Fine coal desulphurization by leaching with bromine containing hydrobromic acid

Sulphur extraction from coal by leaching with bromine-containing aqueous hydrobromic acid has been investigated in the temperature range from ambient to 120 °C. This procedure was found to be selective for the removal of high levels of sulphate and pyritic sulphur within a few minutes of leaching, while no significant reduction of the organic sulphur could be observed. Leaching led to an appreciable reduction of the ash yield and the up-take of substantial quantities of bromine. The bromine can be removed as hydrogen bromide by thermal treatment under nitrogen, without significant loss of volatile matter; for reduction of the bromine level to below 0.1 wt%, treatment for at least 1 h at ≈ 500 °C was needed.     

Model selection for aqueous slurry coal desulphurization

Simple solid-fluid process models developed for uniform size solid bodies (screened or palletized materials), like the shrinking core model, have been applied to multifraction mixtures of solid bodies usually encountered in processing of ground coal or oil shale. The experimental conversion, measuring total effects on all of the size fractions was recalculated to the conversion of the longest surviving single fraction. The calculations used literature data on coal desulphurization by wet oxidation of pyretic sulphur and results are discussed in terms of rate limiting steps.     

Relation between dielectric property and desulphurization of coal by microwaves

Dielectric properties of various coals and aqueous NaOH solutions were determined to study thermochemical coal desulphurization by microwave irradiation. Aqueous NaOH solutions were used as media for irradiation. The coal samples were placed in a rectangular cavity and irradiated with 2450 MHz microwaves, resulting in 70–80% desulphurization efficiency.     

煤粉磁选脱硫技术的研究现状与展望

阐述了煤炭磁选脱硫技术的基本原理及研究现状,对煤系黄铁矿磁性强化技术进行了详细评述,指出发展有中国特色的煤炭燃前脱硫技术,应优先考虑干法磁选脱硫技术。     

Kinetics of chemical desulphurization of coal in aqueous ferric chloride

The kinetics of the chemical desulphurization of Lafia coal by the oxidation of the pyritic sulphur component with aqueous ferric chloride has been investigated. The oxidation rate was found to increase significantly with increasing temperature (60 to 102°C) and ferric chloride concentration (0.2 to 1.0M) but decreased with increasing coal particle size (-0.210 mm to +0.841 mm). The kinetic data were well described by the unreacted shrinking core model with the indication that the desulphurization was predominantly chemical reaction controlled. The rate of reaction was also found to be well correlated by a two-parameter pseudo-homogeneous kinetic model. The specific rate constant obtained showed a true Arrhenius temperature dependence.     

高硫煤加氢热解脱硫研究

在常压固定床上,温度450—750℃,氢气流速300—900 mL/m in和升温速度15℃/m in的实验条件下,对沟底高硫煤加氢热解脱硫的影响因素进行了研究。实验结果表明,适当增加氢气的流速,提高反应最终温度和延长停留时间,对高硫煤加氢热解脱硫效率的提高和降低残留物中的硫质量分数都是有利的;利用气相色谱研究了硫化氢气体的逸出规律,随着热解温度的提高,硫化氢气体逸出曲线表现为2个峰。研究认为,高温峰源于硫铁矿和噻吩类含硫化合物中硫的脱除,而低温峰源于脂肪族含硫化合物硫的脱除。煤脱硫反应的热力学也表明,随热解温度升高煤加氢热解脱硫分为2段。     

Surface-area reduction of coal during slurry-phase chlorinolysis

The effects of reaction time, solvent and temperature on the internal surface area of coal during slurry-phase chlorination were experimentally studied. Areas established using nitrogen as the adsorbate were found to decrease sharply with reaction time, especially in the early stages of the chlorination. Reduction of the surface area decreased with increasing temperature and the effect was independent of the amount of chlorine taken up by the coal. The loss of porosity during chlorination of coal was attributed to swelling of the coal matrix because of the considerable uptake of chlorine.     

多功能脱硫塔在氨法烟气脱硫中的应用

氨法烟气脱硫技术具有脱硫效率高、无二次污染、副产品资源化程度高等优势,而存在的氨损耗和亚铵氧化等问题却长期制约其推广应用。针对这一问题开发的多功能脱硫塔,从设备和工艺两方面综合考虑,基本解决了这一问题,以此为核心的脱硫系统在260 t/h循环流化床锅炉烟气脱硫工程运行三年多表明,该系统脱硫效率达95%～99%,尾气中SO₂含量在50～190 mg/m³;副产硫铵满足国家标准。     

Solvent treatment of coals: 1. Effects on microporosity at ambient temperature

The effects of extraction with thirteen solvents and three solvent mixtures at ambient temperature on the surface areas of three bituminous coals were investigated. The total surface area of each coal, measured by CO₂ at 298 K, was substantially increased by extraction with pyridine, ethylenediamine, methylpyrrolidinone and THF. The maximum surface area attained was nearly the same for the three coals—evidence for a similar, highly crosslinked macromolecular network type of structure in all three coals. Given enough time, the mixed solvents were also effective in increasing the total surface area when the ‘solubility parameter’ of the coal was equal to the ‘solubility parameter’ of the mixture. None of the solvents increased the surface area measured by nitrogen significantly, indicating that the pores opened by the extraction of soluble pore material were < 0.5 nm in size. All the effective solvents satisfied the donor and acceptor number requirements for extraction of pore material based on the donor-acceptor model of coal extraction.     

