H_2S气氛中LaCl_3催化磷石膏低温分解制CaS研究

对磷石膏在硫化氢气氛中制备CaS的过程进行研究,通过热分析实验和管式炉实验,探讨了反应温度、反应时间、H_2S流量和浸渍不同浓度LaCl_3对磷石膏分解率及硫化钙产率的影响。结果表明,LaCl_3的添加能显著降低磷石膏反应温度,在反应温度为900℃、反应时间为60min、H_2S流速为300m L·min~(-1)、LaCl_3添加量为0.5mol·L~(-1)的条件下,磷石膏分解率达到92.8%,硫化钙产率达到48.3%。     

磷石膏还原制备硫化钙工艺参数研究

采用磷肥工业副产的磷石膏作为主要原料,煤粉作还原剂,经还原焙烧制备了硫化钙。研究了反应配比、反应时间、反应温度、反应气氛等对所制备的硫化钙样品的影响。通过单因素实验探索了最适宜的还原分解条件,在此基础上进行了正交优化实验,得到了还原分解反应的优化工艺条件为:煤粉过量25%、反应温度为870℃、反应时间为2 h,采用碘量法分析产物中的硫化钙含量。在此条件下计算得到磷石膏的转化率可达98%以上。     

硫磺分解磷石膏制硫化钙工艺研究

研究了以硫磺为还原剂分解磷石膏得到硫化钙产物的方法。在热力学研究的基础上,考察了反应温度、反应时间、硫磺物质的量分数和二氧化硫物质的量分数对硫磺分解磷石膏的影响。通过实验得出优化工艺条件:反应温度为800℃、反应时间为2 h、硫磺(以S1计)物质的量分数为40%。在该条件下磷石膏的分解率达到98%以上。同时证明了二氧化硫对反应有明显的抑制作用。借助X射线衍射(XRD)对磷石膏分解产物进行物相解析,结果表明所得产物主要为硫化钙。     

实验研究磷石膏分解制备硫化钙反应的最佳工艺条件

针对云南磷石膏中二氧化硅高的特点,通过磷石膏分解基本反应的热力学分析,实验研究了反应温度、碳硫摩尔比和铁粉加量对硫化钙收率的影响。得到磷石膏分解制备硫化钙的最佳工艺条件为n(C)/n(SO3)=3、反应温度900℃、反应时间150min,硫酸钙转化率可达99.0%以上。研究结果为开展磷石膏分解制硫酸新工艺的开发和设计提供了基础数据。     

循环流化床中高硫煤还原分解磷石膏中试研究

通过利用高硫煤作为还原剂在自行设计的循环流化床中试装置中对磷石膏进行了高温热分解实验,随着反应温度的升高,磷石膏的分解率与脱硫率升高,磷石膏的分解率达到97%的反应时间逐渐减少.而且在还原性气氛增加的情况下,反应时间会减少.还原性气氛越强,磷石膏的分解率越高,反之,则磷石膏的脱硫率越低,说明磷石膏在弱还原性气氛下分解是较为有利的.     

磷石膏脱硫工艺及应用研究

研究了以磷石膏为原料烧制硫化钙并用二氧化碳碳酸化分解硫化钙来生产硫化氢的工艺路线.通过单因素分析和正交实验设计,确定硫化钙碳酸化制备硫化氢的最佳工艺参数.最佳工艺参数为:反应温度为室温、二氧化碳气体流速为(110±10)个/min(以气泡计)、液固体积质量比为3 mL/g、反应时间为3 h.在此条件下硫的转化率为99%以上,残渣中硫质量分数可以降到1%以下.     

不同气氛对硫化钙和磷石膏反应的影响研究*

硫化钙与磷石膏之间的固-固反应,以生成氧化钙和二氧化硫的反应为优势反应,同时反应中存在许多副反应。考虑到实际工业生产情况,在高温管式炉中,控制硫化钙与硫酸钙物质的量比为1.2∶3,在氮气、二氧化硫混合气氛基础上,逐步引入二氧化碳、一氧化碳、氧气等气氛,研究外加气氛对磷石膏分解率的影响。结果表明,不同的气氛对固-固反应有不同的影响。高物质的量分数的二氧化硫和氧气会抑制反应,使得磷石膏分解率大幅度降低;一氧化碳可以促进磷石膏的分解;二氧化碳的存在对反应几乎没有影响。     

5%氯化钙存在下高硫煤还原磷石膏实验研究

以磷肥工业废渣磷石膏为原料,在磷石膏中掺入5%氯化钙(以质量分数计),以高硫煤为还原剂,在氮气吹净空气后焙烧还原磷石膏制备硫化钙、氧化钙,并采用碘量法分析产物中硫化钙、氧化钙的含量,考察硫酸钙的还原率。研究了原料配比、焙烧时间、焙烧温度、颗粒细度等因素对还原磷石膏的影响。在此基础上进行了正交实验,得到还原磷石膏制备硫化钙、氧化钙的优化工艺条件:硫酸钙与碳物质的量比为1∶1.3、焙烧温度为900℃、焙烧时间为2.5 h,在此条件下,磷石膏中硫酸钙的还原率可达到98%以上。在磷石膏中掺入5%氯化钙能降低磷石膏的还原分解温度。     

