蒸焦加热炉在焦炉气甲烷部分氧化工艺中的作用

1 概述 在焦炉气作为合成氨原料气时,要将焦炉气中所含20％～25％的甲烷转化成一氧化碳和氢气,可采用蒸汽转化法和部分氧化法。我公司采用部分氧化法。甲烷的转化是在温度1000℃、压力2MPa、借助催化剂的作用在转化炉中进行的。部分氧化法,由于进转化炉中的蒸汽一焦炉气(蒸焦)混合气加热方式不同。

关于制甲醇项目中蒸焦混合气管道的优化设计

焦炉气制甲醇项目中,焦炉气与一定比例的蒸汽混合进入到综合加热炉的辐射段,加热至约600℃进入纯氧转化炉,从综合加热炉到转化炉的这一段管线,管径大,温度高,材质都是不锈钢,是整个项目的至关重要的管线。而加热炉管口受力比较小,管道走向直接影响加热炉的管口受力,且影响项目的整体费用。因此,本文采用CAESARII管道应力分析软件分别对方形加热炉和圆形加热炉出口的蒸焦混合气管道走向进行优化设计,满足加热炉管口荷载要求,且满足一次应力和二次应力,确保加热炉长久、安全运行。而且分析结果为以后焦炉煤气制甲醇项目中相同管道的布置起到一定的指导和参考作用,具有十分重要的意义。

万众瞩目汽车召回

中国入世后,汽车召回一直是业界的热门话题,但好事多磨,原来有望在今年二月出台的汽车召回政策的喜讯再度搁浅,是否应该实行汽车召回,让消费者享受国民待遇的争论也由此进入新的高潮。近日国家质检总局正式向社会公布了《缺陷汽车产品召回管理规定(草案)》,这标志着中国广大消费者热切关注的汽车召回制度终于有了定数。

岁末随想

一年前,大多数中国人几乎是怀着既渴望又惧怕的复杂心情跨进WTO的门槛的。尽管我们曾经为这一天的到来奋斗了15年,也准备了15年,一旦如愿,却反而顾虑重重,显得底气不足。毕竟对于大多数中国人来说,对WTO的了解太少太少,而对“狼来了”的警告听得太多太多。一想到即将与一群张着血盆大口的恶狼共舞,谁能不感到心惊胆战呢?

Investigation on the catalytic effects of AAEM during steam gasification and the resultant char reactivity in oxygen using Shengli lignite at different forms

The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species （AAEM） on char conversion during the gasification in steam and the changes in ex-situ char reactivity in oxygen after the gasification in steam using different forms （i.e. H-form, Na-form） of Shengli brown coal. The surface area, AAEM concentration and carbon crystallite of chars were obtained to understand the change in char reactivity. It was found that not only Na concentration and carbon structure were the main factors governing the char reactivity in the atmosphere of steam and oxygen, but also they interacted each other. The presence of Na could facilitate the formation of disordering carbon structure in char, and the amorphous carbon structure would in turn affect the distribution of Na and thus its catalytic performance. The surface area and pore volume had very little relationship with the char＇s reactivity. Addi- tionally, the morphology of chars from different forms of coals were observed using scanning electron microscope （SEM）.

Ni nanoparticles supported on carbon as efficient catalysts for steam reforming of toluene(model tar)

This paper investigated the influences of surface properties of carbon support and nickel precursors(nickel nitrate, nickel chloride and nickel acetate) on Ni nanoparticle sizes and catalytic performances for steam reforming of toluene. Treatment with nitric acid helped to increase the amount of functional groups on the surface and hydrophilic nature of carbon support, leading to a homogeneous distribution of Ni nanoparticles. The thermal decomposition products of nickel precursor also played an important role, Ni nanoparticles supported on carbon treated with acid using nickel nitrate as the precursor exhibited the smallest mean diameter of 4.5 nm. With the loading amount increased from 6 wt% to 18 wt%, the mean particle size of Ni nanoparticles varied from4.5 nm to 9.1 nm. The as-prepared catalyst showed a high catalytic activity and a good stability for toluene steam reforming: 98.1% conversion of toluene was obtained with the Ni content of 12 wt% and the S/C ratio of3, and the conversion only decreased to 92.0% after 700 min. Because of the high activity, good stability, and low cost, the as-prepared catalyst opens up new opportunities for tar removing.