Microbial desulphurization of lignites by a thermophilic bacterium

As a possible means of abatement of air pollution the use of thermophilic thiobacilli in lignite desulphurization has been investigated in lab-scale batch experiments and 50% organic sulphur 58% total sulphur removal has been achieved in 10% lignite slurries at 50 °C.     

Bioprocessing of coal

A computer-assisted survey and evaluation of the international literature on microbial transformations of coal and relevant organic compounds was performed to identify candidate microorganisms and biological processes potentially applicable to coal bioprocessing. The vast majority of the literature on coal bioprocessing deals with desulphurization via pyrite removal, and some bioprocessing schemes have been proposed. Reports on organic sulphur and metals removal from coal have recently appeared. As yet unevaulated are systems for removal of other elements from coal such as oxygen and nitrogen. However, model substrates resembling certain important O and N functional groups in coal are degraded by microorganisms. These microorganisms could be potentially useful in coal bioprocessing.     

Auto-desulphurization of coal

The effect of atmospheric oxidation or weathering on different forms of sulphur in coal has been studied using a coal sample ground to <63 μm and kept exposed to the atmosphere for up to 228 days. Occasionally, samples were taken from the exposed coal for analysis of total-, sulphate-, pyritic- and organic sulphur. Significant amounts of total-, pyritic- and organic sulphur were reduced up to 106 days of exposure, resulting in a total sulphur content within the permissible limits of utilization. Thus, commercial desulphurization of coal may be possible by using the simple process of atmospheric weathering.     

经济实用的烟气脱硫方法

针对当前低浓度ＳＯ２烟气脱硫工艺因处理成本高而受到限制这一问题，介绍了粉煤灰、低品位菱镁矿、天然沸石的烟气脱硫方法．     

组合式除雾脱硫塔在烟气脱硫中的应用

介绍了组合式除雾脱硫塔在烟气脱硫项目中的应用情况.重点介绍了组合式除雾脱硫塔的设备结构和运行优势.该脱硫塔将一段电除雾器通过法兰连接在脱硫塔的上部,通过电除雾器对烟气中的烟尘、酸雾、及砷、铅等有害杂质进行深度净化,以达到满足环保排放指标的目的.该脱硫塔可节约设备占地面积,节省投资成本.     

取消旁路对脱硫系统的影响简析

介绍了燃煤锅炉电站烟气脱硫工艺流程及旁路烟道的作用。分析了取消旁路烟道后对现有及新建脱硫装置的设计及运行的影响。提出了取消烟道旁路的主要优势及对原有脱硫装置稳定运行的技术难点。为使取消烟道旁路后的装置安全稳定运行,必须设计合理,严格控制吸收塔入口烟气温度并减少油污及粉尘。     

草木灰促进CaO粉末高温烟气脱硫实验研究

为了研究草木灰添加剂对氧化钙脱硫性能的影响,用HSC5分析了在200~1 000℃的温度范围内草木灰对氧化钙脱硫过程的改善,分别以CaO和CaO与草木灰的混合物为吸收剂进行实验,并加以比较。研究了加入草木灰添加剂后,对高温烟气脱硫性能和固定床干法烟气脱硫最佳温度的影响,草木灰配比对氧化钙脱硫性能的影响等。结果表明,加入一定量的草木灰,可以显著提高脱硫效率和钙利用率。当温度在800~900℃时,草木灰与氧化钙的配比为10∶100时效果最好,脱硫效率可达96.2%,钙利用率57%。     

煤直接液化低分油加氢脱硫脱氮反应动力学研究

为了进一步了解煤直接液化油中硫氮化合物的形态和性质,采用石油研究中的先进分析手段GC-PFPD和GC-NCD,对煤直接液化低分油进行了分析,获得了详细的硫氮化合物组成含量。结果发现:煤直接液化低分油中含有大量的杂环化合物,S主要以苯并噻吩类和二苯并噻吩类化合物存在,N主要以五元环化合物形式存在。在高压釜中进行了催化剂添加量和不同温度条件下的加氢实验,对总硫总氮的加氢反应动力学进行了研究。通过计算得到了高压釜煤液化油加氢脱硫反应的一级反应动力学模型,且通过模型计算的S含量与反应实测的S含量相对误差仅为7.8%;对实验得到的震荡式高压釜中煤液化油加氢脱氮反应的一级反应动力学模型进行验证,发现相对误差也仅为0.97%。     

石灰石-石膏法单塔双循环烟气脱硫工艺介绍

主要介绍了石灰石-石膏法单塔双循环烟气脱硫工艺原理、流程、主要设备以及工业应用情况。该新工艺是在典型石灰石-石膏法脱硫工艺基础上改进而来,克服了典型工艺的缺点与不足,能在满足脱硫效率的同时,降低系统能耗,节约投资和占地面积,达到国家最新的排放要求ρ（SO2）低于50 mg/m^3。