In the field of petrochemical industry in China, thesolvent recovery of rubber plants such as BR, SBR, SBS, EPR and IR mostly usethe steam stripping wet process in which the consumption of steam account formore than half the total amount of the whole plant. With three stages process,the longer residence time of water slurry make the solvent spread out of therubber crumb easier so that the consumption of solvent is reduced but alsoenvironmental pollution from solvent gas or the risk of explosion and fire wereavoided in the subsequent drying process. The gas phase countercurrenttechnology of three stages process make full use of the waste heat of thelatter two slipping stages to reduce the steam consumption. The reduction of operating temperature and pressure in thethird slipper is also beneficial the excessive flash loss of solvent when thewater slurry goes into the post-processing unit.

The three stages stripping technology developed byYanshan Branch of BRICI was applied successfully in the30 kt IR plant ofSinopec Yanshan Petrochemical in May 2013. The technical indicators of slippingsystem all reach the design requirements. This technology can enhance the levelof saving energy and reducing consumption and make the products morecompetitive in market.

Figure 34   stripping unitof 30000 tpy IR plant in yanshan petrochemical