hydrocarbons (72.82%). The presence of AS-OPA and AS-EAF catalysts enhanced deoxygenation degree of bio-oil to 81.13% and 85.49%, respectively. The catalytic performance of AS-EAF at different temperatures (400-600 °C) and AS-EAF/durian shell ratios (1:30, 2:30, 3:30) was investigated. Increasing catalytic temperature enhanced production of bio-oil, reduced oxygenates and enhanced formation of esters. The liquid yield and yield of esters decreased with increasing catalyst loading. Hydrocarbons (mainly neopentane) were the major chemical compounds found in bio-oil produced over AS-EAF. Besides that, AS-EAF showed good deoxygenation performance with highest selectivity of hydrocarbons at 500 °C and AS-EAF/durian shell ratio of 2:30. Catalytic fast pyrolysis of durian shell using waste-derived catalysts is an effective waste management strategy as the bio-oil produced can be a potential alternative source of energy or chemical feedstocks.

Utilizing Infrared Spectroscopy to Analyze the Interfacial Structures of Ionic Liquids/Al₂O₃ and Ionic Liquids/Mica Mixtures under High Pressures

The interfacial interactions between ionic liquids (1,3-dimethylimidazolium methyl sulfate and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate) and solid surfaces (mesoporous aluminum oxide and mica) have been studied by infrared spectroscopy at high pressures (up to 2.5 GPa). Under ambient pressure, the spectroscopic features of pure ionic liquids and mixtures of ionic liquids/solid particles (Al₂O₃ and mica) are similar. As the pressure is increased, the cooperative effect in the local structure of pure 1,3-dimethylimidazolium methyl sulfate becomes significantly enhanced as the imidazolium C–H absorptions of the ionic liquid are red-shifted. However, this pressure-enhanced effect is reduced by adding the solid particles (Al₂O₃ and mica) to 1,3-dimethylimidazolium methyl sulfate. Although high-pressure IR can detect the interactions between 1,3-dimethylimidazolium methyl sulfate and particle surfaces, the difference in the interfacial interactions in the mixtures of Al₂O₃ and mica is not clear. By changing the type of ionic liquid to 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, the interfacial interactions become more sensitive to the type of solid surfaces. The mica particles in the mixture perturb the local structure of 1-ethyl-3-methylimidazolium trifluoromethanesulfonate under high pressures, forcing 1-ethyl-3-methylimidazolium trifluoromethanesulfonate to form into an isolated structure. For Al₂O₃, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate tends to form an associated structure under high pressures.

Catalytic fast pyrolysis of biomass: Selective deoxygenation to balance the quality and yield of bio-oil

Firstly, the operating conditions were screened for biomass pyrolysis in a fixed bed with respect to higher oil yield. A temperature of 600 °C with an N₂ flow of 80 ml/min exhibited the highest bio-oil yield. Then, the catalytic pyrolysis of biomass with various catalysts (Al₂O₃, CaO, MgO, CuO, Fe₂O₃, NiO, ZnO, ZrO₂, TiO₂, HZSM-5 and MCM-41) was studied to identify the selective deoxygenation method with respect to improve bio-oil quality with smaller drop in bio-oil yield. With the addition of CaO, the oxygen was mainly removed in the form of CO₂, while, in other cases, more oxygen was removed in the form of H₂O. Furthermore, more decarboxylation or less dehydration is better for the balance between yield and deoxygenation amount, and the preferred decarboxylation would lead to a higher pH and lower moisture content of bio-oil.