Coprocessing Of Coal Research Articles

Synergistic effects and its influencing factors during co-processing of coal and biomass in a wire-mesh reactor

The study investigated the synergistic effects of co-gasification between coal and biomass at various blending ratios, temperatures, and contact conditions using a wire-mesh reactor. This reactor ensured high heating rate and relatively separated particles at all times. The influence of biomass volatiles on the co-conversion process was isolated and analyzed to evaluate their contribution to the overall synergistic effects. Results showed that the addition of biomass volatiles significantly promoted the reaction performance of the blends, leading to more efficient synergy between the two types of particles. A new indicator, ηvol, was proposed to quantify the contribution of biomass volatiles, which revealed that, at a blending ratio of approximately 10 wt%, the promotion of volatiles from biomass became more significant than catalytic effects of AAEMs as temperature increased from 700 to 1000 °C. The contact conditions between the two types of particles also influenced the synergy of the blends, with greater synergy observed when contact conditions were improved. Furthermore, the study showed that synergy was more sensitive to the distance between the particles at higher temperature. The findings suggest that enhancing the synergistic effects through improved contact conditions in co-gasification of coal and biomass could significantly improve the gasification kinetics of higher rank coals.

Coliquefaction of coal-plastic mixtures by two-stage methods

The two-stage co-processing of coal with medium-density polyethylene (MDPE) was investigated using ammonium tetrathiomolybdate (ATTM) as a catalyst. The first-stage plastic pyrolysis carried out at 420 °C, 6.0 MPa hydrogen pressure and HZSM-5 as catalyst. The second-stage coal and MDPE co-liquefaction had been performed in a hydroprocessing unit at 430 °C and 6.0 MPa hydrogen pressure with ATTM catalyst. A competitive experiment was performed by the way of one stage co-liquefaction of coal with MDPE using ATTM as catalyst and tetraline as solvent. The aim of the experiments was to determine the effect of the use of the waste plastic pyrolysis product as solvent. The results indicate that the hydroprocessed liquids of both the one stage and the two-stage co-processing of coal with MDPE have about 70% of compounds with boiling point below 350 °C, and meet the sulphur and nitrogen specifications for refinery feedstocks.

Influence of co-processing of coal and oil shale on combustion characteristics, kinetics and ash fusion behaviour

Combustion characteristics and ash fusion behaviours of Qinghai coal (QH) and Fushun oil shale (FS) and their blends were investigated. It was found that ignition index and burnout index of the blends reached maximum for the blend with 10 wt% FS, while its comprehensive combustibility index remained nearly unchanged when compared with the coal sample. With the increase in heating rates, combustion performance of the samples improved significantly. The statistical analysis demonstrated that combustion temperature contributed significantly (about 73% of the impact ratio) to the thermogravimetric mass loss, followed by oil shale blending ratio and heating rate. In addition, there is noticeable deviation between the experimental and theoretical curves of the blends in the temperature range of 410–480 °C, which indicates the existence of synergistic interactions. Moreover, the lowest apparent activation energy, determined using two model-free integral methods, was found to be 64.1 kJ/mol for the blend with 10 wt% FS. In addition, slag formation and mineral transformation of different samples were determined using the thermochemical database package FactSage 6.3. For the blend with 10 wt% of FS, anorthite, hematite, diopside and quartz were found to be the main crystalline phases at high temperatures. It is shown that the addition of FS mitigated the slagging and fouling tendency of the QH coal combustion.

Pyrolytic topping of coal-algae composite under mild inert conditions

Co-processing of coal and biomass has been a focus of several research studies aimed at addressing the negative environmental attributes associated with thermal processing of coal alone, as well as improving the thermal behaviour of coal. Biomass materials are regarded as a clean, renewable source, so thermal co-processing of biomass with coal is considered an effective way to utilise coal in a sustainable manner. In this study, coal fines were blended with Scenedesmus microalgae slurry to form a coal-algae composite. Pyrolytic topping of coal-algae composite was performed at 450 ºC on a batch reactor. Parent fuels and resultant chars were analysed for their proximate properties using an Eltra thermostep TGA; a Vario EL cube Elementar was used to determine the elemental composition of the chars and oils. A simulated distillation (SimDis) method was used to determine the boiling point distribution of the produced oils. The objective of the study was to examine the effects of microalgae slurry on the pyrolytic behaviour of waste coal fines with respect to product yields, composition and quality. Results showed that the yields of volatile components from pyrolysis of coal-algae composite were high compared with those from pyrolysis of coal alone. A significant degree of deoxygenation, dehydrogenation and denitrification was observed in coal-algae char than coal char. SimDis results showed that the fossil bio-crude oil has different boiling point characteristics from coal tar. The study has shown that microalgae slurry has potential to influence the pyrolytic behaviour of waste coal under mild inert conditions.

