液体石蜡分离技术在费-托合成油中的应用研究进展

介绍了液体石蜡分离技术在费-托合成油生产中的应用研究进展,并对国内几种现有的液蜡分离技术进行了对比。以石油基油品为原料,采用异丙醇-尿素脱蜡法生产的液体石蜡产品中正构烷烃的质量分数稍高于90%;分子筛脱蜡法生产的产品中正构烷烃的质量分数达96%以上;采用5A分子筛脱蜡、10X分子筛精制联合工艺,能够生产出优质的重液蜡产品,产品纯度可达95%;NWA-Ⅲ等新型吸附剂生产的产品纯度大于98.5%,正构烷烃回收率一直保持在96%以上。费-托合成产物具有正构烷烃含量高的特点,将费-托合成产物中的液体石蜡(C_(10)~C_(18)正构烷烃)分离出来,不仅可以生成高端的液体石蜡产品,还能联产高端低凝柴油。最后对液蜡的生产工艺技术、产品质量、综合利用等方面提出了发展建议。     

超声尿素包合法分离测定重质油中的正构烷烃

选用大庆减压馏分油为原料，通过超声尿素包合法准确地分离了其中的正构烷烃和非正构烷烃组分，得到了纯度较高的正构烷烃。采用GC／MS进行了分析验证，测得正构烷烃的碳数范围为C20～C38。研究了活化剂、溶剂、尿素用量、温度、超声时间等因素对正构烷烃分离效果的影响，确定了最佳反应条件。在选定的反应条件下。2g大庆减压馏分油，加入15mL异丙醇，3g尿素，正构烷烃的平均收率为42．51％。该方法准确度高，重复性好，正构烷烃定量分离的相对标准偏差为0．54％。     

络合法分离富集重石脑油中正构烷烃

从石脑油中分离或富集正构烷烃可以降低催化重整和乙烯生产的成本,优化原料组成,提高生产效率。使用尿素和硫脲为络合剂、质量分数95%的乙醇为活化剂,将正辛烷、异辛烷、甲基环己烷、甲苯按不同比例混合作为模拟石脑油进行络合富集,考察络合相产品中各组分含量及正辛烷收率。结果表明：使用尿素/硫脲络合富集重石脑油中的正构烷烃是可行的,络合试验最佳反应条件为：质量分数为95%的乙醇活化剂用量80 mL,模拟石脑油用量60 mL,尿素/硫脲质量比50/21,络合温度-10℃,时间1 h;少量芳烃会对正辛烷分离效果产生一定的负面影响,工业上可以先用萃取法分离芳烃,然后再进行络合分离。     

低温费-托合成低温冷凝物加氢精制反应集总动力学

在200~300℃、液时空速1~40h-1、压力3MPa以及氢/油体积比300的条件下,采用Ni-W催化剂在固定床反应器中对低温费-托合成低温冷凝物(L-LC)加氢精制的集总动力学进行研究。将L-LC加氢精制反应体系划分为5个集总,构建了反应网络和动力学模型。依据实验数据计算动力学参数,得到其中正构烯烃加氢生成正构烷烃、正构烯烃异构化、异构烯烃加氢生成异构烷烃和异构烷烃生成正构烷烃反应的表观活化能分别为77.247、9.570、58.692、35.150kJ/mol。实验数据与该模型计算结果吻合,检验了该模型的准确性。利用模型讨论了烷烃异构化反应的平衡组成、中间产物的动力学规律和各集总组分反应速率的变化。     

梯度冷却尿素包合法分离脂肪酸甲酯

实验以梯度冷却尿素包合法,将废弃油脂生物柴油分成包合脂肪酸甲酯与非包合脂肪酸甲酯两种产品.考察了降温速率、冷却搅拌速度、尿素/甲酯比、溶剂/甲酯比,及最终冷却温度等因素对分离效果的影响.实验结果表明,梯度冷却尿素包合的适宜条件为:降温速率1.0℃/min,搅拌速率300 r/min,m(尿素)∶m(甲酯)=1.3∶1,...     

