With the continuous increase in the production and ownership of the automobiles in China as well as the widespread application of new technology in automobiles, the call to improve the fuel quality from the automobile industry is getting increasingly louder. The ever tightening emission regulation also demands higher fuel quality. As a major fuel producer and supplier, the petrochemical industry must steer the production of clean fuel to stay in step with the development of the automobile industry and conform to the laws and regulations of the environmental protection authorities. The industry must develop and apply new production technology to produce high quality gasoline and diesel in order to meet the market demand. The environmental improvement also requires unremitting coordinated efforts from the automobile industry, petrochemical industry, the environmental protection agencies and even the transportation department.
Comparing the existing gasoline quality standard in China with that of the other countries and the II category gasoline quality specifications of the World Fuel Standards, the main differences are seen in the areas of high olefin content, high sulfur content, low Motor Octane Number (MON), no set specification for the gasoline cleanness and no mandatory requirement for detergent addition. These differences result from the characteristics of China?s gasoline production, such as high ratio (more than 80%) of catalytic cracked gasoline, low ratio of reformed gasoline and high octane number gasoline blending components and no unified quality inspection of various gasoline detergent additives in the market.
　　In comparing the existing diesel quality standard in China with that of the other countries and the II category diesel quality specifications of the World Fuel Standards, the main differences are: high sulfur content, low cetane number, relatively high density of some diesel and no restriction on the aromatics and polycyclic aromatics content. These differences result from the characteristics of China?s diesel production, such as high ratio of secondary processing diesel, low cetane number, insufficient hydrotreating capacity for diesel products, wide diesel distillation range, no set specification for the cleanness (cleanness of the jet nozzle) and the lubricity of the diesel product.
　　With the ratio of imported sour crude increasing year by year, and the catalytic cracking process continuing to be the main process for gasoline and diesel production, the key to improve the quality of China?s gasoline and diesel is to reduce the sulfur and olefin content of the catalytic gasoline and to reduce the sulfur, olefins and aromatics from and increase the cetane number of the diesel through hydrotreating techniques. The objective of the technical development is to meet the quality specification of the World Fuel Standards, taking into consideration the diversified crude resources, production structure, gasoline and diesel components as well as process flow.
　　Progress of Clean Gasoline Production Techno-logy
　　1. Technology for the Reduction of Olefin content in Gasoline
　　Technology that have been developed and applied:
　　GOR series catalysts to reduce olefin content of catalytic gasoline
　　Compared with the conventional catalytic cracking catalyst, the GOR series catalyst that has been developed and applied, can reduce the olefin content of the gasoline by 8-12%. Compared with GOR-I catalyst, the new GOR-II catalyst can increase the light oil and gasoline yield by 1.7 to 2 % while lowering the olefin content. The RON of the catalytic gasoline is greater than 90. See Table 1 for the result of its industrial applications.
　　The new catalytic cracking process for maximizing isohydro-carbon Production (The MIP Process)
　　The industrial application test result of the new process showed a reduction of 8-10% in olefin content of the gasoline and increase of 2-3% in liquid yield as compared with the conventional catalytic cracking process, while the gasoline antiknock index remained unchanged. The new process has enabled an annual incremental profit of 34 million RMB for the enterprises and has been widely applied in domestic refineries. Please see Table 2 for its industrial test result.
The catalytic cracking process for maximal diesel and LPG production (The MGD Process)
　　With a slight modification to the conventional catalytic cracking unit, one can reduce the olefin content of the gasoline by 9% and increase the octane number by some extent with the MGD process, while maximizing the diesel and LPG production. Please see Table 3 for the typical result of the industrial application. The first industrial application led to an average annual incremental profit of 19 million RMB. The process has been widely used in more than 30 catalytic cracking units in China.
　　The technology under development are :
　　Special catalyst currently under development for the MIP process
　　Compared with the existing catalyst, this new catalyst can increase the light oil yield by 2% , increase the isoparafins by 1%, and reduce the olefin content of the gasoline by 3%, while keeping the gasoline octane number unchanged (please see Table 4). Also under development is a catalyst promoter that reduces the olefin content of the catalytic cracked gasoline by 6 D 8% while keeping the RON of the gasoline at ?Y90.
　　1. Technology for Reducing the Sulfur Content of the Gasoline
　　The RSDS Process
　　Already developed and applied is the RSDS selective hydrodesulfurization process for catalytic gasoline. This process has a good adaptability to China?s various kinds of catalytic gasoline. It can reduce the gasoline sulfur content to a level of 100-200ppm while the gasoline RON loss is less than 2 (please see Table5).
