Products’ composition of food waste low-temperature slow pyrolysis

Food waste generation is one of the most crucial problems of our constantly developing world. There are several common methods of its treatment, however each one has its own advantages and disadvantages. Pyrolysis attracting attention in this field since a long time, because it allows to utilize this valuable resource with energy and material recovery. Moreover, the environmental impact of the process is relatively low. In this paper, products of low temperature household waste pyrolysis underwent a detailed chemical analysis. Liquid and solid residues was examined. Composition and concentration of particular compounds and elements indicates presence of long chain alkane, alkene and carboxylic acid molecules together with small amounts of aromatics within the bio-oil samples. The presence of heavy metals in residues was detected, too. Since the products are usually described as non-toxic, the idea of waste’ low-temperature thermal treating in household was analyzed. In general, examined residues from the process are safe for the environment, thus pyrolysis can be considered as a legitimate mechanism to treat kitchen waste combined with energy recovery for homes

Experimental analysis of waste tyres as a sustainable source of energy

© The Authors, published by EDP Sciences, 2019. Nowadays, the stability of energy supply that additionally should be sustainable is one of the most important global issues. Thus, many new potential energy sources are being investigated. Since automobile industry is growing, a huge amount of waste tyres (WT) occur each year. Pyrolysis of scrap tyres can be considered as a sustainable way to recover significant amounts of energy as well as the valuable materials. Potential of waste tyres in the energy sector is studied in this work. Proximate, ultimate and thermogravimetric (TG) analysis of mechanically grounded WT sample was done. Waste tyres feature high heating value combined with carbon content as high as 87.90 % (on dry ash-free basis). Additionally, TG analysis allows to choose optimal operating temperature for pyrolysis process which is between 350 and 500°C. However, the sulphur content is also relatively high - around 2 wt.% - and it is the most important challenge for utilizing this waste in a thermochemical way.The paper was financial supported by Department of Air Conditioning, Heating, Gas Engineering and Air Protection; Wroclaw University of Science and Technology (No. 0401/0055/18)

Experimental investigation of waste tyres pyrolysis gas desulfurization through absorption in alkanolamines solutions

Copyright © 2022 The Authors. Pyrolysis of waste tyres produces harmful hydrogen sulfide and other mercaptan compounds as by-products. The current study is concerned with the purification of hydrogen-rich pyrolysis gas from hydrogen sulfide gas that is present in a great amount (up to 5.1% mol at 420 °C), and mercaptans that are also problematic impurities. The method proposed is absorption by alkanolamines which is one of the most economical methods applied in natural gas sweetening. However, it has not been adopted in waste tyre pyrolysis gas purification yet. Two organic absorbents were tested, diethanolamine (DEA), N-methyldiethanolamine (MDEA) as well as theirs blends, at various concentrations. The application of 30 wt% DEA in water reduced H2S emission by 98%. In turn, 40 wt% MDEA aqueous solutions reduced H2S emission by 97%. The best results were produced when 30 wt% DEA was mixed with 40 wt% of MDEA (1:1 vol ratio) which allowed a removal of 99% of H2S from the pyrolysis gas. Moreover, the maximum H2S emission was 7 ppm, and a level below 5 ppm was kept for 99% of experiments duration. Finally, the application of this mixture also reduced significantly the concentrations of other sulfur-containing compounds such as methyl mercaptan and carbonyl sulfide (a minimum of 98%), ethyl mercaptan (∼90%), and carbon disulphide (by more than 99%). Thus, aqueous solvent mixture of 30 wt% DEA with 40 wt% of MDEA (1:1 v/v) can be recommended as a potential desulfurization method for waste tyres pyrolysis gas.Department of Air Conditioning, Heating, Gas Engineering and Air Protection; Wroclaw University of Science and Technology (No. 8211204601 - N_RRB_PODST_BAD_ EXP_BAM)

Municipal waste management systems for domestic use

© 2017 The Authors. Every year, the average citizen of a developed country produces about half a tonne of waste, thus waste management is an essential industry. Old waste management systems based on the collection of mixed/ sorted waste and transporting it a long way to disposal sites has a significant negative impact on the environment and humans. This paper will review the available waste management systems for house- holds. Biological methods (such as composting or anaerobic digestion) and physicochemical methods (such as burning or pyrolysis) of waste utilization will be considered from the householder’s point of view. The most important features of each system will be discussed and compared. Municipal waste management systems for domestic use could eliminate or significantly reduce the stage of waste collection and transportation. Additionally, they should not require special infrastructure and at the same time should allow garbage to be changed into safe products or energy sources with no harmful emissions. The aim of the work is to identify the best available waste disposal systems for domestic use.This reported work was conducted as part of the“Design Optimisation of the HERU Waste Treatment System”project that wasfunded by Manik Ventures Limited Project ID: 10300

TGA-DSC-MS Analysis of Pyrolysis Process of Various Biomasses with Isoconversional (Model-Free) Kinetics

Slow pyrolysis characteristics of different biomasses (hazelnut shell (HS), sawdust (Beech), and sawdust chemically treated (SDCT)) were investigated by simultaneous thermal analysis (STA), coupled with mass spectrometry (MS). Thermal decomposition of these samples was divided into three stages corresponding to removal of water, devolatilization, and formation of bio-char. It was found that differences in thermal behavior of the samples are due to differences in their composition. Mass spectrometry results showed that H-2, CH4, H2O, CO2 (C3H8), CO, and C2H6 were the main gaseous products released during pyrolysis. It was shown that HS could be a good fuel, since during its pyrolysis at high temperature, more gaseous products are released compared to other systems. Isoconversional (model-free) method was used in order to determine variation magnitudes of effective activation energy (E-a) values on conversion fraction (alpha) during pyrolysis. It was found that identified variations of E-a with alpha arise from the different chemical structures among cellulose, hemicelluloses and lignin in tested samples that may affect on their effective activation energies