Catalytic activity of iron compounds for coal liquefaction

The catalytic activity of pyrite and synthesized -FeOOH in coal liquefaction was investigated using batch autoclaves with the aim of developing an industrial iron catalyst. The results indicate that the presence of H₂S helps gaseous hydrogen transferring and prevents deactivation so that the catalyst promotes hydrocracking of coal and hydrogenation of the products. The activity converges with excess H₂S and sulfur addition equivalent to an S/Fe molar ratio of 2.0 being reasonable for the activation. The active site is located on the outer surface, with finely divided catalysts exhibiting high activity. Both pulverized pyrite and synthesized -FeOOH are sufficiently fine as to exhibit high activity in the process. Pulverized pyrite is an industrially feasible iron catalyst for coal liquefaction process, because it is inexpensive and does not require sulfur addition.     

煤液化残渣中硫的迁移和转化研究现状及展望

为了解煤液化残渣利用过程中,硫化物迁移和转化规律,介绍了煤液化残渣中硫的来源及分布,总结了煤液化残渣在加氢液化、气化制氢、热解、燃烧等过程中硫化物的迁移和转化过程及影响因素,并对煤液化残渣中硫的迁移和转化的研究前景进行展望。结果表明,无机硫逐渐向有机硫转化,H2S是转化过程中的重要介质;H_2S、CS_2、SO_2等气态硫化物是煤液化残渣利用过程中的主要气态副产物;部分硫化物转化为大分子有机硫进入二次产品,影响产品质量和使用效果。为了合理有效地利用煤液化残渣,需寻找残渣中无机硫转化为单质硫或大分子有机硫的新方法,循环利用气体硫化物,开发新型煤液化催化剂,减少单质硫助剂使用量。     

Properties and liquefaction activities of ferrous sulfate based catalyst impregnated on two Chinese bituminous coals

Activities of ferrous sulfate based catalysts impregnated on two Chinese coals were studied in coal liquefaction, and compared with an impregnated iron sulfide catalyst. Chemical forms and particle size distribution of the impregnated ferrous sulfate based catalysts were determined using EXAFS, XRD and SAXS techniques. The impregnated ferrous sulfate shows significant activity in the liquefaction of bituminous coals, but is less active than the impregnated iron sulfide catalyst. Addition of Na₂S or urea to the ferrous sulfate in the impregnation process increases the coal conversion to the level of the impregnated iron sulfide catalyst. Addition of Na₂S does not significantly promote the formation of iron sulfide on coal surface as usually believed. The iron impregnated on the coal surface existed mainly in the form of γ-FeOOH regardless of the forms of iron and the promoters. The most probable diameter of the impregnated ferrous sulfate based catalyst determined by SAXS is around 40-50 Å.     

Direct Coal Liquefaction Using Iron Carbonyl Powder Catalyst

Direct coal liquefaction involves catalyzed interactions between molecular hydrogen and coal‐oil slurries at elevated pressure and temperature, typically in the presence of an iron‐based catalyst. Iron carbonyl powder as an alternative first‐stage catalyst was investigated. A series of experimental tests under mild liquefaction conditions were carried out with a high‐pressure batch reactor in order to compare the performance of the iron carbonyl precursor to the traditional superfine iron oxide catalyst. The carbonyl iron powder performed very well in terms of total conversion of coal as well as yield of coal oil product. The iron carbonyl powder acts as an effective precursor for the in situ generation of active iron sulfide. The simple kinetic models for coal liquefaction in the literature were found to be qualitatively consistent with the yields of preasphaltenes, asphaltenes, and oils obtained from the experiments.     

