神华上湾煤恒温阶段直接液化反应动力学

为考察神华上湾煤的直接液化性能及反应动力学,以加氢蒽油-洗油混合油作为溶剂、负载型FeOOH作为催化剂,在0.01 t·d~(-1)煤直接液化连续实验装置上考察了不同反应温度(435~465℃)、不同停留时间(7~110 min)下液化产品组成的演变规律。研究发现,随着煤的裂解及加氢反应的进行,煤及沥青类物质(PAA)收率不断减小,重质液化产物逐步向轻质液化产物转化。当反应温度为455℃、停留时间为90 min时,煤转化率为90.41%(质量分数),油收率为61.28%(质量分数)。随着反应条件进一步苛刻,油收率下降。基于上湾煤直接液化反应特性及其产物收率变化规律建立了11集总煤直接液化反应动力学候选模型,以BFGS优化算法对实验数据搜索、选优,确定了动力学模型参数。检验结果表明所建立的动力学模型可用于恒温阶段直接液化行为的模拟计算。     

神华上湾煤恒温阶段直接液化反应动力学

为考察神华上湾煤的直接液化性能及反应动力学,以加氢蒽油-洗油混合油作为溶剂、负载型FeOOH作为催化剂,在0.01 t·d^-1煤直接液化连续实验装置上考察了不同反应温度（435~465℃）、不同停留时间（7~110 min）下液化产品组成的演变规律。研究发现,随着煤的裂解及加氢反应的进行,煤及沥青类物质（PAA）收率不断减小,重质液化产物逐步向轻质液化产物转化。当反应温度为455℃、停留时间为90 min时,煤转化率为90.41%（质量分数（,油收率为61.28%（质量分数（。随着反应条件进一步苛刻,油收率下降。基于上湾煤直接液化反应特性及其产物收率变化规律建立了11集总煤直接液化反应动力学候选模型,以BFGS优化算法对实验数据搜索、选优,确定了动力学模型参数。检验结果表明所建立的动力学模型可用于恒温阶段直接液化行为的模拟计算。     

基于十集总反应动力学的重油下行床碱性催化裂解CFD模拟

重油下行床碱性催化裂解工艺能够有效抑制催化剂结焦,从而达到较高的重油转化率,获得高收率的轻质油品和低碳烯烃,实现劣质重油的分级高值化转化。为了给该新型工艺的设计优化以及工业放大提供参考,本文建立了能够预测各低碳烯烃产率的十集总重油碱性催化裂解反应动力学模型,基于四阶Runge-Kutta法和BFGS最优化算法求解,获得了各反应路径的指前因子及活化能,并与实验数据进行对比,以验证所建立的动力学模型的准确性。基于耦合十集总反应动力学模型和双流体模型,对200万t·a^-1下行床反应器内的碱性催化裂解过程进行流体力学数值模拟计算,考察了剂油比、反应温度、反应时间、回炼比等操作因素对产物分布的影响规律。     

内蒙古褐煤加氢液化反应动力学的探索与研究

根据内蒙古褐煤加氢液化反应规律,按照集总的划分规则,提出了反应动力学模型。以一氧化碳为加氢液化气氛、水为液化溶剂,在高压反应釜中考察了不同反应温度下内蒙古褐煤的液化性能,通过灰平衡法计算得到液化产物中的沥青质产率、油气产率、总转化率。依据动力学方程,采用非线性最小二乘法对数据进行优化拟合,得到反应过程动力学参数,从而进一步得到反应的阿伦尼乌斯表观活化能。研究结果表明:在330~370℃,所建立的液化动力学模型能较好地模拟褐煤液化动力学过程;内蒙古褐煤的液化主反应为煤中易反应组分向前沥青烯、沥青烯和油气的转化,其反应速率常数为0.002 4~0.156 7 min-1,表观活化能为64.790~218.071 k J/mol。     

重油催化裂解集总动力学模型研究

建立了重油催化裂解七集总动力学模型,给出了模型的反应网络和数学表达式.利用小型固定流化床实验装置对大庆常压渣油进行了催化裂解实验,获得求取动力学参数的实验数据.提出了一个新的基于原料性质和操作条件的裂解催化剂失活模型.结合实验数据,编程求取了集总模型的动力学参数,催化裂解的反应活化能基本上都大于100kJ/mol,介于催化裂化活化能和热裂化活化能之间.根据所建立的集总动力学模型,预测了原料转化率、裂解产品产率和分布随操作条件的变化趋势,发现重油催化裂解宜采用高温、短油气停留时间的操作方式.     

