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Trends in the Development of New Technologies in the Six Current Petrochemical Fields Chen Qingling The development trend of contemporary petrochemical technologies is to use high-tech to improve traditional processes, develop more efficient new catalysts, advance clean production methods, and produce environment-friendly products, thereby raising petrochemical technology to a new level and providing strong support for the sustainable development of the petrochemical industry. The current trends in technological advancements in the six petrochemical sectors are outlined as follows: 1. New technologies for ethylene production – The Ethylene2000 production process developed by LUMMUS has been widely adopted in recent years. This process is characterized by a pyrolyzer with a short residence time, a rapid quenching transfer line exchanger (TLE), and on-line coking removal technology. The Ethylene2000 process has been adopted in the 860 Kt/a ethylene plant of the petrochemical company NROC in Port Arthur, the 760 Kt/a ethylene plant of Yanpet Company in Saudi Arabia, and the 700 Kt/a ethylene plant of Kemya Company. Dow Chemical Company has developed a new ethylene production process that reduces the costs associated with ethylene manufacturing, by employing the catalytic oxidative dehydrogenation of ethane under autothermal conditions. Ethane/oxygen/hydrogen are fed in a certain ratio and preheated to 275°C, passing through a Pt/Cu catalyst supported on MgO at a pressure of 0.135 MPa and a space velocity of 125752 h-1. Upon contact with the catalyst, the reaction temperature rose to 925°C within a few seconds. Under autothermal conditions, the ethylene selectivity is 81%, and the ethane conversion rate is 75%. Although the selectivity is roughly the same as that of steam cracking, the conversion rate **exceeds 65% typically. The main by-products are methane (6.4%), carbon monoxide (6.0%), and carbon dioxide (1.4%). The presence of hydrogen in the feed increased the conversion rate of ethane, while the carbon dioxide produced by deep oxidation **decreased**. This process is also applicable to fluidized beds, with an ethylene selectivity of 83%, which is slightly higher than that of fixed-bed systems. Another advantage of fluidized bed reactors is the ease of recovering heat from exothermic reaction processes. Luoyang Petrochemical XX Company has developed a patented technology for the direct cracking of heavy oil to produce ethylene (HCC). This technology has been successfully tested on an industrial scale at XX Company in Qiqihar, Heilongjiang, reaching a leading level among similar technologies worldwide. This HCC unit, converted from a catalytic cracking unit, is the world’s first industrial facility for the direct pyrolysis of heavy oil to produce ethylene. It has a processing capacity of 60 kt/a, and its feedstock is 100% Daqing atmospheric residue oil. A dedicated LCM-5 catalyst with good activity, selectivity, and stability is used. The mass yields for the one-way cracking of ethylene and propylene reached approximately 22.0% and 15.5%, respectively. The mass yield of mixed butene is 8%, and the mass yield of ethylene is 6%–7%. In cases such as ethane reprocessing, the mass yield of ethylene can be increased to 26%–27%, while the mass yield of propylene increases by about 16%. Recently, scale-inhibiting agents and furnace tube coating technologies to extend the operating cycle of ethylene cracking furnaces have also been developed. Dow Chemical Canada has introduced an antiscalant called CCA-500, which **reduces** the production of coke and carbon monoxide in the steam cracking process carried out by Chevron-Phillips Chemical. Depending on the conditions of the furnace tubes, this scale inhibitor can extend the operating time of the pyrolysis furnace by 2 to 8 times, and allow it to operate at higher feed flow rates, thereby increasing the conversion rate and pyrolysis depth. Dow Chemical has completed industrial trials of CCA-500 at the ethylene plant in Saskatchewan, Canada. In addition to the ethylene complex already in use in Sweeny, Texas, USA, it has also been licensed to Daelim Corporation in South Korea for its Yangchun facility, as well as to ExxonMobil’s facility in Houston, Texas, USA. Nippon Steel & Sumitomo Metal Corporation and Shell jointly developed reaction furnace tubes with inner wall coatings for ethylene cracking units; these new type of tubes are known as Plasma Power Welding (PPW) technology tubes (PIT). Pilot tests have shown that this coating prevents coke deposition on the inner surface of the furnace tubes, extending the operating cycle between two coke cleaning operations by 50%, and simultaneously increasing the lifespan of the furnace tubes by 2 to 3 times. Using PPW technology, a coating 2–4 mm thick is formed on the inner wall of the reaction tube, free of bubbles and pores, which is then polished to a mirror finish. Shell has promoted this technology worldwide, aiming to capture 15% of the market share for all ethylene reactor tubes, worth an estimated over $300 million per year. Simple olefin separation