煤加氢液化残渣利用研究进展

综述了液化残渣的组分性质及加氢裂解中原料的交互影响;系统总结了当前国内外关于煤加氢液化残渣的利用研究进展,主要包括气化、热解、制备碳材料以及改性沥青等,并对应用过程中存在的问题进行了探讨。液化残渣的高效合理利用,不仅能减轻环保压力,还能提升煤液化工艺过程的经济效益。     

煤加氢液化残渣利用研究进展

介绍了两种典型的工业装置副产的煤加氢液化残渣性质;从气化、热解、改性沥青、二次加氢、制备炭材料等方面系统总结了当前国内外关于残渣利用的研究进展;从规模化、经济效益、环境保护、资源利用方面考虑,残渣气化制氢是最有效的利用途径,未来的研发重点应集中在萃取剂和脱灰技术研发上。     

煤液化残渣利用的研究进展

论述了国内外煤液化残渣的加氢及热解性能以及不同液化残渣不同反应条件其加氢动力学的研究现状,并介绍了煤液化残渣的加氢液化、气化、干馏(热解、焦化)以及燃烧等方面的研究进展及取得的成果,在总结国内外研究成果的基础上,提出了今后煤液化残渣的利用的研究方向。     

煤直接液化残渣的性质及利用现状

为了高效地利用煤直接液化残渣,从液化残渣的组成、结构特性、热解特性、溶解特性4个方面论述了液化残渣的物理化学性质的研究现状。研究发现:残渣在组成和结构特性上都保留了原煤的部分特性。在对直接液化残渣热解特性的研究中,论述了各种不同研究手段,例如热重分析仪、实验室移动床、小型焦炉、高压釜等对液化残渣的热解过程的研究进展及热解机理的解析现状。在对液化残渣的溶解性进行研究时,讨论了残渣溶解性研究的意义及其在各种溶剂中表现出的不同特征。最后论述了煤直接液化残渣的利用研究现状、分析了其潜在的高附加值利用方式、发展前景和存在的问题。     

神华煤液化残渣的加氢反应动力学

在微型反应管中,以神华煤液化残渣为原料,四氢萘为溶剂,在氢初压6 MPa、反应温度425～485℃、反应时间为0～30 min条件下,进行了煤液化残渣加氢实验,研究了煤液化残渣的加氢动力学特性。将氢化产物分为油气、沥青质和四氢呋喃不溶有机质,根据集总概念建立了煤液化残渣的加氢动力学模型,所建模型与实验值吻合程度高。在实验条件下,四氢呋喃不溶有机质向沥青质转化的活化能为147.41 kJ·mol^-1,沥青质向油气转化的活化能为34.81 kJ·mol^-1,沥青质缩合为四氢呋喃不溶有机质的活化能为173.48 kJ·mol^-1。     

煤液化残渣性质及应用研究进展

介绍了煤液化残渣产生背景、概念及性质,综述了国内外在煤液化残渣性质及其转化利用方面的研究现状、取得的成绩及面临的问题。在总结前人研究成果的基础上,指出了今后的研究方向,这对于中国的煤化工事业具有重要的指导意义。     

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。     

煤直接液化残渣资源化利用研究进展

煤直接液化残渣是直接液化工艺副产物,产量约占原煤质量的10%～30%。液化残渣组成成分复杂、环境危害大且处理成本高,同时其含有重质油和沥青烯等物质,有潜在的二次利用价值,因而资源化利用煤直接液化残渣,间接提高煤有机质原子利用率并降低工艺经济成本,成为当前煤直接液化工艺亟待解决的关键技术问题。综述了煤直接液化技术及液化残渣资源化利用的最新研究进展,深入探讨了不同影响液化残渣高效转化的关键因素,分析比较了不同液化残渣处理工艺技术的特点,以期为煤直接液化技术发展及液化残渣资源化利用提供指导。     