尿素装置CO_2脱氢催化剂的再生及其工业应用实例

对尿素装置失活CO2脱氢催化剂的研究表明,无论是以煤、天然气还是以渣油为原料的尿素厂,硫都是导致脱氢催化剂失活的主要原因。结合工业应用实例,介绍硫中毒失活的TH-3脱氢催化剂经过再生处理后,可恢复到接近新鲜脱氢催化剂的活性,完全能够满足工业生产的要求,从而节省装置的运行费用。     

煤粉还原芒硝法制无水硫化钠工业化实践

工业硫化钠是重要的化工原料和还原剂。中国工业化大规模生产工业硫化钠主要采用煤粉还原芒硝 法,所得硫化钠产品纯度仅为60%,产品附加值低。在煤粉还原芒硝法生产低铁硫化钠基础上,将半成品硫化钠浓碱液蒸发、浓缩、结晶制得结晶硫化钠,结晶硫化钠再经干燥制得无水硫化钠,所得硫化钠产品纯度达到92%以上。制备无水硫化钠产品延伸了硫化钠产品的产业链。主要介绍了生产无水硫化钠小型工业化装置系统、工艺控制条件和产品质量。     

Improvement and characterization of an impregnated iron-based catalyst for direct coal liquefaction

An impregnation method to prepare an active iron-based catalyst for direct coal liquefaction was improved. With the same catalytic activity, the water usage in the improved method is only 1% of that used in the unmodified method. The improved method not only simplifies the impregnation procedure and reduces cost, but also generates small catalyst particle size on coal surface. Water in the coal promotes thermal liquefaction, but deactivates the impregnated catalyst (possibly due to the adsorption of H₂O molecular on the catalyst surface). Electron probe microanalysis (EPMA), X-ray diffraction (XRD) and extended X-ray absorption fine structure spectroscopy (EXAFS) analyses show that the catalyst precursors prepared by both methods are in nanometer size and highly dispersed on coal surface. The irons deposited on coal surface are not only in sulfide forms, but also coordinate with oxygen from moisture- and oxygen-containing groups of coal. The impregnated iron may be composed of FeOOH and FeS or in the forms of Fe–O–S or Fe–S–O. The iron transforms to crystalline pyrrhotite in coal liquefaction.     

铁系催化剂对煤高温快速液化的影响

以兖州煤为研究对象,采用微型反应釜研究了两种铁系催化剂对煤高温快速液化的影响.结果表明,担载Fe2S3的催化剂和高分散铁系催化剂对煤的热解行为影响较小;担载Fe2S3催化剂促进了氢气参与反应和煤液化产物向轻质化转化,在优秀和足量的供氢溶剂条件下,溶剂的供氢速度明显优于氢气转换的供氢速度,催化剂的作用不明显;对比添加高分散铁系催化剂并加助剂S和添加Fe2S3催化剂的煤高温快速液化,发现元素S的作用与S和主催化剂铁的结合形态有关.     

从低阶煤直接制取苯类产品的项目研究

基于市场对粗苯的需求,进行以低阶煤为原料直接制取粗苯的研究。我国低变质程度煤炭资源丰富,且储量巨大,选择性地对某些低阶煤在一定的溶剂、催化剂、温度、压力条件下加氢液化,可得到含芳香烃较高的油品,经过重整精馏可进一步得到苯、甲苯、二甲苯等产物。初步探讨了低阶煤加氢液化制粗苯的工艺过程和过程条件。     

煤直接液化工业化示范装置操作预案的试验研究

为探索和积累神华处理能力为6000t／d的煤直接液化示范装置的操作经验,在6t／d的工艺开发装置（PDU）上分别进行了模拟催化剂、助催化荆硫供应减少或中断等异常情况下的操作预案研究。研究结果表明当催化剂供应量减少一半或助催化剂硫供应中断时,对煤直接液化操作的影响可以通过采取适当提高煤浆预热炉负荷的措施加以克服;尽管催化剂供应全部中断时可以维持装置操作,但对煤液化产品质量有较严重影响。     

Hydroliquefaction of low-sulfur coals using iron carbonyl complexes—Sulfur as catalysts

