Advances and Reviews in Ethylene Production Technologies at Home and Abroad (prepared in 2007)

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1 Production Status 1.1 World As of January 1, 2007, the world’s total production capacity for ethylene was approximately 117.5752 million tons per year, with an operating rate of around 91%. By the end of 2010, global ethylene production capacity is expected to rise to 156 million tons per year, while the utilization rate will drop to 86%. The growth in production capacity will come mainly from the Middle East and the Asia-Pacific region. The production capacities of the world’s top 10 ethylene producers in 2006 are shown in Table 1, while the list of the world’s top 10 ethylene manufacturers is provided in Table 2. Table 1 Ranking of the world’s top ten ethylene producers
Company | Number of plants | Total capacity/(10,000 t·a⁻¹) | Domestic capacity/(10,000 t·a⁻¹)
1 | Dow Chemical | 14 | 1315.50 | 1036.95
2 | ExxonMobil | 15 | 1146.00 | 832.70
3 | Saudi Sabic | 7 | 898.50 | 718.25
4 | Shell Chemicals | 10 | 894.50 | 682.10
5 | Ineos | 8 | 654.60 | 509.10
6 | Lyondell Chemical | 6 | 488.00 | 488.00
7 | Sinopec | 9 | 437.50 | 407.50
8 | Chevron Phillips Chemical | 4 | 395.60 | 370.10
9 | Total Petrochemicals (France) | 9 | 552.30 | 332.70
10 | BASF | 7 | 495.52 | 310.91

Note: Data as of January 1, 2007. Table 2: Ranking of the world’s top 10 ethylene producers Company Location Capacity/(10,000 t/yr)1 Novartis Chemicals Alberta, Joffre 281.22 SABIC Jubail, Saudi Arabia 225.03 ExxonMobil Chemicals Beaton, Texas 219.74 Chevron Phillips Chemicals Sweeny, Texas 186.85 Dow Chemicals Terneuzen, Netherlands 180.06 Ineos Olefins and Polymers Chocolate Bayou, Texas 175.27 Star Chemicals Channelview, Texas 175.08 Yanbu Petrochemicals Yanbu, Saudi Arabia 170.59 Dow Chemicals Freeport, Texas 164.010 Shell Chemicals Norco, Louisiana 155.6 Note: As of January 1, 2007. The focus of global ethylene development will shift from the Gulf of Mexico to Asia and the Middle East, particularly the Middle East, which has an advantage in terms of cheap raw materials. Although the United States, Europe, and Japan account for 60% of the world’s total ethylene production capacity, no new ethylene plants will come online in these regions by 2010; some existing plants may be shut down permanently, while the remaining plants will focus on upgrades to overcome capacity constraints. By 2012, the ethylene production capacity in the Middle East will be on par with that in North America, and multiple ethylene plants will come online in the Chinese mainland, Singapore, India, and Taiwan, China. Table 3 shows the distribution of ethylene production capacity and its growth trends in major regions of the world. Table 3: Ethylene production capacity by region in the world (in 10,000 tons per year); Growth rate (%). January 1, 2007 vs. January 1, 2006. Asia-Pacific: 3,160.20 vs. 3,159.70, growth rate of 0.02%. Eastern Europe/Soviet Union: 846.20 vs. 845.20, growth rate of 0.12%. Middle East/Africa: 1,236.70 vs. 1,235.70, growth rate of 0.08%. North America: 35,687.77 vs. 35,542.60, growth rate of 0.41%. South America: 501.85 vs. 493.85, growth rate of 1.62%. Western Europe: 2,443.80 vs. 2,444.30, growth rate of -0.02%. Total: 11,757.52 vs. 10,733.01, growth rate of 0.21%. 