煤、油页岩和石油焦混烧特性及其动力学

为了充分利用劣质燃料油页岩和难以利用的高硫石油焦,以煤、劣质燃料油页岩及高硫燃料石油焦的混合燃料为研究对象,采用热重-差热的试验方法和差减微分法,对其混烧特性曲线和混烧特性机理进行分析,计算出试样各种燃烧特性参数及燃烧动力学参数。结果表明:煤、油页岩、石油焦的质量比为1∶6∶3的混烧试样S7的DTG曲线先后出现挥发分的析出着火燃烧峰和剩余固定碳的着火燃烧峰;煤、油页岩、石油焦的质量比为6∶3∶1的混烧试样S4的可燃特性指数及着火特性指数均大于油页岩及石油焦的值,而且混合试样的燃尽指数均大于煤及石油焦的值,同时,混合样品的综合燃烧特性指数均大于油页岩的值;试样S4的活化能最小,该混合试样的燃烧反应最容易进行。只要煤、油页岩及石油焦混合比例适当,其混合燃烧特性将优于油页岩及石油焦单独的燃烧特性。     

The upgrading of petroleum residuum and coal in catalytic coprocessing

The combined catalytic reactions using different types of petroleum residuum and coal were performed at 425°C and 60 minutes in the presence of hydrogen to upgrade both materials to high quality synthetic fuels. In order to improve this coprocessing technology, the effect of the chemical and physical properties of both materials on the coprocessing product yields was investigated through a parametric study. In all reaction combinations, substantial increase in maltene production and high coal conversions of over 84% were observed regardless of petroleum residuum type and coal rank. The petroleum residuum properties of specific gravity and conradson carbon residue had effects on asphaltene production and coal conversion. The results of quantitative analysis for the amount of coal upgraded during coprocessing lead to conclude thata large amount of coal converted to maltene fraction due to high catalytic activity and reactive hydrogen donor richness of coprocessing system. However, most of the heavier fractions were formed primarily from coal regardless of the type of residuum used.     

Fractionation of coal by use of high temperature solvent extraction technique and characterization of the fractions

The authors have recently presented a new coal fractionation method that can separate a bituminous coal into several fractions, just like petroleum distillation, without decomposing coal. In this paper this method was applied to two bituminous coals and a brown coal. Sequential solvent extraction at different temperatures lower than 350 °C successfully separated the two bituminous coals into several fractions having different molecular mass compounds. Since all the extracted fractions are almost free from mineral matter, and some fractions were found to be fusible like a synthesized pitch when heated, the possibility of producing high performance carbon materials from the coal fractions was investigated. On the other hand, fractions obtained from the brown coal by the sequential solvent extraction were very close in both chemical composition and molecular mass, although the sequential extraction could greatly suppress the decomposition of the brown coal below 350 °C. The difference in the extraction behavior between the bituminous coals and the brown coal were attributed to the difference in their chemical structure.     

高硫石油焦气化研究进展和技术经济分析

分析我国高硫石油焦的生产现状和利用过程中存在的问题,对影响石油焦气化反应活性的因素、石油焦的催化气化和石油焦与煤或生物质共气化等方面的研究以及石油焦气化的工业应用进展进行了总结;探讨高硫石油焦配煤气化的可行性,对高硫石油焦配煤气化和干煤粉气化方案分别进行了模拟计算及技术经济分析,并与工业上掺烧高硫石油焦气化的运行结果进行了比较,与干煤粉气化相比,高硫石油焦配煤气化的比氧耗、比煤耗降低,有效合成气产量增加,具有较好的经济性;采用高硫石油焦配煤气化制取合成气既可以解决高硫石油焦的利用问题,又能拓宽煤气化的原料范围,是一条高效、清洁利用高硫石油焦的新途径。     

