scholarly journals Pyrolysis of Plastics to Liquid Fuel Using Sulphated Zirconium Hydroxide Catalyst

2019 ◽  
Vol 11 (11) ◽  
pp. 6337-6345 ◽  
Author(s):  
Achyut K. Panda ◽  
Abdullah Alotaibi ◽  
Ivan V. Kozhevnikov ◽  
N. Raveendran Shiju
Keyword(s):  
Energy Demand ◽  
Liquid Fuel ◽  
Reaction Rate ◽  
Catalytic Pyrolysis ◽  
Fossil Fuel ◽  
Product Distribution ◽  
Zirconium Hydroxide ◽  
Optimum Conditions ◽  
Reaction Conditions ◽  
Different Types

Abstract A world without plastics is unimaginable now and probably also in future. With the growing use of plastic, the problem of waste plastic disposal is also growing. Recycling the plastics is a promising option to avoid the serious environmental challenge caused by them. Among the various options for recycling, catalytic conversion of plastics to hydrocarbons is very attractive. Catalytic pyrolysis depolymerizes the plastics to an oil which can be used as a liquid fuel. This is a sustainable way to utilize the waste, simultaneously promising to meet the energy demand. We studied the use of sulphated zirconium hydroxide as a catalyst for the pyrolysis of different types of plastics such as polypropylene, low density polyethylene, high density polyethylene and a mixture of all three. The objective was to understand the effect of the catalyst and the temperature on the composition of the oil as well as to find an optimum condition for maximum oil yield. Various reaction conditions and their influence on the product distribution are studied. The catalyst is effective in enhancing the reaction rate, altering the product selectivity and narrowing the product distribution of the reaction. At optimum conditions, we obtained more than 79% yield of oil which contains mainly C10–C24 hydrocarbons. The fuel properties are suitable to be used as a fossil fuel substitute. Graphic Abstract

scholarly journals Catalysts for Biodiesel Production: A Review

2021 ◽  
Vol 33 (9) ◽  
pp. 1985-1999
Author(s):  
K.A.V. Miyuranga ◽  
D. Thilakarathne ◽  
Udara S.P.R. Arachchige ◽  
R.A. Jayasinghe ◽  
N.A. Weerasekara
Keyword(s):  
Energy Demand ◽  
Fossil Fuels ◽  
Reaction Rate ◽  
Fossil Fuel ◽  
Sustainable Energy ◽  
Biodiesel Production ◽  
Energy Sources ◽  
World Population ◽  
Economic Issues ◽  
The World

As the world population and modernization increase, energy demand increases. One of the non-sustainable energy sources is fossil fuels. However, fossil fuel consumption raises various environmental and economic issues. Most of the studies focus on sustainable energy sources, which can replace fossil fuel dependence. Biodiesel is an alternative sustainable fuel for diesel power. Biodiesel can produce through the transesterification process. Since the catalyst plays a significant role in the biodiesel yield during a defined reaction time, the addition of a catalyst can increases the reaction rate. This article is outlined the several catalysts used by multiple researchers over the years to increase biodiesel yields.

scholarly journals Effect of Potassium Carbonate Catalyst on Pyrolysis of Milicia excelsa in a Fixed Bed Reactor

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Pious O Okekunle ◽  
Oluwatobi S Awani ◽  
Daniel O Jimoh
Keyword(s):  
Potassium Carbonate ◽  
Liquid Fuel ◽  
Catalytic Pyrolysis ◽  
Fixed Bed ◽  
Product Distribution ◽  
Fixed Bed Reactor ◽  
Catalyst Amount ◽  
Different Temperatures ◽  
Definite Pattern ◽  
Milicia Excelsa

The effect of potassium carbonate catalyst on the products distribution from pyrolysis of Milicia excelsa (Iroko) at various temperatures (400, 500 and 600 oC) was investigated. Milicia excelsa sawdust was obtained from a sawmill in Ogbomoso, South-Western Nigeria and was sundried for five days in order to reduce its moisture content. Catalytic pyrolysis of the sawdust was performed with different amounts of catalyst (10, 20, 30 and 40 wt.%). Non-catalytic pyrolysis was also performed for the same temperatures and the products distributions from both batches were compared. Char yield generally increased with increase in catalyst amount for all the temperatures considered. Tar yield did not follow any definite pattern with increasing amount of catalyst as different trends were obtained for different temperatures. Gas yield generally decreased with increase in catalyst amount in the feed. Char yields from non-catalytic experiments were higher than those obtained from catalytic runs, with the highest value of 68% at 400 oC. Tar yields from catalytic pyrolysis were higher than those from non-catalytic process at 400 oC (biomass/catalyst ratio of 90/10) and at 500 oC (biomass/catalyst ratios of 70/70 and 60/40), the highest yield being 29.47% at 500 oC and biomass/catalyst ratio of 60/40. Gas yields from catalytic pyrolysis were higher than those from non-catalytic runs except at 500 oC (biomass/catalyst ratio of 60/40), the highest being 51.3% at 600 oC (biomass/catalyst ratio of 90/10). By making use of appropriate biomass/catalyst ratio and temperature, the yield of liquid fuel from catalytic pyrolysis of Milicia excelsa can be increased.Keywords— Catalyst, potassium carbonate, pyrolysis, biomass, product distribution

