Char Reactivity Research Articles

Study of gasification reactivity of some Indonesian coals using thermogravimetry – mass spectrometry (TG-MS) approach

ABSTRACT Four coal samples from the Upper Kutai, South Sumatra, and Meulaboh basins were analyzed using chemical, petrographic, and thermogravimetric – mass spectrometry (TG-MS) methods to characterize their composition and thermal behavior during pyrolysis and gasification. Chemical and petrographic analyses revealed that the samples vary in rank, ranging from sub-bituminous C to high-volatile A bituminous coal (vitrinite reflectance, Rr, between 0.34% and 0.86%). Vitrinite is the predominant maceral, comprising 71.90% to 86.30% by volume. Thermal decomposition during both pyrolysis and gasification was found to be more strongly influenced by coal rank than by maceral composition. During pyrolysis, higher-rank coals exhibited lower thermal decomposition rates. CO₂ was the first gas released during thermal cracking, followed sequentially by CH4, H₂O, and H₂. The latter becoming the dominant gas in the later stages of pyrolysis. In CO₂-driven gasification, the sub-bituminous C coal exhibited a maximum char reactivity of 0.61 mg/min, compared to just 0.01 mg/min for the high-volatile A bituminous coal. Carbon monoxide (CO) was the primary syngas produced during the gasification process.

Insight into the structural properties and CO2 gasification reactivity of biomass and lignite co-pyrolysis char

Insight into the structural properties and CO2 gasification reactivity of biomass and lignite co-pyrolysis char

Exergy destruction analysis of coal gasification with O2-H2O combined with chemical kinetics

Exergy destruction analysis of coal gasification with O2-H2O combined with chemical kinetics

Assessment of Iron(III) chloride as a catalyst for the production of hydrogen from the supercritical water gasification of microalgae

Assessment of Iron(III) chloride as a catalyst for the production of hydrogen from the supercritical water gasification of microalgae

Investigation of the Products and the Migration of Sodium and Chlorine During Pyrolysis of High‐Sodium Coal Mixed With Phosphorite

ABSTRACTThe impact of adding phosphorite during the pyrolysis of high‐sodium Shaerhu coal to address severe deposition and corrosion issues caused by the release of volatile sodium and chlorine compounds was explored. During pyrolysis, sodium compounds volatilize and condense on cooler surfaces, leading to deposits that corrode metal and reduce boiler efficiency. By copyrolyzing phosphorite with coal, the study finds that tar yield decreases, whereas char yield increases, with slightly improved char reactivity. The pyrolysis gas yield also increases, with higher concentrations of methane and hydrogen, enhancing energy utilization. Calcium compounds in phosphorite react with sodium chloride and sodium sulfate, forming high‐melting‐point, insoluble sodium compounds and water‐soluble chlorides, thereby reducing the release of sodium and chlorine. This reduces fouling and corrosion, improving equipment efficiency. Additionally, recycling copyrolyzed phosphorite for yellow phosphorus production can enhance conversion ratios, supporting the production of higher‐value phosphorus chemicals.

Role of secondary char on the fuel properties and pyrolysis behaviors of hydrochars: Effect of temperature and liquid-solid ratio

Role of secondary char on the fuel properties and pyrolysis behaviors of hydrochars: Effect of temperature and liquid-solid ratio

Structure-Reactivity- and Modelling-Relationships during Thermal Annealing in Biomass Entrained-Flow Gasification: The Effect of Temperature and Residence Time

Biomass entrained-flow gasification enables the sustainable production of chemicals and liquid fuels. For reliable and accurate gasifier operation and design, the analysis of biomass char reactivity represents one of the key studies. Therefore, the annealing-induced char reactivity loss needs to be investigated for biogenic feedstocks from microscopic to reactor level. In the present work, the influence of pyrolysis temperature and particle residence time on solid digestate char reactivity and structure is studied. Several char types are prepared in a pressurized entrained-flow reactor between 1200 °C and 1600 °C with varying residence times between 0.4–2.4 s. Isothermal char reactivity in O2 and CO2 atmosphere is measured by TGA and reactivities are determined. Strong char deactivation between 1200 °C and 1400 °C resulted from severe heat treatment, especially toward the CO2 reaction. At 1600 °C, the influence of residence time becomes less relevant since all measured reactivities are comparably low. Experimental data are fitted to a coal deactivation model and verified for biogenic residues with very good agreement. The results are further corroborated by char structure analysis using FT-IR, XRD, Raman spectroscopy, SEM-EDX and ETV-ICP-OES. The decrease in char reactivity is mainly attributed to graphitization and the formation of aromatic ring structures. Char deactivation is further promoted by the loss of catalytic mineral matter and by high concentrations of inhibiting elements like phosphorus.