费-托合成蜡分质分级-萃取精制工艺研究

以内蒙古伊泰费-托合成蜡为原料，采用减压蒸馏与溶剂萃取相结合的工艺技术脱除费-托合成蜡中的异构烃类和含氧化合物以降低其油含量。考察了不同萃取剂、操作条件对脱油效果的影响，采用傅里叶红外光谱（FT-IR）和高温气相色谱对蜡样品进行分析。结果表明：选用N-甲基吡咯烷酮为溶剂，在萃取温度为120 ℃、剂油质量比为2.0:1的操作条件下，萃取得到的精制蜡收率和含油率最佳，分别为93.75%和0.097%，精制蜡滴点为112 ℃，针入度为0.1 mm，产品满足Sasol公司H105费-托合成蜡产品质量标准。精制费-托蜡的碳数分布在C19~C120之间，FT-IR表征结果表明其结构简单，主要由长链正构烷烃组成，C35的含量最高。     

费-托合成蜡中轻烃组成的气相色谱分析

建立了费-托(F-T)合成蜡中烃类组成的气相色谱分析方法。通过附带的反吹附件吹扫出高碳数物质,实现F-T合成蜡直接色谱进样,详细分析蜡中低于400 ℃馏分中的正构烷烃、烯烃及正构醇含量。实验优化了色谱柱类型、柱箱温度、反吹压力、反吹时间等色谱参数,所建分析方法已应用于高、低温F-T合成蜡的不同类型烃类的组成分析。分析结果表明：相对于低温F-T合成蜡,高温F-T合成蜡中含有更多的α-烯烃、正构烷烃和正构醇;此外,随着反应温度的升高,高温F-T合成蜡中异构烃含量增加,α-烯烃、正构烷烃和正构醇含量有所降低。     

液体石蜡生产技术及其市场分析

液体石蜡（简称液蜡）是指以煤油或柴油馏分为原料．经分子筛吸附分离或异丙醇一尿素脱蜡．得到的含正构烷烃的石蜡,因常温下呈透明无色或浅黄色液体．故称液体石蜡。根据馏分,可以分为轻质液体石蜡（简称轻蜡）和重质液体石蜡（简称重蜡）．烷烃中碳原子数C9～C13者为轻蜡．C14～C16者为重蜡。     

尿素络合纸层析法分离支链—环烷烃和正烷烃

正烷烃和支链-环烷烃的分离,一般采用5埃分子筛吸附法和尿素络合法。5埃分子筛吸附法能把正烷烃比较完全地吸附,但操作麻烦,时间较长,仅回流就需要半天至一天的时间;尿素络合法是尿素在活化剂——甲醇存在的情况下,与正烷烃及其衍生物络合,虽络合时操作简便,但络合后的分离很费时,且不能将正烷烃和支链-环烷烃截然分开。      

从焦化柴油中分离富含直链α—烯烃的蜡油

对尿素脱蜡工艺从焦化柴油中分离直链α-烯烃和直链烷烃的工艺路线进行了试验研究，用异丙醇和水混合溶剂溶解尿素，与焦化柴油进行络合反应。研究结果表明，用该脱蜡工艺，可从焦化柴油中分离得到直链α-烯烃和直键烷烃，焦化柴油可作为C8～C20。直链α-烯烃和直链烷烃的一个重要来源。对220～320℃的焦化柴油馆分，采用异丙醇：尿素：水为50：40：15的比例组成的尿素饱和溶液，以5：1～6：1的比例与焦化柴油进行络合反应，络合反应可在20min内接近或达到平衡，约30％的直链烃分离出来，其中α-烯烃含量在16％～17％之间。     

尿素包合法制取低熔点石蜡的研究

以市售石蜡为原料用尿素包合法制得了具有合适相变温度 (熔程在 2 6～ 2 6 .6℃ )的石蜡。实验证明影响反应的主次因素依次为包合温度、尿素与石蜡的质量比、反应时间、乙醇与尿素的质量比 ;在反应温度为 70℃、尿素与石蜡的质量比为 3∶1、反应时间为 2 .5h、乙醇与尿素的质量比为 0 .2时 ,得到初熔点为 2 6℃ ,终熔点为 2 6 .6℃的石蜡 ,该石蜡可进一步微胶囊化制成相变材料用于建材中     

