冶炼烟气高浓度SO2制酸设计运行总结

介绍了国投金城冶金有限责任公司冶炼烟气高浓度SO_2制酸装置的工艺流程和运行情况。该装置采用"4+1"预转化制酸工艺、"ⅢⅠⅣⅡ"换热流程,设计SO_2总转化率大于99.9%。制酸尾气采用双氧水法脱硫工艺,将排放气体ρ(SO_2)控制在100 mg/m~3以下。技术人员在预转化段装填低温活性和高温活性均较好的催化剂,通过降低进口温度使催化剂床层不超温,提高预转化段的转化率。     

两转两吸流程

近年来世界硫酸工业单套系统的生产能力不断扩大,已达到日产1300吨、1400吨、1800吨。而且往往几个大系列集中布置于一个企业内,年产高达130万吨、150万吨。我国硫酸工业也存在上述特点,有些酸厂还位于“鱼米之乡”,由此带来了防止大气污染的问题。众所周知,硫酸尾气排放的SO_2量随着转化率的提高而下降,现以年产20万吨酸厂(硫铁矿制酸,SO_2入转化的浓度9％)为例,其尾气中SO_2与转化率的关系列于表1。     

两转两吸新流程治理硫酸尾气技术报告

一、前言我厂的硫酸生产原来是采用土法生产的,1969年改造为以沸腾炉焙烧的普通水洗流程生产,生产规模是1万吨/年。以普通一次转化一次吸收流程去生产硫酸,尽管在工艺操作上很注意,其SO_2转化率的极限数值仍只有97％左右。生产时从烟囱里排放出来的尾气含SO_2浓度较高,对厂区附近的大气环境产生污染,影响人们的身体健康,危害农作物的正常生长。特别是生产时,SO_2转化率低于部颁标准,尾气的污染就更为严重。我厂在1978年下半年起硫酸生产的各项工艺技术指标虽已全面达到部颁标准,SO_2转化率达到96～97％,但     

关于硫酸转化器开车时的反应动力学与尾气排放的研究

对硫酸转化器开车时的反应动力学与尾气排放进行了研究和模型模拟,并与硫酸装置的运行数据进行了比较。给出关于开停车程序、催化剂类型和活性如何影响转化器动态响应和SO_2排放的典型案例。研究表明,降低SO_2与SO_3排放量的关键在于预热、SO_2浓度升高速度、催化剂选择和停车时催化剂吹扫的恰当组合,这也是具体装置的独特特征。     

提高硫酸系统SO_2转化率的研究及改造实践

介绍了大冶有色硫酸三系列提高SO_2转化率的研究和改造实践。通过技术改造,解决了硫酸系统存在的转化器气流分布不均匀、催化剂装填系数偏低及Ⅲ换热器腐蚀影响转化热平衡的问题。改造后SO_2转化率提升至99.81%,硫酸产量略有增加,尾气脱硫系统碱耗降低近40%,环保装置运行成本大幅度降低。     

浅论(3+2)SO_2两次转化流程

本文对需要(3+2)五层触媒才能使SO_2两次转化的总转化率稳定在99.5％以上;尾气达到直接放空的排放标准;流程不复杂;投资增加不多;还可相应回收硫酸;社会效益和经济效益又都较理想诸方面进行了论证。文章对提高转化率的理论基础及其在实践生产中的检验进行了论述。     

硫酸厂尾气二氧化硫的治理

硫酸生产尾气中含有二氧化硫,污染大气。随着硫酸工业生产的发展,尾气的治理已成为环境保护工作的重要课题。国外,尾气排放标准控制较严,生产厂家对尾气的治理大都采用提高 SO_2转化率,降低尾气中 SO_2含量的办法。如单转单吸工艺老厂改造,安设尾气处理装置;双转双吸工艺     

降低硫酸厂SO2的排放

硫酸工业的当前趋势是:在保持或增加硫酸生产能力的同时,降低排放到大气中的SO_2数量。应用孟山都的含铯催化剂,无论是一次转化还是两次转化的硫酸厂,均能有效地降低其SO_2排放量。本文介绍应用孟山都含铯催化剂来降低SO_2排放的可能性以及使用孟山都便携式气体分析装置(PeGASyS)来优化工厂操作的情况。便携式气体分析仪是一种优化工厂操作和显示含铯催化剂在降低SO_2排放方面优越性的得力手段。含铯催化剂和便携式气体分析装置在众多工厂的应用将勾硫酸转化器的性能建立一个新的标准。     

硫酸生产中尾气回收的Peracidox(R)工艺

Peracidox(R)工艺用以降低来自两转两吸硫酸装置排放尾气中残留SO2含量,从而控制污染物的排放量,改善大气质量.""该工艺的特点是控制便,所需机械设备量较少,还可用以在开车和停车阶段(这时催化剂的转化率不是最优状态)改善排放尾气的条件.     

硫酸尾气氨洗法工业化技术开发

硫酸尾气氨洗法技术即在氨洗塔的吸收段采用氨水吸收硫酸尾气中的SO_2,该技术应用在600 kt/a和800 kt/a硫酸装置上可减排SO_2量为2 596.81 t/a,副产硫酸铵溶液量为5 360 t/a[折100%(NH_4)_2SO_4计],且硫酸尾气中SO_2浓度大大低于国家排放标准要求的限值400 mg/m~3。该技术投资费用和运行成本较低,吨酸增加运行费用仅为4.04元。     

水碳比对尿素合成系统的影响

分析水碳比对尿素合成系统转化率的影响以及改进的方法。     

Incompleteness of conversion in a traveling polymerization wave in the presence of heat loss

The steady-state propagation of a polymerization wave in an infinite bulk is studied. It is assumed that the heat release law is specified by a truncated Arrhenius function. It is shown that in the presence of heat loss, complete conversion of the substance is impossible. __________ Translated from Fizika Goreniya i Vzryva, Vol. 43, No. 6, pp. 75–77, November–December, 2007.     