神华煤液化残渣的液化特性研究

液化残渣有着许多不同于未液化煤的特性,研究液化残渣的特性对整个煤炭液化工艺过程以及对液化厂的经济性和环境保护都具有极大的现实意义。通过高压釜液化神华煤液化残渣,从液化恒温反应时间、温度和氢初压对神华煤液化残渣的液化特性影响进行了研究,为煤液化残渣的液化机理研究奠定基础。     

煤液化残渣灰分的测定

煤炭液化过程中的残渣是煤液化的主要产物这一,残渣中的灰分是计算煤炭液化过程中转化率的重要参数。目前,国内外测定残渣中的灰都是先经过正己烷、甲苯和四氢呋喃的一系列萃取,萃取后的不溶物,经真空干燥后测定其灰含量。这种方法分析时间长,不利于及时指导煤炭液化工艺条件的设定。本文通过残渣进马弗炉灼烧之前经电炉加热和未经加热的灰含量数据进行了比较。建立了一种简单快速测定残渣中灰含量的方法。     

煤与废塑料共热解特性研究进展

煤与塑料共热解既能回收废塑料中的碳氢资源,又可以实现废塑料的资源无害化处理,是一种很有前景的废塑料资源化回收利用方式。本文概述了煤与塑料共热解的热解特性及其产物性质,分析了煤与塑料共热解的机理及共热解过程中氯的迁移规律,简要介绍了煤和塑料的不同混合方式及其对共热解特性的影响。文中指出煤与塑料共热解具有明显的增油减水效应,在煤热解过程中添加一定量的废塑料不仅可以改善焦油品质,同时对热解半焦的结构和反应性也有一定的影响,因此煤-塑料共热解是一种绿色高效资源化的废塑料处理方式,对于废塑料循环利用、解决白色污染问题及提高煤炭利用率具有重要意义。     

生物质与聚乳酸塑料共热解特性

生物质与塑料、煤等物料之间的共热解是环境友好、具有极大发展潜力的生物质热解升级处理方式。通过自制快速固定床热解反应器研究了玉米芯与聚乳酸的热解。结果表明,玉米芯与聚乳酸的共热解使热解油产率和热值增加,而水分含量降低。通过TGA/FTIR联用实时考察了玉米芯、聚乳酸及其二者混合条件下的热解气体析出特性,FTIR分析表明玉米芯与聚乳酸在共热解条件下存在明显的耦合作用。     

Thermogravimetric characteristics and kinetic of plastic and biomass blends co-pyrolysis

Co-pyrolytic behaviours of plastic/biomass mixtures were investigated using a thermogravimetric analyser under heating rate of 20 °C/min from room temperature to 650 °C. The biomass sample selected was Chinese pine wood sawdust, while high density polyethylene (HDPE), low density polyethylene (LDPE) and polypropylene were selected as plastic samples. Results obtained from this comprehensive investigation indicated that plastic was decomposed in the temperature range 438–521 °C, while the thermal degradation temperature of biomass is 292–480 °C. The difference of weight loss (ΔW) between experimental and theoretical ones, calculated as algebraic sums of those from each separated component, is about 6–12% at 530–650 °C. These experimental results indicate a significant synergistic effect during plastic and biomass co-pyrolysis at the high temperature region. In addition, a kinetic analysis was performed to fit thermogravimetric data, the global processes being considered as one to three consecutive first order reactions. A reasonable fit to the experimental data was obtained for all materials and their blends.     

