The synergistic effect between macerals during pyrolysis

Sun, Qingle; Li, Wen; Li, Baoqing

doi:10.1016/s0016-2361(01)00205-8

Cited by 13 publications

(4 citation statements)

References 3 publications

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“…In the end, it must be emphasized that pulverized fuel coal particles do not necessarily exist as pure reflectance particles, and the vitrinite and inertinite are usually mixed together, which is referenced as microlith type. It has been found that synergistic effects exist between macerals during pyrolysis. This leads to the increasing formation of volatile matter than the pure maceral.…”

Section: Resultsmentioning

confidence: 99%

A Mechanistic Approach To Characterize Coal Heterogeneity in Predicting High-Temperature Volatile Matter Yields

Tang¹,

Gupta²,

Sheng³

et al. 2004

Energy Fuels

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The reflectance distribution of coal (the reflectogram), which shows the heterogeneity of coal, can be represented by several reflectance bins. In this paper, in considering the heterogeneity of coal, coal is regarded as a mixture of particles. Each particle is characterized by reflectance and is treated as being homogeneous, without considering the intraparticle heterogeneity. The chemical compositions (volatile matter (VM), carbon content (C%), ratio of hydrogen to carbon (H/C)) of a single particle have been estimated from previous works and are used to derive the 13C NMR parameters of this particle. These parameters are input into the chemical percolation devolatilization (CPD) model to predict the high-temperature VM yields of this particle. The total VM yields of the coal can be obtained by a summation of the results of all of the particles. In the experimental portion, the sink−float technique has been used to separate a series of coals into different maceral-rich fractions, which exhibit very different reflectance distributions. The high-temperature VM yields of these samples have been obtained from drop tube furnace pyrolysis experiments at 1400 °C to validate the model. The results from pyrolysis experiments and the single-particle modeling approach show that, under high temperature, the inertinite-rich fraction produces less VM than does the vitrinite-rich fraction of the same coal. The inertinite-rich fraction has a lower Q factor, which is defined as the ratio of high-temperature VM yields and proximate VM, than its vitrinite counterpart. The high-temperature VM yields also have been estimated from bulk properties of coal samples from the CPD model. These estimations do not agree with the experimental data. The model could not be applied to those coals that showed abnormal reflectance features.

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Section: Resultsmentioning

confidence: 99%

A Mechanistic Approach To Characterize Coal Heterogeneity in Predicting High-Temperature Volatile Matter Yields

Tang¹,

Gupta²,

Sheng³

et al. 2004

Energy Fuels

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“…The present work is to compare the performance indicators from simulated coals and the calculated values based on the weight of the macerals assuming additive properties apply. According to the previous studies [19,21,[42][43][44], the reasons for synergistic effect among macerals might be concluded as below. Liptinite holds the highest H/C followed by Vitrinite and Inertinite, when macerals are blended in gasifier, a large amount of hydrogen donors (H and OH radicals) produced from Liptinite involve in the decomposition of the remained macerals and suppress re-polymerization and crosslinking reactions of free radicals during gasification [43,44].…”

Section: Effect Of Oxygen To Coal (Otc) Mass Ratiomentioning

confidence: 99%

“…Liptinite holds the highest H/C followed by Vitrinite and Inertinite, when macerals are blended in gasifier, a large amount of hydrogen donors (H and OH radicals) produced from Liptinite involve in the decomposition of the remained macerals and suppress re-polymerization and crosslinking reactions of free radicals during gasification [43,44]. On the other hand, based on the works of [19,21,42], because Liptinite and Vitrinite occupy more hydrocarbon aliphatic and lower aliphatic, they are prone to produce more metaplast, which acts as the hydrogen donor solvent and stabilize more rupture fragments and free radicals produced by the Inertinite, resulting in enhancement of gasification performances.…”

Section: Effect Of Oxygen To Coal (Otc) Mass Ratiomentioning

confidence: 99%

“…The interaction between macerals during thermal processing is of significance for the basic understanding of the coal chemistry, developing new coal utilization technology and improving thermal efficiency. Sun et al [19] compared the volatile yield of the pyrolysis of parent coal and its macerals and concluded the existence of synergism among macerals. Chang et al [20] also studied the interaction during the pyrolysis of inertinite and vitrinite using FTIR, TG and fixed bed reactor and gave a thorough explanation of the interaction mechanisms at molecule levels.…”

Section: Introductionmentioning

confidence: 99%

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Comparative Study of the Gasification of Coal and Its Macerals and Prediction of the Synergistic Effects Under Typical Entrained-Bed Pulverized Coal Gasification Conditions

Jiang

Guo

Luo

et al. 2019

Journal of Energy Resources Technology

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This research is focused on the gasification performance of coal and its corresponding macerals as well as on the interactions among macerals under typical gasification conditions by Aspen Plus modeling. The synergistic coefficient was employed to show the degree of interactions, while the performance indicators including specific oxygen consumption (SOC), specific coal consumption (SCC), cold gas efficiency (CGE), and effective syngas (CO + H2) content were used to evaluate the gasification process. Sensitivity analyses showed that the parent coal and its macerals exhibited different gasification behaviors at the same operating conditions, such as the SOC and SCC decreased in the order of inertinite > vitrinite > liptinite, whereas CGE changed in the order of liptinite > vitrinite > inertinite. The synergistic coefficients of SOC and SCC for the simulated coals were in the range of 0.94–0.97, whereas the synergistic coefficient of CGE was 1.05–1.13. Moreover, it was found that synergistic coefficients of gasification indicators correlated well with maceral contents. In addition, the increase in temperature was found to promote the synergistic coefficients slightly, whilst at an oxygen to coal mass ratio of 0.8 and a steam to coal mass ratio of 0.8, the highest synergistic coefficient was obtained.

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