Assessing the effectiveness of a high-temperature-programmed experimental system for simulating the spontaneous combustion properties of bituminous coal through thermokinetic analysis of four oxidation stages

Experimental methods in chemical engineering: Thermogravimetric analysis—TGA

A review of the energy recovery from waste tyres is presented and focuses on the three thermochemical processes used to valorise waste tyres: pyrolysis, gasification, and combustion/incineration After recalling the chemical composition of tyres, the thermogravimetric behaviours of tyres or their components under different atmospheres are described Different kinetic studies on the thermochemical processes are treated Then, the three processes were investigated, with a particular attention given to the gasification, due to the information unavailability on this process Pyrolysis is a thermochemical conversion to produce a hydrocarbon rich gas mixture, condensable liquids or tars, and a carbon-rich solid residue Gasification is a form of pyrolysis, carried out at higher temperatures and under given atmosphere (air, steam, oxygen, carbon dioxide, etc) in order to yield mainly low molecular weight gaseous products Combustion is a process that needs a fuel and an oxidizer with an ignition system to produce heat and/or steam The effects of various process parameters such as temperature, heating rate, residence time, catalyst addition, etc on the energy efficiency and the products yields and characteristics are mainly reviewed These thermochemical processes are considered to be the more attractive and practicable methods for recovering energy and material from waste tyres For the future, they are the main promising issue to treat and valorise used tyres However, efforts should be done in developing more efficient technical systems

Thermochemical conversion of waste tyres—a review

Combustion mechanism and model free kinetics of different origin coal samples: Thermal analysis approach

Critical particle size analysis of gas emission under high-temperature oxidation of weathered coal

Co-combustion of coal and waste in pulverized coal boiler

Thermal behavior of an engineered fuel and its constituents for a large range of heating rates with emphasis on heat transfer limitations

The combustion of fuel derived from municipal solid waste is a promising cheap retrofitting technique for coal power plants, having the added benefit of reducing the volume of waste disposal in landfills. co-combustion of waste-derived fuel (WDF) and coal, rather than switching to WDF combustion alone in dedicated power plants, allows power plant operators to be flexible toward variations in the WDF supply. Substituting part of the coal feed by processed high calorific value waste could reduce the NOx, SO2, and CO2 emissions of coal power plants. However, the alkaline content of WDF and its potentially harmful interactions with the coal ash, as well as adverse effects from the presence of chlorine in the waste, are important drawbacks to waste-derived fuel use in large-scale power plants. This chapter reviews these points and gives a centralized review of co-combustion experiments reported in the literature. Finally, this chapter underlines the importance of lab-scale experiments previous to any large-scale application and introduces the idea of combining waste and additives dedicated to the capture of targeted pollutants.

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Municipal Solid Waste Cofiring in Coal Power Plants: Combustion Performance

Reduction of pulverized coal boiler's emissions through ReEngineered Feedstock™ co-combustion

This paper presents the modeling and simulation of an industrial-scale chemical looping combustion (CLC) power plant, including all process units (reactors, flue gas treatment units, heat integration, steam cycle, and CO2 compression train). A model of a 525 MWth CLC power plant was built using a rigorous representation of the solid fuel and oxygen carrier. Petcoke was considered the main fuel of interest in this study, and it is compared with other solid fuels. The flue gas compositions obtained with the model show that cleanup units are mandatory to comply with CO2 quality requirements. High levels of flue gas treatment, including 97.1% deNOx and 99.4% deSOx, are needed to achieve typical specifications for captured CO2. This is mainly due to the high level of contaminants in the fuel, but also to the absence of nitrogen in the CLC flue gas, thus resulting in higher concentrations for all substances. The high level of flue gas treatment is thus one of the important challenges for solid fuel combustion in CLC. The overall CO2 capture efficiency of the plant is estimated to be as high as 94%. Regarding the energy balance, a process net efficiency of 38% is obtained. Comparing the results with other available technologies shows that CLC exhibits one of the highest net plant efficiencies and carbon capture rates. CLC is thus a promising technology to produce clean energy from solid fuels. Finally, based on a sensitivity analysis, it is shown that process efficiency is mainly affected by the design and performance of the CLC furnace, the steam injection rate in the fuel reactor, the char separation efficiency, and the excess oxygen in the air reactor.

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Odile Vekemans

Papers

Co-combustion of coal and waste in pulverized coal boiler

Thermal behavior of an engineered fuel and its constituents for a large range of heating rates with emphasis on heat transfer limitations

Municipal Solid Waste Cofiring in Coal Power Plants: Combustion Performance

Reduction of pulverized coal boiler's emissions through ReEngineered Feedstock™ co-combustion

Modeling and Simulation of an Industrial-Scale 525 MWth Petcoke Chemical Looping Combustion Power Plant