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1.
A comparative study of liquid product on non-catalytic and catalytic degradation of waste plastics using spent FCC catalyst 总被引:1,自引:0,他引:1
Non-catalytic and catalytic degradation of waste plastics (high-density polyethylene (HDPE), low-density polyethylene (LDPE),
polypropylene (PP) and polystyrene (PS)) using spent fluid catalytic cracking (FCC) catalyst into liquid product were comparatively
studied with a stirred semi-batch reactor at 400 ‡C, under nitrogen stream. Liquid product characteristics were described
by cumulative distribution as a function of lapse time of reaction, paraffin, olefin, naphthene and aromatic (PONA) composition,
and also carbon number distribution on plastic type of reactant. For degradation of waste PE with relatively high degradation
temperature, the effect of adding spent FCC catalyst greatly appeared on cumulative distribution of liquid product with a
reaction lapse time, whereas those for waste PP and PS with low degradation temperature showed a similar trend in both non-catalytic
and catalytic degradation at 400 ‡C. In PONA and carbon number distribution of liquid product, the characteristics of waste
PS that was mainly degraded by end chain scission mechanism were not much altered in presence of spent FCC catalyst. However,
waste polyolefinic polymer that was degraded by a random chain scission mechanism significantly differed on PONA and carbon
number distribution of liquid product with or without spent FCC catalyst. The addition of spent FCC catalyst in degradation
of polyolefinic polymer, which economically has a benefit in utilization of waste catalyst, significantly improved the light
olefin product by its high cracking ability and also the aromatic product by cyclization of olefin as shape selectivity in
micropore of catalyst. 相似文献
2.
Liquid-phase catalytic degradation of waste polyolefinic polymers (HDPE, LDPE, PP) over spent fluid catalytic cracking (FCC)
catalyst was carried out at atmospheric pressure with a stirred semi-batch operation. The effect of experimental variables,
such as catalyst amount, reaction temperature, plastic types and weight ratio of mixed plastic on the yield and accumulative
amount distribution of liquid product for catalytic degradation was investigated. The initial rate of catalytic degradation
of waste HDPE was linearly increased with catalyst amount (4-12 wt%), while that was exponentially increased with reaction
temperature (350-430 ‡C). Spent FCC catalyst in the liquid-phase catalytic degradation of polymer was not deactivated fast.
The product distribution from catalytic degradation using spent FCC catalyst strongly depended on the plastic type. The catalytic
degradation of mixed plastic (HDPE: LDPE: PP: PS=3: 2: 3: 1) showed lower degradation temperature by about 20 ‡C than that
of pure HDPE. 相似文献
3.
催化汽油改质降烯烃多产丙烯反应规律的研究 总被引:1,自引:0,他引:1
在小型固定流化床实验装置上,以燕山石化催化汽油为原料,对催化汽油改质过程进行了实验研究,并对反应过程气体产品和液体产品的组成进行了详细分析,考察了反应温度、重时空速、剂油比以及催化剂的活性对改质过程产物分布的影响,发现在催化汽油改质过程中,各操作条件对改质过程产物分布均有不同程度的影响,通过选择合适的操作条件,在保证低烯烃含量的同时,实现多产丙烯是可行的,在适宜的条件下,汽油烯烃体积分数可降到11.8%,同时,液化气中丙烯质量分数达到了44.4%. 相似文献
4.
A commingled post-consumer polymer (CPW#1) was pyrolysed over spent fluid catalytic cracking (FCC) commercial catalyst (ECat-1) using a laboratory fluidised-bed reactor operating isothermally at ambient pressure. The influence of reaction conditions including catalyst, temperature, ratios of commingled polymer to catalyst feed and flow rates of fluidising gas was examined. The conversion for spent FCC commercial catalyst (82.7 wt%) gave much higher yield than silicate (only 14.2 wt%) and the highest yield (nearly 87 wt%) was obtained for ZSM-5. Greater product selectivity was observed with ECat-1 as a recycled catalyst with about 56 wt% olefins products in the C3–C7 range. The selectivity could be further influenced by changes in reaction conditions. Valuable hydrocarbons of olefins and iso-olefins were produced by low temperatures and short contact times used in this study. It is also demonstrated that the use of spent FCC commercial catalyst and under appropriate reaction conditions can have the ability to control both the product yield and product distribution from polymer degradation, potentially leading to a cheaper process with more valuable products. 相似文献
5.