STUDY OF THE TEMPERATURE AND ENTHALPY OF THERMALLY INDUCED PHASE-TRANSITIONS IN n-ALKANES, THEIR MIXTURES AND FISCHER-TROPSCH WAXES

A precise determination of the temperatures and enthalpies of thermally induced various phases of n-alkanes, especially those having the molecular weights in the petroleum wax range, have been done by using a differential scanning calorimeter (DSC). These phase transitional parameters are shown to be dependent on the rate of heating/cooling, particularly on the faster rates. Also, the parameters measured during heating cycle (melting) differ from those obtained during the cooling cycle (crystallization). The typical shape of the solid-solid transition curve in the DSC thermograms(cooling cycle) of even n-alkanes readily distinguishes these from the odd n-alkanes, which is greately influenced by the increase in the carbon numbers in the chain (n-C₃₄ and beyond) and the purity of the sample.High molecular weight n-alkanes also showed instability in the structures at the phase transitions

The formation of solid solutions of n-alkanes have been studied by measuring phase transitional parameters and studying nature of the DSC thermograms of various binary and multicomponent mixtures of n-tetracosane (n-C₂₄) with other n-alkanes. It is observed that the immiscibility between two n-alkanes of the binary mixture begins when chain-length difference between them is more than four carbon atoms. In between the two extremes of solid solution and eutectic formations, there also existed the partial miscibility of two n-alkanes, particularly at high temperatures

The DSC thermograms of multicomponent n-alkane mixtures and Fischer-Tropsch waxes revealed that perfect solid solution is formed when the involved n-alkanes have carbon number very close to each other or the carbon number distribution is in a narrow range with smaller chain n-alkanes dominating.     

Research on paraffin removal and prevention by Bacillus spp. in high-salinity reservoirs

Problems in paraffin deposition occur frequently in oil exploitation. Considering the problem that some paraffin removal and prevention strains cannot grow in high-salinity reservoirs, we domesticated four salt-tolerant laboratory bacterial strains. Crude oil emulsification effect, paraffin removal rate, and paraffin prevention rate of the strains were evaluated. KB and JH-A strains exhibited good paraffin removal and prevention effects, with paraffin removal rates of 51.82% and 81.56%; and 51.82% and 80.90%, respectively. Gas chromatography mass spectrometry analysis of paraffin components before and after biodegradation was performed on KB and JH-A strains. Results showed that relative contents of n-alkanes between C15–C23 and C27–C30 evidently decreased, indicating their good biodegradation. This technique provides a new method for practical application of paraffin removal and prevention in high-salinity reservoirs.     

STUDY OF THE TEMPERATURE AND ENTHALPY OF THERMALLY INDUCED PHASE-TRANSITIONS IN n-ALKANES,THEIR MIXTURES AND FISCHER-TROPSCH WAXES

ABSTRACT

A precise determination of the temperatures and enthalpies of thermally induced various phases of n-alkanes, especially those having the molecular weights in the petroleum wax range, have been done by using a differential scanning calorimeter (DSC). These phase transitional parameters are shown to be dependent on the rate of heating/cooling, particularly on the faster rates. Also, the parameters measured during heating cycle (melting) differ from those obtained during the cooling cycle (crystallization). The typical shape of the solid-solid transition curve in the DSC thermograms(cooling cycle) of even n-alkanes readily distinguishes these from the odd n-alkanes, which is greately influenced by the increase in the carbon numbers in the chain (n-C₃₄ and beyond) and the purity of the sample.High molecular weight n-alkanes also showed instability in the structures at the phase transitions

The formation of solid solutions of n-alkanes have been studied by measuring phase transitional parameters and studying nature of the DSC thermograms of various binary and multicomponent mixtures of n-tetracosane (n-C₂₄) with other n-alkanes. It is observed that the immiscibility between two n-alkanes of the binary mixture begins when chain-length difference between them is more than four carbon atoms. In between the two extremes of solid solution and eutectic formations, there also existed the partial miscibility of two n-alkanes, particularly at high temperatures

The DSC thermograms of multicomponent n-alkane mixtures and Fischer-Tropsch waxes revealed that perfect solid solution is formed when the involved n-alkanes have carbon number very close to each other or the carbon number distribution is in a narrow range with smaller chain n-alkanes dominating.     

