分子筛再生气余热利用解决再生塔热吹偏低问题

王 强，曹培盛

（渤南龙口天然气处理终端，山东 烟台 265700）

摘 要：天然气深加工生产流程中分子筛脱水及再生是必不可少的步骤,它吸附饱和了天然气中水份后,切换到再生程序热吹是带除其水份再次转入吸水关键的一步, 渤南终端天然气深冷生产流程随着海上油气井来气含水量变化上升及波动,现分子筛床层热吹后温度与原设计工况偏低20 ℃,它直接危及到后续流程深冷降低和冻堵,对此为改善此工况,分析发现再生后热天然气在分子筛冷吹程序结束还有余热温度可以利用,通过改造流程增设一台新再生气预热器把这部分热能用于加热初始再生气,从而相应提高了最终再生热气温度,且减少了燃料气的消耗。

关键词： 天然气深冷工艺分子筛脱水后再生；分子筛热吹后温度降低；余热回收利用，增设一台预热器提高分子筛再生热吹温度；降低天然气深冷区水露点；

Effective utilization of residual heat from molecular sieve regeneration gas to solve the problem of low heat blowing in the regeneration tower

WANG Qiang ，CAO Pei Sheng

Abstract: Molecular sieve dehydration and regeneration in the production process of natural gas deep processing is an essential step, it saturated the adsorption of natural gas after the water, switch to the regeneration program hot blowing is a key step to remove its water into water absorption again, production process of Bonan Terminal rises and fluctuates with the change of water content of incoming gas from offshore oil and gas Wells. The temperature of molecular sieve bed after hot blowing is 20 points lower than the original design condition ℃, it directly endangers the cryogenic reduction and freezing blocking of the subsequent process. In order to improve this working condition, it is found that the residual heat temperature of the reclaimed hot natural gas can be utilized at the end of the molecular sieve cold blowing program. A new regas preheater is added through the transformation process to heat the initial regas, and the fuel gas consumption is reduced.

  Key words: regeneration of natural gas cryogenic process molecular sieve after dehydration；temperature decrease after molecular sieve hot blowing；waste heat recovery and utilization, adding a preheater to increase the hot blowing temperature of molecular sieve regeneration；reduce water dew point in deep cooling areas of natural gas；

      1  起因

渤南天然气终端厂120万系列流程在对天然气进行深冷处理前，采用分子筛同压再生对原料气进行脱水。分子筛脱水分为脱水和再生两个阶段，两座分子筛交替进行工作；再生阶段分为热吹和冷吹两个阶段，热吹的作用是靠热量将分子筛内部吸收的水分蒸发出来达到再生的目的。热吹阶段用气为脱水后的原料气，经换热器热油加热后进入再生分子筛，热吹阶段再生气的温度是影响再生效果的决定性因素。

近年来生产人员观察发现，再生气热吹时其温度已经达不到预期温度，原设计经换热后再生气为240℃，现在为220℃左右，导致原料气水露点高于设计值，再生效果变差，影响后续天然气深冷回收液化气流程的低温段露点和产品质量。

原设计再生气经过压缩机增压至2.6MPa，温度升至33℃，再经再生气加热器E-1307与导热油换热至260℃。再生气温度达到上述温度时的流量为7749Nm3/h，再生气加热器负荷为1082kW。出分子筛的再生气温度降至240℃，直接经冷却器E-1301冷却，进再生气分水罐分离出游离水后返回分子筛入口与原料气汇合进入分子筛干燥器。

（王强）分子筛再生气余热利用解决再生塔热吹偏低问题.pdf