Fluidized catalytic cracking (FCC) is an important link in heavy oil processing. Industrial FCC catalyst which mainly consists of molecular sieves, substrates and adhesives is used in large quantities every year. Spent FCC catalyst is one kind of hazardous solid waste that is hard to handle. In this paper, we used a spent FCC catalyst as a desulfurization adsorbent, and show that it displays advanced desulfurization property. Furthermore, regeneration experiment showed that calcination was an effective method to remove the sulfides adsorbed in spent FCC catalyst, after four cycles it still owned a high sulfur adsorption ability. The results of metal impregnation indicated that the high ability to remove sulfur in LPG was due to those metals deposited on WC. The sulfur removal further increased by calcination of the spent catalyst since carbon deposition on the catalyst surface which blocked the active sites was minimized by calcination, thus leading an increase in the number of active sites available. 相似文献
6.
为了认识催化裂化烟气轮机垢样和预测垢样形成原因,选择新鲜剂、待生剂、平衡剂、三旋细粉和催化烟机垢样代表催化裂化催化剂全生命周期,采用X射线衍射、X射线荧光、扫描电镜、同步热分析和激光粒度分析技术,得到新鲜剂、待生剂、平衡剂、三旋细粉和催化烟机垢样样品的元素组成、晶相结构、表面形貌、差热曲线和粒径分布等物性分析数据。通过对比各样品分析结果,发现催化剂全生命周期中金属元素和非金属元素的富集和脱离规律与低熔点化合物存在关联关系,得出垢样中Y型分子筛发生晶格变化的结论,预测多种低熔点化合物和烟机工艺条件是导致烟机结垢的根本原因,这些结果可以为后期机理研究奠定基础。 相似文献
7.
Catalytic degradation of high-density polyethylene (HDPE) was carried out under nitrogen using a laboratory fluidised bed reactor operating at 360 °C with catalyst to polymer feed ratio of 2:1 and at 450 °C with catalyst to polymer feed ratio of 6:1 under atmospheric pressure. The catalysts used in this study were ZSM-5, US-Y, ASA, fresh FCC (fluid catalytic cracking) commercial catalyst (Cat-A) and equilibrium FCC catalysts with different levels of metal poisoning were studied. The initial results for polymer degradation at 360 °C (catalyst to polymer ratio of 2:1) in a fluidised bed reactor in terms of the yield of volatile hydrocarbon products were: model catalysts>commercial FCC catalyst>E-Cats. However, when the process conditions more closely resembled to FCC conditions, the fresh commercial FCC catalyst was more favourable in terms of the yield of volatile hydrocarbon products. The degradation of HDPE over E-Cats although reduced was similar to ASA in product selectivity and yield, and the level of metal contamination did not affect the product stream generated. A simple economic evaluation of polymer recycling process is reported showing that a catalytic system based on E-Cats appears comparable in costs to a commercial thermal cracking plant. 相似文献
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采用工业Ni-Mo/Al2O3-HZSM-5催化剂在小型固定床加氢微反装置上对催化裂化(FCC)汽油临氢改质过程的反应特性进行了研究,通过考察反应温度、压力、空速和氢油体积比对改质后的FCC汽油烃类组成的影响,分析了汽油中不同烃类的转化性能。结果表明,氢油比对产物组成影响不大,高温、低压、低空速有利于增加芳烃的选择性,低温、高压、高空速则有利于增加异构烷烃的选择性;临氢改质后,FCC汽油的烯烃含量明显降低,芳烃和异构烷烃含量增加,因而产品汽油的辛烷值基本保持不变;全馏分、轻馏分和重馏分FCC汽油临氢改质实验结果表明,烯烃含量较高的轻馏分具有更高的转化活性;在FCC汽油临氢改质过程中,同碳数的端烯烃反应活性高于内烯烃,直链烯烃的反应活性高于支链烯烃。 相似文献
10.