Fractionation of brown coal by sequential high temperature solvent extraction

Separation of brown coal into fractions having rather uniform structure is believed to be one of the promising pretreatment methods for effective utilization of brown coal. The authors have recently presented a new coal fractionation method that can separate a bituminous coal into several fractions having different molecular weight compounds without decomposing the coal. The method extracts coal using a flowing stream of non-polar solvent such as tetralin or 1-methylnaphthalene by increasing the extraction temperature stepwise up to 350 °C. In this study the fractionation method was applied to fractionate a brown coal. Water was used as an extracting solvent in addition to tetralin and 1-methylnaphthalene by intending to utilize inherent water of brown coal as the extraction solvent. An Australian brown coal was successfully fractionated into six fractions by any solvents, but the properties of the fractions were significantly different depending on the extraction solvent. This is because tetralin, 1-methylnaphthalene, and water interacted significantly with the brown coal in different ways even at less than 350 °C. The difference in chemical structure and thermal properties of the fractions were examined in detail through ultimate analysis, ¹³C NMR, molecular weight distribution, and thermogravimetric and thermomechanical analyses.     

Characteristics of the ignition of organic coal–water fuels for boiler installations

The ignition processes of organic coal–water fuels (OCWFs) in the flow of a heated oxidant (temperature, 700–1000 K; velocity, 0.5–5 m/s) were studied. The experiments were carried out with the small single drops of OCWFs (radii, 0.2–0.5 mm), which correspond to the injection devices of typical boiler installations. The component base of the test composition fuels included B2 brown coal, typical waste coals (the filter cakes of G and D coals), spent motor and transformer oils, and petroleum residue. The influence of the component composition (the properties and concentrations of solid and liquid combustible components) on the characteristics of the initiation of the combustion of single OCWF drops was found. The dependences of the delay times of ignition and complete combustion on the temperature of an oxidant and on the drop sizes of OCWFs were determined. It was established that, at maximum oxidant temperatures (above 900 K) and minimum drop sizes (smaller than 300 μm), difference between the integral characteristics of ignition was sufficiently small (smaller than 10%) for the fuels prepared from components with substantially different properties.     

Some factors influencing the rheological properties of concentrated brown coal—oil suspensions on storage

Rheological properties of coal—oil suspensions are strongly dependent on the characteristics of coal and the medium of suspension. The variations in the rheological properties of brown coal—KC220 oil suspensions with storage time were strongly influenced by the moisture content in the coal, coal concentration, medium of suspension, and to a lesser degree, by the extent of mechanical agitation. The increase of both plastic viscosity and yield stress of the brown coal—KC220 oil suspension with storage time was due to an overall reduction of free oil in the suspension, particle aggregation, solvation and swelling. The increase of relative viscosity due to ageing in moist coal—KC220 oil suspensions could be an order of magnitude higher than a suspension of similar concentration, but containing only dry coal.     

淮南气煤直接液化特性的研究

笔者从淮南矿区具有方便的交通、适中的地理位置、充足的电力和丰富的水源以及宜人的气候等综合条件考虑,结合矿区丰富的气煤资源和良好的液化特性,并根据气煤的元素组成（碳、氢、氧）和发热量（Qgr,dmmf及Qnet,ar）比长焰煤和褐煤更接近于天然石油的事实,可以认为淮南气煤适于直接液化县综合经济效益将明显优于低煤化度的不粘、长焰煤和褐煤。     

以褐煤为原料制取甲醇合成气煤气化技术的选择

在了解褐煤煤质特性的情况下,对国内、外煤气化工艺进行分析比较,确定适合褐煤煤种的制取甲醇合成气大型煤气化工艺技术;     

Investigation of slag containing refractory materials for gasification processes

In gasification processes the reaction of carbon feedstocks with oxygen and water leads to production of synthetic gas. The development of a new gasification technique reduces the temperature at the liner wall in the range of 1300 °C. Thus, the currently used high chrome oxide based materials can be replaced by new chrome oxide free materials fulfilling economical as well as ecological aspects. In this contribution the performance of alumina castables with different brown coal ash-contents (slag containing refractory materials) and sintered in different atmospheres have been investigated according to their thermo-mechanical properties, phase formation as well as resistance against thermal shock and corrosion attack under gasification-similar conditions. The slag containing refractory material with 11 wt.% brown coal ash sintered in reducing atmosphere has shown the best results with regard to mechanical properties and corrosion resistance and will be a promising liner material for gasification processes up to 1400 °C.     