technologies are also under development. ExxonMobil has developed an attractive new system for separating ethylene from ethane and other gases (World Patent AppI 00/61527). II. Technologies for increasing propylene production The annual demand growth rate for propylene exceeds that of ethylene, at 5.6%. The world’s annual propylene production capacity is expected to increase from 60 Mt in 2000 to 63 Mt in 2002, 66 Mt in 2004, and 76 Mt in 2008. To increase propylene production, propylene production technologies have become more diversified. Steam cracking and catalytic cracking are the two main sources of propylene. The ethylene produced by steam cracking is twice that of propylene; catalytic cracking (FCC) converts 4% of VGO into a C3 stream, from which 70% propylene and 30% propane can be separated. Propane dehydrogenation is the third source of propylene, with a conversion rate of 80%. Building a 300kt/a plant requires an investment of approximately $119 million. To date, 8 units have been built worldwide, with a total capacity of 1.20 Mt/year. It is predicted that by 2010, 4 Mt/year of propylene can be produced through propane dehydrogenation. Another process specifically used for producing propylene is the disproportionation reaction process. Ethylene reacts with 2-butene to produce 2 molecules of propylene. When the disproportionation reaction is combined with steam cracking, the propylene to ethylene production ratio can be increased to 1.0–1.2, compared to 0.6 for conventional naphtha cracking. The Triolefins disproportionation process, originally developed by Phillips and now owned by Lummus with the rights to technology transfer, uses a fixed-bed reactor with tungsten-based catalysts at temperatures of 330–400°C, and one industrial installation of this type already exists. The disadvantages of the disproportionation reaction technique are high investment costs, sensitivity to impurities in the raw materials, and the economic issue of converting expensive ethylene into lower-value propylene. An alternative approach is to modify lower-value feedstocks such as C4, C5, pyrolysis gasoline, and gas oil into olefins through catalytic cracking. The Superflex process owned by AkzoNobel and KBR, which includes rights for technology transfer, is based on KBR’s FCC technology; when combined with an olefin complex, it can increase the overall propylene/ethylene ratio. Before entering the reaction system, C4 and C5 are first subjected to selective hydrogenation to convert alkynes and dienes into alkenes. An alternative approach to converting C4 and C5 olefins into ethylene and propylene is fixed-bed catalytic cracking. III. Activation technologies for light alkanes: In the 21st century, petrochemical feedstocks are likely to shift toward cheaper alkanes derived from natural gas; therefore, the transition from olefins to alkanes as feedstocks will be one of the key focuses in the research and development of petrochemical technologies in the new century. Alkane activation technologies that may be industrialized in the 21st century include the conversion of ethane to acetic acid, isobutane to methacrylates, catalytic dehydrogenation of ethane to ethylene, and propane to acrylic acid. Acetic acid for producing ethylene from ethane ； Direct production of vinyl chloride from ethane ； Alkane activation technologies such as the direct production of acrylonitrile from propane and 1,4-butanediol from n-butane are nearing industrialization. IV. New catalyst technologies: New types of catalysts such as hydrogenation catalysts, isomerization catalysts, and polyolefin catalysts are continuously being developed. The new catalyst developed by IFP for the isomerization of ethylbenzene to p-xylene increases the yield of p-xylene from the usual 88% to 93%. Known as Oparis, this new catalyst can convert up to 40% of ethylbenzene, while reducing the loss of C8 aromatics to less than 2%. Enghard Company and Ascot Fine Chemicals have developed a newly created catalyst intended for industrial use, which boasts the high selectivity of homogeneous catalysts and can be recovered using filtration methods. Unlike conventional heterogeneous catalysts, it is not poisoned by sulfur, aromatic bromides, and nitro and benzyloxy functional groups present in the feedstock. In the field of catalysts for polyolefin production, metallocene catalysts and other single-active-center catalysts are being increasingly adopted, while catalysts with even higher activity are also under development. V. Clean production technologies: Environmentally friendly clean production processes represent an inevitable trend in the development of petrochemical technology in the 21st century. These include the use of non-toxic and harmless raw materials, minimal generation of waste gases, wastewater, and solid waste, thereby achieving \"zero emissions\" as part of environmental protection measures. They also involve the effective recycling of waste materials, as well as the recycling of products after they have been used, such as discarded plastics. Environmental protection technologies suitable for industrial application are mainly new technologies that enable the