加氢装置高压空冷器阻垢缓蚀剂的研究

加氢装置反应流出物空冷器腐蚀失效的原因主要是NH4HS的形成、析出和沉积,其机理包括NH4HS水溶液垢下腐蚀和冲蚀。阻垢缓蚀剂一方面具有阻垢功能,阻止铵盐低温析出,形成一种新的化合物能够全部溶解在液相水中,避免NH4HS沉积造成垢下腐蚀;另一方面具有缓蚀作用,在空冷器表面能够形成致密、稳定的保护膜,一定程度地避免管束受NH4HS溶液冲蚀。在实验室条件下,考察了阻垢缓蚀剂的阻垢和缓蚀的效果;在中试装置上,采用挂片质量损失法考察了阻垢缓蚀剂对空冷器的缓蚀效果。实验结果表明研制的阻垢缓蚀剂同时具有阻垢和缓蚀功能,能有效抑制NH4HS析出结垢,当加剂量为50μg/g,缓蚀率达到98.6%。

Study on fouling inhibitor for HP air cooler in hydrogenation unit

The corrosion failure of hydrogenation reactor effluent air cooler was mainly caused by the formation,precipitation and deposition of NH4HS,and corrosion mechanisms include the foul deposition corrosion and impingement erosion of NH4HS.In one respect,the fouling and corrosion inhibitor has fouling inhibition performance which can prevent the low-temperature precipitation of ammonium salt.The new compound formed can completely dissolved in liquid water phase,and underdeposit corrosion by NH4HS deposition is prevented.In another,the fouling and corrosion inhibitor has corrosion inhibition performance.It can form compact stable protection film on the surface of air cooler to protect the tubes from impingement erosion of NH4HS solution.The fouling and corrosion inhibition performances of the fouling and corrosion inhibitor are investigated in the laboratory and the corrosion inhibition results of the inhibitor is studied by coupon testing in a pilot plant.The tests results demonstrate that the fouling corrosion inhibitor has both fouling inhibition performance as well corrosion inhibition performance,which can effectively inhibit the fouling of NH4HS precipitation.The corrosion inhibition rate is 98.6% at a dosage of 50 ppm.