金属污染是导致流化催化裂化(FCC)催化剂失活的重要因素,充分利用沉积的重金属是废FCC催化剂资源化的关键。本文将废FCC催化剂引入到轻质油品吸附脱硫领域,以脱除液化石油气(LPG)中的二甲基二硫醚作为考核目标,验证了废FCC催化剂作为脱硫剂的可行性。除去废FCC催化剂表面积炭后,其脱硫性能得到明显改善,在常温、质量空速为4.0h-1的条件下,LPG中硫化物质量分数从382mg/m3脱除至40mg/m3。镧、铁、镍、钒、钙、锑6种金属在新鲜催化剂和焙烧后废催化剂上的总质量分数从10.2%升高至46.6%,6种金属按照对应含量分别固载在新鲜催化剂上,脱硫效果较未改性新鲜催化剂均有明显提升。验证实验表明,导致FCC催化剂失活的金属具有较高脱硫活性,废FCC催化剂作为轻质油品脱硫剂具备工业前景。 相似文献
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以混合废塑料和焦化蜡油为原料,共催化裂解制备燃料油,克服了废塑料裂解中塑料粘稠度大且传热效率低、裂解炉中温度极不均匀、反应时间长、气体和固体收率高、液体收率低和易结焦等难题。详细考察焦化蜡油与混合废塑料质量比和催化剂用量对产物组成的影响以及FCC催化剂的重复使用性能。结果表明,在焦化蜡油与混合废塑料质量比为2、FCC催化剂用量为混合废塑料质量的10%、终温460 ℃并保持4 h条件下,燃料油收率达到96.67%,气体收率和釜残率分别仅有0.27%和1.53%。焦化蜡油的添加使液相产物中重组分增多,轻组分减少。FCC催化剂的重复使用性能好,催化剂重复使用5次,液体收率大于85%。采用混合废塑料与焦化蜡油共催化裂解的工艺不仅为“白色污染”的处理开辟了一条新途径,而且扩大了焦化蜡油的应用范围。 相似文献
13.
For the purpose of efficient utilization of waste polystyrene, the recovery method of a styrene oligomer having a molecular weight of 1000–3000 was studied. Thermal and catalytic degradations were carried out. It was impossible to obtain a styrene oligomer with a molecular weight less than 5000 by thermal degradation in the temperature range of 300–500°C. Catalytic degradation in the presence of silica–alumina catalyst in the temperature range of 190–230°C made it possible to control the decrease in molecular weight and to obtain a styrene oligomer having a molecular weight of 500–3000. Simultaneously, the molecular structures of the reaction products from thermal and catalytic degradations were determined by NMR analysis. 相似文献
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Md.Azhar UddinThallada Bhaskar Jun KanekoAkinori Muto Yusaku Sakata Toshiki Matsui 《Fuel》2002,81(14):1819-1825
Dehydrohalogenation during pyrolysis of brominated flame retardant containing polystyrene (brominated high impact polystyrene (HIPS-Br)) mixed with polyvinylchloride (PVC) was carried out in a laboratory scale batch process. Thermal and catalytic degradation of HIPS-Br mixed with PVC on carbon composite of iron oxide (TR-00301) catalyst was investigated. The thermal degradation of waste plastics (HIPS-Br/PVC) yielded liquid products with 55,000 ppm bromine and 4300 ppm chlorine content in oil. Catalytic degradation (4 g; TR-00301) of HIPS-Br/PVC waste plastics at 430 °C produced halogen-free clean oil, which can be used as a fuel oil or chemical feedstock. The main liquid products during catalytic degradation were benzene, toluene, styrene, ethyl benzene, α-methyl styrene, butyl benzene, 1,2-dimethyl benzene etc. The average carbon number of the liquid products produced during catalytic degradation (9.3) of waste plastics was less than that of the thermal degradation (10.4) and the density of liquid products was found to be lower during the catalytic degradation than the thermal degradation. The possibility of a single step catalytic process for the conversion of halogenated waste plastics into fuel oil with the simultaneous removal of chlorine and bromine content from the oil was demonstrated. 相似文献
16.