Novel Products in the CO2-Laser Induced Reaction of Trichloroethylene

1995 ◽  
Vol 60 (1) ◽  
pp. 104-114 ◽  
Author(s):  
Boyd L. Earl ◽  
Richard L. Titus
Keyword(s):  
Irradiation Time ◽  
Product Distribution ◽  
Incident Power ◽  
Cell Geometry ◽  
Reaction Conditions ◽  
Peak Areas ◽  
Induced Decomposition ◽  
Nmr Methods ◽  
Induced Reaction ◽  
Novel Products

Previous reports on the thermal or CO2-laser induced decomposition of trichloroethylene have identified only one condensible product, hexachlorobenzene (in addition to HCl and mono- and dichloroacetylene). We have found that trichloroethylene vapor exposed to cw irradiation on the P(24) line of the (001 - 100) band of the CO2 laser at incident power levels from 8 - 17 W produces numerous products, of which the 13 major ones have been identified using IR, GC/MS, GC/FTIR, and NMR methods. All of these products have 4, 6, or 8 carbons, are highly unsaturated, and are completely chlorinated or contain a single hydrogen. C4HCl5 and C6Cl6 isomers (three of each) account for S 55% to 85% of total products (based on peak areas in the total ion chromatograms in GC/MS runs), depending on reaction conditions. In addition to characterizing the products, we discuss the dependence of the product distribution on laser power, irradiation time, and cell geometry, and we outline a possible mechanism.

scholarly journals Reaction Mechanism for Methane-to-Methanol in Cu-SSZ-13: First-Principles Study of the Z2[Cu2O] and Z2[Cu2OH] Motifs

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Unni Engedahl ◽  
Adam A. Arvidsson ◽  
Henrik Grönbeck ◽  
Anders Hellman
Keyword(s):  
Liquid Fuel ◽  
Density Functional ◽  
Reaction Pathway ◽  
Direct Conversion ◽  
Reaction Conditions ◽  
Oxidation Of Methane ◽  
Small Pore ◽  
Desorption Step ◽  
Solution Gas ◽  
Stable Motif

As transportation continues to increase world-wide, there is a need for more efficient utilization of fossil fuel. One possibility is direct conversion of the solution gas bi-product CH4 into an energy-rich, easily usable liquid fuel such as CH3OH. However, new catalytic materials to facilitate the methane-to-methanol reaction are needed. Using density functional calculations, the partial oxidation of methane is investigated over the small-pore copper-exchanged zeolite SSZ-13. The reaction pathway is identified and the energy landscape elucidated over the proposed motifs Z2[Cu2O] and Z2[Cu2OH]. It is shown that the Z2[Cu2O] motif has an exergonic reaction path, provided water is added as a solvent for the desorption step. However, a micro-kinetic model shows that neither Z2[Cu2O] nor Z2[Cu2OH] has any notable activity under the reaction conditions. These findings highlight the importance of the detailed structure of the active site and that the most stable motif is not necessarily the most active.

scholarly journals Optimizing the Reaction Conditions for the Formation of Fumarate via Trans-Hydrogenation

2021 ◽  
Author(s):  
Laura Wienands ◽  
Franziska Theiß ◽  
James Eills ◽  
Lorenz Rösler ◽  
Stephan Knecht ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Thermal Equilibrium ◽  
Reaction Rate ◽  
Low Cost ◽  
Hydrogen Gas ◽  
Metabolic Imaging ◽  
Reaction Conditions ◽  
Precursor Molecule ◽  
Solution Preparation

AbstractParahydrogen-induced polarization is a hyperpolarization method for enhancing nuclear magnetic resonance signals by chemical reactions/interactions involving the para spin isomer of hydrogen gas. This method has allowed for biomolecules to be hyperpolarized to such a level that they can be used for real time in vivo metabolic imaging. One particularly promising example is fumarate, which can be rapidly and efficiently hyperpolarized at low cost by hydrogenating an acetylene dicarboxylate precursor molecule using parahydrogen. The reaction is relatively slow compared to the timescale on which the hyperpolarization relaxes back to thermal equilibrium, and an undesirable 2nd hydrogenation step can convert the fumarate into succinate. To date, the hydrogenation chemistry has not been thoroughly investigated, so previous work has been inconsistent in the chosen reaction conditions in the search for ever-higher reaction rate and yield. In this work we investigate the solution preparation protocols and the reaction conditions on the rate and yield of fumarate formation. We report conditions to reproducibly yield over 100 mM fumarate on a short timescale, and discuss aspects of the protocol that hinder the formation of fumarate or lead to irreproducible results. We also provide experimental procedures and recommendations for performing reproducible kinetics experiments in which hydrogen gas is repeatedly bubbled into an aqueous solution, overcoming challenges related to the viscosity and surface tension of the water.

