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 households. 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.
5 April 2022 in International Journal of Hydrogen Energy
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.
In 2016 4.94 million tonnes of tyres were produced. Each tyre eventually become waste and pyrolysis has been considered an effective way of utilizing scrap tyres for several decades. However, pyrolysis has failed many times because the process has a great energy demand and the quality of products is unstable or insufficient for commercial use. Usually plants are focused on the production of pyrolytic oil or char and the gaseous phase is only a by-product. In this paper the importance of composition and quality of pyrolytic gas is emphasized. The main chemical properties make this gas a valuable biofuel that may satisfy energy requirements of the whole process (except for the start-up phase). Available data from literature concerning composition and other features of the pyrolytic gas from scrap tyres obtained at temperatures up to 1000 °C are compared with experimental results. The quality of evolved gases is discussed in the context of the Industrial Emissions Directive (IED), too. Finally, an analysis of the mass balances obtained allows a decision about the business profile and profitability.