S-DMDAAC-AM强阳离子型天然高分子絮凝剂的合成

用淀粉为基材 ,石蜡油为油相 ,MT-1 (无机铵类化合物 )尿素混合物为引发剂合成了淀粉二甲基二烯丙基氯化铵 (DMDAAC)丙烯酰胺 (AM)接枝共聚物。考察了共聚条件对产物的接枝率、接枝效率和阳离子化度的影响 ,合成最佳条件为 :[MT 1 ]=0 .2 60 mmol/ L,[NH2 CONH2 ]=2 .0 0 mmol/ L,w (总单体 ) =40 % ,m (淀粉 ) =6.0 2 g,DMDAAC/ AM(质量比 ) =3∶ 7,w (Span 2 0 ) =8% ,V (石蜡油 ) =5 5 m L,油 /水(体积比 ) =1 .2∶ 1 ,反应温度 45℃ ,反应时间 4h。接枝率 1 2 6.67% ,接枝效率 94.5 2 % ,固含量 3 7.5 6%     

Fischer-Tropsch synthesis in a slurry reactor in the presence of nanosized cobalt catalysts synthesized in situ in a hydrocarbon medium

Fischer-Tropsch synthesis in a slurry reactor at a pressure of 20 atm and a temperature of 220–300°C in the presence of 100Co : 2Pd : (5–50)Al₂O₃ and 100Co : 2Pd : (20–50)ZrO₂ (parts by weight) catalysts in situ synthesized in a hydrocarbon medium has been studied. The catalysts were prepared by the decomposition of cobalt salts and promoters in melted petroleum paraffin P-2 at 300°C and in situ reduced with hydrogen. It has been found that the nanocatalyst containing 20 parts by weight of ZrO₂ exhibits the highest activity in the Fischer-Tropsch synthesis and provides the yield of liquid products of 70 g/m³ at a CO conversion of 80%.     

尿素脱蜡制备低熔点相变蜡的工艺研究

通以减一线馏分油（简称减一线油）为原料进行尿素脱蜡工艺研究,得到尿素络合制备低熔点相变蜡的适宜工艺条件为：络合温度为25 ℃、尿素溶液加入量（w）为91%、尿素溶液组成为m（尿素）：m（异丙醇）：m（水）＝45∶35∶20、反应时间为60 min、洗油量（w）为76%。在此条件下得到的粗蜡收率为28.2%,熔点为29.6 ℃,正构烷烃质量分数为94.9%,脱蜡油凝点小于－60 ℃。对该粗蜡进行发汗后处理可以得到相变蜡,其熔点为31 ℃,焓值为201.9 kJ/kg     

长链烷烃和双环烷烃混合原料加氢异构规律的研究——工艺条件的影响

将正十六烷和十氢萘按85∶15的质量比配成混合原料,以负载Pt的氢型TON结构分子筛作为催化剂,考察温度、压力、液时空速和氢/油体积比对于混合原料中链烷烃和环烷烃加氢异构转化活性和产物分布组成的影响。结果表明,混合原料中的十氢萘在异构体系中的反应活性很低,高温、低压下脱氢生成四氢萘,液时空速、氢/油体积比对十氢萘的转化几乎没有影响。对于混合原料中的正十六烷,低压有利于提高其转化率和异构烃的选择性,但相近转化率下,压力不改变单支链异构烃收率分布。低液时空速可以提高正构烷烃的转化率,但不改变产物分布。实验范围内,氢/油体积比的变化对正构烷烃的临氢转化几乎没有影响。