神华煤直接液化工艺中硫元素的回收利用

神华煤直接液化原料煤中的硫元素和催化剂助剂中的硫元素在煤直接液化过程中大部分转化为H2S气体,并分散于中压气、干气、液化气和酸性水中。为满足产品质量和工艺技术指标要求,并回收循环利用硫元素,鄂尔多斯煤直接液化项目采用气体脱硫工艺回收中压气、干气、液化气中H2S气体,装置运行稳定,回收率分别为97.28%、99.92%和99.99%;采用污水汽提工艺分离收集酸性水中H2S气体,回收率达99.6%;脱硫回收和汽提收集到的含H2S酸性气混合后采用Claus硫磺回收工艺将H2S转化成硫磺,平均每年回收硫磺14 683.5 t,硫磺产品作为催化剂助剂供煤液化反应和加氢稳定反应注硫使用,从而实现硫元素循环利用,减少了环境污染。     

煤直接液化循环溶剂加氢体系中元素的转化与迁移

为深入解析煤直接液化循环溶剂的加氢反应并进行过程优化,分别以内蒙古褐煤液化粗油和内蒙古长焰煤液化粗油为原料,在固定床连续装置中进行加氢实验,对加氢全流程的物料平衡和元素平衡进行测算,开展了加氢产物及催化加氢性能的分析评价。通过研究碳、氢、氮、硫、氧五大元素在原料和各加氢产物中含量的变化,分析了各元素在加氢过程中的转化与迁移。结果表明:煤液化循环溶剂加氢反应的油产率接近100%(质量分数,下同),气产率仅为0.5%,原料中不足0.2%的碳元素进入有机气体中,80%~90%的氢耗用于芳烃部分加氢饱和反应,原料中约95%的硫元素进入H_2S中,褐煤液化粗油中12.69%的氮以及长焰煤液化粗油中27.49%的氮向氨气迁移,循环溶剂加氢体系中废水产率仅为0.5%,硫化氢和氨气不足1.5%,可与煤炭液化其他单元同类废弃物汇集处理。     

煤直接液化加氢工艺氢气系统优化研究

介绍了煤直接液化加氢工艺的氢气需求和为提高氢气利用率所采取的措施。该工艺采用两套煤气化制氢、一套天然气制氢和一套重整装置制氢为煤炭液化和液化油品加氢等提供所需的氢气。煤直接液化装置采用膜分离系统将循环氢中的氢气含量从86%提高到96%。同时,采用变压吸附装置(PSA)回收煤直接液化加氢工艺的富氢排放气中的氢气。因膜分离系统受原料制约,其使用效率随运行周期逐渐降低,致使氢气回收率下降、尾气中氢气含量逐渐升高,即降低了膜分离效率,又增加了后续PSA运行能耗;各工段塔顶气经过轻烃回收后所产干气含氢量在49～61%之间,氢气没有得到有效回收利用,直接进入燃料气管网用于燃烧加热,造成了氢气的浪费。因此膜分离系统进行优化配置、干气系统进行氢气回收,对提高煤直接液化加氢工艺的氢气利用率及整个工艺过程的节能降耗具有重要意义。     

沸腾床加氢工艺在煤直接液化项目中的应用及优化

简述了T-Star沸腾床加氢工艺的特点,并分析了其技术优势。介绍了T-Star沸腾床加氢工艺在神华煤直接液化项目中的应用,该工艺操作稳定,产品完全能够满足配套神华煤直接液化工艺的需要。详细介绍了T-Star工艺在催化剂优化、催化剂脱油系统改造和反应系统注水优化等方面情况。生产运行实践表明,T-Star工艺运用在神华煤直接液化项目中具有较好的经济效益和社会效益。     

