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• Chlorine-rich RDF can cause corrosion of metal surfaces. • Ash deposition rate increases with addition of RDF to coal. • Biodegradable- and non-biodegradable-rich RDF separation has a beneficial on ash deposition. • Biodegradable-rich RDF potentially as co-firing fuel. • Blend of 5 wt% non-biodegradable-rich RDF with coal has medium to high risk. The potential impact of ash deposition during the combustion of separated biodegradable- and non-biodegradable-rich waste of refuse-derived fuel (RDF) was evaluated in this study. Theoretical prediction, drop tube furnace experimental combustion, and ash observation were performed to comprehensively investigate their ash deposit behaviour. The results show that high CaO and Cl in RDFs result in severe sintering and rust in the metal surface. The high ash deposit weight and aggregated sticky particles are observed during single-firing RDFs. Furthermore, adding 5 wt% of biodegradable-rich RDF or mixed RDF to coal has a less significant effect on ash deposition. However, several aggregate particles and metal degradation are observed during the combustion of mixed coal with the addition of 5 wt% non-biodegradable-rich RDF. The high Cl in non-biodegradable-rich RDF affects the ash deposition behaviour significantly. This research provides valuable insights into optimising coal-RDF co-combustion, especially with separating biodegradable- and non-biodegradable-rich RDFs. [ABSTRACT FROM AUTHOR]

Coal calorific value is one of the main considerations for using coal as a power plant fuel. In addition, the requirements for indications of slagging and fouling are also important to maintain combustion efficiency. However, coal power plants often experience problems in boiler operations due to the use of certain types of coal, even though they have a relatively high calorific value. This research investigates the effect of coal blending on ash fouling and slagging in an experimental investigation using a drop tube furnace with or without additives. Five different types of coal from different locations have been used in this study. Pulverized low-rank coal samples are burned in a drop tube furnace at 1,175°C with probe temperatures of 550°C and 600°C, corresponding to the combustion chamber of 600 MW power plants, including superheater and reheater areas. The ash particles' characteristics and material composition were also analyzed using scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD), respectively. All coal mixture combinations demonstrated potential as a fuel for power plants that use pulverized coal-fired boilers. Because of its capacity to reduce slagging and fouling potentials, combining coal blending with the use of chemical additives yielded the greatest results. [ABSTRACT FROM AUTHOR]

• The effect of ash deposits on corrosion resistance in high Cr material must be investigated. • The corrosion investigation is carried out on a laboratory scale and depends on observations of ash effects with material degradation. • The majority molten phase of alkali and chlorine has degraded the oxide layer. A high chromium concentration in the boiler material is believed to increase corrosion resistance, especially at high temperatures. It is related to the formation of a protective layer on the surface of the metal, called a chromium oxide (Cr 2 O 3) layer. However, the impact of alkali and chlorine from co-combustion coal with biomass in power plants can harm this protective layer, reducing its effectiveness and potentially leading to increased corrosion. Therefore, it is important to evaluate the impact of these factors on the corrosion resistance of high-chromium materials. This research investigates coal co-combustion with empty fruit bunch (EFB) and plastic waste on the corrosion resistance of austenitic stainless-steel material on a laboratory scale using drop tube furnaces. The investigation steps included probe observation, SEM-EDS on ash and probe material, and XRD. The analysis indicates that the ash from the coal sample did not affect the probe, unlike the coal with EFB or EPL (mixture of EFB and plastic crackles), which caused up to 14% oxide layer degradation. The existence of alkali chloride, sulfate, and silicate in the ash that is still adhered to the surface of the probe can reduce the corrosion resistance of the metal. [ABSTRACT FROM AUTHOR]

Environmental concerns and the generation of municipal solid waste (MSW) continues to increase linearly to the population growth. The co-firing of solid recovered fuel (SRF) can substitute for fossil fuels and minimize waste disposal in landfills. However, SRF contains chlorine and alkali components that may cause issues related to ash deposition on boiler surfaces. This study aims to investigate the impact of additives during the co-firing of SRF and high-sulfur coal, specifically in mitigating the ash deposition propensities. The primary fuels used in this investigation are SRF and high-sulfur coal. Various additives, including aluminosilicate (Al–Si), aluminum (Al), and magnesium (Mg)-based compounds, are examined for their effectiveness in reducing ash deposits. The research employs a combination of theoretical calculations, experimental methods, and observation of ash melting behavior, for various scenarios of additive dosages (0.10 and 1.00 wt%). The findings revealed that using Al–Si and Al-based additives at a dosage of 0.10 wt% results in cleaner test probe surfaces and fewer melting spots than other additives. Consequently, incorporating Al–Si and Al-based additives at a dosage of 0.10 wt% exhibits promising potential for mitigating ash deposition issues during co-firing of a mixture comprising of 15 wt% SRF and 85 wt% high-sulfur coal. • Alkali, chlorine, and sulfur can cause ash deposition problems. • The impact of Al–Si, Al, and Mg-based additives during co-firing is evaluated. • Dosage of 0.10 and 1.00 wt% were used to evaluate the additives. • The research involves theoretical, experimental, and ash observation methods. • Al–Si and Al-based additives show promising result to reduce ash deposition problems. [ABSTRACT FROM AUTHOR]

This paper comprehensively assesses oil palm biomass and coal blends, focusing on evaluating thermodynamic and kinetics parameters. The experimental approach employs thermogravimetric differential thermal analysis (TG–DTA) with varying heating rates of 5, 10, 15, and 20 K min−1. Laboratory tests are conducted on six blended samples of different coal and oil palm biomass ratios. The evaluation encompasses key combustion parameters, including ignition index (Di), burnout index (Db), combustion performance index (S), reactivity (R), flammability index (C), and index of intensity (Hf). Additionally, thermodynamic parameters such as a change in enthalpy (ΔH), change in Gibbs free energy (ΔG), and change in entropy (ΔS) are analyzed. The results demonstrate that the optimal co-combustion material is a blend of 76% low-rank coal, 19% medium-rank coal, and 5% oil palm fronds, identified as L80M20F. This blend exhibits superior combustion performance, as evidenced by the highest values for Di (31.17 × 10–8% min−3), Db (28.91 × 10–11% min−3 K−1), and R (39.18 × 104 mg min−1). Furthermore, it displays the lowest ΔH of 73.11 kJ mol−1 and ΔS of − 0.0452844 J mol−1 K−1, along with the highest ΔG of 179.77 kJ mol−1. The accuracy of these findings is confirmed through verification with the Gram–Charlier peak function, which yields a negligible margin of error. In conclusion, this study provides crucial insights for decision-makers by assessing combustion and thermodynamic parameters of oil palm biomass and coal blends. The L80M20F, identified as the optimum blended fuel, showcases its potential to enhance combustion efficiency and contribute to the energy transition toward net-zero emissions. [ABSTRACT FROM AUTHOR]