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This study addresses the pressing environmental problem of the emissions of ecotoxic heavy metals from high-temperature waste combustion processes, including incineration and pyrolysis. Such emissions pose a serious threat to ecosystems and human health. This study investigated the behaviour of the heavy metals Cu, Ni, and Pb during the combustion of various waste materials such as plastic waste, pharmaceutical waste, and pesticide waste. To limit the release of heavy metals into the exhaust gas stream, various additives were used: divanadium pentoxide (V2O5), borax (Na2B4O7), and their mixtures with calcium oxide (CaO). Additionally, this study examined the impact of the content of chlorine heteroatoms (Cl) in burned waste materials on the emission levels of Cu, Ni, and Pb. The findings shed light on the mobility of ecotoxic heavy metals in high-temperature waste incineration processes (1273, 1373 K) and offer insight into strategies to improve their immobilisation in grate residues. At a temperature of 1273 K, V2O5 with CaO reduced Pb emissions by ~65% for plastic waste and by ~40% for pesticide. [ABSTRACT FROM AUTHOR]

The aim of the study was to present the possibility of reducing the emission of HCl to the atmosphere and the possibility of limiting the formation of PCDD/F in the technologies of incineration of waste fuels and incineration of animal waste. Waste fuel and animal biomass were burned in a two-stage system i.e.: Io-gasification and IIo-combustion of gas products of gasification. As part of the implementation, the reduction of HCl emissions to air was investigated when Ca(OH)2 was added as an additive to the fuel from waste. Ca(OH)2 bonded HCl releasing into the gas space in the combustion process. HCl binding in the combustion chamber not only limited its emission to the atmosphere. Its elimination also limited the possibility of creating PCDD/F. In case of animal waste, HCl was captured with CaO produced from the decomposition of bone material (hydroxyapatite). The efficiency of this process was low. It was thus necessary to remove it in the built-in exhaust purification plant.

The paper presents the results of research on gasification of olive pits and production of a generator gas with calorific value enabling its combustion in microturbines. Gasification was carried out in a laboratory gasification reactor, where the converting factor was air. The influence of the flow rate of its stream on the composition of the generator gas was investigated. The research involved searching for optimal process conditions for gasification of this biomass, to obtain a generator gas with an increased CH4 content (methane is the most calorific component).The air flow in subsequent tests was 0.5m3/h, 0.85m3 /h, 1.1m3/h,. 1.4m3/h 1.7m3/h. The quantitative composition of the generated generator gases differed. These conditions were obtained with an air flow of 1.4m3/h, in a tubular reactor, at the bed temperature T3= 456–462oC. A gas was obtained, with a calorific value of 9.2MJ/m3, characteristic for the following gas composition: H2=3.88%, CO=18.52%, CO2=6.27%, CH4=16.02%, O2=1.28%.

The study presents a concept of integration a gasifier system with distributed generation of electricity and heat cogeneration system based on a gas microturbine. The gas generator is supplied by the RDF fuel from waste and biomass fuel Bio-CONOx. In the scale considered, the cogeneration system is designed to produce 30kWe of electricity and approx. 50kW of heat. Important perspective directions of technology development are: (i) the possibility of gas microturbine to cooperate with the gasifier (up to date, in such systems were used, and continue to apply only piston engines), (ii) the production of syngas in the gasifier (for efficient cogeneration) in the composition of which there is a high content of methane (CH4 = 18%-22%). In the first step of possible commercialization a mathematical model to simulate single shaft gas turbine cogeneration plant has been developed. In conceptual design is application of microturbine as the prime mover of Combined Heat and Power (CHP) system but with especial emphasis on possible use of a low calorific gas attainable from presented in details a gasifier unit. To support the calculations for preliminary design analysis, a computer program is developed in EES software environment.

In the work there are shown the results of experimental studies on methane rich gasification of pinewood pellets in Bio-CONOx technology. The experiment was carried out on a laboratory scale gasifier (5 kW), which design features allow producing a high quality gas with a high methane content. In the results there was identified the impact of the quantity of Bio-CONOx on the amount of flammable gas compounds (methane, hydrogen and carbon monoxide) in the synthesis gas and the gas calorific value. The additive was added in 10,20,30 and 50% concentrations to the gasifier chamber. It has been shown that increasing the amount of the additive has a positive effect on the calorific value of the synthesis gas (Fig.1,2). Gas with a high content of methane (and high calorific value) was obtained from gasification of biomass with a 50% addition of Bio-CONOx. There was also examined the proportion of blowing air (gasifying medium) for which the properties of obtained syngas were the best.

Abstract: The paper presents the results of the experimental research conducted on an industrial scale and directed at stabilizing the process of the thermal destruction of biomass in the form of animal post-slaughter waste and dead animals. During the realization of the combustion process with the participation of oxygen from 6 to 17% the interaction between such gas products of the process of thermal destruction as SO2 and HCl was analyzed. The results of the experiment clearly indicate that the concentration of SO2 in flue gas is dependent on the participation of O2 in the process of combustion. Hydroxyapatites in the high temperature atmosphere were decomposed, among others, to CaO and P2O5. Particles of CaO, in largely oxidizing atmosphere, carried in the stream of exhaust gases bonded SO2. When the participation of O2 oscillates around 16 to 17%, the concentration of SO2 is close to zero. However, at the same time there are no clear premises concerning the influence that the participation of O2 has on the concentration of HCl. The results in the form of the dependence HCl → f(O2) only suggest that the concentration of HCl in outlet gases decreases for large participation of oxygen of more than 13%. [Copyright &y& Elsevier]

The paper presents a description of the mathematical formalism for blending to obtain ternary formed fuels from waste. The methodology assures obtaining fuels of required technological properties that result, for example, in a limited gram fraction of chlorine in dry mass of fuel, and an appropriate calorific value in the working state. The procedure results makes it possible to determine mass fractions of particular components of produced formed fuels, which in turn creates a possibility of performing stoichiometric calculations for both total and complete combustion. The modeling of both technological as well as calorific and emission properties of fuels from waste at their initial formation stage can have a significant importance for the implementation of new technologies of thermal waste processing, i.e. the production of synthetic fuels for power industry. [ABSTRACT FROM AUTHOR]