电石渣在煅烧/氯化反应中的HCl脱除特性研究

采用钙基废弃物———电石渣煅烧后脱除HCl。在煅烧/氯化反应器上研究脱氯反应温度、HCl体积分数、颗粒粒径和煅烧温度对电石渣脱氯性能的影响。结果表明,电石渣在700℃时取得最高氯化转化率;脱氯反应温度高于650℃后,电石渣氯化转化率均高于石灰石,电石渣高温脱氯更有优势。电石渣氯化转化率随反应气氛中HCl体积分数提高呈线性增长。随电石渣颗粒粒径增大,氯化转化率缓慢降低。高于900℃的煅烧温度不利于电石渣脱除HCl。煅烧后电石渣分布在2~10 nm的孔隙较多,氯化后分布在此孔径范围内的孔容和孔面积分别降低了56.2%和62.2%,2~10 nm孔隙是煅烧后电石渣吸收HCl的主要区域。     

电石渣负载氟化钾的催化酯交换特性研究

通过浸渍法制备以氟化钾为活性体、电石渣为载体的负载型钙基酯交换催化剂,并在借助X射线荧光光谱仪、热分析天平、X射线衍射仪、氮气吸附-脱附仪、扫描电子显微镜以及哈米特指示剂法等手段对催化剂表征,以及气相色谱仪对原料油成分分析的基础上,通过间歇式酯交换实验系统,从催化剂添加量、醇油物质的量比、酯交换温度与时间等影响因素出发,研究了电石渣负载氟化钾催化花生油与甲醇酯交换的特性。电石渣负载氟化钾后,产生KCaF3、CaF2以及KF等新物相,并且在催化剂添加量为5%、反应温度为62℃、反应时间为2 h以及醇油物质的量比为15的酯交换条件下,能够取得91.58%的甘油收率,相比较氢氧化钙和未有活性体负载的电石渣,其催化酯交换性能得到提高。     

渣油加氢反应样品中含铁和含钙化合物溶解性能研究

以某原油及其对应的减压渣油、加氢原料和加氢产品为研究对象,通过柱色谱分离法和溶剂抽提法,对油样中铁和钙化合物在组分中的含量、分布以及存在形态进行了研究。研究结果表明,柱色谱分离过程中,油样中的含铁或钙的化合物在色谱柱上产生吸附,损失了58%的铁化合物和76%的钙化合物;溶剂抽提法能够有效减少组分中金属元素的损失。原油中97%以上的铁和钙分布在减压渣油馏分中,减压渣油中60%-90%的铁和钙分布在胶质、沥青质组分中。渣油加氢反应过程中,铁、钙化合物主要是从胶质中得到脱除,整体脱除率接近30%,铁化合物更易结合在沥青质中而难以脱除。原油经过常减压蒸馏后,油溶性铁相对分布由95.6%降低为64.7%,水溶性铁相对分布由4.4%升高为35.3%。经过加氢反应后,38%左右的油溶性铁在反应中转化为水溶性铁,30%左右的油溶性钙在反应中转化为水溶性钙。     

天然气与硫酸盐热化学还原反应的模拟实验研究

为探讨天然气中高含量硫化氢形成的化学机制，利用高温高压反应装置，对天然气与固态硫酸钙反应体系进行了热模拟实验研究。使用气相色谱仪、微库仑仪、傅里叶变换红外光谱仪和X射线衍射仪对产物进行了分析，探讨了硫酸盐热化学还原反应的热力学特征，并进行了反应动力学研究。结果表明，高温下天然气与固态硫酸钙可以发生反应，产物主要为硫化氢、二氧化碳、碳酸钙、水和炭。热力学研究表明，天然气与固态硫酸钙的反应可行，升高温度对反应有利，同一温度下长链烷烃与固态硫酸钙发生反应的可能性要比短链烷烃大。根据动力学模型得到反应活化能为96.824kJ/mol。     

电石法生产聚氯乙烯过程中汞的流向及处理技术分析

汞是对环境有高度敏感性的重金属,汞污染已经成为全球高度关注的敏感议题。我国汞资源相对匮乏,对汞资源的过度消耗和汞污染是电石法生产聚氯乙烯(PVC)行业发展的巨大障碍。本文针对电石法生产PVC中的严重汞污染问题,分析了生产过程中汞的来源、流向,并且提出对应的处理技术,为电石法生产PVC中的汞污染防治提供思路。     

丹参酮与胺类化合物的反应研究

研究了隐丹参酮与氨、甲胺、乙胺等有机胺的作用。发现丹参酮二氢呋喃环部分在氨及NaOH的作用下发生亲核开环,且亲核加成反应与开环反应协同进行。与甲胺、乙胺等有机胺作用则分别生成丹参酮的咪唑环及恶唑环衍生物。探讨了可能的反应历程。     