磷石膏流态化分解与甲烷燃烧反应热量耦合研究

在振动流化床中对磷石膏分解与甲烷催化燃烧热量耦合强化磷石膏分解过程进行了研究。考察了反应温度、碳硫摩尔比、甲烷浓度、物料高径比、气体流量和反应时间对磷石膏分解率、脱硫率以及产生气体SO2浓度的影响。实验表明,强化磷石膏分解反应适宜的耦合条件为:反应温度1 030℃,气体流量140 mL/min,φ(CH4)4%,碳硫摩尔比1.0,物料高径比4.8,反应时间60 min,磷石膏分解率和脱硫率分别达到95.42%和85.62%,SO2体积分数达到17.86%。     

硫化钙碳酸化制备硫化氢工艺参数的研究

研究了以磷石膏为原料烧制硫化钙和碳酸化硫化钙生产硫化氢的工艺路线,并用正交设计法找出了硫化钙碳酸化制备硫化氢的最优工艺参数.通过实验得到最优工艺参数为气流速度110个气泡/min、温度60℃、反应时间5 h,此时硫的转化率达93%.     

Carbon-supported sulfide catalysts

The activities of sulfided $\text{Mo}\text{C}$, $\text{W}\text{C}$, $\text{Co}\text{C}$, $\text{Ni}\text{C}$, $\text{Co-}\text{Mo}\text{C}$, and $\text{Ni-W}\text{C}$ catalysts for thiophene hydrodesulfurization and butene hydrogenation were studied using a flow microreactor operating at atmospheric pressure. The following parameters were varied: type of carbon support, carbon pretreatment, catalyst preparation method, and content of active material. The results are compared with those obtained for series of sulfided Mo/γ-Al₂O₃, W/γ-Al₂O₃, $\text{Mo}\text{SiO}{}_2$, and $\text{W}\text{SiO}{}_2$. Some samples, viz., $\text{Mo}\text{C}$, $\text{Co}\text{C}$, and $\text{Co-Mo}\text{C}$, were also studied by X-ray photoelectron spectroscopy (XPS). The carbon-supported catalysts demonstrated outstanding performance for thiophene hydrodesulfurization. XPS analysis showed the presence of low-valence-state sulfur, e.g., S^? or (S-S)^2?, in $\text{Mo}\text{C}$ and $\text{Co}\text{C}$ catalysts with low molybdenum or cobalt content. These sulfurspecies are supposedly connected with the catalytic activity for hydrodesulfurization. $\text{Co}\text{C}$ and $\text{Ni}\text{C}$ were found to have a hydrodesulfurization activity which was higher (Co) or the same (Ni) as that measured for $\text{Mo}\text{C}$ or $\text{W}\text{C}$. Therefore Co (Ni) ions in Co $\text{(Ni)-Mo (W)}\text{C}$ catalysts are considered as promoters for the MoS₂ (WS₂) phase (low $\text{Co}\text{Mo}$ or $\text{Ni}\text{W}$ ratios) or as additional active species.     

利用硫化氢制备氢气和硫化锌新方法

利用电化学溶解-沉淀法回收利用硫化氢制取氢气和硫化锌.考察了不同硫化氢含量、进气流速对吸收反应的影响,并对电解制氢和硫化氢吸收反应的双系统匹配运转进行了详细研究.结果表明,在温度为25℃、搅拌速率为100 r•min^-1条件下,硫化氢的一次吸收率可达99.9%以上,电解液可循环使用;电解反应可在低电压0.5 V和25℃条件下进行,制氢电耗低于1.2 kW•h•m^-3H₂.     

Aminothiol polyalkylene sulfide oligomers

The carbonates and oxides of zinc and cadmium polymerize propylene sulfide to elastomeric materials, but with the addition of ammonia low molecular weight polymers are produced. The effect of the ammonia is to react with some of the propylene sulfide to give aminopropanethiol, which will itself polymerize monomer by a stepwise reaction or, after reaction with the metal carbonate, form a metal bis(aminopropanethiolate) which is an active initiator. Chemical and spectroscopic examination of these polymers shows them to be essentially bifunctional, with one NH₂ and one SH terminal group. There is, however, evidence to suggest that further reaction of monomer occurs with the terminal amine groupings to give polyfunctional compounds. From the relative proportions of ammonia, zinc carbonate, and monomer, the rate of polymerization, molecular weight, and degree of endgroup coordination with catalyst residue can be controlled as desired. Due to the highly reactive endgroups, the polymers are readily crosslinked with epoxy resins, aziridinyl compounds, and hexamethoxymethylene melamine to give useful products exhibiting high solvent resistance.     

