1000MW燃煤电厂商业SCR脱硝催化剂的失活

以浙江某燃煤电厂1000MW商业SCR脱硝催化剂为研究对象,通过催化表征和活性评价综合分析该电厂1000MW商业SCR脱硝催化剂的失活原因.研究表明,催化剂的失活是多种因素共同作用的结果,(1)Fe,S,K和As元素中毒,其元素含量较新鲜催化剂分别增加了318.0%,233.3%,199.3%和99.8%;(2)催化剂表面孔道的飞灰堵塞,硫酸盐类沉积以及长时间高温反应造成催化剂的烧结和颗粒物的团聚,导致失活SCR脱硝催化剂比表面积较新鲜催化剂下降了20.3%;(3)活性组分V的价态变化造成V^(4+)/V^(5+)的比值由6.46下降至1.35,以及Lewis酸位点减少了34.2%,从而导致催化剂的失活.

基于失活商业脱硝催化剂制备的再生SCR催化剂性能研究

为了解决燃煤电厂废弃商业SCR催化剂的处理以及充分利用锰基SCR催化剂的低温活性,提出了失活商业SCR催化剂再生的新方法:将失活的商业SCR催化剂作为载体,利用多步浸渍法,将锰氧化物(MnO_x)负载于载体上,制备成新的脱硝催化剂。利用XRF,XRD,SEM,XPS和N_2等温吸附等测试技术对新鲜催化剂、失活催化剂以及再生催化剂进行表征,以探究再生方法制备的催化剂相比失活催化剂带来的变化。结果发现,针对采用的原始失活催化剂来说,MnO_2负载质量分数为4.67%时,催化剂的综合理化性能和催化剂的脱硝活性最优。另外,再生的催化剂在250℃条件下仍然可以保持较高的脱硝活性,说明再生的催化剂具有更宽的活性温度窗口。再生催化剂中起到催化作用的是未中毒的V_2O_5以及负载的MnO_x。MnO_x可能为催化剂带来了低温活性。同时,催化剂在高空速下依然可以保持较高的催化活性。该再生方法不仅可以实现废弃的SCR催化剂的再生,还可以提升催化剂的催化性能。

可商业化催化剂Cu/γAl_2O_3的制备和活性研究

用浸渍法制备出低成本的可商业化的Cu/γAl2O3催化剂,催化剂在NH3做还原剂下对NO有良好的活性。研究了Cu负载量和煅烧温度对催化剂结构和催化活性的影响,借助XRD和N2吸附法对催化剂的晶体结构、比表面积和平均孔径进行了表征;以NH3为还原剂,NO转化率为活性评价指标,对所制备催化剂进行了选择催化还原反应研究。结果表明:Cu负载量对催化活性有影响,而煅烧温度的影响不大。煅烧温度为723K,Cu负载量为质量分数10%时,催化剂的活性最高。

蜂窝式SCR催化剂烟气脱硝试验研究

用模具挤出的方法制备了蜂窝式0.98%V2O5-9.65%WO3/TiO2的SCR脱硝催化剂,采用BET、XRD、SEM、XRF等方法对微观结构进行考察。在SCR脱硝试验装置上测试各种条件下催化剂的性能,并与结构类似的商业催化剂进行对比。通过试验发现,在空速比（SV）为4 000 h-1、NH3/NO=0.9-1.0、300-400℃范围内,自制催化剂的NO脱除率、SO2氧化率、N2O生成率和氨逃逸量,与商业催化剂相比性能接近,基本达到商业应用的要求。在水蒸气含量超过5%时对NO脱除率影响不大,因此催化剂适用于实际烟气。试验中未观察到SO2对NO脱除的促进作用。自制催化剂结构强度低于商业催化剂,有待进一步改进。

SCR催化剂的组成对其脱硝性能的影响

在以TiO2为载体的基础上,考察了活性组分WO3和V2O5的质量分数以及SiO2和Al2O3的加入对SCR催化剂脱硝性能的影响,筛选出的最佳催化剂组成与某商业催化剂的催化活性、制备方法和催化剂组成进行比较。结果表明,SiO2和Al2O3的加入会降低催化剂的脱硝性能,筛选出的最佳催化剂组成为0.5%V2O5~10%WO3/TiO2;与实验室通过溶胶-凝胶法制备载体然后负载活性组分的制备方法不同,商业催化剂是将粒径均匀的锐钛矿型TiO2与玻璃纤维(主要成分为SiO2和Al2O3)通过黏合剂混合制备成型的催化剂载体,然后负载活性组分;由于制备方法和催化剂组成等方面的较大差异,0.5%V2O5~10%WO3/TiO2在低于603 K时具有很好的NO脱除率,而商业催化剂在实际烟气温度(603 K^663 K)范围内,能稳定保持90%以上脱硝率。