碳铵沉淀法制备纳米氧化钇过程中氯离子的行为

研究了碳酸氢铵沉淀法制备纳米氧化钇过程中氯离子的行为及去除方法,认为沉淀物的组成为Y(OH)0.1Cl0.1(CO3)1.4·2H2O。讨论了氯离子的存在形式,氯离子主要以氯化铵吸附或夹带和碳酸钇复合物的形式存在,其中碳酸钇复合物和颗粒内部夹带的氯离子是影响最终纳米氧化钇中氯含量的关键。通过实验研究证明采用洗涤和提高煅烧温度和延长保温时间可以有效减少氯离子的含量,制得了氯离子含量为0.054%的纳米氧化钇粉体。     

催化裂化过程中热裂化反应与二次反应的研究

利用连续式小型提升管催化裂化实验装置,研究了重油催化裂化过程中热裂化反应和二次反应的特点;考察了反应温度、剂油比和油气停留时间对热裂化和二次反应（氢转移和异构化反应）的影响;给出了不同反应条件下催化裂化过程中的过裂化点,考察了过裂化点前后热裂化反应在催化裂化过程中所占比例及氢转移和异构化反应的变化。结果表明,降低反应温度,缩短停留时间,增加剂油比可以抑制催化裂化过程中不利的热裂化反应,有利于氢转移和异构化反应的发生;在由反应温度、剂油比和停留时间引起的过裂化点前后,热裂化、氢转移和异构化反应表现出各自的变化特点。     

新型有机锡化合物的制备及对酯化反应的催化活性

制备了2种新型有机锡化合物,并利用元素分析、红外光谱、核磁共振测试技术对其进行了表征,研究了它们对酯化反应的催化活性。结果表明,该有机锡化合物是合成酯的优良催化剂,产品收率高,饱和一元羧酸酯的收率为87%~98%,对不饱和羧酸酯和空间位阻大的叔醇酯也能得到较满意的收率,分别为90%~94%和54%~68%。有机锡化合物作为催化剂用量少,并能回收再利用。     

有机过渡金属化合物与CO2的反应

本文主要综述以下四个方面内容;(1)过渡金属与CO_2的配位络合物,(2)CO_2对过渡金属络物的可逆插入,(3)CO_2对过渡金属络合物的不可逆插入,(4)CO_2的还原和歧化反应。     

Use of Taguchi approach for synthesis of calcite particles from calcium carbide slag for CO2 fixation by accelerated mineral carbonation

This study is focused on the conversion of harmful materials (calcium carbide slag [CCS] and flue gas) into CaCO₃ particles through an accelerated mineral carbonation process. The influences of reaction temperature, amount of Na-oleate, solid-to-liquid ratio, and stirring speed on the properties of CaCO₃ particles were determined using XRF, XRD, SEM, FTIR, TG, and contact angle measurements. Experiments were designed based on an orthogonal array L9 (3⁴) of the Taguchi approach. The gas mixture of CO₂/N₂ (16.3% of CO₂ cons.) gas was used to represent the flue gas for each experiment. The formation of CaCO₃ particles from CCS depending on time was monitored via SEM. Experiments showed that the presence of Na-oleate in the slurry played a curial role in the carbonation process, and the conversion ratio of CO₂ into a solid carbonate phase was higher than that in the experiments conducted without Na-oleate. The crystallite size of CaCO₃ particles varied between 11.55 and 38.11 nm depending on the production conditions. Each obtained CaCO₃ particles were identified as calcite (cubic-like rhombohedral), which is in high demand in many industrial applications.     

Thermal analysis of high-speed high-temperature reactions of refractory carbide synthesis

A new thermoanalytikal method, called electrothermal explosion (ETE) is described in which uniform heating of samples at extremely high rates (up to 10⁵ deg. sec^?1) is achieved. Heating is by direct passing of an electric current through the sample in the initial stages and by chemical heat release after the ignition conditions have been attained. ETE is the only direct method that allows the macrokinetics of heterogeneous reactions occurring in condensed systems to be studied at high temperature and at short conversion times, which are prohibitive for traditional thermoanalytical devices (up to 3500 K and 10^?2 sec respectively). Kinetic data on high-temperature, high-speed interactions in powder mixtures of carbon with titanium, silicon and tantalum are presented. The rate of heat release in the Ti?C system depends only to a small extent on temperature after the metal has melted, being mainly determined by the solution rate of carbon particles. The interaction mechanism in the Si?C system is similar to that in Ti?C, but the high enthalpy of carbon solution in liquid silicon results in a bulk activation energy ofE=55 kcal. mol^?1. Synthesis of tantalum carbide from the elements in the temperature range 1500–3000 K occurs by the mechanism of reaction diffusion and proceeds with strong self-retardation.     

Thermal analysis of carbide slag solutions

A model of slag refining processes and a method of determining the reduction capability of slag solutions are presented. Carbide slags were analysed by DTA methods.     