Kinetic model on coke oven gas with steam reforming

The effects of factors such as the molar ratio of H2O to CH4 (n(H2O)/n(CH4)), methane conversion temperature and time on methane conversion rate were investigated to build kinetic model for reforming of coke-oven gas with steam. The results of experiments show that the optimal conditions for methane conversion are that the molar ratio of H2O to CH4 varies from 1.1 to 1.3 and the conversion temperature varies from 1 223 to 1 273 K. The methane conversion rate is more than 95% when the molar ratio of H2O to CH4 is 1.2, the conversion temperature is above 1 223 K and the conversion time is longer than 0.75 s. Kinetic model of methane conversion was proposed. All results demonstrate that the calculated values by the kinetic model accord with the experimental data well, and the error is less than 1.5%.

Comparison of steam-gasification characteristics of coal char and petroleum coke char in drop tube furnace

The steam-gasification reaction characteristics of coal and petroleum coke （PC） were studied in the drop tube furnace （DTF）. The effects of various factors such as types of carbonaceous material, gasification temperature （1100- 1400 ℃） and mass ratio of steam to char （0.4：1, 0.6：1 and 1：1 separately） on gasification gas or solid products were investigated. The results showed that for all carbonaceous materials studied, H2 content exhibited the largest part of gasification gaseous products and CH4 had the smallest part. For the two petroleum cokes, CO2 content was higher than CO, which was similar to Zun-yi char. When the steam/char ratio was constant, the carbon con- version of both Shen-fu and PC chars increased with increasing temperature. When the gasification temperature was constant, the carbon conversions of all char samples increased with increasing steam/char ratio. For all the steam/char ratios, compared to water gas shift reaction, char-H2O and char-CO2 reaction were further from the thermodynamic equilibrium due to a much lower char gasification rate than that of water gas shift reaction rate. Therefore, kinetic effects may play a more important role in a char gasification step than thermodynamic effects when the gasification reaction of char was held in DTF, The calculating method for the equilibrium shift in this study will be a worth reference for analysis of the gaseous components in industrial gasifier. The reactivity of residual cokes decreased and the crystal layer （L002/d002） numbers of residual cokes increased with increasing gasification temperature. Therefore, L002/d002, the carbon crystallite structure parameter, can be used to evaluate the reactivity of residual cokes.

Analysis of Energy Consumption and Energy Conservation Measures for RFCCU at Shengli Petrochemical Company

This article introduces a string of energy conservation measures adopted over the past sev- eral years by the RFCC unit at Shengli Petrochemical Complex, including the optimization of feedstock properties, the adoption of high-efficiency atomizing nozzles, the revamp of CO boiler, the atomization by means of dry gas, the post-burning of flue gas as well as the application of frequency converting machines and pumps, resulting in ideal effects. The energy consumption of the RFCC unit was gradually decreased to 2984.25 MJ/t from the original level of 3716.99 MJ/t. After comparing basic energy con- sumption values with actual consumption values, the authors have set forward measures for further energy conservation, such as the recovery of low-temperature excess heat contained in oil/gas streams exiting from the fractionation tower top, addition of the fourth cyclone, delivery of hot oil slurry, and heat tracing with hot water.

Automatic Stamping Charger---Stamping of Blended Coal-Theorical Study and Practice Analysis at TKCSA

The coke plant of a steel plant corresponds to the area that transforms a blend of coal into coke for using in blast furnace and steam to power plant. The coking plant of ThyssenKrupp CSA uses the heat recovery technology with stamping charger for stamping and preparation a blend of coals for charging and coking. Stamping technology adds several benefits to the process, such as increased density, homogeneity and alignment of the coal cake charged into the oven, as well as provides better control of the coking process, improves parameters of coke quality and allows coal blending with lower coking power, thereby reducing the production cost of coke and power generation. Through the automation of stamping charger, it is possible to evaluate and calculate the stamped coal density charged and the productivity gains this system provides.

Changes in char reactivity due to char-oxygen and char-steam reactions using Victorian brown coal in a fixed-bed reactor

This study was to examine the influence of reactions of char–O2and char–steam on the char reactivity evolution.A newly-designed fixed-bed reactor was used to conduct gasification experiments using Victorian brown coal at800 °C. The chars prepared from the gasification experiments were then collected and subjected to reactivity characterisation(ex-situ reactivity) using TGA(thermogravimetric analyser) in air. The results indicate that the char reactivity from TGA was generally high when the char experienced intensive gasification reactions in 0.3%O2in the fixed-bed reactor. The addition of steam into the gasification not only enhanced the char conversion significantly but also reduced the char reactivity dramatically. The curve shapes of the char reactivity with involvement of steam were very different from that with O2 gasification, implying the importance of gasifying agents to char properties.