Thermogravimetric characteristics and kinetic study of biomass co-pyrolysis with plastics

The pyrolysis of pure biomass, high density polyethylene (HDPE), polypropylene (PP) and polyethylene terephthalate (PET), plastic mixtures [HDPE+PP+PET (1: 1: 1)], and biomass/plastic mixture (9: 1, 3: 1, 1: 1, 1: 3 and 1: 9) were investigated by using a thermogravimetric analyzer under a heating rate at 10 °C/min from room temperature to 800 °C. Paper was selected as the biomass sample. Results obtained from this comprehensive investigation indicated that biomass was decomposed mainly in the temperature range of 290–420 °C, whereas thermal degradation temperature of plastic mixture is 390–550 °C. The percentage weight loss difference (W) between experimental and theoretical ones was calculated, which reached a significantly high value of (−)15 to (−)50% at around 450 °C in various blend materials. These thermogravimetric results indicate the presence of significant interaction and synergistic effect between biomass and plastic mixtures during their co-pyrolysis at the high temperature region. With increase in the amount of plastic mixture in blend material, the char production has diminished at final pyrolysis temperature range. Additionally, a kinetic analysis was performed to fit with TGA data, the entire pyrolysis processes being considered as one or two consecutive first order reactions.     

Synergy in devolatilization characteristics of lignite and hazelnut shell during co-pyrolysis

Coal/biomass blends were prepared in the lignite/biomass ratios of 98:2, 96:4, 94:6, 92:8, 90:10, and 80:20 using a Turkish lignite from Elbistan region and hazelnut shell. Co-pyrolysis characteristics were investigated in a thermogravimetric analyzer (TGA) from ambient to 1173 K with a linear heating rate of 20 K/min under dynamic nitrogen flow of 40 ml/min. Char products from pyrolysis were investigated using XRD and SEM techniques. Devolatilization yields from the blends were evaluated in a synergistic manner and found that the overall yields for all the blends exceeded the expected yields which calculated from the additive behavior. As regards to devolatilization characteristics in given temperature intervals, it was concluded that there was significant synergy between 400 and 600 K, whereas additive behavior took place beyond 600 K. No evidence of synergy was observed in the activation energies. It was also concluded that the addition of hazelnut shell into lignite contributed to the sulfur fixing potential of char in the form of CaS and CaSO₄.     

Effect of microwave radiation on processing characteristics of sulphide minerals in inert atmosphere

The influence of microwave radiation on sulphide minerals in inert atmosphere has been investigated with respect to their processing characteristics such as magnetic susceptibility and floatability. Pure sulphide mineral samples were prepared in different size fractions. Microflotation tests were performed and magnetic susceptibilities of samples were measured after treating with microwave energy in inert atmosphere at three power levels for six time intervals. Possible modifications on the mineral surfaces due to microwave energy and exposure time were evaluated by XRD and optical microscopy. The results showed that selective separation of sulphide minerals in terms of floatability and magnetic separation could be possible.     

生物质与烟煤程序升温共热解产物特性分析

研究了富含半纤维素的玉米芯(CB)和富含木质素的松木屑(SD)分别与烟煤(YL)程序升温共热解产物产率和组成变化规律,并对焦油族组成进行分析。结果表明:生物质与煤共热解造成热解产物组成和产率显著变化,且其变化程度与生物质的组成和结构有关。对于富含纤维素的玉米芯与烟煤共热解过程,玉米芯质量掺混质量比为75%时,共热解气体产率减小18.87%,其中CO2产率减少29.15%,而热解水产率增加16.77%。由于半焦和玉米芯中碱/碱土金属,尤其是K对焦油中重质组分裂解具有催化作用,共热解焦油中沥青质产率减小43.40%,而极性组分增加63.21%。与富含半纤维素类的玉米芯不同,富含木质素的松木屑与烟煤共热解造成气体和焦油产率增加,而半焦和热解水产率略有减小,气体中CO2和CO略有增加。松木屑中活性H的转移作用,造成共热解焦油中脂肪烃产率增加,极性组分产率减少。松木屑掺混质量比为50%时,脂肪烃增加89.30%,而极性组分减小17.40%。     

Investigations into the characteristics of oils produced from co-pyrolysis of biomass and tire

