The green deacidification technology of diesel by the ammonia-alcohol method without using strong acid and strong base can achieve zero-emission.But it has some problems,such as requiring larger amounts of ammonia and solvent,and higher energy consumption of regeneration solvent.To overcome the shortcomings of the ammonia-alcohol method,this paper experimentally studied the green deacidification technology of diesel by the ammonia-alcohol method,which used low-temperature coalescence filtration in a self-made experimental device.The effects of coalescence filtration temperature,amount of ammonia,alcohol consumption,volume ratio of solvent to oil on the deacidification process,material regeneration of coalescence filtration,deacidification’s turndown ratio and the product quality of naphthenic acid were studied.The results showed that under the optimum operation condition,the acidity of straight-run diesel could decrease from 62.9 mg KOH·(100 ml)-1 to 4.2 mg KOH·(100 ml)-1,the acid removal rate was as high as 93.3%,and product recovery could reach 98.6%.After refining,the quality of diesel could meet industry requirements [acidity X<7.0 mg KOH·(100 ml)-1],and raw acid value of naphthenic acid could meet No.2 acid standards of SH/T 0530—92.This method had the advantages of simple technological process,low operating temperature of deacidification,less ammonia and solvent consumption,low solvent regeneration energy consumption and higher turndown ratio.