Catalytic conversion of waste biomass by hydrothermal treatment

The purpose of the work presented here is the production of liquid biofuels from wet organic waste matter in a continuous one-step catalytic process under hydrothermal conditions. The catalytic reaction of wet organic matter at near-critical water conditions (T > 300 °C, p > 22.1 MPa) is used to produce a mixture of combustible organics which can be used as liquid biofuel. In order to achieve a good product quality in a continuous one-step process, two catalysts were applied, a homogeneous potassium carbonate catalyst and a heterogeneous ZrO₂ catalyst. In addition, the reaction mixture was recirculated. The continuous flow of concentrated waste biomass feed at low flow rates and recirculation of the hot reaction mixture were the most challenging obstacles to overcome. The scale of the plant (0.1 l reactor volume) allowed for a variation of the feed, reaction temperature, and recirculation rate in order to optimise the process conditions. Still, the product quantity obtained was sufficient to perform a analytical characterisation. The experimental results confirmed the feasibility of the process. Hydrothermal treatment of waste biomass, after dewatering, resulted in a biocrude oil of high calorific value.     

The low-temperature conversion of methyl formate on zirconium oxide

Zirconium oxide samples prepared by a variety of methods were found to have surface areas from 7 to 226 m²/g and relative amounts of tetragonal to (tetragonal + monoclinic) phases from 0 to 100%. Methyl formate is converted to carbon monoxide and methanol on these samples at temperatures of 220–265 °C. All catalyst samples examined are stable at these temperatures for times-on-stream up to 3 h. Although the conversion varies with the relative amounts of tetragonal phase present and decreases with increase in the calcination temperature, a clear dependence on surface area is also observed. The conversion of methyl formate is found to be first order with activation energies of 80 (±10) kJ/mol. The data can be fitted to a Langmuir-Hinshelwood equation.     

化学工程科学发展的回顾与思考

简述了化学工程科学发展的主要成果,重点介绍了近期发展的“产品工程”,化学工程中的尺度问题及化工过程“场”和“流”分析等方面的进展及其对化学工程科学内容的贡献;提出以“质量传递与转化”,“能量传递与转化”及“信息传递与转化”来描述现代化学工程学科体系。本文还对我国化工科学及产业发展进行了展望。     

天然气制氢技术简介及应用中的关键问题

大型化工行业中以天然气为原料的制氢工艺主要是天然气蒸汽转化，该工艺流程主要由原料气预处理、蒸汽转化、一氧化碳变换和氢气净化提纯四大单元组成，其中转化炉是蒸汽转化的技术核心和关键设备。本文主要对上述四个单元的作用原理、工艺流程及关键操作参数进行了详细的介绍，并依据作者的工作经验，提出了天然气蒸汽转化制氢技术在工程化和试车过程中要注意的关键问题。     

生物质能利用技术研究进展

介绍了生物质能概念、开发利用生物质能的意义和价值以及其转化利用技术和现状。阐述了其开发前景。目前,生物质能的利用技术主要有直接燃烧法、生物化学法、热化学转化法、固体成型和生物柴油制取。我国生物质能利用的重点将是发展农林生物质发电、生物液体燃料、沼气及沼气发电、生物固体成型燃料技术四大领域。     

一种具有充电功能的交直流转换电路的设计与实现

介绍了一种具有充电功能的交直流转换电路的设计方法,分别对交直流转换电路、直流电压转换电路和电池充电电路进行设计。实际应用表明:在有220V(AC)或电池的情况下,电源都可以稳定输出24、12、3.3V直流电压。     

A review of Canadian wood conversion technologies for the production of fuels and chemicals

Canada has 347 million ha of forest cover, contributing to the potential large availability of wood-based resources. Although Canada's forest sector contributed $23.7 billion to the national nominal gross domestic product (GDP) in 2019, the GDP contribution of the wood product manufacturing subsector shrank by 6%. To reposition the Canadian forest industry, new forest management practices and wood-based conversion technologies should be applied. In this context, the use of woody biomass in biorefineries to produce clean energy, fuels, and chemicals is becoming increasingly significant. There is a need to understand the current status and challenges of the wood-based biomass conversion technologies that have been and are being developed in Canada. This information will help decision-makers in formulating and implementing forest sector-related policies for a sustainable bioeconomy in Canada. This study is focused on a review of Canadian woody biomass conversion technologies. Our critical review identified considerable potential biomass conversion technologies specialized for woody feedstock, all in the Canadian setting. We focused on the prospects of revitalizing Canada's pulp and paper industry through the integration of pre-treatment processes and biochemical technologies. The thermochemical conversion pathway was identified as the dominant route for woody feedstock valorization. The review also identified pathways with the potential to diversify the existing product mix that generate products from wood streams, such as chemicals and biomaterials. Most of the biochemical and thermochemical research done in institutional and multi-institutional research collaborations from laboratory scale to industrial scale will boost the chances of the commercialization of a wood-based biorefinery in Canada.