Pyrolysis

Municipal solid waste generation is a rapidly increasing challenge that is leading to severe pollution and environmental degradation in many urban areas of developing countries. Globally, the solid waste sector accounts for 18% of methane emissions and 3e4% of greenhouse gas emissions overall. Waste handling and disposal systems in most large cities have largely been designed with minimal accounting of environmental issues. This study presents the Waste to Energy Recovery Assessment (WERA) framework, a new quantitative decision support model for initial evaluation and alternative comparisons of different thermochemical treatments of municipal wastes. The framework not only accounts for benefits through electricity generation but also accounts for emissions from facilities and the associated social cost of carbon in a cost-benefit assessment. The assessments are conducted with Monte Carlo simulations that explicitly account for uncertain factors such as future composition and generation of solid waste, technical efficiency of treatment processes, capital and operating costs, as well as future policies. The framework is used to study waste-to-energy (WtE) systems for Abu Dhabi, Riyadh, Tokyo and New York. The results show that WtE systems can fulfill only 1.4e3.6% of 2014 electricity demand in the analyzed cases. Furthermore, the net present value for different technologies can be positive if collection fees and electricity rates (potentially set through feed-in-tariff policies) are sufficiently high. The analysis for Abu Dhabi and Riyadh also reveals that in a limited set of conditions (of technology efficiencies, and waste collection rates etc.) the WtE facilities can be self-sustaining investments.

The disposal of 280 million tires generated each year in the U.S. is a great environmental problem. The tires take up large amounts of valuable landfill space and also present fire and health hazards. Tire-pyrolysis plants have been in operation for years, but the economics are poor, and most of these facilities have been shut down. This is mainly due to the low value of the end products, which are usually fuels (oil, pyrolysis gas, char). It is believed that reprocessing of waste tires into value-added products would improve the economic leverage. This study addresses reprocessing of oils derived from waste-tire pyrolysis into carbon black - a valuable feedstock for the manufacture of tires, other rubber products, paints, pigments, ink, powder coating, toner, etc. Such a process would form a recycling loop for the carbon black recovered from waste tires. The objective of this work was to demonstrate the feasibility of the proposed approach in a laboratory scale. More specifically, the goal was to show that carbon black produced in the furnace process (1) using waste-tire oil as a feedstock could possess similar characteristics as the carbon black made from a traditional petroleum-based feedstock. Materials and Experimental Techniques Four oil samples were used in this study: (a) tire-pyrolysis oil prepared at Advanced Fuel Research, Inc. (AFR) in a two-inch diameter packed-bed reactor; (b) tire-pyrolysis oil obtained from a large-scale tire pyrolysis plant operated by Conrad Industries in Chehalis, Washington; (c) tire-pyrolysis oil obtained from a pilot-scale tire pyrolysis facility operated by Metso Minerals (formerly Svedala) in Danville, Pennsylvania; and (d) Exxon bunker oil provided by Caleb Brett. The highly aromatic Exxon oil is a typical high-grade feedstock that carbon-black manufacturers use in their normal operations. This oil was used as a reference for the tire-derived feedstocks. In addition, a sample of the AFR tire oil (a) that had been aged for two years was examined to determine oil stability during extended storage at ambient temperature and pressure.

The chemical structure of the milled-wood lignin isolated from Paulownia fortunei wood was investigated. The lignins were characterized by analytical pyrolysis and two-dimensional NMR that indicated a predominance of guaiacyl (G) over syringyl (S) units, and only showed small amounts of p-hydroxyphenyl (H) units, with a H:G:S molar ratio of 1:59:40. The heteronuclear single quantum correlation (HSQC) NMR spectrum gave additional information about the relative abundances of the different inter-unit linkages present in the lignin structure. Paulownia lignin showed a predominance of -O-4� aryl ether linkages (62% of total side-chains), followed by � resinol-type (12%) and -5 � phenylcoumaran-type structures (11%) and with lower amounts of other condensed structures such as spirodienone (3%) and dibenzodioxocin (2%) structures. The high lignin content (ca. 23% Klason lignin), together with the low S/G ratio and the abundance of condensed (carbon–carbon linked) structures (together with ...