《爱伦·坡短篇小说精选》译后记

爱伦·坡是一位充满传奇色彩的作家,命运多舛而身后盛名。他被尊为恐怖小说大师、侦探小说鼻祖。被奉为美国文学的先驱之一,被法国象征主义诗派尊为始祖,是欧洲文学史上极富盛誉的人物。多年来,国内外学者一直对他和他的小说津津乐道,笔者有幸翻译他的作品,也深受作品中的哥特因子、狂欢情结、女性情结、死亡美学和商业催化等特点感染,故而一表拙见。

Modelling-based Optimisation of the Direct Synthesis of Dimethyl Ether from Syngas in a Commercial Slurry Reactor

In the present study, we developed a multi-component one-dimensional mathematical model for simulation and optimisation of a commercial catalytic slurry reactor for the direct synthesis of dimethyl ether （DME） from syngas and CO2, operating in a churn-turbulent regime. DME productivity and CO conversion were optimised by tuning operating conditions, such as superficial gas velocity, catalyst concentration, catalyst mass over molar gas flow rate （W/F）, syngas composition, pressure and temperature. Reactor modelling was accomplished utilising mass balance, global kinetic models and heterogeneous hydrodynamics. In the heterogeneous flow regime, gas was distributed into two bubble phases： small and large. Simulation results were validated using data obtained from a pilot plant. The developed model is also applicable for the design of large-scale slurry reactors.

Advances in DCC Process and Catalyst for Propylene Production from Heavy Oils

In the past several decades,SINOPEC has devoted continuously great efforts to the development of DCC technology,the only commercial process using heavy feeds aiming at propylene production.Recently,a series of research breakthroughs have been achieved in molecular refining.Based on the detailed analysis on the complex DCC reaction network,an innovative catalyst technology has been developed to Optimize Catalysis Kinetics (OCK in brief).The deep-cracking process can be improved with optimizing the availability of the active sites.The updated MFI and beta zeolites are used to boost the propylene selectivity.The latest generation catalyst DMMC-1 has been applied commercially.Compared with the best historical records in the past,the propylene yield upon application of the catalyst DMMC-1 increases by 2.4 m% coupled with an improved distribution of products.The DCC technology continues to assume a leading position for manufacturing propylene from heavy feedstocks.

Conversion and reaction kinetics of coke oven gas over a commercial Fe-Mo/Al_2O_3 catalyst

Producing methanol from coke oven gas(COG) is one of the important applications of COG. Removal of sulfur from COG is a key step of this process. Conversion and reaction kinetics over a commercial Fe-Mo/Al2O3 catalyst(T-202) were studied in a continuous flow fixed bed reactor under pressures of 1.6-2.8 MPa, space time of 1.32-3.55 s and temperatures of 240-360 °C. Though the COG contains about 0.6 mol/mol H2, hydrogenation of CO and CO2 is not significant on this catalyst. The conversions of unsaturated hydrocarbons depend on their molecular structures. Diolefins and alkynes can be completely hydrogenated even at relatively low temperature and pressure. Olefins, in contrast, can only be progressively hydrogenated with increasing temperature and pressure. The hydrodesulfurization(HDS) of CS2 on this catalyst is easy. Complete conversion of CS2 was observed in the whole range of the conditions used in this work. The original COS in the COG can also be easily converted to a low level. However, its complete HDS is difficult due to the relatively high concentration of CO in the COG and due to the limitation of thermodynamics. H2 S can react with unsaturated hydrocarbons to form ethyl mercaptan and thiophene, which are then progressively hydrodesulfurized with increasing temperature and pressure. Based on the experimental observations, reaction kinetic models for the conversion of ethylene and sulfur-containing compounds were proposed; the values of the parameters in the models were obtained by regression of the experimental data.