Co-Liquefaction of Elbistan Lignite with Manure Biomass; Part 1. Effect of Catalyst Concentration

The hydrogenation of coal by molecular hydrogen has not been appreciable unless a catalyst has been used, especially at temperatures below 500 °C. Conversion under these conditions is essentially the result of the pyrolysis of coal, although hydrogen increases the yield of conversion due to the stabilization of radicals and other reactive species. Curtis and his co-workers has shown that highly effective and accessible catalyst are required to achieve high levels of oil production from the coprocessing of coal and heavy residua. In their work, powdered hydrotreating catalyst at high loadings an oil-soluble metal salts of organic acids as catalyst precursors achieved the highest levels of activity for coal conversion and oil production. Red mud which is iron-based catalysed has been used in several co-processing studies. It was used as an inexpensive sulphur sink for the H2S evolved to convert Fe into pyrrohotite during coal liquefaction. In this study, Elbistan Lignite (EL) processed with manure using red mud as a catalyst with the range of concentration from 3% to 12%. The main point of using red mud catalyst is to enhance oil products yield of coal liquefaction, which deals with its catalytic activity. On the other hand, red mud acts on EL liquefaction with manure as a catalyst and represents an environmental option to produce lower sulphur content oil products as well.

Identification of nitrogen-polyaromatic compounds in asphaltene from co-processing of coal and petroleum residue using chromatography with mass spectrometry

Asphaltene, from co-processing of coal and petroleum residues is one of the most precious and complex molecular mixtures existing, with tremendous economic relevance. Asphaltene was separated by Soxhlet extraction with methylbenzene and then divided into three parts by distillation. Gas chromatography (GC) and high-performance liquid chromatography (HPLC) were coupled with quadrupole time-of-flight mass spectrometry (Q-TOF MS) to separate and characterize organic nitrogen species in the distillates of asphaltene at molecular level. Molecular mass of compounds was mainly distributed from 150 to 600 μ. Number of rings plus double bonds (rdb) and synchronous fluorescence spectra indicated that most of the organonitrogen compounds (NPAC) contained heterocyclic aromatic rings, including pyridines, anilines, quinolins, pyrroles, carbazoles and indoles plus various alkyl groups. Constant-wavelength synchronous fluorescence spectrometry (CWSFS) indicated NPAC with 2–3 rings were the main structures of organonitrogen compounds and the corresponding structural information was proposed. Some organic nitrogen isomers were separated and identified by atmospheric pressure chemical ionization (APCI) GC-Q-TOF MS and electrospray ionization (ESI) HPLC-Q-TOF MS. The methodology applied here contained chromatographic injection of the diluted sample using conventional columns sets and Data Analysis 4.2 software. Identifying molecular structures provides a foundation to understand all aspects of coal-derived asphaltene, enabling a first-principles approach to optimize resource utilization.

1-14.石炭とプラスチックのコプロセッシング反応におけるPVCの影響((4)共処理・灰・プロセス,Session 1 石炭・重質油等)

1-14.石炭とプラスチックのコプロセッシング反応におけるPVCの影響((4)共処理・灰・プロセス,Session 1 石炭・重質油等)

16.合成パイライト触媒を用いる合成ガス-水を水素源とする石炭・重質油のコプロセッシング

16.合成パイライト触媒を用いる合成ガス-水を水素源とする石炭・重質油のコプロセッシング

5-6.石炭・石油セパレートコプロセッシング(Session(5)実用化を迎える石炭利用技術)

5-6.石炭・石油セパレートコプロセッシング(Session(5)実用化を迎える石炭利用技術)

A novel index for the study of synergistic effects during the co-processing of coal and biomass