Considerable controversy exists concerning the rate of coal pyrolysis. At 800°C the reported rates derived using a single first-order process to define weight loss vary from < 1 s-1 to ~100 s- 1. In an attempt to resolve this controversy, a new pyrolysis experiment has been designed which allows direct measurement of coal temperature and reaction time. It uses a small-diameter electrically heated tube into which coal and helium are injected. The reaction distance is varied by moving the electrode positions. Temperature is measured inside and outside the tube with a thermocouple. Temperatures of the solids are determined at the tube exit using FT-i.r. emission and transmission spectroscopy. The transit time for a pulse of coal is measured using phototransistors at the top and bottom of the tube. Particle velocities are also determined using FT-IR transmission. Measurements have been made on sieved size fractions of a North Dakota lignite, Rosebud subbituminous coal and Illinois No. 6 bituminous coal in tubes up to 240 cm long at asymptotic tube temperatures of 600, 700, 800 and 935°C. At 800°C primary pyrolysis was completed in a period of 14 ms, during which the maximum coal temperature was increasing from 600 to 740°C. The results are in good agreement with a previously developed functional-group model of coal pyrolysis which employs a distribution of activation energies to describe the evolution of individual pyrolysis species. The results are also in reasonable agreement with predictions of a single first-order model for weight loss which uses a rate constant k=4.28 x 1O4 exp(-228500/RT) Jmol-’ s-1. This rate,which is over 1000 s-l at 800°C, is inconsistent with the low rates. Reasons for discrepancies in reported rates are discussed

Vacuum pyrolysis of pure PVC at various temperatures and under a total pressure of 2 kPa has been performed to identify and quantify the main pyrolysis products obtained during the different stages of thermal degradation. A system consisting of a bench scale batch reactor with a condensation train was used to collect the pyrolysis products. The main gaseous and liquid

The issue of sustainability is a growing concern and has led to many environmentally friendly chemical productions through a great intensification of the use of biomass conversion processes. Thermal conversion of biomass is one of the most attractive tools currently used, and pyrolytic treatments represent the most flexible approach to biomass conversion. In this scenario, microwave-assisted pyrolysis could be a solid choice for the production of multi-chemical mixtures known as bio-oils. Bio-oils could represent a promising new source of high-value species ranging from bioactive chemicals to green solvents. In this review, we have summarized the most recent developments regarding bio-oil production through microwave-induced pyrolytic degradation of biomasses.

CdS has been proved to be an ideal material for use as the window layer for heterojunction solar cells especially with n-CdS/p-CdTe. CdS, Cd0. 9Sn0. 1S and Cd0. 8Sn0. 2S films were deposited onto glass substrates at 300° C substrate temperature by using ultrasonic spray ...

— Algae are gaining broad consideration as a substitute renewable source of biomass for the manufacture of bioethanol, due to this reason categorized under the " third generation biofuels " .İn this work, GC-MS analysis and FTIR has been done of bio-oil obtained from fast pyrolysis of Freshwater Algae(Spirogyra) in this paper we have shown a simple process of converting biomass of fresh water algae to bio-oil through pyrolysis and explained it with the help of graphs and tables. Pyrolysis is a thermal process for converting various biomasses , residues and wastes to produce high-energy-density fuels (bio-oil, biochar). The bio-oil was obtained in two step pyrolysis in which temperature of the system kept 25ºC and then increased up to 650ºC time by time. After pyrolysis these fractions were analyzed by gas chromatography/mass spectrometry (GC-MS) and FTIR which show different peaks and data of different compounds and functional groups present in this bio-oil

Energy is essential for the nature of life and the development of countries. The main demand for the 21st century is to fulfill growing energy needs. Pakistan, through the use of fossil fuels, meets energy demands. There is pressure on the economy of the country due to the massive reliance on fossil fuels, and this tendency is influenced by various environmental impacts. To overcome the burden on fossil fuels, more attention has been drawn to provide fossil fuel substitution. Tire pyrolysis is among the effective substitutes of the fuel technology that generates useful products of liquid oil, char, and pyro gas. This research focuses on the environmental, social, and economic viability of tire pyrolysis oil in Pakistan. This study estimates the production and potential of tire pyrolysis oil (TPO) in Pakistan. Based on the calculations, the potential of tire pyrolysis oil production in Pakistan from 2015–2019 is 468,081 to 548,406 tons. The potential production of TPO in 2018–2019 wa...

Tribenzyl tin(IV) chloride complexes of morpholine N-thiohydrazide (L1), aniline-N-thiohydrazide (L2),N-(morpholine-N-thio)-1,3-propanediamine (L3) and (aniline-N-thio)-1,3-propanediamine (L4) of the type (C6H5CH2)3Sn(L)Cl (where L=L1, L2, L3 and L4) have been synthesised in dioxane and in H2O and acetone mixture. These were characterized by C,H,N-analysis, UV, IR and 1HNMR spectral studies. In both the complexes ligands act as bidentate, coordinating through sulphur and terminal nitrogen. The complexes are 1:1 metal ligand complexes. Various thermodynamic parameters have been calculated for the decomposition steps using TG/DTA curves in air as well as nitrogen atmosphere.