1.2 Domestic: With the completion and operation of the CNOOC Shell ethylene project, the number of ethylene producers in China increased to 19 in 2006, with a total of 23 production units. By the end of 2006, China’s ethylene production capacity had reached 9.845 million tons per year, an increase of 25% compared to 2005 ； In 2006, ethylene production reached 9.226 million tons, an increase of 22.3% compared to 7.541 million tons in 2005. Among them, China National Petroleum Corporation produced 2.068 million tons of ethylene, a year-on-year increase of 9.6% ； Sinopec produced a total of 6.331 million tons of ethylene, representing a year-on-year increase of 15.19% ； CNOOC produced 646,000 tons of ethylene. The device’s operational rate is about 97%, **higher than the world average. The increase in China’s ethylene production capacity is mainly attributed to the commissioning of the CNOOC Shell ethylene project, the expansion of Sinopec’s Maoming ethylene plant, and the expansion of the Lanzhou ethylene plant. In 2006, the capacity expansion of the two 700,000 t/a ethylene plants at Jilin Petrochemical and Lanzhou Petrochemical in China was successfully completed ； CNOOC Shell project completed and put into operation ； The Sino-foreign joint venture Shanghai Sinopec Petrochemical increased ethylene production by 336,000 tons, while Nanjing Yangba Petrochemical increased its ethylene production by 306,000 tons. Table 4 shows China’s ethylene production capacity in 2006, while Table 5 presents the increase in ethylene production for each company in 2006 compared to 2005. Table 4: Names of major ethylene production enterprises in China in 2006, their production capacities in 10,000 tons per year, and the timing of their next upgrades, along with their updated production capacities in 10,000 tons per year
China National Petroleum Corporation – Daqing Petrochemical Company: 600, 2009–2010; upgraded to 1200. Jilin Petrochemical Company: 850, Fushun Petrochemical Company: 1420, 2008; upgraded to 800. Liaoyang Petrochemical Company: 1220, 2007; upgraded to 200. Lanzhou Petrochemical Company: 700, Dushanzi Petrochemical Company: 2220, 2008; upgraded to 1000. Total: 2630.

Sinopec – Yanshan Petrochemical Company: 710, Qilu Petrochemical Company: 800, Yangzi Petrochemical Company: 650, Shanghai Petrochemical Company: 845, Maoming Petrochemical Company: 1020, Guangzhou Petrochemical Company: 2020, 2008; upgraded to 800. Tianjin Petrochemical Company: 2020, 2009; upgraded to 1000. Zhongyuan Petrochemical Company: 1820, 2007; upgraded to 360. Beijing Dongfang Petrochemical Company: 150, Sinopec Syngene: 900, Yangba Petrochemical: 600. Total: 615.5. CNOOC Shell: 800, Liaoning Huajin Chemical Co., Ltd.: 1620, 2009; upgraded to 460. Total: 984.5.

Table 5: Growth in ethylene production from 2005 to 2006, showing enterprise names, production volumes in tons, and growth rates in percentages
2006 vs. 2005: Yanshan Petrochemical Company: 8200 vs. 14811, growth rate: 18.22%; Qilu Petrochemical Company: 8388 vs. 8251, growth rate: 1.65%. Yangzi Petrochemical Company: 7550 vs. 7758, growth rate: -2.68%. Shanghai Petrochemical Company: 9602 vs. 9623, growth rate: -0.22%. Tianjin Petrochemical Company: 23168 vs. 20705, growth rate: 11.9%. Maoming Petrochemical Company: 5221 vs. 16348, growth rate: 49.98%. Zhongyuan Petrochemical Company: 21446 vs. 19157, growth rate: 11.95%. Guangzhou Petrochemical Company: 19594 vs. 21362, growth rate: -8.28%. Beijing Dongfang Petrochemical Company: 16821 vs. 17751, growth rate: -5.24%. Sinopec Syngene: 9779 vs. 6641, growth rate: 52.33%. Yangba Petrochemical: 6466 vs. 5434, growth rate: 89.5%. Sinopec Group: 63311 vs. 19745, growth rate: 724.02%. Daqing Petrochemical Company: 51669 vs. 55555, growth rate: -6.99%. Lanzhou Petrochemical Company: 24005 vs. 24571, growth rate: -2.3%. Liaoyang Petrochemical Company: 13242 vs. 14621, growth rate: 3.14%. Fushun Petrochemical Company: 17966 vs. 16768, growth rate: 7.14%. Dushanzi Petrochemical Company: 24722 vs. 21261, growth rate: -5.43%. Jilin Petrochemical Company: 75180 vs. 95113, growth rate: 47.03%. China National Petroleum Corporation: 206787 vs. 31887, growth rate: 59.56%. CNOOC Shell: 6462000, Liaoning Huajin Chemical Co., Ltd.: 180561 vs. 15742, growth rate: 14.7%. Total: 92258317541136223.