　　The RIDOS Process
　　The RIDOS process is a world leading technology for the catalytic gasoline hydroisomerization and desulfurization. The result of its industrial application is as follows: reduce the olefin content from 50.3 v% to 19.8 v%; reduce the sulfur to less than 30ppm; keep the antiknock index loss at a level of less than 1.4. This process opens a technical avenue for the petrochemical industry to supply Beijing and the other two major cities with clean gasoline that meets or exceeds the national new standards, which is equivalent to II and III category gasoline of the World Fuel Standards, thus laying a steady technical foundation and also providing a technical guarantee for Beijing?s òGreen Olympicsó in the year 2008. Please see Table 6 for the industrial correlation data. With an addition of 5-10% reagent to reduce the sulfur content of the catalytic gasoline, the gasoline sulfur content can be reduced by 10-20%. The reagent is now under industrial test.
　　Progress of Clean Diesel Production Technology
　　1. Technology that have been developed and applied
　　Diesel hydrotreating catalyst RN-10
　　The diesel hydrotreating catalyst RN-10 has a high activity in hydrodesul-furization and hydrodenitrogenation and high aromatic saturation capacity. Please see Table 7 for the correlated data of relative activity of hydrotreating catalyst.
　　The medium pressure hydrotreating technology MHUG
　　The MHUG technology can produce diesel that meets the specification of II and III category diesel of the World Fuel Standards. The sulfur content of the diesel thus produced can be reduced to 30-300ppm. Its aromatic content reduced to 15 D25v% and cetane number increased to 53-55 (please see Table 8).
The RICH technology
　　The RICH hydrotreating technology that improves the cetane number of diesel employs a new type of catalyst that has excellent hydrotreating performance as well as selective ring-opening cracking properties. With the conventional hydrotreating process, the sulfur content of the diesel can be brought down to less than 50ppm, density reduced by 0.035 units and the cetane number increased by 8-10 units. The technology is ready for application. Please see Table 9 for the result of its commercial application.
　　The RMC Technology
　　With the RMC medium pressure hydrocracking technology, one can produce diesel that meets the II category diesel specification of the World Fuel Standards while producing high aromatic content reformer feedstock and premium ethylene feedstock. Using a feedstock with a density of 0.8547 g/cm3 (20??), sulfur content of 794ppm , nitrogen content of 416ppm and distillation range of 237-516?? and operated at a hydrogen partial pressure of 8.22Mpa, based on the plan to maximizing diesel production, one can produce 32.46% diesel (as to feedstock) which has a sulfur content of 1.1 ppm, nitrogen content less than 0.5 ppm and cetane number of 61.2, while producing heavy naphtha with a aromatic content of 50.7%. The tail oil produced (BMCI 8.48) has a higher ethylene yield than that of the naphtha cracking process.
　　2. Technology under development
　　The SSHT process
　　This single-step hydrodesulfurization and dearomatization process can be used to produce diesel that meets the II category specifications of the World Fuel Standards.
　　The two-step deep hydrosulfurizaiton and dearomatization process can be used to produce the diesel that meets the III category specification of the World Fuel Standards.
　　The RHT Process
　　This high pressure hydrocracking process can be used to directly produce diesel that meets the III category specification of the World Fuel Standards with heavy feedstock.
　　There are other technology under development, such as technology to produce ultra low sulfur content diesel, diesel hydroisomerization and hydrovisbreaking technology.
　　Additional technology underdevelopment to produce clean fuel includes a new process to reduce the sulfur and olefin content of the catalytic gasoline; a catalytic gasoline aromatization technology, a new generation of gasoline and diesel detergents; catalysts for automobile emission gas conversion meeting the European emission gas regulation; C5 and C6 isomerization technology; solid acid alkylation technology; high liquid yield and low coke formation reforming catalyst; extraction desulfurization and absorption desulfurization technology and additives to improve the gasoline and diesel properties, etc.
Conclusion
　　1. To produce gasoline that meets the II category specifications of the World Fuel Standards, we have developed and now recommended to use the following technology:
　　Promoter to reduce the sulfur content of catalytic cracked gasoline
　　Cracking catalyst to reduce the olefin content of the catalytic gasoline
　　MGD technology
　　MIP technology and MIP special catalyst
　　RSDS, RIDOS technology, etc.
　　To produce diesel that meets the II category specification of the World Fuel Standards, we have developed and now recommended to use the following technology:
　　New generation diesel hydrotreating catalyst
　　MHUG technology
　　RICH, RMC technology etc.
　　All these technology can be selected by the enterprises according to their own needs.
　　2. To realize the clean fuel production, we must have a timely readjustment of the gasoline and diesel production configuration, give priority to the improvement of the catalytic cracking technology, improve the quality of the catalytic gasoline and diesel and endeavor to bring up the percentage of gasoline and diesel hydrotreatment and the extent of hydrotreatment.
　　3. To produce the gasoline and diesel that meet the III category specification of the World Fuel Standards, we still need to continue our research and development work in the area of technology to further reduce the sulfur and olefin content of the catalytic gasoline, technology to further remove the sulfur and aromatics content of the diesel and the technology to improve the octane number of the gasoline and the cetane number of the diesel. Less investment should be made in technical development and application in order to bring about new technology based on the existing ones.
　　We are confident that we will be able to meet the technical challenge of producing clean fuels that meet or exceed the international standards.
　　Li Dadong