The test run showed that under a reaction temperature of 505℃ with a feedstock possessing 40. 63% aromatics potential content, the RON of the reformate reached 100. 3, and the stabilized gasoline yield was 89. 04% with an aromatics content of 77. 81%.
Phenolic compounds in RFCC(residue fluid catalytic cracking) stabilized gasoline and gasoline preliminarily washed by alkali from Yanshan petrochemical company and Shijiazhuang refinery were separated by using 100 g/L NaOH as an extracting agent and CH2Cl2 as a reextracting agent. The ratio of the gasolines to extractant was 5∶1 by volume.
Using C_5 fraction from stabilized gasoline and industrial methanol as raw materials, the etherification reactions were carried out in a cylindrical expanded-bed bi-reactor filled with sulfonic acid cation resin catalyst to investigate the effect of reaction conditions on conversion.
The experiment analysis has found that titratic potentals of sulphur-mercaptans(S-mercaptans) in RFCC's stable gasoline have two obvious sudden changes: the first sudden change of potentials is in the range of -100～100 mV,the second is about in the range of 100～300 mV. The original titratic potential of the refined gasoline is larger than 0 mV,and its titrative curve has only one sudden change.
Since 2002, some measures have been adopted such as decreasing vapor pressure and C 4 content of stable gasoline, application of advanced control and increasing blending ratio of residue and coker gas oil. Economic benefits of the unit has been increased by more than 800×10 4 RMB yuan/yr. (Process capacity of the unit is 20 000 b/d).
The results showed that the olefin content in cracked naphtha could be reduced to below 35% when GOR C reached 28% of the catalyst inventory. The RON and introduction period of the FCC naphtha was 92.6 and 1 740 min respectively.
Three kinds of catalyst and MGD process were in series triumphantly applied to the RFCC unit in Jinzhou Petrochemical company for decreasing gasoline olefin content to meet the requirement of clean fuel production. It can make olefin content of steady gasoline reduce from initial 61 % to less than 40 %,approach 35 %.
The result of one year running shows that the aromatization unit worked safely and reliably. Yields of gasoline and LPG have reached 93.02% and gasoline RON has been increased from 62.6 to 90.1. Appropriate operation conditions and the experience from production practice were summarized and measures have been proposed as well for further improvement.