The ethylene industry is a key focus for the development of China’s petrochemical sector. The domestic market has always been in a state of demand exceeding supply. To meet this demand, China will continue to build large-scale ethylene production facilities during the 11th Five-Year Plan period. By 2010, China’s total ethylene production capacity is expected to reach 15 million tons per year. Table 6 lists the large-scale ethylene projects planned to be constructed in China during the 11th Five-Year Plan period. Table 6: Scale of large-scale ethylene projects planned to be built in China during the 11th Five-Year Plan period / (10,000 t·a-1); Commissioning dates: Fujian Ethylene – 2009; Sichuan Ethylene – 2009; Zhenhai Ethylene – 2009; Tianjin Ethylene – 2009; Fushun Ethylene – 2009; Dushanzi Ethylene – 2008; Wuhan Ethylene – 2012. 2 Market Analysis 2.1 World: Due to strong global economic growth, the global demand for ethylene reached a growth rate of 5% in 2006, with global consumption of ethylene exceeding 110 million tons. Over the next 5 years, the annual growth rate of global ethylene demand will average over 4%. By 2010, the world’s demand for ethylene will reach 135 million tons. The global ethylene capacity utilization is expected to remain high in 2007 and 2008, but it will decline by 2010. Due to the increase in production capacity in the Middle East, the net exports of products from the United States and Japan will decline significantly. Around 2010, the United States will become a net importer, while Europe will also turn into a net importing region. In Asia, Japan, South Korea, and Thailand have an olefin production volume that exceeds their domestic demand. World ethylene consumption composition in 2006: PE 59%, PVC 14%, ethylene oxide/ethylene glycol 12%, styrene 7%, others 8%. 2.2 Domestic market: In 2006, China’s apparent consumption of ethylene was 9.485 million tons, an increase of about 25% compared to 2005; the equivalent consumption was around 18.7 million tons, representing a 10.4% increase on a year-on-year basis. In terms of apparent ethylene consumption, China has a high self-sufficiency rate for ethylene; however, when looking at ethylene-equivalent consumption, the self-sufficiency rate is quite low, and it is far from sufficient to meet the demands of sustained rapid economic development. China’s ethylene production is unable to fully meet downstream demand, and this situation is not likely to change significantly in 2007. There is still a significant gap in the ethylene market, and the ethylene industry has considerable room for growth. In particular, provinces and regions along China’s southeast coast, such as Jiangsu, Shanghai, Zhejiang, Fujian, and Guangdong, possess huge market potential. The consumption composition of ethylene in China in 2006 was: polyethylene 60%, PVC 23%, ethylene oxide/ethylene glycol 6%, and others 11%. The supply and demand situation of ethylene in China from 2006 to 2010, along with forecasts, is shown in Table 7. Table 7: Supply and demand situation of ethylene in China from 2006 to 2010, along with forecast figures
Year: 2006, 2007, 2010
Capacity/(10,000 t·a-1): 96, 711, 561, 784
Production/(10,000 t): 94, 111, 241, 410
Apparent consumption/(10,000 t): 948.5, 1131.5, 1438.9
Imports/(10,000 t): 101, 113, 2
Equivalent consumption/(10,000 t): 1870, 2169, 2684.2

3. Technical advancements
3.1 Low-carbon olefin conversion technologies
The C4 and C5 fractions produced by catalytic cracking units and ethylene plants in refineries, as well as light pyrolysis gasoline or light catalytic gasoline, contain large amounts of low-carbon olefins with molecular weights between C4 and C8. These can be converted into propylene and ethylene through either catalytic cracking or olefin disproportionation processes. 