DIFFUSION-CONTROLLED ADSORPTIVE UPTAKE OF COAL AND PETROLEUM ASPHALTENES IN A NiMo/Al2O3 HYDROTREATING CATALYST

In this work, hindered diffusion of one coal and two petroleum asphaltenes was studied by adsorptive uptake in THF from a bath surrounding a NiMo/Al₂O₃ catalyst. A mathematical model for the adsorption-diffusion of asphaltenes was developed. The model parameters were obtained by simulating the experimental data with the model solution. Several asphaltene fractions were defined via SEC (Size Exclusion Chromatography), with the molecular weight of each fraction being determined by its elution characteristics. It was found that both the coal and petroleum asphaltenes have very broad molecular weight distributions; however, the molecular weights of the coal asphaltenes (50-2000) were much smaller than those of the petroleum asphaltenes (200-30000). The uptake rates for asphaltene fractions with different molecular weights varied, depending on their diffusion rates and adsorption constants. Simulation results showed that even though the properties of coal and petroleum asphaltenes were quite different, the values of model parameters for the fractions of the three asphaltenes had the same trend and could be estimated by same numerical expressions; with increasing molecular weight of the fraction, the adsorption constant monotonically increased, and the effective diffusivity decreased. The experimental uptake data for the three asphaltenes as a function of molecular weight were well represented by same mathematical model.     

Variation in Victorian brown coal characteristics and hydrogenation potential

A detailed study of the variation of properties and characteristics of Victorian brown coal both within seams and between fields has been carried out. Within a seam, the organic coal properties are lithotype dependent whilst the exchangeable inorganic elements, Na, Mg, Ca and Fe, show no relation to lithotype and, hence, are believed to be of post-depositional origin. Considerable variation in coal properties between different brown coal fields has been demonstrated by analyses of 219 samples from 10 coal fields. The coal properties which correlate best with hydrogenation reactivity are primarily associated with the hydrogen content of the coal. The mineral matter also influences the hydrogenation reactivity, as demonstrated by the occurrence of the value for ash level in multiple linear regression equations.     

油泥焦与褐煤共燃特性及动力学

采用热重分析法研究了不同升温速率下油泥焦、褐煤及其混合物燃烧特性,并利用Kissinger-Akahira-Sunose（KAS）、Flynn-Wall-Ozawa（FWO）和Friedma（FR）等方法计算其燃烧动力学参数。结果表明,油泥焦燃烧主要是固定碳燃烧过程,而褐煤燃烧是挥发分和少量固定碳连续燃烧的过程。褐煤比油泥焦具有更好的燃烧特性,平均活化能更低。油泥焦和褐煤共燃过程中存在明显的协同促进作用,当混合燃料中褐煤占比为75%时协同促进效应达到最强。通过比较KAS、FWO和FR的结果发现,FR法能够更好地体现反应变化的趋势,而KAS法和FWO法的结果具有较高的准确性。通过比较油泥焦和褐煤共燃动力学参数的理论计算值与实验计算值发现,利用热重分析预测混合燃料的燃烧性质具有较高的可靠性,对油泥焦与褐煤共燃技术的应用具有重要的指导作用。     

Combined cracking of brown coal and petroleum residue in the presence of initiating additives

The combined cracking of brown coal and petroleum residue was performed, and the composition of the products obtained was studied. The effects of initiating additives (fly ash ferrospheres from heat and power plants) and coal/residue ratios in the source material on the yields of distillate fractions in the course of cracking were examined.     

