活化MDEA溶液用于天然气脱碳性能的研究

发布时间：2018-04-09 20:52

  本文选题：天然气　切入点：MDEA　出处：《中国海洋大学》2015年硕士论文

【摘要】：在低碳经济成为经济发展趋势的今天,天然气已经成为一种非常重要的清洁能源。CO2是天然气中含量较高的酸性组分之一,CO2不仅降低天然气品质,同时腐蚀金属管道、设备等带来诸多安全隐患,甚至造成温室效应等环境问题。2012年国家强制性标准对一类天然气中CO2的浓度作出新的要求,CO2浓度由小于或等于3.0%(1999年标准)提高为小于或等于2.0%,这就使天然气净化工艺要深度脱除C02。目前醇胺法是天然气工业中最常用的脱碳方法之一。在众多醇胺中,N一甲基二乙醇胺(MDEA)由于吸收负荷高,化学稳定性好,腐蚀性小,再生热负荷低,溶液不易发泡和降解等优点,成为应用最广泛的脱碳剂之一。由于MDEA是叔胺,不能与CO2直接反应,导致反应速率较慢,在实际应用中需要向MDEA溶液添加少量活化剂以提高其对CO2的吸收速率。本论文的主要内容是围绕活化MDEA溶液对CO2的吸收性能的研究。用N2、CO2配制成CO2浓度为100g/m3的原料气模拟含酸性组分的天然气进行天然气脱碳实验,首先考察一乙醇胺(MEA)、二乙醇胺(DEA)、环状胺类化合物等不同活化剂对MDEA活化性能的影响,探讨活化剂对促进MDEA吸收CO2的反应机理,挑选出最佳活化剂。其次,天然气中H2S组分的存在对活化MDEA溶液吸收CO2效果造成影响,实验亦考察了H2S的加入量对活化MDEA溶液吸收CO2的影响。最后对活化MDEA溶液的再生、发泡性、腐蚀性等性质逐一进行了测试。不同活化剂对MDEA溶液脱碳效果影响的实验研究结果表明：活化效果HZPZ(哌嗪)DEAMEA,添加等量HZ时MDEA溶液穿透时间和穿透碳容最大,确定活化剂HZ为最佳活化剂：在模拟气中加入H2S后,通过考察不同添加量的HZ,得出HZ添加量越多,C02的吸收效果越好,同时对H2S的吸收效果也会略有提高；再生温度对活化MDEA溶液脱除酸性气体的效果影响115℃125℃105℃,再生次数对MDEA溶液脱除酸性气体的能力基本没有影响,静态实验的最佳再生时间为30min。天然气中的酸性组分、腐蚀产物(FeS)进入到活化MDEA溶液中都会增加其发泡趋势。实验从多种消泡剂中筛选出一种最佳消泡剂DF.112,能大大降低泡沫高度、缩短消泡时间,即能有效地抑制活化MDEA溶液的发泡趋势,其最佳用量为0.80‰。富液的腐蚀性远大于贫液,活化剂HZ的加入并没有使得MDEA溶液的腐蚀性增强。缓蚀剂环烷酸咪唑啉能有效地抑制活化MDEA富液对设备的腐蚀,其适宜用量为5‰。
[Abstract]:Equipment and other security risks,There are even environmental problems such as Greenhouse Effect. The 2012 national mandatory standards set new requirements for the concentration of CO2 in a class of natural gas. The CO2 concentration increased from less than or equal to 3.0 (1999 standard) to less than or equal to 2.0, which resulted in natural gas purification.The process is to remove C02 in depth.At present, alcohol-amine method is one of the most commonly used decarburization methods in natural gas industry.In many alcohols, N-methyldiethanolamine (MDEAA) has become one of the most widely used decarburizers because of its high absorption load, good chemical stability, low corrosion, low regenerative heat load, and the solution is not easily foamed and degraded.Because MDEA is a tertiary amine and cannot react directly with CO2, the reaction rate is slow. In practical application, a small amount of activator should be added to MDEA solution to increase its absorption rate of CO2.The main content of this thesis is to study the absorption of CO2 in activated MDEA solution.The reaction mechanism of activator on MDEA absorption of CO2 was discussed, and the best activator was selected.Secondly, the presence of H _ 2S in natural gas has an effect on the absorption of CO2 by activated MDEA solution. The effect of H _ 2S addition on the absorption of CO2 by activated MDEA solution is also investigated.Finally, the regeneration, foaming and corrosion properties of activated MDEA solution were tested one by one.The experimental study on the effect of different activators on decarbonization of MDEA solution shows that the activation effect of HZPZ (piperazine DEAMEA), when the same amount of HZ is added, the penetration time and penetrating carbon capacity of MDEA solution are the largest. It is determined that the activator HZ is the best activator: after the addition of H2S in the simulated gas,Through the investigation of HZs with different amount of HZs, it is concluded that the higher the HZ addition amount is, the better the absorption of H2S is, and the effect of regeneration temperature on the removal of acid gas from activated MDEA solution at 115 鈩，

本文编号：1728102