3.1.1 Catalytic cracking The selective catalytic cracking processes are represented by Lyondell/KBR’s Superflex process (fluidized bed) and the Propylur process developed by LuChi (fixed bed). The Superflex process can convert 2/3 of the feedstock into ethylene and propylene; Sasol Technologies in South Africa launched a plant in 2005 using this technology to produce propylene and ethylene. The Propylur process can use butene, pentene, and hexene as raw materials, and a pilot plant of this process is already in operation at BP’s facility in the Worringen area of Germany. Furthermore, the catalytic cracking process OCP developed by UOP and Atofina has been validated using a pilot plant. 3.1.2 Olefin Disproportionation The olefin disproportionation process is a catalytic reaction that involves the breaking of olefin double bonds to produce new olefin products; notable examples include Ruess’s OCT process and IFP’s Meta-4 process. The OCT technology is used for the disproportionation of ethylene and 2-butene to produce propylene; this technology has been applied to the 900,000 t/a ethylene plant at Sinopec in Shanghai, China. It is reported that by 2008, 7 companies in Asia would be using OCT technology. The Meta-4 olefin conversion process has undergone pilot-scale testing at the Kaohsiung refinery of China National Petroleum Corporation in Taiwan Province, China. 3.2 Progress in the localization of ethylene technology (1) In terms of cracking technology, CBL-Ⅰ, II, III, IV, and V types of cracking furnaces have been successfully developed; these are suitable for cracking feedstocks such as ethane, naphtha, light diesel, and hydrogenation tail oil. They have been put into industrial use at Liaoyang Chemical Fibers, Qilu Petrochemical, Jihua Company, Fushun Petrochemical, Yanshan Petrochemical, Zhongyuan Ethylene, and Tianjin Ethylene. Recently, CBL technology was again used to build a 90,000 t/a ethane furnace and two 60,000–80,000 t/a liquid feedstock cracking furnaces for Qilu Petrochemical. To date, a total of 18 CBL furnaces with a capacity of less than 100,000 t/a have been built, resulting in an aggregate production capacity of 940,000 t/a. In recent years, cooperation with Rums Company has been carried out to develop large-scale cracking furnace technologies with a capacity of 100,000 t/a. The total capacity of cracking furnaces that have been built or are under construction using the SL-I and SL-Ⅱ types of furnaces developed through this collaboration amounts to 3 million t/a. Among them, 4 SL-I type furnaces based on CBL technology are already in operation or under construction. Eleven large-scale cracking furnaces with a capacity of 160,000 t/a each for Tianjin’s 100 t/a ethylene plant are currently in the design phase, and the cracking furnaces for Zhenhai’s 1 million t/a ethylene plant will also utilize SL-I technology ； (2) Developed process software packages and related engineering technologies; the capacity expansion of the Zhongyuan Ethylene and Tianjin Ethylene plants was successfully carried out using CBL technology and ethylene process software packages ； (3) The CFT technology for fractional condensation and fractionation was developed, experimental verification was successfully completed, and it has been applied in plant renovation ； (4) C2 and C3 hydrogenation technologies have been developed; a series of catalysts and process technologies for the hydrogenation of C2 and C3 gases derived from pyrolysis have been successfully created and put into practical use. (5) Heat transfer enhancement techniques using twisted tube assemblies in pyrolysis furnaces, coking inhibitors for such furnaces, as well as high-efficiency tray and heat exchanger technologies have been developed, and these have achieved good results when applied in industry ； (6) The new ethylene recovery technology developed through the cooperation between Sinopec and Ruums has been applied to the Maoming ethylene renovation project ； (7) Significant progress has been made in technologies for producing ethylene and propylene from heavy feedstocks, including hydrocracking of heavy oil for ethylene production (HCC) and catalytic cracking (CPP) technologies. 