双组份脱氯剂的制备与应用研究

采用混合法制备了以CaCO3为主活性组分、SrCO3为第二种活性组份的双组份高温脱氯剂,探讨了脱氯剂的制备条件,研究了反应温度、进口HCl浓度、空速和还原气氛对脱氯剂氯容的影响。结果表明：在CaCO3/SrCO3的配比为5：1,粘合剂高岭土和胶粉用量占15%,焙烧温度为500℃左右脱氯剂性能较好。该双组份脱氯剂适用于温度400℃~600℃,空速小于5000h-1,进口HCl浓度小于3000ppm的工况。以煤气为原料气时,脱氯剂的氯容可达32.7%。     

稀土氧化物对高炉炉顶煤气中HCl脱除过程的影响

在脱氯剂制备过程中分别添加CeO_2、La_2O_3制得含稀土氧化物的高炉炉顶煤气脱氯剂,借助于固定床高炉炉顶煤气脱除HCl气体试验发现:CeO_2和La_2O_3可以改善脱氯剂的孔隙结构,细化晶粒,增加比表面积和活性度;增加活性组分在黏结剂中的分散度,提高各元素的结合能,从而同时改善脱氯剂的化学性能和机械强度。考虑到高炉炉顶煤气脱氯剂制备的生产成本,高炉炉顶煤气脱氯剂中CeO_2、La_2O_3的质量分数应该控制在6%左右。     

国内动态

工业气体高温脱氧剂研制成功化工部西北化工研究院研制出工业气体高温脱氯剂。该脱氯剂可用于高温下脱除煤气、合成气、氢气、氮气等工业气体中的氯化物,具有使用温度范围宽、选择性好、脱氯精度高、抗压强度好、适用范围广等特儿脱氯剂外观为白色球状物,堆密度0．8～0．gkg／L,破碎强度＞50N／粒,磨耗率＜3％,比表面hi20m’／g,在常压或加压、温度400～700C、空速1000～3000h－’、含湿量约20％时,可将原料气中l、1000ppm的氯脱除至小于0．正。l．opphi,穿透氯容ifswt％。当煤气中含有40mg／m‘左右的COS时,该脱氯剂同时具有水…     

一种新型高温煤气脱氯剂的研究与开发

以价廉易得的天然矿物及碱为化学活性组分 ,制得一种新型高温煤气脱氯剂 GH1。该脱氯剂在 65 0°C高温、空速 2 5 0 0 h-1和进口 HCl气体体积浓度 1 80 0 mg/m3 条件下的穿透氯容量达到37.2 % ,同时机械强度合格。实验还考察了主要成分配比、空速和温度对脱氯性能的影响 ,并讨论了有关机理。     

高效脱氯剂与气体中HCl高温脱除的研究

对五种脱氯剂在固定床反应器中与HCl气体反应研究发现 ,在温度为 30 0℃ ,空速为 30 0 0h-1 ,进口HCl气体质量浓度为 1× 10 -3 mg m3 条件下 ,所有脱氯剂都能迅速与HCl气体发生反应 ,并且在反应开始的一段时间内 ,能使混合气体中的HCl气体质量浓度降低至小于 0 5× 10 -6 mg m3 ,其中EC0 2脱氯剂具有较好的化学反应性和较高的氯容量。同时发现在相同反应时间和相同空速条件下 ,随温度的升高 ,EC0 2脱氯剂的氯容量也随之升高 ,此外还研究了 5 5 0℃时EC0 2脱氯剂床层的氯分布。     

钙基脱氯剂床层出口HCl含量的热力学计算

利用纯物质热化学数据对重整工况中钙基脱氯剂出口HCl平衡含量进行了热力学计算。计算结果表明在重整装置工况条件下,HCl与钙基脱氯剂的反应倾向于自发发生;实际工况中,钙基脱氯剂中的Ca(OH)_2会逐渐转化为CaCO_3;实际脱氯剂床层HCl出口含量更接近HCl与CaCO_3反应平衡计算结果。     

高炉煤气脱氯剂的开发及工业应用

为保护高炉煤气脱硫工段所用的水解催化剂,开发出了高炉煤气专用脱氯剂,并在实验室小试装置上进行了性能测试,实验数据表明,W407B高炉气专用脱氯剂的最佳的使用温度应大于90℃,空速以不超过1 000 h-1为宜,原料中Cl含量的高低对其氯容影响不大。工业应用数据表明,W407B脱氯剂具有脱氯精度好,强度高,压降低的特点。     

