脱甲烷塔未达标的原因初探

从分析低压法脱甲烷流程的工艺特点入手,通过将设计条件与现实操作数据的对比、计算、分析,找出目前该塔不能实现达标操作的关键所在,为攻关改造提供了依据。     

乙烯装置脱甲烷塔的改造

介绍了大庆石化总厂化工一厂乙烯装置中脱甲塔于１９９７和１９９９年两次改造前后的运行情况及问题及分析,强调了加压精馏塔采用填料时应注意的问题及措施。     

乙烯装置低压甲烷氢流程优化改造

介绍了国内某石化公司乙烯装置低压甲烷氢流程改造项目的背景、改造过程、运行状况、能耗分析,并对改造后的效果进行分析与评价。此次流程优化改造需增加1台甲烷氢压缩机,回收利用冷分离系统的低压甲烷氢,利用新增压缩机将低压甲烷氢进行增压并送至燃料气管网。流程改造提高了装置的操作灵活性,为后续原料轻质化提供了支撑,降低了装置能耗。     

乙烯装置脱甲烷塔系统的运行分析

对脱甲烷塔的运行现状进行了分析,找出了存在的问题,并进行了技术改进和工艺参数优化,使脱甲烷塔顶的乙烯损失减少,增加了乙烯收率。     

改造后脱甲烷塔运行状况分析

介绍改造后脱甲烷塔运行状况,出现的问题及其对策。     

80万吨/年乙烯装置脱甲烷塔设备选型计算

脱甲烷塔系统是乙烯装置深冷分离流程中裂解气分离的关键,既要保证乙烯的回收率,又要保证乙烯产品的纯度,同时也是冷量的主要消耗所在.因此,设计一个能耗低、投资小的脱甲烷塔尤为重要.     

乙烯装置脱甲烷系统中甲烷分离浅析

对高压脱甲烷系统中甲烷分离进行了讨论.通过对甲烷在脱甲烷系统内的走向分析,讨论了碳二洗涤塔进料温度对乙烯冷剂负荷的影响;将液相甲烷从-140℃甲烷氢分离罐跨线补充至脱甲烷塔回流罐,可降低乙烯损失和乙烯冷剂消耗;最后,以碳二洗涤塔进料温度和跨线流量2个变量进行综合分析,得到了局部最优解.     

改造甲烷氢外送流程 提高副产品利用价值

独山子乙烯装置由于加大轻烃裂解负荷,组分轻质化使得约2 500 m3/h（标准状况）以上的甲烷氢富余,通过燃料气压力控制阀PV19008B放火炬以控制燃料气系统的平衡。为提高副产品的附加值,将冷箱低压甲烷和脱甲烷塔高压甲烷外送给制氢装置和乙二醇装置作为原料和致稳剂使用,并将富足氢气并入公司氢气管网,不但稳定了下游装置生产,而且减少了放火炬的损耗,提高了乙烯装置副产品综合利用率和经济效益。     

优化脱甲烷塔操作 降低乙烯损失

通过分析大庆乙烯装置裂解顺序分离工艺流程的特点,找出了顺序分离过程中乙烯主要损失的部位。研究发现,C2RX反应器、ET-421/431/432运行稳定,乙烯损失很小;而前冷、ET-405顶温高,尾气温度高,则乙烯损失较大。通过优化ET-405操作,降低了顺序分离过程中的乙烯损失,提高了乙烯收率。     

ENRICHMENT OF HEAVY WATER BY THERMAL DIFFUSION

Equations of the best wire angle of inclination for the maximum separation, maximum output and minimum column height for enrichment of heavy water in a concentric-tube wired thermal diffusion column have been derived. Considerable improvements in performance were obtained by employing the wired column instead of using the open column (without wire). It was also found that the wire inclination for maximum separation is also the wire inclination required to obtain the maximum production rate, or minimum column height, for a specified degree of separation.     

THERMAL DIFFUSION IN A FLAT-PLATE COLUMN WITH TRANSVERSE SAMPLING STREAMS

The optimum angles of inclination for maximum separation, maximum production rate and minimum column length in a fiat-plate thermal diffusion column with transverse sampling streams, have been determined. Considerable improvement in performance is obtainable if the column is tilted at the optimum angle, instead of being placed vertically, so that the convection strength can be properly reduced and controlled, resulting in suppressing the undesirable remixing effect while still preserving the desirable cascading effect.     

电化学方法研究碳钢高温水体系中的氢扩散和渗透

本文应用Devanathan渗透装置的原理,设计了一套能用于测量碳钢-高温水体系中氢在碳钢中的扩散和渗透的实验装置,找出了该装置用于测量的最佳工作参数,并用该装置测量了373—473K下氢在碳钢中的扩散系数和扩散速率,讨论了氢在碳钢上还原的机理。     

微通道内甲烷/湿空气重整转化效率实验研究

用沉淀法制备了涂覆在微通道内壁面的Ni/Al2O3催化剂,在自行搭建的实验系统上进行了微通道内甲烷/湿空气催化重整的实验研究,考察了催化壁面温度、空碳比及甲烷体积流量对甲烷/湿空气重整转化效率的影响,并与数值计算结果进行对比.结果表明,随着催化温度的升高,甲烷转化率不断升高;相同水碳比下,甲烷的催化转化率随着空碳比的增大而增大;随着甲烷体积流量的增大,甲烷转化效率呈现先增大后减小的变化规律.反应温度为1 023 K,甲烷体积流量为20 mL/min时,实验所得甲烷转化率达到最大值,为61.3％.     