4 Development Trends (1) Steam cracking of saturated hydrocarbons remains the main source of olefins. Ethylene production will continue to rely primarily on steam cracking, with an emphasis on designing larger plants in order to take full advantage of the economic benefits associated with larger investment scales. (2) Scaling up of the pyrolysis furnace. Naphtha steam cracking units utilizing modern technology now have an industrial capacity of 1.2 to 1.4 million tons per year. The 5 major steam cracking patent holders are all planning to design units with a single-line capacity of 1.5 million tons per year; when using gas as the feedstock, the capacity can reach 300,000 tons per year, and when using liquid as the feedstock, it is 230,000 tons per year. Some cracking units can achieve a production capacity of 250,000 tons per year. (3) The operation cycle is extended. From an operational perspective, the new naphtha cracking unit can operate for over 5 years between two routine maintenance periods; the cracking furnace tubes can remain in service for 10×104 hours, and the frequency of routine steam and air cleaning operations is no more than once every 60 days. (4) The design is continuously improved. For naphtha cracking units, the design improvements recognized by most patent holders include: a modified propane removal sequence, reducing the number of compression stages for the cracking gas from 5 to 3, the use of binary or tertiary refrigeration, driving the main process compressors with gas turbines, employing reactive distillation for the conversion of dienes, re-compressing the gases from the propylene fractionation tower, using HP50 alloy steel with a hard coating for the cracking furnace tubes, increasing the steam pressure in the waste heat boilers to over 12 MPa, the widespread use of online gas chromatography analysis, integrating control systems based on open fieldbus architecture, the use of online economic optimization systems, combining steam and power generation, and changing the sources from which naphtha is purchased. (5) Front-end hydrogenation and dual-furnace pyrolyzer design have become trends in the development of ethylene plant design. (6) The key to improving pyrolyzer technology lies in using new materials for pyrolyzers and developing various anti-coking techniques. 5 Recommendations: (1) Focus on the digestion, absorption, and application of introduced technologies to ensure the safe, high-quality, and efficient operation of the equipment. Thoroughly study the newly introduced technologies, summarize the operational experience since commissioning, determine the optimal parameters, and optimize the operation plan. Actively engage in technical exchanges with similar domestic enterprises, learn advanced production and management practices, master key control methods, and ensure the safe, stable, high-quality, and efficient operation of the facilities. (2) Focus on technological research and development, and strengthen the promotion and application of new technologies. Identify the production bottlenecks in the expanded facility, and actively organize efforts to address these issues in order to ensure stable and high-level production. Properly carry out the trial use of coking inhibitors for ethylene cracking furnaces to extend their operational cycle. (3) Extend the operating cycle of the ethylene plant. Long-term high-load operation of the device generates significant economic benefits. Practice has shown that, compared to the start-up and shutdown processes associated with planned maintenance or upgrades, the risk of failures or accidents during the long-term operation of an ethylene plant is not high. As long as there is excellent design, manufacturing, construction, and operational standards, as well as scientific and comprehensive management and advanced technologies, the risk of continuous operation of such plants can be controlled. (4) Adopt advanced control technologies to improve the operational efficiency of the ethylene plant. Advanced control is implemented for operational units in the ethylene plant, such as the cracking furnace, ethylene distillation tower, and propylene distillation tower; optimization is carried out on the COT and load control of the cracking furnace, as well as on the control of the propylene distillation tower and the ethylene distillation tower, thereby improving the operational efficiency of the ethylene plant.