【作者】 吴浪；

【导师】 张永春；

【作者基本信息】 大连理工大学 ， 工业催化， 2005， 硕士

【摘要】 硫化氢是一种具有臭鸡蛋气味的恶臭气体,对人体而言毒性很大,而且易燃易爆,极易腐蚀金属,堵塞管道,工厂排放的尾气里及天然气即使含有少量的硫化氢也会对环境造成很大污染,有时甚至因为低浓度的硫化氢存在而浪费了很多资源。所以硫化氢的排除尤其是低浓度的硫化氢的排除是急需解决的问题而用活性炭作为催化剂氧化硫化氢则被充分的研究和应用,它具有成本低,操作简便,脱硫效率高等优点。 本文在前人的研究基础上,用活性炭为催化剂,在以下四个不同角度对活性炭脱除硫化氢的原理做了研究,主要研究内容如下: 一 氧气充足和不足的情况下活性炭脱除硫化氢的研究 研究了氧气充足和氧气不足的两种情况下活性炭对硫化氢的脱除,考虑了温度的影响,不同浸渍剂的影响以及原料气中二氧化碳的存在对反应的影响,活性炭在有氧情况下,温度在120℃硫容量最大,在两种情况下,用K₂CO₃改性后的活性炭硫容量都最大,二氧化碳的浓度越高,两种情况下的硫容量都越低,在氧气充足的情况下,湿度的增加能提高硫容量,但在缺氧的情况下反而使硫容量降低。最后在两种情况下对活性炭的再生做了考察,在缺氧情况下,四次再生后仍能保持较高活性,而在有氧情况下,容易失活。 二 从含二氧化碳原料气中脱除硫化氢的研究 用活性炭从含二氧化碳的气体中脱除低浓度的硫化氢是一种经济有效的方法。分别在低温（25℃）和高温（500℃）下研究了二氧化碳对活性炭脱除低浓度硫化氢的影响,在两种条件下,二氧化碳的作用是完全不一样的。在常温下二氧化碳的酸性起着主要作用,其它条件一定时,二氧化碳含量越高,硫容量越低;湿度在20%左右活性炭的硫容量达到最大。但是用NaOH等改性的活性炭硫容量变化不大。在高温时,二氧化碳的氧化性起着主要作用,硫容量随着二氧化碳浓度和湿度的增加而增加。 三 过渡金属改性的活性炭脱硫化氢的研究 研究了过渡金属改性后的活性炭的催化氧化脱硫化氢的性能,通过两种不同的改性方法使过渡金属离子负载在活性炭上:一种是直接用过渡金属离子的水溶液浸渍活性炭,一种是加入Al₂O₃粘合剂的方法将过渡金属离子负载在活性炭上,结果表明:第一种改性方法硫容量比未浸渍的活性炭都有提高,而Zn离子浸渍的活性炭硫容量是最大的;第二种方法改性的活性炭只有Cu和Ag离子改性后的硫容量得到提高,其它反而论文题目下降。根据两种方法产生的结果最后推测了过渡金属离子在活性炭上脱除硫化氢的可能机理。 四脱硫化氢活性炭的再生方法研究 采用了溶剂再生法和气体再生法对脱硫化氢失活后的活性炭进行再生,溶剂再生时所用溶剂为凡仇溶液、州03溶液以及Na0H溶液,结果表明Na0H溶液不能使活性炭得到再生,而氏q溶液、洲q溶液能够通过氧化的方法使活性炭得到再生;气体再生时所用气体分别为高纯从,含20呱的蝇以及凡,它们再生的原理分别是热再生,通过氧化单质S再生和通过还原单质S再生。再生效果最好的是30%的洲氏溶液和氏,它们能将活性炭孔道内单质S分别脱出69 .8%和81 .2%,再生后的活性炭硫容量能超过原来的70%。再生后活性炭的比表面积和州值是再生性能的两个重要指标。 通过上述的研究工作,能够更加清楚的认识到活性炭脱硫化氢的原理以及各种因素的影响,从而为进一步工业应用积累基础数据。关键词:硫化氢活性炭;氧气;二氧化碳;过渡金属;再生一ll更多还原

【Abstract】 Hydrogen sulfide is a kind of mephitic gas with rotten-egged odor, and it can be of great harm to humans. It even combusts and explodes easily and metals are likely to be eroded by it so that the pipelines are often blocked. Tail gas and natural gas would pollute the air terribly even if there is a little hydrogen sulfide in them and lots of resources are abandoned because of low concentration of hydrogen sulfide in them. Thus, to remove H2S especially low concentration of H2S is an important issue that should be solved as soon as possible. One of the popular solutions is catalytic oxidation it with activated carbon, which is economical, easily operated and effective.On the basis of the research been conducted before, four aspects about the principles of removing H2S with activated carbon have been studied, the core of which are listed as follows:1 The role of O2 in the catalytic oxidation of H2S with activated carbonRemoval of hydrogen sulfide by activated carbon was conducted in different conditions: with plenty O2 or with little O2 .The reaction was affected by lots of factors including temperature, various promoters, and the percentage of CO2 in the feed gas. The biggest sulfur capacity of the activated carbon was at 120 ℃ with sufficient O2 assisted in the reaction. In both conditions, the sulfur capacity of AC impregnated by K2CO3 was much bigger than others, and it dropped with the increasing concentration of CO2. In the case that little O2 was in the reaction. Although the increasing relative humidity led to a higher sulfur capacity when enough O2 was in the reaction, the sulfur capacity decreased in the case of lacking of O2. The regenerated carbon was still active after 4 times, while it was likely to lose activity in the case of enough O2.2 The effect of CO2 to the removal of low concentration of IKS with activated carbon It is economic and effective to remove low concentration of hydrogen sulfide from the feedgas containing carbon dioxide by activated carbon. The experiment was conducted in ambient temperature (25 ℃) and high temperature (500 ℃) respectively and a totally different result was found .In the ambient temperature, acidity of CO2 was the most important factor to the reaction, so a higher content of CO2 in feed gas led to a lower sulfur capacity, and the biggest sulfur capacity was found when the humidity was about 20%. However, in the high temperature, the oxidability of the CO2 is the most important factor, so with increase of the content of CO2 and water in feed gas, the sulfur capacity grew up.3 The role of transition metals in the catalytic oxidation of H2S with activated carbonCatalytic oxidation of H2S with activates carbons modified with transition metals have been studied. There were two different methods to modify the activated carbon: one was impregnation of carbon in the solution of cations of transition metals, the other wasmodification of carbon with cations of transition metals containing Al2O3 (a chemical bond). The result showed that the sulfur capacity of all of the activated carbon modified by the first method developed and the biggest one was the carbon impregnated with Zn, however, not sulfur capacity of all activated carbon modified with the second method developed but only modified with Cu and Ag increased, sulfur capacity of others even decreased. Finally, the possible mechanism of role of trans-metals in the catalytic oxidation of H2S with activated carbon was presume according to the two different results. 4 Methods of regeneration for used activated carbonTwo methods-solvent regeneration and gas regeneration have been used for the used activated carbon, which had removed H2S. The solvents used were H2O2, HNO3and NaOH, it showed that NaOH solvent was ineffective while H2O2 and HNO3 can regenerate the activated carbon by oxidation ;The gases utilized were pure N2, 20%O2 in N2 and H2, the principle of them regenerated activated carbon were thermal regeneration, oxidation and reduction respectively. The best result was found in 30% HNO3 and H2, they can removed S f更多还原