神华煤直接液化示范工程废水处理工艺分析

神华煤直接液化示范工程中来自煤液化、加氢稳定、加氢改质和硫磺回收等装置排出的含硫、含酚等高浓度污水以及循环水场排出的含盐污水,由于废水排放量大、浓度高,国内外没有类似的处理经验可借鉴。根据污水排水的水质差异和废水回用的要求,增加了废水处理的难度。详细介绍了煤直接液化示范工程废水处理工艺流程与特点,并通过监测结果表明,煤直接液化产生的废水达到了循环冷却补充水的水质标准,充分体现了废水再生利用的原则。     

降低硫磺回收装置烟气SO_2排放的探讨

一般来说,导致硫磺回收装置中的二氧化硫排放的浓度较高主要原因是制硫系统反应效果差、加氢反应器反应不完全、胺液吸收效果差。因此,将对降低硫磺回收装置烟气二氧化硫排放问题进行分析。     

煤炭直接液化残渣加氢研究进展

在煤炭直接液化生产过程中,会产生占液化原煤质量30％左右的液化残渣。它是一种高碳、高灰和高硫的物质,主要由未转化的煤、液化中间产物、无机矿物质以及煤液化催化剂组成。煤炭直接液化残渣有很高的利用价值,无论从经济角度还是环保角度出发,都需要对残渣进行利用,这也是煤炭直接液化工业化必须解决的问题。综述了煤炭直接液化残渣的来源、组成、性质、加氢研究现状及应用等。     

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。     

神华煤直接液化项目工程示范性的思考

煤直接液化是煤炭转化的高技术产业,介绍了神华煤直接液化项目进展情况,阐述了神华煤直接液化工艺流程和技术特点以及项目采用的先进技术,结合项目对煤炭液化技术的产业化进行了分析,指出神华煤直接液化项目是煤炭液化产业化发展的典范。     

铁系催化剂催化淖毛湖煤加氢液化反应研究

煤直接液化的关键是催化剂体系的优化。文中采用小型加氢反应装置和多种仪器分析方法,研究了铁系催化剂催化淖毛湖煤直接加氢液化反应性能及过程杂原子分布特征。发现升华S作为助剂较SO_4~(2-)催化效果更好;FeOOH和S对沥青质有较好的催化转化作用。复合Fe/Ni催化活性较单Fe活性略低,对沥青质的转化效果较差。液化产物中正己烷可溶组分含有较多的正构烷烃,碳数可达到C_(28)。含氮杂环化合物中,主要含喹啉和异喹啉。含硫杂环化合物主要为噻吩类,苯并噻吩类和苯硫醚等。硫化物部分来自原煤并与添加的硫助剂有关。液化过程中氧元素和硫元素反应活性较高,氮元素反应活性较低,其在液化残渣中的含量几乎不变。     

Dependence of coal liquefaction behaviour on coal characteristics. 8. Aspects of the phenomenology of the liquefaction of some coal

Steps are now being taken to define in more detail the phenomenology of coal liquefaction and to provide a scientific basis for empirical correlations previously established between liquefaction conversion and basic compositional characteristics of coals. The rates of production of oils, asphaltenes and preaphaltenes have been determined at four temperatures for three coals, two of Carboniferous and one of Creaceousage. Products are formed more slowly from the younger coal (which is of slightly lower rank) than from the others, but oxygen, partly as OH but probably mostly in a type of ether, is lost more rapidly. It is estimated that the maximum content of O as cleavable ether is 7.7 atoms/100 C atoms for the younger coal (from Wyoming) and 4.1 and 5.1 for the other two (from Oklahoma and Ohio, respectively). Until ≈ 50% of the amount present in the Oklahoma coal is lost, the rates of removal of oxygen and organic sulphur are approximately equal; beyond this level, the removal of S is more rapid. The loss of organic sulphur from the Ohio coal is slightly faster. Even so, the data do not support the idea that cleavage of thioethers is more rapid than that of ethers and that this is the basic reason why a high organic sulphur content tends to promote liquefaction. Conversion of the pyrite in the Ohio coal to pyrrhotite occurs considerably more rapidly than the pyrite in the Oklahoma coal. In preliminary experiments, it is shown that a curve-resolving programme allows two aromatic and five aliphatic C-H stretching vibrations to be distinguished in FTIR spectra of the hexane-insoluble products, and the distribution changes with degree of conversion. In particular, there is evidence that new aryl methyl are generated during liquefaction, in agreement with evidence from oxidation studies.     