SO2氧化转化规律及其对商业SCR催化剂的影响分析

以商业SCR催化剂为研究对象,探究SO2氧化转化规律及其对SCR催化剂的影响,并用BET、NH3-TPD、H2-TPR、XRD、XPS、DRIFT等方法表征反应前后催化剂表面变化情况。研究表明:随着温度和O2体积分数的增加,SO2氧化转化效率升高;随着SO2初始浓度和空速的增加,SO2氧化转化效率降低。SO2发生氧化后,商业催化剂的比表面积和平均孔径减小,催化剂晶体结构没有发生变化,催化剂表面酸性位点整体增加且其氧化还原活性略微降低。由于SO2与催化剂相互作用,催化剂表面的元素价态发生一定的迁移,且产生了金属硫酸盐(OSO),消耗表面羟基。同时SO2与V5+反应使其转化为V4+。可为进一步进行催化剂安全运行和维护提供参考。

Commercial Application of Polymetallic Reforming Catalysts PRT

The commercial application results showed that the polymetallic reforming catalysts PRT exhibited high activity, good selectivity and stability. The performance of said catalysts could be restored completely through regeneration. After long period of operation, the activity of said catalysts still exhibited good sensitivity to temperature rise. Compared with the PR series catalysts, the PRT series catalysts had obviously better stability and lower coking rate.

Development and Application of DCC Catalysts to Meet New Demands

The new generation of DCC catalysts, the DMMC/RMMC series catalysts developed by RIPP are introduced in this paper. The large molecule cracking ability is enhanced by increasing the portion of large pores; and the coke selectivity is improved by adjusting the acidity site density on the matrix surface, while the selective cracking reactions are increased. The sphericity of catalysts is improved by adopting new preparation method. The commercial application results have shown that applying DMMC/RMMC series catalysts with the mixed VGO, VGO plus AR, and hydrotreated VGO feed can increase the propylene yield by 2.43, 1.3 and 0.8 percentage points, respectively, as compared to the previous catalysts along with improvement in some products yields. The refining enterprises can make more profits after applying new series of DCC catalysts.

Study and Commercial Application of Graded Optimization of Catalysts for Fixed Bed Residue Upgrading Unit

The SHIFT-G technology of inverse catalyst loading is used to optimize the catalyst grading in the residue hydrotreating unit. The results, taken from pilot tests and commercial units, have showed that the optimized catalyst grading system can reasonably distribute the reaction load, effectively improve the prop- erties of hydrotreated products, prolong the operating cycle and promote economic benefits.

Study on Commercial Application of FP-DSN Sulfur Transfer Additive in FCC Unit

The FCC unit with addition of various inventories of the FP-DSN type sulfur transfer additive was tested in a commercial scale. The effect of the sulfur transfer additive was analyzed by investigating the indicators related with the regenerator flue gas composition,the dry gas composition before desulfurization,the LPG composition before desulfurization,the acid gas,and the yield of gasoline and diesel. The test results indicated that the sulfur was trans ferred from the feed stream into the dry gas,LPG and acid gas,and the sulfur transfer effect was obvious only when the inventory of sulfur transfer additive exceeded over 2.0% of total FCC catalyst inventory.

Propane Dehydrogenation over a Commercial Pt-Sn/Al2O3 Catalyst for Isobutane Dehydrogenation： Optimization of Reaction Conditions

The applicability of a commercial Pt-Sn/Al2O3 isobutane dehydrogenation catalyst in dehydrogenation of propane was studied. Catalyst performance tests were carded out in a fixed-bed quartz reactor under different operating conditions. Generally, as the factors improving propane conversion decrease the propylene selectivity, the optimal operating condition to maximize propylene yield is expected. The optimal condition was obtamed by the experimental design method. The investigated parameters were temperature, hydrogen/hydrocarbon （HE/HC） ratio and space velocity, being changed in three levels. Constrains such as the susceptibility of the catalyst components to sintering or phase transformation were also taken into account. Activity, selectivity and stability of the catalyst were considered as the measured response factors, while the space-time-yield （STY） was considered as the variable to be optimized due to its commercial interest. A STY of 16 mol.kg^-1.h^-1 was achieved under the optimal conditions of T= 620 ℃, H2/HC = 0.6 and, weight hourly space velocity （WHSV） = 2.2 h^-1. Single carbon-carbon bond rupture was found to be the main route for the formation of lower hydrocarbon byproducts.