To develop a novel catalyst system that has excellent olefin reduction capability for FCC gasoline without loss in octane number, different catalysts supported on multiple composite carriers consisting of SAPO-11, Hβ, HMOR and HZSM-5 were prepared and their catalytic performances for FCC gasoline upgrading were assessed in the present investigation. The pore structure and acidity of the catalysts were characterized by N2 adsorption and pyridine adsorption FTIR, respectively. Based on the results obtained over the catalysts supported on binary-zeolite carriers (Hβ/HZSM-5, HMOR/HZSM-5 and SAPO-11/HZSM-5) using FCC gasoline as the feedstock, various multiple-zeolite supported catalysts were developed from different combinations of the binary-zeolite systems. It was found that the SAPO-11/HMOR/β/ZSM-5 quadruple composite zeolite supported catalyst gave higher liquid yield, improved gasoline RON, and lower coke deposit amount for the hydro-upgrading of FCC gasoline and thus can be considered as a potential catalyst system. A comprehensive analysis based on the catalytic activities and acidity measurements revealed that acid strength and acid type were two very important factors influencing hydroisomerization and aromatization activities, and the difference in catalyst acid strength determined which factor predominates. 相似文献
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以甲醇制烯烃(MTO)与催化裂化(FCC)汽油降烯烃组合反应工艺为研究目标,采用分子筛催化剂,在小型固定床微型反应装置,研究MTO反应、汽油降烯烃反应以及甲醇与汽油混合炼制反应,比较了典型酸性分子筛催化剂的催化性能。结果表明,组合反应过程呈现出非稳态特征,小分子烯烃具有自催化现象,导致产物组成分布随反应时间显著变化。NH3-TPD分析表明,具有中强酸与强酸相结合分布特点的催化剂适合于反应过程的协同催化作用要求。适宜的反应条件为:以SAPO-34分子筛作催化剂,反应温度400 ℃,甲醇混炼比15%,反应时间30 min。该条件能同时较好满足MTO和FCC汽油改质要求,产物汽油中烯烃含量较FCC汽油中的含量下降50%,并可获得较高的小分子烯烃产率,实现MTO转化。 相似文献
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This article describes a novel non-hydrogenating FCC gasoline upgrading catalyst system consisting of a kaolin/γ-Al2O3 binary-matrix and an active component zeolite HZSM-5. Different catalysts made from the different combinations of HZSM-5 with the three matrices (two kaolins and γ-Al2O3) or their binary mixtures were prepared and their catalytic performances were assessed in a continuously flowing fixed-bed reactor using FCC gasoline as feedstock. The results showed that compared with the single-matrix based HZSM-5 catalysts, the binary-matrix based HZSM-5 catalysts had much better catalytic performance. The characterization results of the acidity, specific area and pore structure properties of the catalysts revealed that the synergisms between the matrices and HZSM-5 in the acidity and pore distribution of the binary-matrix based catalysts accounted for their improved catalytic performance. Our results demonstrated that the non-hydrogenating catalyst system developed in the present investigation can convert olefins in FCC gasoline into aromatics that have higher research octane number (RON) and thus has potential application for FCC gasoline upgrading because of its excellent olefin reduction ability and RON preservability. 相似文献
20.
利用催化裂化催化剂在小型固定流化床实验装置上对催化裂化汽油催化改质降烯烃过程的反应规律进行了实验研究,详细考察了反应温度、剂油比和重时空速对产物收率和汽油辛烷值的影响,得到了催化裂化汽油改质过程的最佳实验操作条件:反应温度为400~430℃,剂油比为7左右,重时空速为20~30 h-1。在此基础上,计算了汽油改质过程的反应热,分析了反应条件对反应热的影响,揭示了反应热的变化规律。结果表明,低温改质为放热过程,高温改质为吸热过程。改质条件对反应热影响的强弱顺序为反应温度>剂油比>重时空速。 相似文献