China Petrochemical achieves a major breakthrough in producing ethylene through direct steam cracking of crude oil

In 2015, relying on its strong technical advantages accumulated over many years in the ethylene sector, Beijing Institute of Chemical Technology made every effort to develop crude oil steam cracking technology. The research team has focused on studying the steam cracking properties of feedstocks with high unsaturation levels, wide-range distillate oils, heavy oils, and crude oil. They have developed models for optimizing and designing crude oil steam cracking processes; through evaluation tests, they identified the key process control points for crude oil steam cracking. By combining these approaches with established technologies such as twisted plate tubes to enhance heat transfer and reduce coking, they have managed to address the problem of coking that occurs during the long-term operation of cracking furnaces. Since 2017, BEIC has begun to develop its intellectual property portfolio in the field of crude oil cracking; to date, it has filed 38 Chinese invention patents, of which 5 have been granted, and 1 international invention patent has been filed. In April 2020, the Technology Department of Sinopec organized Beihua Research Institute, the Engineering Company, and Tianjin Petrochemical to carry out joint research on the industrial application of crude oil steam cracking for the production of olefins. The R&D team started with integrated innovation in crude oil separation and steam cracking, developing low-cost crude oil separation technologies as well as engineering solutions for steam cracking of wide-range feedstocks. They also carried out facility upgrades on the 60,000-ton/year ethylene cracker at the Tianjin branch. On August 24, the pyrolysis furnace using this technology was successfully started up for the first time and operated stably for 33 days, with the test results meeting the expected objectives.

Projects for converting crude oil directly into chemicals, represented by ExxonMobil – ExxonMobil was at the forefront of developing commercial projects for converting crude oil directly into chemicals. In January 2014, ExxonMobil commissioned an olefin production facility using direct steam cracking of crude oil on Jurong Island in Singapore, capable of producing 1 million tons per year of ethylene directly from crude oil. The biggest advantage of ExxonMobil’s technology for producing olefins through direct steam cracking of crude oil is that it eliminates refining units such as atmospheric and vacuum distillation, thereby greatly simplifying the process flow. Its innovation lies in completely bypassing the conventional refining process by feeding crude oil directly into the steam cracking furnace, and adding a flash tank between the convective section and the radiant section of the cracking furnace. The process flow involves the crude oil being preheated in a convection section before entering a flash tank, where gas and liquid components are separated. The gas phase proceeds to a radiation section where it is cracked in the usual manner. The heavy liquid phase collected at the bottom of the flash tank is sent to an adjacent ExxonMobil refinery as raw material for refining processes, or it is sold directly.

The Crude Oil to Chemicals technology (COTC) simplifies the process and reduces investment by omitting key refining steps such as atmospheric and vacuum distillation as well as catalytic cracking; its aim is to maximize chemical production by generating large amounts of chemical feedstocks such as olefins and aromatics, with a chemical conversion rate of 50% to 80%. The technology for converting crude oil into chemicals is also constantly improving, and the impact of the next generation of such technologies will be even greater. Saudi Aramco is trying to integrate its current refining processes in the best possible way, in order to produce more chemical products per barrel of oil. This innovation process involves adjusting the existing mature technologies and processes in integrated refining complexes to increase the chemical yield per barrel of oil from the conventional 8% to 12%, with potential to reach up to 50%. In January 2021, Saudi Aramco stated that it was expanding the technology for producing chemicals from thermocatalytically processed crude oil, with the goal of achieving a conversion rate of 70% or higher for oil into chemicals.