我国非炼焦煤在炼焦中的应用

介绍了我国无烟煤、贫煤、不黏煤和长焰煤等非炼焦煤的性质及在炼焦生产中的应用情况。利用非炼焦煤代替部分焦煤炼焦,成本优势十分明显,既可缓解焦煤资源不足的压力,还能优化我国煤炭资源的利用。     

煤化工技术研究概况

煤炭作为我国能源主体的格局将在很长一段时间内不会改变。随着我国出现越来越严重能源安全问题,煤化工已成为社会关注的热点,并因此得到快速发展。文章综述了煤化工技术研究进展,展望了现代煤化工新技术发展方向。     

国内煤化工的现状及发展

介绍了国内煤化工行业的现状,详细介绍了煤制油、煤制烯烃、煤制天然气、煤制乙二醇、煤制芳烃项日的技术、经济情况,指出通过开发下游产品,合理利用CO2来改善产品单一、节能减排压力大问题。     

神华动力用煤燃烧特性研究

整理了10年来神华矿区各矿点的煤质常规及非常规试验数据,并根据动力煤特性判别方法,对神华煤进行评价.同时,将前述基础特性与国内主要烟煤进行比较,以便更为确切的了解神华煤特点,为燃用神华煤的电厂及电力设计院等提供参考.     

开滦煤化工产业发展思路探讨

结合开滦集团煤化工产业发展现状,分析了开滦可用于煤炭气化的资源情况,通过建设方案比选探讨,提出以现有煤-焦-化产业为支撑,以小气化带动大气化,建设大型煤气化制烯烃项目,促进新型煤化工产业链尽快形成,实现开滦煤化工产业的持续快速发展。     

500万t／a煤炭洗选技术工艺探析

洁净煤技术是解决环境污染的重要途径,洗选煤技术是洁净煤技术的源头技术。煤炭的洗选方法很多,介绍了几种洗选加工工艺流程,选出合适的工艺流程处理煤,有助于保护环境．     

Some physical properties of Canadian coals and their effects on coal reactivity

The pore volume, surface area and compressibility of eleven Canadian coals, varying in rank from lignite to semianthracite, have been determined by mercury porosimetry, gas adsorption method and relations derived from helium and mercury densities. The total pore volume was measured in the diameter range of 0.2 nm–2.98 μm, which was subdivided into two groups, namely the micropore region (< 0.0036 μm) and the combined meso- and macropore region (0.0036–2.98 μm). It has been determined that the porosity of the eleven coals studied varies from 2 to 39%. It has been found that the total pore volume, micropore volume, surface area and the apparent compressibility of these coals decrease with increase in the carbon content, or the rank of the coals. The effect of the total pore volume, micropore volume and surface area on chemical reactivity of the coal is discussed separately. A good correlation was obtained between the carbon content and helium density of the coal after correction is made for the mineral content.     

Origin of the Mn2+ e.p.r. spectrum in Pittsburgh No. 8 bituminous coal

The e.p.r. and i.r. spectra of hand-picked samples of calcite from Pittsburgh No. 8 coal, show that it contains the Mn²⁺ paramagnetic ion and clay minerals as impurities. Furthermore, comparison of the e.p.r. spectra of hand-picked and natural calcite shows that the Mn²⁺ spectrum in this coal originates from calcite, which when diluted in KBr or coal produces a spectrum similar to that reported by other investigators. The results obtained when coal-derived calcite was treated with dilute H₂SO₄ and HCI rules out the possibility that the Mn²⁺ originates from the pyrite or clays present in the coal.