城市生活垃圾热处理中氯元素转化的热力学平衡分析

利用FactSage软件,采用热力学平衡分析法,研究了燃烧气氛、反应温度及脱氯剂对城市生活垃圾热处理过程中氯元素转化的影响。结果表明,MSW在空气或富氧气氛下焚烧,低温时氯元素的主要产物为Cl_2和HCl,超过一定温度后,全部转化成HCl,这一温度节点会随着垃圾的具体组分不同而变化;富氧下,O_2含量越高,Cl_2越多,而HCl越少;而在全实验温度范围内热解,氯元素几乎全部转化为HCl。超过一定温度(不同工况下400～800℃)时,脱氯剂丧失脱氯效果。脱氯剂的效果:CaO>CaCO_3,添加比例15%>10%>5%,热解>空气>富氧气氛(富氧时CO_2与脱氯剂生成CaCO_3,O_2含量越少脱氯效果越好)。脱氯效果与垃圾组分有关,因MSW样本2中含大量硫元素,硫元素氧化生成CaSO_4,抑制脱氯效果,故MSW样本1脱氯效果优于MSW样本2,适宜脱氯温度范围较广。     

脱氯剂的研制与应用

介绍了T402、T403新型脱氯催化剂的性能、条件试验、评价结果及工业化应用情况。T402寸用于合成气、氫氮气、各种烃类等原料的净化,能将1～1000 ppm氯脱至0.1ppm以下。使用温度140～380℃,氟容量可达15～20％(重)。T403可以在常温加压液相烃类条件下脱除原料中的氯,氯容量为10％。脱氯催化剂的应用达到了保护各种催化剂活性、延长其使用寿命的目的。     

常温脱氯剂与HCl气体反应动力学的研究

在固定床反应器中研究了自制的铁系常温脱氯剂与HCl气体的反应动力学,导出了计算脱氯剂氯容的动力学方程q=0.309[(exp(0.036t))/(exp(0.036t)+exp(61.9Z)-1)]×100%.根据该方程,可以计算各个时刻、床层不同深度处脱氯剂的氯容,从而判断脱氯剂的性能及其使用寿命.     

A thermodynamic study of the removal of HCl and H2S from syngas

Advanced integrated-gasification combined-cycle (IGCC) and integrated-gasification fuel cell (IFGC) systems require high-temperature sorbents that are capable of removing hydrogen chloride and hydrogen sulfide from coal derived gases to very low levels. HCl and H₂S are highly reactive, corrosive, and toxic gases that must be removed to meet stringent environmental regulations, to protect power generation equipment and to control the emissions of contaminants. The thermodynamic behavior of 13 sorbents for the removal of HCl and H₂S under various conditions including: initial toxic gas concentration (1–10000 ppm), operating pressure (0.1–11 Mpa), temperature (300 K–1500 K), and the presence of H₂O were investigated. The correlation between HCl and H₂S was also examined. Thermodynamic calculations were carried out for the reactions of the 13 sorbents using a FactSage 5.2 software package based on free energy minimization. The sorbents, Na₂CO₃, NaHCO₃, K₂CO₃, and CaO are capable of completely removing chlorine at high temperatures (up to ~1240 K) and at high pressures. Water vapor did not have any significant effects on the dechlorination capability of the sorbents. Nine of the sorbents namely; Cu₂O, Na₂CO₃, NaHCO₃, K₂CO₃, CaO, ZnO, MnO, FeO, and PbO, were determined to have great potential as desulfurization sorbents. Cu₂O and ZnO had the best performance in terms of the optimum operating temperature. The addition of water vapor to the reactant gas produces a slightly detrimental effect on most of the sorbents, but FeO exhibited the worst performance with a reduction in the maximum operating temperature of about 428 K. The dechlorination performance of the alkali sorbents was not affected by the presence of H₂S in the reactions. However, the desulfurization capability of some sorbents was greatly affected by the presence of HCl. Particularly, the performance of Cu₂O was significantly reduced when HCl was present, but the performance of FeO improved remarkably. The thermodynamic results gathered are valuable for the developments of better sorbents.     

中低温煤焦油电脱盐处理技术研究

采用电脱盐法,在破乳剂和脱金属剂共同作用下,对一种中低温煤焦油进行脱水、脱盐及脱金属预处理研究。确定电脱盐工艺最佳条件为:电场强度为1 000 V/cm,处理温度为140℃,注水比例为6%,破乳剂加入量为30~50 ppm,处理时间为20 min。在此工艺条件下处理后的煤焦油中盐含量由19.73 mg/L降低到12.96 mg/L,脱盐量达到34%以上,水含量由100%降低到13%,金属脱除量达到27%以上。经过预处理的煤焦油能够满足后续加工过程的需求。     

我国自主创新粉煤加压气化技术介绍

我国具有自主知识产权的气流床粉煤加压气化技术中试装置在兖矿鲁南化肥厂成功运行,各项技术指标优越,有效气成分89%~93%,碳转化率98%~99%,每生产1000 m3CO+H2耗氧300~320 m3,每生产1000 m3CO+H2耗煤530~540 kg,冷煤气效率≥84%,达到国际先进水平。具有广阔的应用前景。     