In this study, synergistic interaction between coal and biomass and its intensity were investigated systematically using a low rank coal and its blends with different biomass samples at various blending ratios. The catalytic effects of minerals originated from biomass were also studied. It was found that some of the minerals existing in the ash derived from oat straw catalysed the combustions process and contributed to synergistic interactions. However, for the coal and rice husk blends, minimal improvements were recorded even when the biomass and coal blending ratio was as high as 30wt%. Biomass volatile also influenced the overall combustion performance of the blends and contributed to synergistic interactions between the two fuels in the blends. Based on these findings, a novel index was formulated to quantify the degree of synergistic interactions. This index was also validated using data extracted from literature and showed satisfactory correlation coefficients. It was found that at a blending ratio of 30wt% oat straw in the blend, the degree of synergistic interaction between coal and oat straw showed an additional SF value of 0.25 with non-catalytic and catalytic synergistic effect contributing 0.16 (64%) and 0.09 (36%) respectively. This index could be used in the selection of proper biomass and proper blending ratio for co-firing at coal-fired power stations aiming at improving the combustion performance of poor quality coals via enhancing synergistic interactions during co-processing.

Characteristics and interactions between coal and carbonaceous wastes during co-combustion

This work focuses on the combustion characteristics of an Australian coal, a suite of carbonaceous materials, and their blends. A drop in both ignition temperature and burnout temperature was observed when carbonaceous wastes were blended with coal at different proportions (10 wt% and 30 wt%). The ignition index values of coal/polystyrene and coal/oat straw blends increased by 78% and 52%, respectively when the blending ratio increased from 10 wt% to 30 wt%. Similarly, 2.6 times increase in combustion index was also observed in coal/oat straw blend due to a large increase of mass loss rate contributed by the devolatilisation of oat straw. The significant drop in both peak and burnout temperatures for all the blends studied in this research demonstrated that there were strong interactions during the co-processing of coal with carbonaceous materials, which could be quantified by the root mean square interaction index (RMSII). It was found that coal/oat straw and coal/polystyrene blends had the highest RMSII values, which indicated the presence of strong interactions between coal and oat straw/polystyrene in the blends during co-combustion.

Study of oils from co-processing of coal and petroleum catalytic cracking slurry

Study of oils from co-processing of coal and petroleum catalytic cracking slurry

Catalytic coprocessing of coal and petroleum residues with waste plastics to produce transportation fuels

Coprocessing reactions with waste plastics, petroleum residues and coal were performed to determine the individual and blended behavior of these materials using lower pressure and cheaper catalysts. The plastic used in this study was polypropylene. The thermodegradative behavior of polypropylene (PP) and PP/petroleum residues/coal blends were investigated in the presence of solid hydrocracking (HC) catalysts. A comparison among various catalysts has been performed on the basis of observed temperatures. The higher temperatures of initial weight loss of PP shifted to lower values by the addition of petroleum residues and coal. The catalysts were also tested in a fixed-bed micro reactor for the pyrolysis of polypropylene, petroleum residues and coal, alone and blended together in nitrogen and hydrogen atmosphere. High yields of liquid fuels in the boiling range 100–480°C and gases were obtained along with a small amount of heavy oils and insoluble material such as gums and coke. The results obtained on the coprocessing of polypropylene with coal and petroleum residues are very encouraging as this method appears to be quite feasible to convert plastic materials into liquefied coal products and to upgrade the petroleum residues and waste plastics.

Catalytic methods in coal processing to syn-gas, carboneous and liquid fuels contributing to sustainable development

Abstract The processes of brown coal autothermal carbonization and steam gasification in a fluidized bed of catalytically active materials, catalytic hydrogenation of brown coal and its mixtures with waste polyolefines and sapropelitic coal liquefaction have been studied. The application of fluidized bed of iron-containing materials, which are able to catalyse the volatives oxidation provides the autothermal conditions of coal carbonization without the formation of harmful polycyclic compounds and pyrolysis tars. Based on catalytic method of coal carbonization, the integrated process of fuel-gas and syn-gas synchronous production from brown coal was suggested. The circulation of hot char-product particles between carbonization and gasification reactors supplies by heat the steam-gasification process. Therefore it goes at the low oxygen consumption and produces more clean syn-gas as compared to conventional gasification processes. The various approaches were used in order to increase the yield and quality of liquids produced from brown coal. They including the application of inexpensive iron-ore catalysts, hydrogen-donor organic solvents, activation treatment of coal by ozone, co-processing of coal with polymer wastes. It was found that sapropelitic coal can be converted to liquids with the yield by 7 times higher as compared to brown coal.

Effect of the ozonization of brown coal from the Kansk-Achinsk Basin on its pyrolysis in a mixture with polyethylene

It was found that the treatment of brown coal from the Kansk-Achinsk Basin with an ozone-oxygen mixture at 25–100°C for 1–8 h was accompanied by the formation of oxygen-containing structural groups in the organic matter of coal; the thermal stability of these groups was comparatively low. The preliminary ozonization of coal resulted in an increase in the degree of conversion and the yield of liquid distillation products in the course of coprocessing of coal with polyethylene.