Development of the Novel Grid Type Multi-stage Regeneration Technology for FCC Unit

Based on the results of cold model tests, LPEC has developed a technology for regeneration of FCC catalyst in a regenerator with novel grid type internals in order to intensify the contact between gas and solid and enhance the coke burning efficiency in the regenerator. Test results have revealed that the density change in the fluidized bed equipped with grid internals is relatively homogeneous and the bubbling fre- quency is obviously reduced with apparent improvements in the dead fluidized zone adjacent to the regen- erator wall, and this device can be applied to the intensified regeneration of catalyst in the FCC regenerator. The commercial application of this device in a 0.8 Mt/a RFCCU at the refinery A had indicated that the carbon content of regenerated catalyst was reduced to 0.03% from 0.18%, and the amount of coke burned was increased by 5% with a definite reduction in main air consumption of the regenerator and some density reduction in the dilute phase section of the regenerator.

Comparison on Commercial Application of Two Types of C_8 Aromatics Isomerization Catalysts

The results of commercial application of two types of C_8 aromatics isomerization catalysts under different feed conditions were compared to gain an insight in the techno-economical basis for selecting proper technological route at the plant.The comparison reveals differences in every aspect of feed consumption,unit capacity,product output,product distribution,and unit process parameters depending upon which catalyst type is adopted by the integrated PX complex.The type of aromatics isomerization catalyst has its influence on the plant scale,the construction cost,the process unit capacity and the product cost,with the magnitude of its impact varying with changing feed conditions.

Commercial Application of the PS-VI Catalyst in the Revamped 0.8 Mt/a Catalytic Reforming Unit

This article makes an analysis on the major technical difficulties encountered in the process of revamping and expanding the capacity of the continuous catalytic reforming （CCR） unit from 600 kt/a to 800 kt/a at Tianjin Petrochemical Company. The requirements for expanding the CCR unit capacity to 800 kt/a have been met through adopting the low carbon-make PS-Ⅵ catalyst, properly lowering the RONC of the reformate, and appropriately retrofitting the towers and furnaces while keeping the reaction system, the catalyst regeneration system and the recycle hydrogen compressor intact. The calibration results have revealed that the liquid yield of reformate products, the octane rating of reformate, the pure hydrogen yield, the aromatics yield and the overall conversion rate all have met the revamp design targets.

Commercial Application of the MIP-CGP Technology for Olefin Reduction in FCC Unit

The refinery of Yanshan Petrochemical Company has twice retrofitted a 2.0-Mt/a RFCC unit with the MIP-CGP technology aimed at maximization of isoparaffins/clean gasoline and increased output of propylene. By modifying the riser reactor with addition of the second reaction zone coupled with an added external catalyst cooler outside the regenerator and adoption of the CGP catalyst to control the cracking depth the refiners have realized the target of reducing olefin content in gasoline and increasing the yield of LPG. The results of retrofitting the RFCC unit have revealed that after revamp of FCC unit the yield of LPG was increased by 7.31%, the conversion rate was increased by 9.06%, and the total liquid yield was decreased by 0.3%. After revamp of the RFCC unit the olefin content in gasoline was reduced by 19.5 v%, and the RON rating of gasoline was increased by 0.7 units to meet the demand of Beijing municipality for manufacture of the Olympic clean gasoline.

Development of Light Cycle Oil(LCO) Hydrocracking Technology over a Commercial W-Ni Based Catalyst

Because of its high density and low cetane number, the light cycle oil(LCO) containing heavy aromatics(60%—80%) can hardly be transformed through the conventional hydro-upgrading technology. In this report, a novel LCO hydrocracking technology(FD2G) was proposed for the utilization of LCO to manufacture high value-added products. Through the ingenious combination of hydroprocessing catalyst and the hydrocracking process, the high octane gasoline and the ultra-low sulfur diesel(ULSD) blendstocks were produced simultaneously. The influence of catalyst type, reaction temperature, pressure, respectively, on the research octane number(RON) of produced gasoline was studied in a fixed bed hydrogenation reactor. It indicated that high reaction temperature and medium pressure would favor the production of highoctane gasoline through the conversion of bi-aromatic and tri-aromatic hydrocarbons. The typical results of FD2 G technology on commercial units showed that it could produce clean diesel with a sulfur content of less than 10 μg/g and clean gasoline with a research octane number(RON) of up to 92. It would be contributed to the achievement of the maximum profit of a refinery, the FD2 G technology could provide a higher economic efficiency than the other diesel quality upgrading technology under the current gasoline and diesel price system.