Co-pyrolysis of wood biomass and waste tire with such catalysts as SBA-15, MCM-41 and HZSM-5 was carried out in a fixed-bed reactor. The influences of the mixture composition on liquid yield and characteristics of the oil were investigated. The properties of the oil were determined by gel permeation chromatograph (GPC), elemental analyzer (EA), thermal analyzer (TA), densimeter, ubbelohde viscosimeter and compared with that of diesel oil 0#. The contents of the polycyclic aromatic hydrocarbons (PAHs) in the oils were also determined by gas chromatograph (GC). The result shows that co-pyrolysis is in favor of inhibiting the formation of polycyclic aromatic hydrocarbons (PAHs) produced from tire. There exist a hydrogen transfer and a synthetic effect during co-pyrolysis of the biomass and tire. They improve the quality of the oil. SBA-15 as a catalyst is more significant than MCM-41 or HZSM-5 for reducing the density and viscosity of the oil and it can effectively decompose some large molecular compounds into small ones.     

Effect of industrial microwave irradiation on the physicochemical properties and pyrolysis characteristics of lignite

The surface functional groups and pyrolysis characteristics of lignite irradiated by microwave were comparatively studied to evaluate the feasibility of using industrial 915 MHz for lignite drying. The drying kinetics, micro structure, chemical functional groups, re-adsorption properties, and pyrolysis characteristics of the dried coal were respectively analyzed. Results indicated that for typical Chinese lignite studied in this paper, 915 MHz microwave drying was 7.8 times faster than that of the hot air drying. After industrial microwave drying, the sample possessed much higher total specific surface area and specific pore volume than that of air dried sample. The oxygen functional groups and re-adsorption ratio of microwave irradiated coal decreased, showing weakened hydrophilicity. Moreover, during the pyrolysis of the coal dried by hot air and microwave, the yield of tar largely increased from 1.3% to 8.5% and the gas production increased correspondingly. The composition of the tar was also furtherly analyzed, results indicated that Miscellaneous hydrocarbons (HCs) were the main component of the tar, and microwave irradiation can reduce the fraction of polycyclic aromatic hydrocarbons (PAHs) from 26.4% to 22.7%.     

酸性氧化物和酸碱比对煤灰熔融行为的影响

为了研究酸性氧化物（SiO₂和Al₂O₃）的相对含量和酸碱比对煤灰熔融行为的影响,本文以准东煤灰化学组成为基础,利用分析纯试剂制备了28组合成灰样品,在马弗炉815℃灰化后利用灰熔融特性分析仪、扫描电子显微镜-能谱仪（SEM-EDS）和X射线衍射仪（XRD）对样品熔融特性、表观形貌和矿物组成进行表征。进而采用多元线性回归法建立了灰熔融温度预测模型,并对该模型的适用性进行了检验。结果表明：在相同酸碱比下,当SiO₂含量由9%上升至33.73%,而Al₂O₃含量由35.98%降至11.25%时,合成灰的变形温度（DT）、软化温度（ST）、半球温度（HT）和流动温度（FT）均呈单调下降趋势,这意味着SiO₂含量的增加可能促进了煤灰的熔融过程;在不同碱酸比下,合成灰的熔融温度随着酸碱比的增加呈先下降后升高的变化趋势,在酸碱比为1.25时合成灰的特征温度出现最小值,表明酸碱比对合成灰熔融温度的影响呈非线性关系。通过SEM-EDS和XRD表征发现,合成灰中CaO、Fe₂O₃、Ca₂MgSiO₇、Ca₂Fe₂O₅、SiO₂和Al₂O₃等耐熔矿物和CaSiO₃等助熔矿物的相对含量以及与钠相关的低温共熔反应是改变合成灰熔融温度的主要因素。本文所建立模型对文献中6组灰样4个特征温度的预测结果与其对应测量值之间最大残差绝对值均小于80℃,说明该模型在本文的合成灰化学组分范围内可用性较好,具有一定的应用价值。