柴油加氢精制反应器堆焊层腐蚀缺陷的处理

热壁式加氢反应器在使用过程中,堆焊层出现氯离子点腐蚀,点腐蚀产生的主要原因是原料中氯离子超标以及存在堆焊层制造缺陷等。堆焊层腐蚀缺陷的处理方面有较高的技术要求,尤其是在现场处理方面更需要注重实际操作经验,本文详细介绍了缺陷部位清理、焊前消氢、补焊、焊后热处理等整个处理过程,以及相关的理论依据和预防措施。     

热处理对哈氏合金C-276堆焊层性能的影响

由实验结果得到在焊态和热处理态的哈氏合金C-276堆焊侧弯结果均合格;增加保温时间,SWAM堆焊侧弯试验不合格,而ESSW堆焊侧弯仅有32h热处理试样不合格;焊态试件硬度符合要求,热处理后堆焊层硬度有所提高;应力腐蚀试验合格,SMAW堆焊和ESW堆焊层腐蚀率在焊态和热处理下均合适.哈氏合金C-276堆焊层在焊态和690...     

加氢精制反应器制造中的单层带极电渣堆焊技术

在单层带极电渣堆焊12Cr2MolR不锈钢工艺评定试验的基础上,运用合理的单层带极电渣堆焊参数对堆焊层分别进行了铁素体、化学成分、弯曲性能、耐腐蚀性及氢剥离试验等性能评定。该技术成功应用于加氢精制反应器筒体和封头的堆焊工艺中。     

不同堆焊方法组合堆焊层组织性能研究

加氢反应器是石油化工企业的核心装备,其内壁堆焊是该设备生产制造过程的关键步骤。本文以加氢反应器内壁堆焊为研究背景,在2.25Cr-1Mo钢上采用带极电渣焊与药芯气保焊组合堆焊方法进行双层不锈钢堆焊,并对得到的组合堆焊层进行化学成分、铁素体含量和组织性能分析,结果表明：组合堆焊层的化学成分、铁素体含量、金相组织、硬度、弯曲性能、抗晶间腐蚀性能均满足加氢反应器的制造要求。     

探讨铁素体含量对不锈钢堆焊层磁性测厚的影响

分别就碳钢层与堆焊层的铁素体含量对不锈钢堆焊层磁性测厚的影响进行了探讨,提高了不锈钢堆焊层磁性测厚的准确性。     

锁紧环换热器耐蚀层堆焊工艺研究

锁紧环式换热器在高温、高压、临氢和硫化氢环境条件下工作,需在其内部堆焊不锈钢耐蚀层。但不锈钢耐蚀层的堆焊是制造中的技术难点,堆焊材料选择不当或堆焊工艺不合理会产生堆焊层剥离问题,所以解决堆焊层的抗剥离问题就成为锁紧环制造中的技术关键。通过对不锈钢耐蚀层产生剥离问题的影响因素进行焊接性分析和工艺研究,确定了最佳工艺匹配,成功地完成了耐蚀层堆焊。     

热壁加氢反应器堆焊层氢剥离试验

简要介绍了国外基于AsTM G146-01关于热壁加氢反应器堆焊层与基材之间抗氢致剥离特性的试验方法和试验程序,包括试样尺寸确定、热处理、超声检测、清洗、除气、压力试验、充氢、试块切割、金相检测等.     

不锈钢单层电渣带极堆焊

简要介绍了加氢反应类设备内壁耐腐蚀层的堆焊,通过选用特定的堆焊材料及合理的工艺参数,来实现单层堆焊的焊接技术。     

12Cr2Mo1锻件带极埋弧堆焊Inconel625工艺研究

为保证12Cr2Mo1锻件带极埋弧堆焊Inconel625质量达到设计文件要求,对锻件基材和Inconel625焊接性能进行了分析,模拟承制产品实际生产状态进行堆焊工艺评定试验,采用周向堆焊和直道堆焊相结合的方法制备评定试件,对堆焊层化学成分、弯曲性能、硬度指标、金相组织、耐腐蚀性能进行了检测。试验结果表明,采用EQ62-50/ES200的焊带/焊剂组合可以获得性能优良的堆焊层。对堆焊层进行腐蚀速率检测,其焊态试样腐蚀速率为1.50 mm/a,固溶态试样腐蚀速率为1.17mm/a,两者之比为1.28,满足JB/T 4756—2006标准规定比值小于或等于1.5的要求。根据评定合格的焊接工艺对热高分气/循环氢换热器管板进行了堆焊,堆焊产品已稳定运行三年,未出现焊接缺陷和腐蚀缺陷。     