production of petrochemical products without using toxic and harmful raw materials such as phosgene, sulfuric acid, phosphoric acid, hydrocyanic acid, hydrochloric acid, and aluminum trichloride. Using ion exchange resin catalysts to replace hydrochloric acid in the production of bisphenol-A, or using ion exchange resin catalysts to replace sulfuric acid in the production of sec-butanol ； Production of linear alkylbenzenes using silica fluoride/alumina catalysts instead of hydrocyanic acid ； Change the raw material route by using isobutylene in place of propylene and hydrofluoric acid as raw materials to produce methyl methacrylate ； Production of biodegradable plastics (including biodegradable and photodegradable ones), etc. The production of isopropylbenzene involves the alkylation of benzene with propylene, using a Friedel-Crafts catalyst system: solid phosphoric acid (accounting for 90% of global capacity) and aluminum trichloride. Both of these catalysts pose environmental disposal issues. Mobil has introduced the molecular sieve catalyst MCM-22; the use of this catalyst leads to significant improvements in isopropylbenzene production in terms of yield, energy consumption, product purity, environmental impact, corrosion resistance, and maintenance requirements. Ten plants using this catalyst have been built around the world, accounting for over 50% of the global cumene production capacity. The MCM-21 catalyst is inert to the environment; it requires no special packing or treatment, and can be easily removed from the reactor for regeneration. ??? Polycarbonate is produced by the polymerization reaction of bisphenol-A and phosgene in aqueous or non-aqueous solutions. Several alternative processes that do not use phosgene have been developed. GE has built a PC plant in Cartagena using phosgene-free technology, and Bayer has also constructed a 40kt/a phosgene-free melt process plant in Antwerpen. Asahi Kasei plans to build a facility in Taiwan Province using its phosgene-free technology. Diphenyl carbonate is used as the carbonylating agent in all processes. Wahlco Air Systems has developed the U2A system for converting urea into ammonia on-site. This technology can convert non-toxic urea into ammonia for controlling NOx. Ammonia can be generated on-site when needed, addressing the environmental and health safety issues associated with the transportation and handling of ammonia. Both selective catalytic reduction and selective non-catalytic reduction can use ammonia to remove NOx from combustion exhaust gases. Waste plastic recycling processes that offer both economic and environmental benefits have attracted great interest. The first industrial plant (for recycling PVC and polyester at 5,000 t/a) was put into operation in France in 2001. The cost of recycled PVC is 2/3 of that of the original resin. The Japanese company Teijin has developed a recycling process to recover dimethyl terephthalate (DMT) and ethylene glycol (EG) from discarded polyethylene terephthalate (PET) bottles. VI. High-efficiency equipment technology: The research and development of high-efficiency equipment is an important aspect in advancing petrochemical technology. Maruzen Petrochemical Co., Ltd. and others jointly developed an internal heat-exchange type distillation column that enables significant energy savings; by using this column for the distillation and fractionation of benzene-toluene mixtures for over 100 hours, high-purity benzene and toluene were obtained while saving more than 30% in energy consumption. Planned for large-scale production by 2006. Its basic principle is to compress the vapor moving from the distillation recovery section to the concentration section, thereby raising the temperature of the concentration section above that of the recovery section. When these two sections are combined, heat is transferred from the concentration section to the recovery section, thus reducing the energy required for heating. The tower is a concentric circular distillation tower with an inner concentration section and an outer recovery section. Even with an external reflux ratio of zero (1.5 for existing units), 99.9% benzene can be obtained at the top of the tower and 99.8% toluene at the bottom, while saving more than 30% in energy consumption. The compact heat-exchanger-type reactor (HEX) developed by the British company BHIR Solution has passed its first industrial-scale test, reducing the reaction time for producing organic intermediates from typically 18 hours to 30 minutes. The process involves the two-step catalytic oxidation of thioethers to sulfones via a sulfoxide intermediate. Exothermic reactions require the mixing of two liquid phases. Traditional processes are carried out in a semi-continuous manner in batch stirred reactors. The HEX reactor enables the process to operate in a continuous manner, improves mixing and heat transfer, and reduces residence time. This compact reactor is composed of thin plate assemblies bonded by diffusion, and features specific flow channels created by chemical etching. THE HEX technology has been adopted by 4 chemical companies as reactors for a wide range of chemical reactions.