铁饼状碳酸钙的制备及性能研究

本文以氯化钙和氨水的混合溶液为水相,聚氧乙烯辛基苯酚醚-10(OP-10)为表面活性剂,正辛醇为助表面活性剂,环己烷为油相配制了反相微乳液.并通过向其中通入CO2气体制备微/纳米碳酸钙,得到了铁饼状的微米碳酸钙.采用扫描电子显微镜(SEM),X射线粉末衍射(XRD)和傅里叶变换红外光谱(FTIR)表征了微米碳酸钙的形貌...     

CaO高温吸附捕集CO2-制备CaO的钙基前驱体材料筛选

价格低廉的CaO材料在高温下能高效吸附捕集CO2气体,被认为是碳减排的有效方法之一．然而,CaO长时间循环碳酸化／煅烧解吸后,其CO2的化学吸附容量下降,稳定性较差,限制了该材料的工业应用．本文采用天然钙源（牡蛎壳和方解石等）和化学试剂（醋酸钙）为钙基前驱材料制备CaO．采用扫描电子显微镜（SEM）,X射线衍射仪（XRD）和氮气吸附仪等手段对制备的CaO材料进行形貌和物理结构的分析表征;在高温和模拟的烟道气氛条件下（10％C02和90％N2）,采用热重分析仪测量CaO吸附CO2的能力和长时间循环碳酸化／煅烧解吸后的稳定性．我们经过与目前所报道的其他钙基吸附材料进行比较,并结合钙基前驱材料的市场价格,发现CaO（醋酸钙）的CO2吸附能力和稳定性较为理想,醋酸钙在高温烟气捕碳方面具有非常好的应用前景．     

Reactions of Nadic Anhydride at High Temperatures

The reaction of nadic anhydride(NA) at high temperature under oxygen or oxygen-free conditions was investigated in this report in order to understand the cross-linking behavior of nadic end-capped polyimides. In this study, ¹³C-NMR, mass spectra as well as IR spectroscopy were employed for understanding the reactions involved. In ampule tests, NA was heated after sealing in air or under nitrogen, The dimer, trimer and tetramer of NA were found when heated at 260°C for 30 min. and their possible chemical linkage is shown. More complicated products could be obtained when heating For longer time. The cleavage of double bond was observed when NA was heated at about 340°C and the linkage containing oxygen was found when scaled in air. The molecular weight of product increased in this case.     

烧结脱硫石膏的钙相分析

建立烧结脱硫石膏的钙相分析方法。根据石灰石浆脱硫工艺的特点,利用脱硫石膏中硫酸钙和亚硫酸钙等钙相的不同特征,用EDTA容量法测定总钙,并用ICP法、红外仪器方法测得硫酸钙、亚硫酸钙、碳酸钙等的含量,再利用差减法计算氧化钙的含量。测定结果的相对标准偏差小于1.5%(n=6),硫酸钙、亚硫酸钙、碳酸钙及氧化钙的加标回收率在97%~100%之间。该方法操作简单、快速,可用于烧结脱硫工艺中烧结脱硫石膏钙相的日常检测,实现对脱硫工艺中各阶段反应产物的准确定量。     

Crystallization of inorganic compounds in polymer solutions. Part I: Control of shape and form of calcium carbonate

Calcium carbonate was precipitated by mixing aqueous solutions of sodium carbonate and calcium nitrate in the presence of water-soluble polymers. When the former was poured into the latter, in which a certain amount of sodium poly(styrenesulfonate) was dissolved, monodisperse spherical crystals were created. The crystal form was vaterite, although, in the absence of the polymer, calcite crystals were obtained in rhombic shape. The factors deciding the shape and form of the crystal were investigated and the role of polymer in the formation of unique crystals was discussed.     

NH4Cl和HCl溶液浸取电石渣制备多晶型CaCO3

以电石渣为原料,分别以NH4Cl溶液和HCl溶液为浸取剂提取电石渣中的钙,以NH4HCO3为碳化剂制备CaCO3。研究了两种浸取工艺对电石渣中Ca^2+离子提取率的影响,并对两种体系浸取得到的Ca^2+离子提取率、二次残渣量和滤液中的杂质情况,以及制得的CaCO3的产率和性状进行了比较。结果表明,在浸取时间为30 min,浸取剂浓度为2.5 mol·L^-1,pH为8的条件下,以NH4Cl溶液浸取电石渣,加入量按Cl^-/Ca^2+物质的量比为2.0,得到Ca^2+离子提取率为92.87%;以HCl溶液浸取电石渣,加入量按Cl-/Ca^2+物质的量比为2.2,得到Ca^2+离子提取率为98.65%。Ca^2+离子滤液中的主要杂质通过调节pH均可以得到有效控制。NH4Cl溶液浸取电石渣Ca^2+离子提取率略低,二次残渣量高(22.39%),制得CaCO3的产率为1.065 g·g^-1电石渣;HCl溶液浸取电石渣Ca^2+离子提取率高,二次残渣量小(8.87%),制得CaCO3的产率为1.203 g·g^-1电石渣。两种浸取液碳化后制得的CaCO3产品纯度都在99%以上,白度在92.2-97.1%之间,通过控制碳化条件均可制得方解石型、球霰石型和文石型三种晶型的CaCO3。