Projects aimed at maximizing the conversion of crude oil into chemicals, represented by Hengli and Zhejiang Petrochemical, involve optimizing traditional refining processes in order to maximize the production of chemical raw materials for use in petrochemical plants. This route converts heavy products such as wax oil and residue in the crude oil refining process into lighter products by adding processing units such as hydrocracking, while also increasing the hydrogen-to-carbon ratio. By utilizing existing mature technologies and through reconfiguration, the conversion of crude oil into chemicals is maximized, thereby significantly raising the yield of basic petrochemical feedstocks to 40%~50%. Chinese private enterprises have begun to use advanced domestic and international refining and chemical processing technologies to build such plants designed to maximize the production of chemicals from crude oil, including Hengli Petrochemical’s project on Changxing Island in Dalian, Zhejiang Petrochemical’s project in Zhoushan, and Shenghong’s project in Lianyungang. 1. Hengli Petrochemical Project: This project has a crude oil processing capacity of 20 million tons per year. It primarily processes medium and heavy crude oils from Saudi Arabia or crude oils of similar quality. The refinery is designed to produce naphtha, while the aromatics complex is intended to maximize PX production. The main facilities of Phase I of the project include 20 million tons per year of atmospheric and vacuum distillation, 2 million tons per year of kerosene hydrorefining, 6 million tons per year of diesel hydrocracking, 7.6 million tons per year of wax oil hydrocracking, 6.4 million tons per year of residue hydrocracking, and 1.35 million tons per year of solvent deasphalting ； The products include 4.5 million tons per year of PX, 1 million tons per year of pure benzene, and 1.5 million tons per year of ethylene, resulting in an annual production of over 9 million tons of basic petrochemical raw materials, with a yield of around 46%. At the end of 2018, the atmospheric and vacuum distillation unit was put into operation; in May 2019, the refining project was fully operational, and in January 2020, the ethylene project began trial operations. 2 Zhejiang Petrochemical Project: This project is implemented in three phases. Upon full completion of phases 1 and 2, the crude oil processing capacity will be 40 million tons per year, with the main products being 8 million tons per year of PX, 2 million tons per year of pure benzene, 2.8 million tons per year of ethylene, and 600,000 tons per year of propylene dehydrogenation. The main facilities of Phase I of the project include 20 million tons per year of atmospheric and vacuum distillation, 3 million tons per year of light hydrocarbon recovery, 3 million tons per year of delayed coking, 5 million tons per year of residue hydrodesulfurization, 3.8 million tons per year of wax oil hydrocracking, 8 million tons per year of diesel hydrocracking, 4.2 million tons per year of heavy oil catalytic cracking, and 2 million tons per year of catalytic gasoline hydrogenation. The annual output of petrochemical products is approximately 9 million tons, with a yield of basic petrochemical feedstocks of around 45%. For the first phase of the project, the atmospheric and vacuum distillation unit was put into operation in May 2019, with full-scale production starting at the end of 2019. Phase 2 began construction in March 2020, with completion and operation expected by 2022.

ExxonMobil Huizhou Ethylene Project: On April 22, 2020, the ExxonMobil Huizhou Ethylene Project – a major foreign-investment project in China with a total investment of $10 billion – began construction in the Daya Bay Petrochemical Zone in Huizhou, Guangdong. ExxonMobil’s ethylene project in Huizhou, Guangdong is the first major petrochemical project built solely by an American company in China; it involves the construction of facilities capable of producing 1.6 million tons of ethylene per year. The ExxonMobil Huizhou ethylene project is implemented in two phases. Phase 1 involves the construction of facilities for crude oil steam cracking, polyethylene, polypropylene production, as well as the associated utility systems. Phase II: an ethylene plant with a capacity of 1.2 million tons per year, processes for producing polyethylene, polypropylene, butyl rubber, etc., as well as supporting utility systems, storage and packaging facilities, auxiliary production equipment, and systems engineering. The main bulk products include: 1.2 million tons per year of metallocene polyethylene, 470,000 tons per year of high-pressure polyethylene, 420,000 tons per year of impact-resistant polypropylene, and 420,000 tons per year of homopolymer polypropylene. The total investment for the project is 650,670 million yuan, with an investment plan of 136,000 million yuan for 2020; the funds will be used primarily for land reclamation work and the construction of foundations for heavy-load docks, as well as for building a comprehensive service office building. On April 9, 2021, Sinopec Refining & Chemical Engineering issued a announcement stating that the group had signed a BEPC turnkey contract with ExxonMobil (Huizhou) Chemical Co., Ltd. (EMHCC) for the planned Phase I ethylene project in Huizhou.