A review of lignin hydrogen peroxide oxidation chemistry with emphasis on aromatic aldehydes and acids

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajinkya More ◽  
Thomas Elder ◽  
Zhihua Jiang
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Degradation ◽  
Reaction Medium ◽  
Dicarboxylic Acids ◽  
Aromatic Aldehydes ◽  
Product Distribution ◽  
Reaction Conditions ◽  
Alkaline Conditions ◽  
The Stability ◽  
Oxidation Chemistry

Abstract This review discusses the main factors that govern the oxidation processes of lignins into aromatic aldehydes and acids using hydrogen peroxide. Aromatic aldehydes and acids are produced in the oxidative degradation of lignin whereas mono and dicarboxylic acids are the main products. The stability of hydrogen peroxide under the reaction conditions is an important factor that needs to be addressed for selectively improving the yield of aromatic aldehydes. Hydrogen peroxide in the presence of heavy metal ions readily decomposes, leading to minor degradation of lignin. This degradation results in quinones which are highly reactive towards peroxide. Under these reaction conditions, the pH of the reaction medium defines the reaction mechanism and the product distribution. Under acidic conditions, hydrogen peroxide reacts electrophilically with electron rich aromatic and olefinic structures at comparatively higher temperatures. In contrast, under alkaline conditions it reacts nucleophilically with electron deficient carbonyl and conjugated carbonyl structures in lignin. The reaction pattern in the oxidation of lignin usually involves cleavage of the aromatic ring, the aliphatic side chain or other linkages which will be discussed in this review.

Ring-opening Addition Reactions of 1-tert-Butoxycarbonyl-3,4- epoxypiperidine with Amine Nucleophiles

2010 ◽  
Vol 65 (2) ◽  
pp. 197-202 ◽  
Author(s):  
Boja Poojary ◽  
Lim Hee-Jong
Keyword(s):  
Ring Opening ◽  
Addition Reactions ◽  
Reaction Conditions ◽  
Different Types

Ring-opening addition reactions of 1-tert-butoxycarbonyl-3,4-epoxypiperidine leading to the formation of the corresponding regioisomeric trans-β -aminoalcohols were carried out with three different types of amine nucleophiles under different reaction conditions with a view to study the reactivity and regioselectivity.

scholarly journals Predicted Medium Vote Thermal Comfort Analysis Applying Energy Simulations with Phase Change Materials for Very Hot-Humid Climates in Social Housing in Ecuador

2021 ◽  
Vol 13 (3) ◽  
pp. 1257
Author(s):  
Luis Godoy-Vaca ◽  
E. Catalina Vallejo-Coral ◽  
Javier Martínez-Gómez ◽  
Marco Orozco ◽  
Geovanna Villacreses
Keyword(s):  
Thermal Comfort ◽  
Phase Change ◽  
Social Housing ◽  
Energy Demand ◽  
Phase Change Materials ◽  
Thermal Sensation ◽  
Electricity Consumption ◽  
Different Types ◽  
Climate Influences ◽  
Energy Simulations

This work aims to estimate the expected hours of Predicted Medium Vote (PMV) thermal comfort in Ecuadorian social housing houses applying energy simulations with Phase Change Materials (PCMs) for very hot-humid climates. First, a novel methodology for characterizing three different types of social housing is presented based on a space-time analysis of the electricity consumption in a residential complex. Next, the increase in energy demand under climate influences is analyzed. Moreover, with the goal of enlarging the time of thermal comfort inside the houses, the most suitable PCM for them is determined. This paper includes both simulations and comparisons of thermal behavior by means of the PMV methodology of four types of PCMs selected. From the performed energy simulations, the results show that changing the deck and using RT25-RT30 in walls, it is possible to increase the duration of thermal comfort in at least one of the three analyzed houses. The applied PCM showed 46% of comfortable hours and a reduction of 937 h in which the thermal sensation varies from “very hot” to “hot”. Additionally, the usage time of air conditioning decreases, assuring the thermal comfort for the inhabitants during a higher number of hours per day.

scholarly journals Enhancing Anaerobic Digestion: The Effect of Carbon Conductive Materials

2018 ◽  
Vol 4 (4) ◽  
pp. 59 ◽  
Author(s):  
Judith González ◽  
Marta Sánchez ◽  
Xiomar Gómez
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biogas Production ◽  
Global Energy ◽  
Conductive Materials ◽  
Different Types ◽  
Interesting Approach ◽  
Feasible Alternative

Anaerobic digestion is a well-known technology which has been extensively studied to improve its performance and yield biogas from substrates. The application of different types of pre-treatments has led to an increase in biogas production but also in global energy demand. However, in recent years the use of carbon conductive materials as supplement for this process has been studied resulting in an interesting way for improving the performance of anaerobic digestion without greatly affecting its energy demand. This review offers an introduction to this interesting approach and covers the different experiences performed on the use of carbon conductive materials proposing it as a feasible alternative for the production of energy from biomass, considering also the integration of anaerobic digestion and thermal valorisation.

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