Impacts of acid gases on mercury oxidation across SCR catalyst

A series of bench-scale experiments were completed to evaluate acid gases of HCl, SO₂, and SO₃ on mercury oxidation across a commercial selective catalytic reduction (SCR) catalyst. The SCR catalyst was placed in a simulated flue gas stream containing O₂, CO₂, H₂O, NO, NO₂, and NH₃, and N₂. HCl, SO₂, and SO₃ were added to the gas stream either separately or in combination to investigate their interactions with mercury over the SCR catalyst. The compositions of the simulated flue gas represent a medium-sulfur and low- to medium-chlorine coal that could represent either bituminous or subbituminous. The experimental data indicated that 5–50 ppm HCl in flue gas enhanced mercury oxidation within the SCR catalyst, possibly because of the reactive chlorine species formed through catalytic reactions. An addition of 5 ppm HCl in the simulated flue gas resulted in mercury oxidation of 45% across the SCR compared to only 4% mercury oxidation when 1 ppm HCl is in the flue gas. As HCl concentration increased to 50 ppm, 63% of Hg oxidation was reached. SO₂ and SO₃ showed a mitigating effect on mercury chlorination to some degree, depending on the concentrations of SO₂ and SO₃, by competing against HCl for SCR adsorption sites. High levels of acid gases of HCl (50 ppm), SO₂ (2000 ppm), and SO₃ (50 ppm) in the flue gas deteriorate mercury adsorption on the SCR catalyst.     

T406型脱氯剂的研制与工业应用

报导了型脱氯剂的研制、性能试验和工厂运行结果。与国内外常见同类脱氯剂的对比试验及工业应用表明, 由化工部西北化工研究院开发研制的这一新型脱氯剂具有抗压碎强度高, 净化度高, 氯容量高的特点, 可以在常温下用于气相和液相原料中氯化物的脱除。即使在低温（4℃）下, 净化后原料中氯降至左右的情况下抓容量仍高达18％以上。该脱氯剂还能同时脱除原料中的硫。T406型脱氯剂已工业应用于混合二甲苯和氢原料的脱氯, 使用效果良好。     

A study on the reaction kinetics of HCl removal from high-temperature coal gas

A study on chloride removal from high-temperature coal gas shows that all the tested sorbents can rapidly react with HCl vapor and reduce the HCl vapor concentration to less than 1×10⁻⁶ in a fixed-bed reactor. The ECl1 sorbent lab-made has the highest chloride capacity. The experimental data obtained were analyzed by a model based on fixed-bed reactor and shrinking core models, It is found that reaction between sorbent and HCl vapor is of first-order with respect to initial HCl concentration. The reaction is governed by combination of the chemical reaction and product layer diffusion.     

Advanced experimental analysis of the reaction of Ca(OH)2 with HCl and SO2 during the spray dry scrubbing process

This work evaluates both the removal efficiencies of HCl and SO₂ at different points in a spray dryer using Ca(OH)₂ as the absorbent. The operating conditions were specified in terms of the temperature of the flue gas (200-300 °C), the HCl concentration (120-1000 ppm), the SO₂ concentration (150-500 ppm) and the amount of CaCl₂ added (10-30 wt.%).The experimental results showed that the SO₂ removal efficiencies were higher in the presence of HCl (120-500 ppm) than in the absence of HCl at 250 °C and 20% relative humidity (RH). However, the removal efficiency of SO₂ decreased as the HCl concentration increased. The removal efficiency of SO₂ also increased with the amount of CaCl₂ in the spray dryer.     

加氢还原法制备邻氯苯胺的研究

在2000mL高压反应釜中,采用自制纳米级Ru/PC催化剂进行邻硝基氯苯加氢制备邻氯苯胺。考察了溶剂、温度、压力等工艺参数对加氢的影响。优化的工艺条件:温度100℃、压力1.5~2.0MPa、溶剂甲醇1000mL、邻硝基氯苯500g、催化剂25g、双氰胺5g。在该条件下,邻硝基氯苯转化率为99.8%,邻氯苯胺选择性为96.5%,脱氯率小于1%。催化剂寿命考察16次,活性不减。     

煤种对煤与天然气共气化过程的影响

以移动床为反应器,进行煤与天然气共气化热态模拟实验,对无烟煤、瘦煤、肥煤与焦炭进行了对比研究,考察了煤种在不同喷吹参数H2O/CH4/O2时对高温火焰区温度、合成气有效成分H2+CO和H2/CO、以及CH4与水蒸汽转化率的影响. 结果表明,相对于焦炭,煤为原料时,高温火焰区温度略高,粗合成气有效成分H2+CO体积含量较高,且H2/CO更接近于热力学平衡值. 通过不同煤种的实验,可以直接制备H2/CO在1~2之间可调、有效成分H2+CO体积含量大于92%、残留CH4小于2%的粗合成气,CH4转化率超过90%,水蒸汽转化率高达75%. 煤种中高灰分含量有利于煤与天然气共气化过程.     

N-847系列催化剂在以合成氨弛放气为还原剂脱NOx工艺中的应用

采用合成氨弛放气作为还原剂，弛放气中部分H2和NH3同时在N-847系列催化剂作用下还原硝酸装置或硝酸钠、亚硝酸钠装置尾气中的NOx 组分。在空速2500～10000 h-1、催化剂床层反应温度170～400℃及压力不变的条件下，尾气中NOx 质量浓度由1000～7000 mg/m3（标态）降至＜300 mg/m3（标态），实现达标排放。