Hydroliquefaction of low-sulfur Australian coals (Wandoan and Yallourn) was studied using iron carbonyl complexes as catalyst. The addition of Fe(CO)₅ (2.8 wt% Fe of coal) increased coal conversion from 48.6 to 85.2% for Wandoan coal, and from 36.7 to 69.7% for Yallourn coal in 1-methylnaphthalene at 425°C under an initial hydrogen pressure of 50 kg cm^?2. When molecular sulfur was added to iron carbonyls (Fe(CO)₅, Fe₂(CO)₉ and Fe₃(CO)₁₂), higher coal converions ( > 92%) and higher oil yields (>46%) were obtained, along with an increase in the amount of hydrogen transferred to coal from the gas phase (0.2 to 2.8%, d.a.f. coal basis). In the liquefaction studies using a hydrogen donor solvent, tetralin, Fe(CO)₅S catalyst increased the amount of hydrogen absorbed from the gaseous phase and decreased the amount of naphthalene dehydrogenated from tetralin. The direct hydrogen transfer reaction from molecular hydrogen to coal fragment radicals seems to be a major reaction pathway. Organic sulfur compounds, dimethyldisulfide and benzothiophene, and inorganic FeS₂ and NiS were found to be good sulfur sources to Fe(CO)₅. From X-ray diffraction analyses of liquefaction residues, it is concluded that Fe(CO)₅ was converted into pyrrhotite (Fe_1?xS) when sulfur was present, but into Fe₃O₄ in the absence of sulfur.     

Deactivation of catalysts for fossil coal and biomass conversion

Increasing interest in the use of resources of organic raw materials alternative to petroleum stimulates researchers to study the catalytic intensification of fossil coal and vegetable biomass conversion. The industrial use of the developed technologies is restricted by the problem of enhanced catalyst deactivation. The main reasons for catalyst deactivation in solid organic raw materials conversion are considered in the review. The possible ways of the successful solution of the problem of catalyst deactivation in the processes of coal and biomass liquefaction and gasification and wood delignification and hydrolysis are exemplified by the studies accomplished over the last decade. In the case of technologies using the synthetic catalysts, the methods of their regeneration developed for the catalytic processing of heavy petroleum residues can be applied. The catalyst regeneration is not demanded for the processes accomplished in a fluidized catalytic bed under the conditions of catalyst loss as a result of its attrition and in the case of the application of melted catalysts, cheap iron-containing catalysts, catalytically active slag materials, and natural minerals. The substitution of dissolved catalytic systems for solid catalysts allows for the diminishing of their deactivation in the processes of wood delignification and hydrolysis.     

Iron sulfate/sulfur-catalyzed liquefaction of Wandoan coal using syngas–water as a hydrogen source

Water-soluble iron sulfate/sulfur-catalyzed coal liquefaction using three kinds of hydrogen sources including syngas–water has been investigated. The liquefaction of Wandoan coal, an Australian subbituminous, with iron sulfate/sulfur as a catalyst precursor using syngas–water or carbon monoxide–water afforded higher coal conversions and oil yields than those using pressurized hydrogen gas. The pretreatment at relatively low temperature (200°C) was indispensable to achieve the high coal conversion. In the two-staged liquefaction (400°C, 60 min+425°C, 60 min), the use of syngas–water as a hydrogen source afforded higher coal conversion of 90.1% together with a high oil yield of 46.2% than those using pure hydrogen, and almost comparable to those using carbon monoxide–water, indicating the presence of synergistic effects of two hydrogen sources. At the early stage of the reaction, the contribution of carbon monoxide–water was predominant, whereas hydrogen gas significantly took effect at the latter stage. The XRD and XPS study revealed the formation of pyrrhotite, a possible active species, covered with a small amount of sulfate species.     

利用煤矸石生产优质G级油井水泥的试验研究

油井水泥属专用水泥，生产中原材料往往选择优质天然硅石，随着天然材料的日益紧缺，急需寻找一种成本低性能优的材料替代硅石生产优质油井水泥，本文通过利用工业废渣煤矸石替代硅石生产优质G级油井水泥开展了试验研究，最终确定了高饱和比高硅酸率配料方案，调整了一系列生产工艺和粉磨工艺，获得各大油田配伍性能良好的高质量低成本的油井水泥。     

浅谈埃塞俄比亚水泥厂原燃料的特点

埃塞俄比亚地质形成期较短,且具高原国家构造活动复杂的特质,埃塞俄比亚的水泥厂所使用的原料、燃料、混合材料等具有其特定的资源禀赋特征.其中,砂岩的成熟度较高,对于生料粉磨和烧成均具有一定的影响;黏土中铁质含量高,一般不需要加入铁质校正原料;混合材主要为天然物料-浮石、火山灰、凝灰岩、石灰石等;当地的燃料以褐煤为主,其热力...     

