3/2022
Activation of solid residues from batch pyrolysis of waste tires
Energy saving technology in power plants industry by HFRW
This paper aims at investigating the use of high frequency resistance welding (HFRW) to deploy energy saving technology in power plants industry. The new approach of dissimilar welds A240TP409 finned and 2¼ Cr-1 Mo seamless tube under various conditions of high frequency resistance welding (HFRW) are found in power plant boilers and reducing energy costs is possible through the use of finned tubes. HFRW have accomplished on samples by changing multiple parameters including current of welding, electric potential, travel speed and fin pitch. Microstructural evolution in weld bond, hardness and tensile strength tests revealed that metallurgical bonding more than 90 % was measured at the weld interface and the average of tensile strengths were more than 275 MPa, with setting on appropriate welding parameters and optimum pressure. Since the pitch and fin thickness can be severely reduced, the output transfer surface treatment in final process can be dramatically diminished. Lastly, a well-engineered approach to the design of the best conditions of finned tube welding bond is discussed in modern combined cycle power plant (CCPP).
Investigation of the combustion process of the developed composite granules
The urgent task of each country is to achieve energy independence through the transition from traditional energy sources to alternative ones. Sewage treatment plants can be considered a potential source of additional raw materials. In Ukraine, one of the problems is the disposal of sludge that are more than 30 years old and to which activated sludge has not been added. This sludge has a low content of organic components, which are not suitable for combustion in pure form and fertilizers. Since the old sludge have a small content of organic components, for their better utilization it is proposed to create composite granules, their subsequent drying and combustion, during which the resulting ash will be used for the production of building materials. The aim of the work is to study the combustion of composite granules based on sludge, peat and biomass. The determined specific heat of combustion of composite granules exceeds this index of peat by 1.2 times. The study of the combustion process of composite granules showed that the obtained results can be used in fuel combustion in different ways. The combustion rate of granules is much lower than the combustion rate of the original biomass, but the combustion rate of a separate part of sludge prevails. The combustion rate of granules is much lower than the combustion rate of the original biomass, but the combustion rate of a separate part of sludge prevails. The conducted experiments showed the possibility of decontamination of sludge and its disposal as an alternative fuel.
Properties and Analysis of Liquid Alternative Fuels I: Fatty Acid Esters
The importance of alternative fuels is constantly growing due to environmental reasons, saving fossil fuels and reducing the dependence of the world countries on the supply of fossil raw materials from politically unsta-ble regions. This article is further in a series of review articles focused on an overview of technical requirements and testing methods for selected alternative fuels. It is also the first in a series of papers focused on liquid alter-native fuels. The aim of this series of articles is to provide an overview of the required properties of individual al-ternative fuels, the possibilities of their analysis and the importance of the individual analyzes. This article fo-cuses on fuels containing fatty acid esters.Biodiesel can be burned in diesel engines either in a mixture with conventional diesel or as an individual fuel. Unlike conventional diesel, which is composed of hydrocarbons of petroleum origin, biodiesel contains fatty acid methyl esters. In addition to this main compo-nent, glycerol (by-product of transesterification), metha-nol, free fatty acids, glycerides (mono-, di- and tri-), cat-alyst residues, water, and possibly other components can be present also. These contaminants can, in certain con-centrations, cause some undesirable properties both in pure biodiesel and in biodiesel/diesel blends. Compared to conventional diesel, biodiesel has a higher density and viscosity, but a slightly lower higher heating value, and considerably worse oxidation stability. In terms of pollutant emissions, the combustion of biodiesel pro-duces less hydrocarbons, carbon monoxide and solid par-ticles, but slightly more nitrogen oxides than the combus-tion of mineral diesel. Gas chromatography, infrared spectroscopy, titra-tion methods, and atomic spectroscopy methods have typically been used for the evaluation of these fuels. In addition to the properties monitored by these methods, conventional fuel parameters such as density, viscosity, low-temperature properties, oxidation stability, corrosion properties, flash point, cetane number, and others are monitored for biodiesel and biodiesel/diesel blends. In general, it can be stated that the analysis of fuels contain-ing biodiesel is well managed. Instrumental equipment and (modified) analytical methods used for the analysis of conventional liquid fuels can be used to analyze these fuels.