浮选柱与浮选机分选煤泥的对比试验研究

通过浮选柱和浮选机对不同煤泥的浮选试验，分析比较了２种浮选方法在分选煤泥时的各自优缺点，证实了浮选柱在浮选细粒细煤泥时具有良好的发选效果；并通过试验，给出了各自最佳的浮选粒度范围。     

THE PROPER COLUMN NUMBER FOR BEST PERFORMANCE IN THERMAL DIFFUSION COLUMNS OF THE FRAZIER SCHEME WITH TOTAL SUM OF COLUMN HEIGHT FIXED

The effect of column number on the Frazier scheme performances with total sum of column heights fixed has been investigated. The equations that may be employed to predict the optimal number of columns (generally not integers) for the maximum performance are derived. Accordingly, the proper number of columns, which are the integers nearest to and smaller than the optimal column numbers, are obtained for practical applications. Considerable improvement in performance is obtainable if the scheme is constructed with the proper number of thermal diffusion columns, instead of using a single column, with the same total sum of column heights.     

A STUDY ON THE SEPARATION OF DIFFUSION AND SURFACE EMISSION COEFFICIENTS IN WOOD

ABSTRACT

For a more accurate simulation of the moisture sorption process in wood, the precise separation of surface emission and diffusion coefficients is essential. In this paper, a non-linear simplex technique that was developed to obtain the optimum pair of the surface emission coefficient he, and the diffusion coefficient D from a single sorption curve is presented and tested with experimental data. An easy to use computer program was employed to carry out the evaluation. Data analysis showed that the new method resulted in a more statistically accurate calculation of b_c and D than currently existing methods.     

流化床中甲烷催化裂解制备碳纳米管和氢气

利用高活性的纳米Ni/Cu/Al₂O₃催化剂,在流化床反应器中研究了CH₄裂解制备碳纳米管与H₂的过程.CH₄的转化率受流化床中的操作条件（温度、空速、气速及升温速率等）影响,碳纳米管的形貌也受过程的升温速率影响.在低升温速率下,能够同时得到较高的CH₄转化率与形貌较好的碳纳米管.而且采用低的升温速率,可以在流化床（提供碳纳米管生长的自由空间）中连续生长碳纳米管,从而为将来的连续化大批量制备碳纳米管奠定了基础.     

EXPERIMENTAL STUDIES OF DIFFUSION FLUXES F TERNARY DISTILLATION OF THE ACETONE-METHANOL-ETHANOL YSTEMS BY A WETTED-WALL OLUMN

Measurements of mass and diffusion fluxes for ternary distillation of the acetone-methanol-ethanol systems were made by a wetted-wall column under total reflux conditions for wide ranges of the liquid concentrations. Intermediate component methanol showed peculiar behavior of a finite mass flux near the zero-driving force region. This was explained as being due to the effect of the interfacial velocity caused by mass fluxes of the other components. The diffusion fluxes were shown to be proportional to concentration driving forces, whereas the mass fluxes were not. Discussions on the use of the number of transfer units for correlation of mass transfer data in ternary distillation were also made.     

煤的原子分子结构及吸附甲烷机理研究进展

总结了煤的原子径向分布与微晶结构、稠环芳烃的电子光谱规律与煤的颜色间的关系、煤与CH4分子的相互作用、无烟煤及其炭化样吸附／解吸甲烷的热力学和动力学过程等内容的研究与发展，结果表明：(1)低阶煤的微晶参数d002，Ic和Ia随含碳量呈阶段性变化，其微晶结构特征与纤维素的结构有关，并可用煤化度p定量描述煤化过程中煤的微晶结构变化。(2)煤中存在13个苯环以上稠环芳香结构单元，(3)甲烷分子与煤表面的相互作用各向异性，最大作用势(吸附势)为2．65kJ／mol，旋转势垒为1．34kJ／mol，预计吸附振动光谱的跃迁基频为53cm^-1。(4)煤对甲烷的饱和吸附量几乎不随温度变化，炭化样与活性炭的饱和吸附量则随温度的降低而线性增大；从煤制备的炭化样，以及活性炭的吸附热都接近甲烷液化热，而煤的吸附热则高出近一倍。(5)煤层(粒)吸附解吸甲烷的动力学过程可用通用的一级组合模型和实用的吸附(解吸)扩散控制模型来描述，其三常数动力学公式中的初始吸附(解吸)率Q0／Qmax可作为煤与瓦斯突出预测指标。(6)甲烷在无烟煤中的扩散系统为～10^-10cm^2／s，扩散活化能为14．3kJ／mol；甲烷在煤中的扩散实为通过微孔的流动。