干煤粉气化炉原料煤掺配高硫石油焦气化适应性研究

针对目前高硫石油焦利用率低的问题,选取两种典型高硫石油焦（JL、US）分别与AQ006煤掺配,考查了掺配两种焦的可磨性、灰熔融特性、黏温特性、CO2反应性,并进行了气化模拟计算。结果表明：两种石油焦具有低灰、低挥发分、高硫、高发热量等特点,且两种焦在不同掺配比例下,配煤的可磨性指数均高于80,是优质的粉煤气化配煤原料。AQ006煤分别掺配两种焦的灰熔融温度均高于1500℃,添加石灰石可有效降低掺配质量分数25%JL焦和US焦（焦∶煤=1∶3）的配煤灰熔融温度至1 400℃以下,且在石灰石质量添加量为6%时,两种掺配焦的高温灰渣黏度在2～25Pa.s的温度区间都高于200℃,满足Shell气化炉操作要求。与单独JL焦、US焦相比,配煤的CO2反应性显著提高。模拟计算结果表明掺配石油焦加助熔剂方案与中国石化安庆分公司Shell气化炉现用配煤方案相比,有效气产量增大,比氧耗和比煤耗有所下降。     

Fuel briquettes from brown coals of Yakutia

Experimental data on the development of technology for the manufacture of briquetted fuel from brown coals with the use of various petroleum binders are presented. The influence of the moisture content, the coal particle-size composition, the binder type and concentration, the compacting pressure, and heat treatment regimes on the mechanical properties of the materials was studied. The optimal compositions and optimal values of the engineering parameters for the production of graded briquetted fuel from brown coals of the Kangalassy deposit in the Republic of Sakha (Yakutia) were established.     

Combined cracking of brown coal and petroleum residue in the presence of isopropanol

The combined cracking of mechanically treated brown coal, petroleum residue, and isopropanol was performed, and the composition of the products obtained was studied.     

石油焦与煤混烧特性及动力学

以石油焦与煤的混合燃料为研究对象,采用TG—DTG—DSC联用实验技术对混合试样进行了燃烧热重实验。分析了混烧特性曲线,计算了各个燃烧特性指数,并采用差减微分法Freeman—Carroll计算了燃烧反应动力学参数。结果表明：各混合试样均只出现一个位于高温区段的DTG曲线峰和方向向下的DSC曲线的热量释放峰,混合试样的燃烧过程主要是高温阶段焦炭的着火燃烧过程;混合试样s2,S3及S5热量释放相对较少且不集中,燃烧时间长且不完全;混合试样S4及S6的热量释放集中且时间短,燃烧释放的热量相对较多;烟煤含量最多的混合试样s6的着火特性、燃尽特性指数及综合燃烧特性参数均高于其它混合试样以及石油焦的各个相应值,且试样s6的可燃特性指数也大于石油焦的可燃特性指数;混合试样活化能均小于石油焦燃烧的活化能,混合试样比石油焦更易着火燃烧;只要石油焦与煤的混合比例适当,石油焦掺烧烟煤后的燃烧特性优于石油焦单独燃烧特性,此为解决石油焦难以单独燃烧利用提供了方法。     

Cracking of a mixture of mechanically treated brown coal and petroleum residue

The combined cracking of brown coal and petroleum residue was performed, and the composition of the products obtained was studied. It was found that the mechanical treatment of coal makes it possible to increase the yield of the liquid products of pyrolysis and to improve their quality.     

Preparation and properties of sorbents from the coals of Mongolia

The textural and sorption properties of sorbents prepared by the thermal steam activation of the semicokes of brown and black coals from nine deposits of Mongolia were studied. Their properties were compared with the properties of sorbents prepared from Borodino brown coal and Kuznetsk black coal. A common extremal dependence of the volume of mesopores and the specific surface area on combustion losses was found: a maximum specific surface area of 600–700 m²/g was reached at a combustion loss of 50–60%. Among the Mongolian samples, the sorbents obtained from the brown coals of the Baganuur, Bagankhai, and Shivee Ovoo deposits exhibited the highest surface areas and sorption capacities for iodine. Nearly linear dependence of sorption capacity on specific surface area was found. The sorbents prepared from Borodino brown coals under identical conditions were characterized by a higher degree of combustion losses because of the increased concentrations of catalytically active calcium compounds in them.