煤直接液化催化剂研究进展

我国煤炭储量丰富，煤液化制油技术是缓解我国一次能源结构中原油供应不足的措施。煤液化工艺的各种催化剂中,铁基催化剂以其高效、廉价及低污染而倍受青睐。非铁系催化剂有Sn和Zn水溶液、含碘的煤液化催化剂、碱金属氢氧化物或碳酸盐、Cr-Mo-Ⅷ族的加氢催化液化催化和硫转移剂等。概述了近年来煤液化技术在铁系催化剂研究、回收利用、制备工艺和预处理等方面的研究进展，综述了煤液化催化反应器研究状况。     

无烟煤水煤浆燃烧特性和气化特性研究

为了提高水煤浆成浆浓度,选取一种无烟煤作为研究对象,分别利用常规研磨工艺和分级研磨工艺进行制浆实验考察其成浆性能。结果表明：利用分级研磨工艺优化粒度后,水煤浆浓度能达到67.3%,成浆性良好。选取2种工艺制得的样品进行了燃烧特性实验,发现采用分级研磨工艺制得的样品的燃点和燃烬温度有一定程度的降低,燃烬指数增大,加入助燃剂后该特性更加明显,这是由于分级研磨工艺所制水煤浆中细颗粒含量增加,反应活性变好。重点考察了不同催化剂加入量对煤样气化反应活性的影响。随着催化剂加入量的增加,气化反应活性有不同程度提高,实验样品的催化剂的最佳加入量为0.2%。     

煤矸石盐酸浸溶出铝铁的动力学研究（英文）

The extraction of aluminum from coal mining waste (CMW) is an important industrial process. The two major problems in applications are low aluminum dissolution efficiency and high iron content in the raw material, which affect the quantity and quality of products. To improve the aluminum recovery process, the leaching kinet-ics of CMW with hydrochloric acid was studied. A shrinking core model was used to investigate aluminum and iron dissolution kinetics. Based on the kinetic characteristics, a process for recovering aluminum was proposed and tested experimental y. It is found that the aluminum leaching reaction is controlled by surface reaction at low temperatures (40–80 °C) and by diffusion process at higher temperatures (90–106 °C). The iron dissolution process is dominated by surface reaction at 40–100 °C. The results show that iron could be dissolved or separated by concentrated hydrochloric acid. Fine grinding wil improve aluminum dissolution significantly.     

硫铁矿烧渣富铁除硫研究

利用硫酸厂生产SO2后硫铁矿残渣,用水洗溶解可溶性物质、磁选、球磨法富集铁,化学浸泡去除铁精矿中的硫,浓碱法浮选法去除二氧化硅等。经磁选、浮选等方法处理后,烧渣的含铁质量分数由42.4%提高到63.58%;含硫量由1.37%下降到0.12%。产品可用作炼生铁三级品原料。     

糯东矿无烟煤分选工艺的选择

为提高无烟煤分选效果,分析了糯东矿煤质特性、粒度组成和可选性,确定原煤属低中灰~中灰、中高硫~高硫、低磷、特低抗破碎强度无烟煤,煤中硫以无机硫化铁硫形式为主;煤中细粒级含量较高,需加强细粒煤分选,粗煤泥可单独分选,产品易脱水;原煤可选性为中等可选。结合原煤性质,确定糯东选煤厂产品定位为:17煤分选中、小块煤用于化工用煤,末精煤用于高炉喷吹用煤;20煤分选中、小块煤用于化工用煤,混煤用于动力用煤。通过对比分析常用选煤方法及工艺的特点,确定糯东选煤厂无烟煤分选方案为:选前+100(80)mm检查性手选、-100(80)mm混合跳汰入选、粗煤泥干扰床分选机(TBS)分选、细煤泥浮选、尾煤浓缩压滤的联合工艺流程。