金属基陶瓷磨盘衬板表面堆焊结合性研究

为了实现对金属基陶瓷磨盘衬板高效、高质量的堆焊修复,选用自主研发的药芯焊丝在报废的陶瓷磨盘衬板上进行修复性研究。利用着色探伤、光学显微镜、扫描电镜等技术检测手段,对堆焊层与磨盘衬板的结合性、堆焊层应力释放裂纹的扩展情况进行了检测与表征,研究了堆焊层与磨盘衬板之间界面的结合情况。结果表明,自主研发的药芯焊丝所形成的堆焊层与磨盘衬板结合性良好,应力释放裂纹扩展细密均匀。经实践证明,在确保了堆焊层与母体结合性条件下,可对陶瓷磨盘衬板进行高质量的表面堆焊修复,改变目前陶瓷磨盘衬板只换不修的局面,对水泥行业降本增效有着积极的意义。     

高温变换炉氢腐蚀原因分析及处理

高温变换炉在使用22年后产生了很严重的氢腐蚀鼓包缺陷。对高温变换炉氧腐蚀的原因进行分析，采取去氢及增加内隔热层等办法，有效地延长了该设备的使用寿命。     

4-Lump kinetic model for vacuum gas oil hydrocracker involving hydrogen consumption

A 4-lump kinetic model including hydrogen consumption for hydrocracking of vacuum gas oil in a pilot scale reactor is proposed. The advantage of this work over the previous ones is consideration of hydrogen consumption, imposed by converting vacuum gas oil to light products, which is implemented in the kinetic model by a quadratic expression as similar as response surface modeling. This approach considers vacuum gas oil (VGO) and unconverted oil as one lump whilst others are distillate, naphtha and gas. The pilot reactor bed is divided into hydrotreating and hydrocracking sections which are loaded with different types of catalysts. The aim of this paper is modeling the hydrocracking section, but the effect of hydrotreating is considered on the boundary condition of the hydrocracking part. The hydrocracking bed is considered as a plug flow reactor and it is modeled by the cellular network approach. Initially, a kinetic network with twelve coefficients and six paths is considered. But following evaluation using measured data and order of magnitude analysis, the three route passes and one activation energy coefficient are omitted; thus the number of coefficients is reduced to five. This approach improves the average absolute deviation of prediction from 7.2% to 5.92%. Furthermore, the model can predict the hydrogen consumption for hydrocracking with average absolute deviation about 8.59% in comparison to those calculated from experimental data.     

Hydrocracking: An improved Kinetic Model and Reactor Modeling

Stangeland's kinetic model for predicting hydrocracker yields was modified to explicitly account for the mass balance closure in each individual hydrocracking reaction and for the effect of hydrogen partial pressure on the hydrocracking reaction rate. This improved kinetic model has two additional parameters. The model was applied to the modeling of a fixed bed reactor for mild hydrocracking of vacuum gas oils in the framework of the Aspen Plus® process simulator. The kinetic parameters were regressed using the algorithm of Levenberg-Marquardt such that the mass balance in each individual hydrocracking reaction is satisfied. The reactor model assumed gas-liquid equilibrium and was used to quantify the effect upon conversion of the operating variables--liquid hourly spatial velocity, reactor pressure, and hydrogen-to-feed ratio--showing that both the kinetic and reactor models predict the appropriate trends compared to the reference data. The practical implications of explicitly introducing the mass balance closure for each hydrocracking reaction in the kinetic model are discussed.     

Hydrocracking: An improved Kinetic Model and Reactor Modeling

Stangeland's kinetic model for predicting hydrocracker yields was modified to explicitly account for the mass balance closure in each individual hydrocracking reaction and for the effect of hydrogen partial pressure on the hydrocracking reaction rate. This improved kinetic model has two additional parameters. The model was applied to the modeling of a fixed bed reactor for mild hydrocracking of vacuum gas oils in the framework of the Aspen Plus® process simulator. The kinetic parameters were regressed using the algorithm of Levenberg-Marquardt such that the mass balance in each individual hydrocracking reaction is satisfied. The reactor model assumed gas-liquid equilibrium and was used to quantify the effect upon conversion of the operating variables--liquid hourly spatial velocity, reactor pressure, and hydrogen-to-feed ratio--showing that both the kinetic and reactor models predict the appropriate trends compared to the reference data. The practical implications of explicitly introducing the mass balance closure for each hydrocracking reaction in the kinetic model are discussed.     