Catalytic gasification of a single coal char particle: An experimental and simulation study

Catalytic gasification of a single coal char particle: An experimental and simulation study

In-suit cemented strategy enables intumescent flame retardant transition from hyper-hydrophilic to hydrophobic and aggregation flame retardant effect simultaneously in polypropylene

In-suit cemented strategy enables intumescent flame retardant transition from hyper-hydrophilic to hydrophobic and aggregation flame retardant effect simultaneously in polypropylene

Structural analysis and gasification reactivity of chars derived from the slow pyrolysis of extruded coal fines and recycled plastic

Structural analysis and gasification reactivity of chars derived from the slow pyrolysis of extruded coal fines and recycled plastic

Elevating clean energy through sludge: A comprehensive study of hydrothermal carbonization and co-gasification technologies

Elevating clean energy through sludge: A comprehensive study of hydrothermal carbonization and co-gasification technologies

Structure characteristics and gasification reactivity of co-pyrolysis char from lignocellulosic biomass and waste plastics: Effect of polyethylene

Structure characteristics and gasification reactivity of co-pyrolysis char from lignocellulosic biomass and waste plastics: Effect of polyethylene

Fire-safe and multifunctional epoxy/layered double hydroxide composites via an interfacial catalysis

Fire-safe and multifunctional epoxy/layered double hydroxide composites via an interfacial catalysis

Char formation during pyrolysis of torrefied cellulose: Role of potassium catalysis and torrefaction pretreatment

Char formation during pyrolysis of torrefied cellulose: Role of potassium catalysis and torrefaction pretreatment

Progressive inhibition of [formula omitted] reaction in wood char packed bed by in-situ evolving [formula omitted]: Experimental insights and theoretical analysis

Progressive inhibition of [formula omitted] reaction in wood char packed bed by in-situ evolving [formula omitted]: Experimental insights and theoretical analysis

Mechanism and interaction of alkaline-earth metal migration induced ash transformation and carbon structure evolution for single coal particle high-temperature gasification

Mechanism and interaction of alkaline-earth metal migration induced ash transformation and carbon structure evolution for single coal particle high-temperature gasification

NO emission during the co-combustion of biomass and coal at high temperature: An experimental and numerical study

NO emission during the co-combustion of biomass and coal at high temperature: An experimental and numerical study

Carbon-based Flame Retardants for Polymers: A Bottom-up Review.

This state-of-the-art review is geared toward elucidating the molecular understanding of the carbon-based flame-retardant mechanisms for polymers via holistic characterization combining detailed analytical assessments and computational material science. The use of carbon-based flame retardants, which include graphite, graphene, carbon nanotubes (CNTs), carbon dots (CDs), and fullerenes, in their pure and functionalized forms are initially reviewed to evaluate their flame retardancy performance and to determine their elevation of the flammability resistance on various types of polymers. The early transition metal carbides such as MXenes, regarded as next-generation carbon-based flame retardants, are discussed with respect to their superior flame retardancy and multifunctional applications. At the core of this review is the utilization of cutting-edge molecular dynamics (MD) simulations which sets a precedence of an alternative bottom-up approach to fill the knowledge gap through insights into the thermal resisting process of the carbon-based flame retardants, such as the formation of carbonaceous char and intermediate chemical reactions offered by the unique carbon bonding arrangements and microscopic in-situ architectures. Combining MD simulations with detailed experimental assessments and characterization, a more targeted development as well as a systematic material synthesis framework can be realized for the future development of advanced flame-retardant polymers.

Experimental Study on the Improvement of Char Physicochemical Properties and Reactivity by Activation Process in CFB.

Solid carbon can be transformed into activated char with higher reactivity through the activation process in a circulating fluidized bed (CFB) to improve the Boudouard reaction. A new technology for reducing CO2, the activated-reduction technology, was proposed. In order to investigate the influence of relevant parameters (carbon dioxide addition, oxygen concentration, and O2/C) of the activation process on the physicochemical properties and reactivity of activated char, the experiments were carried out on a bench-scale CFB. The relationship between the parameters and the reactivity of activated char is explored. The result shows that compared with the raw coal, the pore structure of activated char is developed, the number of active sites increases, the degree of graphitization decreases, and higher reactivity is possessed. For the activation process, less of the O2/C and moderate oxygen concentration promote the increase in activated char reactivity, which is conducive to the reduction of CO2. The results of the correlation discussion show that the reactivity is difficult to be characterized by a single simple parameter. The reactive specific surface area (RSSA) obtained by multiplying the mesoporous specific surface area and I D3+D4/I all has a good effect on describing the reactivity.

Oxygen donation of alkali earth metal ferrites for biomass chemical looping gasification: A comparative study

Oxygen donation of alkali earth metal ferrites for biomass chemical looping gasification: A comparative study