Thermogravimetric study of coal and petroleum coke for co-gasification

As a preliminary study of gasification of coal and petroleum coke mixtures, thermogravimetric analyses were performed at various temperatures (1,100, 1,200, 1,300, and 1,400 °C) and the isothermal kinetics were analyzed and compared. The activation energies of coal, petroleum coke and coal/petroleum coke mixture were calculated by using both a shrinking core model and a modified volumetric model. The results showed that the activation energies for the anthracite and petroleum coke used in this study were 9.56 and 11.92 kcal/mol and reaction times were 15.8 and 27.0 min. In the case of mixed fuel, however, the activation energy (6.97 kcal/mol) and reaction time (17.0 min) were lower than the average value of the individual fuels, confirming that a synergistic effect was observed in the coprocessing of coal and petroleum coke.

04/02212 Analysis of group composition in product from coprocessing of coal and petroleum residues by gas-liquid chromatography: Zhang, C. et al. Fenxi Shiyanshi, 2003, 22, (2), 24–26. (In Chinese)

04/02212 Analysis of group composition in product from coprocessing of coal and petroleum residues by gas-liquid chromatography: Zhang, C. et al. Fenxi Shiyanshi, 2003, 22, (2), 24–26. (In Chinese)

石炭とプラスチックのコプロセッシングに及ぼす気相および液相種の違いによる水素供与の影響

The effects of hydrogen donation on coprocessing of coal and three kinds of plastics such as high density polyethylene (HDPE), polypropylene (PP), and polystylene (PS) were investigated under the presence of hydrogen from gas or liquid phase. In the liquefaction reaction of coal alone or each plastic alone, hydro-gen from liquid phase (tetralin) gave a large influence on yield, as compared with hydrogen from gas phase. Contrary to coal, the gasification of plastics was inhibited by the presence of hydrogen from liquid phase.In the coprocessing using decalin solvent under hydrogen gas, the gas yield decreased greatly and the oil yield increased. However, in the coprocessing using tetralin solvent, little interaction was observed. It was suggested that the reactions between coal and plastic radicals were inhibited as a result of rapid stabi-lization of the produced radicals by hydrogen from tetralin.The effect of plastic type on coprocessing reaction under decalin solvent was investigated. All the plastics tested decreased the gas yield, which suggested plastic radicals were stabilized in coprocessing reaction. Furthermore, experimental results suggested that HDPE radical tend to be stabilized by the contact with other radicals, and that PP and PS radicals tend to be stabilized by hydrogen transfer from decomposi-tion products of coal.

Supercritical extraction of scrap tire with different solvents and the effect of tire oil on the supercritical extraction of coal

Scrap tires are a growing environmental problem because they are not biodegradable. In this investigation, supercritical extraction of scrap tire and co-processing of coal with tire oil were studied. In the first stage, tires were extracted at 400 °C with a number of different solvents. The effects of the hydrocarbon and polar solvents used under the supercritical extraction conditions on the conversion and oil product of tire were determined, and it was observed that all volatile organic material of the scrap tire was converted to the liquid or gas product. In the second stage, coal and supercritical extracted tire oil (SCETO) samples were extracted with different solvents using various tire oil/coal ratios. In general, the use of tire oil generated an improvement for coal conversion. Further, the oil yield was higher than those of coal alone runs. The SCETOs were characterized using spectroscopic (FTIR) and chromatographic analytical techniques (GC–MS). GC–MS, and FTIR results showed that the oils are mainly comprised of alkyl aromatic species. A significant amount of alkyl-substituted phenol compounds was also found to be present in the oils.

Measurement of coking value, ash content and softening points of hydrogenated coal fractions

Surface characterization techniques (scanning electron microscopy and X-ray photoelectron spectroscopy) were used to examine toluene-insoluble solids from coprocessing of coal and heavy oil in order to evaluate their physical separation potential. Washability studies, using float-sink tests, were also carried out to provide an empirical estimate of the ash separation attainable. On the basis of the results, agglomeration tests were performed in an attempt to optimize the beneficiation of the organic matter in the residue pitch. Ash rejection in these tests ranged from 30 to 40%. Analysis of the ash from the agglomerated and reject fractions suggested that most of the iron was retained in the agglomerates.