Study On The Improvement Of C3 Content In Dry Gas Of Absorbent Stabilizer Process

The process of catalytic cracking is long and complicated,which is one of the technical difficulties in modern petrochemical industry.The process is divided into four parts:reaction-regeneration section,product fractionation and raw material preheating section,absorption-stabilization section and liquefied gas refined section.With the continuous development of C3 technology,C3 market is getting better and better.In the traditional process,the mole yield of C3 and lighter components is less than 20 percent in dry gas.It shows obvious economic benefits by process improvement or equipment transformation to recover C3 as much as possible.In this paper,the static simulation of the whole process is established for the dry gas absorption-stabilization process section with the treatment capacity of 16000m3/h in the catalytic cracking process.The two production tasks including 1.5%and 3.0%of the content of C3 and above components in the dry gas are studied.The amount of the absorbent are 480kmol/h and 380kmol/h,and 120kmol/h reabsorbent can meet the requirements.In this production conditions,we use a variety of software to calculate the hydraulic performance of four towers in this section.We found that the stripping section of the existing device in the absorption tower,analytical tower,re-absorption tower and stable tower can complete the production tasks,and the floating rate of stable tower using floating valve tray is too high.For this purpose,it is proposed to change the column to Mellapak 250X regular packing,high-throughput new tray or expand the tower diameter to 1.8m.Finally,we make an economic analysis from the operating costs and the product value of the two production tasks and found that the dry gas C3 and above components down from 3.0%to 1.5%can increase the economic benefits of 3.5 million yuan per year.