水催化合成乙醇胺反应动力学

对环氧乙烷和氨反应生成一乙醇胺(MEA)、二乙醇胺(DEA)和三乙醇胺(TEA)反应进行了研究,拟合实验数据,建立乙醇胺反应动力学模型,并采用模型预测氨的质量分数对反应停留时间和产物分布,以及氨与环氧乙烷物质的量之比对产物分布的影响。结果表明,一乙醇胺的反应活化能为61.52kJ/mol,指前因子与水浓度成二次函数关系,生成一乙醇胺、二乙醇胺和三乙醇胺反应的活化能相近。通过非线性最小二乘法回归得出二乙醇胺、三乙醇胺与一乙醇胺反应速率常数的比值,与水浓度成线性关系,且随水浓度的升高而降低。采用4阶龙格库塔法对得到的反应动力学方程进行积分,计算值与实验数据和工厂生产数据吻合较好。环氧乙烷完全反应所需反应管管长随氨的质量分数的增加先减小后增大;MEA比例随氨烷比的增加而提高,DEA比例随氨烷比的提高先提高后下降,TEA比例随氨烷比的提高而下降; MEA和DEA随氨的质量分数升高而降低,TEA比例随氨的质量分数的降低而增加。     

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。     

新鲜SAPO-34催化剂上甲醇制烯烃反应动力学

在固定床反应器内进行了甲醇制烯烃反应动力学研究,借助集总动力学的概念,充分考虑到水和积炭对反应过程的影响,建立了5集总反应动力学模型,并进行了求解,最终获得了新鲜催化剂上可计算各集总组分反应速率的动力学方程.模型计算值与实验值吻合较好,表明模型预测效果很好.     

重油与乳化重油催化裂化反应比较

分别考察了反应温度和空速对重油与乳化重油催化裂化(FCC)反应性能的影响,并建立了反应4集总动力学模型。结果表明:当催化剂用量为100 g和剂油比3.3:1时,重油FCC反应的合适条件为450℃,空速0.25 s~(-1),乳化重油FCC反应的合适条件为440℃,空速0.27 s~(-1);重油和乳化重油FCC反应得到的液体产物性质相似,但由于乳化重油能改善原料的雾化和汽化效果,与重油相比,乳化重油的液体产物收率提高3.31%,生焦量降低3.91%。结合4集总动力学模型给出了合适的反应网络和数学描述,通过非线性最小二乘法,用MATLAB软件对模型求解,得到的模型计算值与实验值吻合良好,表明该动力学模型具有可靠性。     

松节油催化异构-分子间氢转移反应集总动力学

以H2SO4-Pd/C为复合催化剂、N2为保护气研究了松节油直接异构-分子间氢转移反应的集总动力学。在消除内、外扩散影响的条件下,在线跟踪反应产物并用气相色谱法测定反应体系组成随时间的变化关系,借鉴集总思想和方法,建立了单萜烯、对孟烯结构的单环单萜烯、异构单萜烯、对伞花烃和氢化单萜烷复杂反应体系的集总动力学模型;采用Levenberg-Marquart法,以Matlab编程和SPSS软件对实验数据进行回归估算了模型参数,得到该复杂反应体系的活化能分别为77.86,80.18,71.33 kJ/mol,所建动力学模型与实验数据吻合良好。     

煤直接液化低分油加氢脱硫脱氮反应动力学研究

为了进一步了解煤直接液化油中硫氮化合物的形态和性质,采用石油研究中的先进分析手段GC-PFPD和GC-NCD,对煤直接液化低分油进行了分析,获得了详细的硫氮化合物组成含量。结果发现:煤直接液化低分油中含有大量的杂环化合物,S主要以苯并噻吩类和二苯并噻吩类化合物存在,N主要以五元环化合物形式存在。在高压釜中进行了催化剂添加量和不同温度条件下的加氢实验,对总硫总氮的加氢反应动力学进行了研究。通过计算得到了高压釜煤液化油加氢脱硫反应的一级反应动力学模型,且通过模型计算的S含量与反应实测的S含量相对误差仅为7.8%;对实验得到的震荡式高压釜中煤液化油加氢脱氮反应的一级反应动力学模型进行验证,发现相对误差也仅为0.97%。     

Kinetics of thermal liquefaction of coal

A model is presented for the kinetic study of the thermal liquefaction of Belle Ayr subbituminous and Burning Star bituminous coals with anthracene oil, hydrogenated anthracene oil and hydrogenated phenanthrene. All experiments were performed in a continuous-feed, stirred tank reactor, at a temperature of 450 °C and a space time of approximately 5 to 55 min. A kinetic model which includes a reaction: coal + oil→more reactive coal, correlates the data reasonably well. This reaction explains the net consumption of anthracene oil during the initial stages of liquefaction. Such a reaction may account for a portion of the swelling of coal at low space times and the sizable increase of viscosity of reaction slurry during these initial stages of liquefaction. It is also observed that the yield of oil increases when solvents of increasing hydrogen donor capacity are used.     