煤焦油加氢转化技术

分析了国内已经研究开发的煤焦油加氢转化技术,按照各技术的特点和轻油产品收率将现有煤焦油加氢转化技术划分为轻馏分油固定床加氢精制、减压馏分油固定床加氢裂化、全馏分油固定床加氢裂化、延迟焦化-固定床加氢裂化联合加工、悬浮床和沸腾床加氢裂化5类技术,分别介绍了每种技术的工艺流程特点和发展状况,分析了各自的优缺点、局限性、技术难点和实用性。建议今后应关注煤焦油生产芳烃产品、酚类产品技术的开发,以及开发煤焦油脱水脱盐技术,进一步完善、配套煤焦油加氢转化技术。     

Deactivation of a platinum reforming catalyst in a tubular reactor

This work concerns the methodology of characterizing the deactivation of a catalyst by coke deposition. The isomerization of n.pentane on a platinum reforming catalyst was studied in a tubular reactor permitting easy sampling of the gas phase at several positions in the reactor. Runs with high ratios of hydrogen to pentane did not show any deactivation and served to determine the kinetics of the main reaction and the principal side reaction, hydrocracking. At low ratios of hydrogen to pentane the catalyst was deactivated by carbonaceous deposits. At the end of the run the coke was determined in sections of the reactor and was found to be deposited according to a profile. Additional insight into the coking phenomenon was obtained from experiments on a thermobalance. A mathematical model for the performance of the tubular reactor subject to coking was set up and the parameters were determined from the experimental data. The parameters were found to be significantly determined and to obey the Arrhenius temperature dependence. The values of the parameters of the main reaction and of the hydrocracking side reaction which were derived from the experiments in the presence of coking were in agreement with those obtained from the runs in the absence of coking.     

Effect of vacuum gas oil hydrotreating reactor on multiple reactors and hydrogen network

The inlet temperature of the Vacuum Gas Oil (VGO) hydrotreating reactor of a refinery is analyzed with the integration of multiple series reactors and hydrogen network considered. The effect of the inlet temperature (T₁) on hydrogen sinks/sources and the product output is analyzed systematically based on the simulation of the series reactors, including VGO hydrotreating reactor, hydrocracking reactor, fluid catalytic cracking reactor and visbreaking reactor. The general relation between the Hydrogen Utility Adjustment (HUA) and multiple pairs of varying sinks and sources is deduced, and correlations between varying streams and T₁ are linearly fitted. Based on this, the quantitative equation between HUA and T₁ is derived, and corresponding diagram is constructed. The T₁ corresponding the minimum hydrogen consumption is identified to be 345℃.     

F-T合成加氢裂化催化剂的工业应用

F-T合成油低温工艺产物中有大于质量分数40%的石蜡生成,必须对其进行加氢裂化生产优质的中间馏分油。加氢裂化关键在于高性能催化剂的研究开发,概述了近年来加氢裂化催化剂在国内外的应用现状。FC-14及SC-I催化剂在内蒙古伊泰煤制油有限责任公司的运行结果表明,SC-I催化剂表现出良好的活性及较高的中间馏分油选择性,在总进料20 t·h^-1、反应器入口氢分压7.0 MPa、氢油体积比800和总体积空速（2.0~15.0） h^-1条件下,反应器出口温度约340 ℃,总温升14 ℃,表现出较高的反应活性及灵活的温度调控性,柴油收率上升约3~4个百分点,具有较高的中油选择性。     

加氢裂化沸腾床反应器的循环泵技术

主要介绍了加氢裂化沸腾床反应器循环泵的工作原理与结构特点,涉及了循环泵或称沸腾泵在加氢裂化沸腾床反应器内的作用、操作运行及故障的处理。重质油品或含固油品的加氢裂化反应工艺条件苛刻,循环泵或称沸腾泵的设计充分考虑了加氢裂化沸腾床反应器内的高温高压、临氢、油品含固以及催化剂颗粒存在的复杂操作条件,并保证了其可在此复杂环境中长周期运行。