New technologies, new processes, new equipment | Advances and trends in petrochemical technology

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This excerpt is taken from the following source: Wang Zhihui, Zhou Hui, Fu Zhenqi, et al. Current Status and Trends in Refining Technologies. Chemical Engineering Management, 2020, (32). With the continuous economic development, the upgrading of consumption patterns, and the need to build a resource-saving and environment-friendly society, the chemical industry is moving in the direction of diversified raw materials, functionalized products, higher performance, and green recycling. In terms of raw material diversification and low-carbon olefins, in addition to the traditional steam cracking process that uses naphtha as the main raw material, the technologies that have been developed in recent years include direct conversion of crude oil into olefins (COTO), conversion of methanol into olefins (MTO/MTP), propylene production via propane dehydrogenation (PDH), olefin disproportionation for propylene production, and butadiene production via butene oxidation dehydrogenation. In terms of ethylene technology, the steam cracking process for producing ethylene has become quite mature after decades of development. In recent years, there have been no major technological innovations in this area; progress has mainly involved the use of new materials and technologies to improve certain equipment components. The technology for producing olefins directly from crude oil, and the process for manufacturing ethylene directly from crude oil, involve omitting the normal and vacuum distillation steps. These processes are integrated in a thorough manner with other refining units, thereby simplifying the workflow and reducing investment costs. The goal is to maximize the production of chemical products, such as olefins and aromatics. The world’s only commercially operational facility for directly converting crude oil into olefins was put into operation in Singapore in 2014, built by ExxonMobil. SABIC’s technology involves sending crude oil directly to the hydrocracking unit; after desulfurization, the lighter components are separated and sent to the steam cracking unit, while the heavier components are sent to the advanced catalytic cracking unit to maximize olefin production. The processes for producing olefins from methanol are mainly divided into MTO and MTP processes; these are two important new C1 chemical processes that use methanol synthesized from coal or natural gas as raw material, and employ a fluidized-bed reaction mechanism similar to that in catalytic cracking units to produce low-carbon olefins. In recent years, China’s methanol market has remained at high levels for an extended period, sustaining strong public interest in investing in methanol. There are already concerns regarding the market prospects for methanol products in the coming years, while the methanol-to-olefins technology offers a solution to address the challenges faced by this market. In the field of polyolefin technology, it has become mature worldwide, with several mainstream technologies having emerged. The major patent holders continue to make improvements in areas such as increasing plant size, enhancing performance, and reducing costs. Regarding polyethylene: four main production technologies have emerged, namely the vapor-phase method, solution method, slurry method, and high-pressure method. For polypropylene: the liquid-phase bulk method and the gas-phase method are primarily used, with the liquid-phase bulk method including the loop reactor process and the batch reactor process. Catalysts remain an important aspect in the development of olefin polymerization technology, with higher-active metallocene catalysts and advanced α-olefin comonomers being key areas of research. In the field of fine chemical technologies, breakthroughs are being made in various key technologies at the mid- and lower-level stages in China. Examples include the development of domestic production methods for green processes related to acrylic acid, acrylonitrile, and propylene oxide. There are also advances in the production of high-end special materials such as POE elastomers, EVOH resins, and cyclic olefin copolymers like COC/COP ； Special engineering plastics such as polyether ether nitrile and polyethersulfone ； High-performance fibers such as PBO, POD, and PBI still remain in an industrial vacuum. In recent years, the trend has focused on new chemical materials and specialized fine chemicals, utilizing light hydrocarbon resources to produce chemicals through green, low-carbon, and environmentally friendly processes.