Liquefactions of peat in supercritical water with a novel iron catalyst

Raw iron ore has been investigated for use as a catalyst in direct liquefaction of peat into bio-crude by supercritical water treatment. The liquefaction treatments were conducted at temperatures from 350 °C to 500 °C for a residence time from 10 min to 4 h. The supercritical water treatment of peat with the iron ore generally resulted in 19-40 wt% yield of heavy oil (HO) that has a higher heating value (HHV) of 30-37 MJ/kg. An increase in the operating temperature generally increased gas yield and decreased oil and char yields, while a maximum HO formation was observed at around 400 °C. At 400 °C for a residence time of 2 h, the addition of the raw iron ore in the operation produced HO at a very high yield of about 40 wt%, nearly doubling that of the treatment without catalyst. An increase of water-to-peat ratio led to enhanced formation of HO products, accompanied by a decrease in gas or char yield. The optimal reaction time appeared to be 2 h for the maximum HO production, and a longer residence time than 2 h generally led to a decrease in HO yield but an increase in gas yield. Compared with the raw iron ore, its H₂-reduced form and two synthesized iron-based catalysts (FeOOH and Fe₂O₃) all showed a lower activity for HO production. Some conventional biomass liquefaction catalysts (i.e., KOH, FeCl₃ and FeSO₄) showed negligible or even negative effects on the HO yield, while these catalysts were found very active for promoting the gas yields and hydrogen formation.     

Co‐processing of Waste Cooking Oil and Light Cycle Oil with NiW/(Pseudoboehmite + SBA‐15) Catalyst

Light cycle oil (LCO) and waste sunflower cooking oil (WSO) were co‐processed with the aim of obtaining more environmentally friendly fuels. Partial hydrogenation of naphthalene was also investigated as a model reaction. Commercial NiW/SiO₂‐Al₂O₃, as a reference catalyst, and NiW/(pseudoboehmite + SBA‐15), as a new research catalyst, were tested. Liquid products were analyzed by simulated distillation, elemental analysis, and FTIR spectroscopy. Elemental analysis indicated higher efficiency of the research catalyst in hydrodesulfurization, hydrodenitrogenation, and hydrodeoxygenation of pure LCO and mixed feedstock containing WSO. Reactions with pure WSO resulted in less sulfur leaching into the product and a lower degree of deoxygenation compared with the commercial catalyst.     

Liquefaction of coal by SRC-II process: Part III: Reactivity of liquefaction products

Data from experimental studies of the reactivities of SRC-II liquefaction products, in the absence of coal, are analyzed. A general quantitative validation of the new kinetic model for SRC-II coal liquefaction (Singh et al., 1981 a) is obtained by very good agreement between model predicted and measured yields. This shows that the new kinetic model provides a reasonable representation of the overall intrinsic process of SRC-II coal liquefaction and hence, it can be used to explore the regions of process conditions far away from those obtained under normal SRC-II operations.     

反应条件对玉米秸秆水热液化产物分布及特性的影响

利用间歇式生物质水热液化反应釜,通过正交试验设计考察不同反应条件对玉米秸秆水热液化(HTL)的影响,过程参数包括反应温度(250～350℃),反应时间(0～60 min)和含固量(5％～15％).从元素组成、官能团分布、主要化学成分以及结构形貌等对玉米秸秆水热液化产物的特性进行了分析.研究结果表明:玉米秸秆水热液化的较...     

煤间接液化合成油技术研究现状及展望

发展煤炭间接液化技术是缓解我国油品短缺和促进煤炭清洁利用的有效途径。笔者综述了早期经典的费托合成机理如碳化物机理、CO插入机理、中间体缩聚机理,以及近期提出的C2活性物种机理、稀烃再吸附的碳化物理论、网络反应机理等,并指出各机理的合理性和局限性;论述了费托合成反应动力学模型如CO消耗速率动力学模型和详细动力学模型的特点和研究进展。CO消耗动力学模型不考虑碳链增长过程,可很好地预测CO转化率。详细动力学模型含有反应物消耗速率和产物分布信息,其可靠性依据费托合成反应机理。综述了工业上常用的铁基催化剂和钴基催化剂的特点以及在相变、催化机理等方面的研究进展,讨论了新型费托合成催化剂如复合型催化剂、多元金属催化剂和新型载体催化剂的研发进展;介绍了国内外煤间接液化工艺的发展历程,分析了工业化应用中存在的问题和改进方向,重点论述了我国山西煤化所和兖矿集团开发的煤间接液化工艺的特点和工艺流程。最后对未来费托合成反应机理、反应动力学、催化剂及煤间接液化工艺的研究重点和发展方向进行了展望。     