Very slow formation of copper sulfide and cobalt sulfide nanoparticles in montmorillonite

Intercalation of semiconductor nanoparticles, copper sulfide or cobalt sulfide, into montmorillonite was carried out by solid–solid reactions of Cu(II)- or Co(II)-montmorillonite with sodium sulfide at room temperature. The intercalation compounds were characterized by X-ray diffraction, thermal analysis, transmission electron microscopy, Raman, UV–visible and photoluminescence spectroscopy. The photoluminescent copper sulfide and cobalt sulfide nanoparticles in the interlayer spaces formed after the sample storage at room temperature for several months.     

可脱除硫化氢的液体脱硫剂研究进展

一种可通过直接注入法注入管线中的三嗪类可脱除H2S液体脱硫剂,由于具有高效、价格低廉、易制备、抗菌、可减少低碳钢的腐蚀等特点,弥补了海上脱硫空间和成本的限制,近些年在国外海上石油辅助产品中发展迅猛,前景广阔.详细介绍了1,3,5-三(2-羟乙基)-六氢均三嗪的结构、性质、机理、工艺特点、国外应用现况,最后对其发展前景进行了展望.     

过渡金属硫化物对Claus尾气催化加氢制备硫化氢的影响

以γ-Al2O3为载体,考察了第一过渡金属亲硫元素和Cr系元素及其负载量对Claus尾气加氢生成H2S的催化活性。结果表明,经预硫化后上述负载量为10%质量分数的各元素,其催化活性按大小可以划分为4组:Ni、Co、Fe>Mo、W、Cu>Cr>Zn、Mn。针对第一组的3种元素进行物相分析表明,在反应气体积比为SO2/H2/N2=0.5/3/96.5,重量时间空速(WHSV)=6 000mL/(h.g)的强还原气氛下,Ni的催化活性相为稳定的NiS2,但Co和Fe除主晶相CoS2和FeS2外,还分别具有Co3S4和Co9S8或FeS和Fe7S8的贫硫相。     

金属氧化物吸附剂脱硫过程中羰基硫的生成

金属氧化物脱硫剂脱硫过程中产生羰基硫的现象缩小了脱硫剂的使用范围。本文从气体中存在一氧化碳、二氧化碳、单质硫和硫化氢出发给出了均相、非均相生成羰基硫的途径,特别综述了生成羰基硫的催化作用。在总结氧化铁基、氧化锌基、氧化锰基及氧化铜基主流金属氧化物脱硫剂脱硫过程中产生羰基硫研究结果的基础上,发现吸附在金属硫化物表面上的一氧化碳与活性硫化物的相互作用是生成羰基硫的主要反应步骤,活性硫化物可能是硫化氢热解成蒸气硫或硫氢根离子及硫化氢与金属氧化物反应生成的金属硫化物。     

Synthesis and characterization of poly(phenylene sulfide), poly(2-methylphenylene sulfide), and poly(2,6-dimethylphenylene sulfide)

A facile synthesis of poly(phenylene sulfide) (PPS), poly(2-methylphenylene sulfide) (PMPS), and poly(2,6-dimethylphenylene sulfide) (PDMPS) from the respective copper (I) bromothiophenoxides is described. Polymerization was effected in a 10:1 quinoline:pyridine mixture at atmospheric pressure and conditions optimized for the preparation of high-molecular-weight materials. The preparation of PPS in pyridine under pressure at 250°C has been investigated for comparative purposes. Yields and the properties of materials produced by solution polymerization are comparable to or better than those produced in the autoclave reaction. Properties have been investigated as a function of reaction time and molecular weight, and the deficiencies of the molecular-weight assessment methods are discussed. PMPS and PDMPS have been similarly studied and their properties evaluated. The use of heat of crystallization determinations for molecular-weight studies on PPS are described and critically evaluated.     

Thermal degradation of poly(phenylene sulfide) and perfluoropoly(phenylene sulfide)

The thermal and oxidative degradation of poly(phenylene sulfide) and perfluoropoly(phenylene sulfide) have been studied by a weight-loss method. The products of breakdown in vacuum have also been analyzed. The poly(phenylene sulfide) is more thermally stable in inert and oxidizing atmospheres than the fully fluorinated analog. The breakdown products can be accounted for by chain scission and transfer reactions. The formation of a large proportion of residue implies that crosslinking reactions play an important part in the degradation.     

硫化钠法合成聚苯硫醚工艺研究进展

综述了聚苯硫醚的性质、合成方法及目前供需情况.着重介绍了硫化钠法(SSM)工艺(如反应条件、溶剂回收、催化剂、脱水、产物分离、食盐去除等).指出SSM工艺存在产率低、溶剂成本昂贵、产品各项指标较差、纯度低等问题,认为溶剂回收、除盐等工艺还有待深入研究.