Kinetics of coal liquefaction during heating-up and isothermal stages

Direct liquefaction of Shenhua bituminous coal was carried out in a 500 ml autoclave with iron catalyst and coal liquefaction cycle-oil as solvent at initial hydrogen of 8.0 MPa, residence time of 0–90 min. To investigate the liquefaction kinetics, a model for heating-up and isothermal stages was developed to estimate the rate constants of both stages. In the model, the coal was divided into three parts, easy reactive part, hard reactive part and unreactive part, and four kinetic constants were used to describe the reaction mechanism. The results showed that the model is valid for both heating-up and isothermal stages of liquefaction perfectly. The rate-controlled process for coal liquefaction is the reaction of preasphaltene plus asphaltene (PAA) to oil plus gas (O + G). The upper-limiting conversion of isothermal stage was estimated by the kinetic calculation.     

煤直接液化制油技术研究现状及展望

煤直接液化制油技术是促进煤炭清洁高效利用、缓解石油供需矛盾、保障我国能源安全的重要途径。为全面了解煤液化反应机理、动力学、催化剂及工艺的全过程,促进煤直接液化技术基础研究的快速进步和新工艺的开发,笔者综述了国内外在煤加氢液化反应机理、反应动力学、催化剂以及液化工艺方面取得的研究成果,重点介绍了德国IGOR、日本NEDOL和我国的神华煤液化工艺,分析了这些典型煤液化工艺的开发历程和特点;指明了煤直接液化制油技术发展趋势。煤的加氢液化反应是自由基反应机理,是一系列顺序反应和平行反应的综合结果,包含煤的热解、自由基加氢、脱杂原子和缩合反应等,总体上以顺序反应为主。借助同位素示踪、原位实时检测、等离子体技术以及微波快速加热技术等现代分析方法和试验手段,重点研究自由基的产生速率、活性氢产生速率及定量传递机理,有助于深入认识和精准阐明煤加氢液化反应机理。各国学者利用不同的研究方法,针对不同煤种、催化剂、工艺条件和供氢溶剂等,建立了各种各样的动力学模型。动力学模型从单组分到双组分和多组分,从连续反应、平行反应到复杂的网络反应,从最初的一步反应到后来较为合理的多段反应,模型越来越复杂,越来越接近工业应用。根据反应阶段不同进行分段处理的多组分"集总"反应动力学模型将是今后煤加氢液化反应动力学发展的主要方向。借助先进分析手段及科学的处理方法,建立真正揭示不同条件下煤液化动力学规律的通用型动力学模型是未来的发展趋势。借助纳米合成、等离子体等高新技术,调控组分配伍、降低催化剂粒径、优化制备方法是制备高活性催化剂的有效手段。强化系统合理配置和优化集成,重视煤的温和液化和分级转化,优化产品结构,发展直接液化-间接液化耦合技术是煤直接液化未来的发展趋势。     

Assessing the kinetic model of hydro-distillation and chemical composition of Aquilaria malaccensis leaves essential oil

This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identify the chemical compositions of the A. malaccensis leave-oil. By assessing both first-order kinetic model and the model of simultaneous washing and diffusion, the result indicated that the model of simultaneous washing and diffusion better describes the hydro-distillation mechanism of the essential oil from A. malaccensis leaves.The optimum time, solid to liquid ratio, and the heating power for extracting the highest amount of essential oil were found to be around 3 h, 1:10(g·ml-1), and 300 W respectively. Yellow essential oil with a strong smell and a yield of 0.05 v/w was extracted by hydro-distillation Clevenger apparatus. Chemical compounds of the essential oil were analyzed using gas chromatography–mass spectroscopy(GC/MS), which resulted in identification of 42 compounds that constitute 93% of essential oil. Among the identified components,Pentadecanal(32.082%), 9-Octadecenal,(Z)(15.894%), and Tetradecanal(6.927%) were the major compounds.Considering the fact that all the identified major components possess pesticidal properties, A. malaccensis leaves can be regarded as a promising natural source for producing pesticides.