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New toluene-methanol alkylation technology helps aromatics plants enhance competitiveness Author/Source: Yajia Coal Chemical Industry Date: 2018-04-10 Clicks: 12 Compared with the traditional process of producing PX through selective disproportionation of toluene, the advantage of the toluene-methanol alkylation (also known as “toluene-methanol methylation”) method for PX production lies in its use of toluene and low-cost methanol as raw materials; theoretically, only about 1 ton of toluene is required to produce 1 ton of PX, which is half the amount needed in the toluene disproportionation process. In December 2017, Yangzi Petrochemical’s 200,000 tons per year toluene methanol methylation project passed the completion inspection. This project utilizes the fixed-bed toluene-methanol methylation technology for p-xylene production, developed by Sinopec Shanghai Research Institute of Chemical Industry. It was implemented at one of Sinopec Yangzi Petrochemical’s 200,000 tons per year toluene isomerization units by the end of 2012, becoming the world’s first toluene-methanol methylation plant. In September 2016, the Shaanxi Coal Chemical Technology and Engineering Center signed the first demonstration license agreement for the new technology of producing p-xylene from toluene and methanol along with low-carbon olefins (hereinafter referred to as the “new p-xylene production technology”) with Shandong Shengxing Chemical ； In April 2017, a meeting to discuss the process package design for Shandong Shengxing’s new 200,000 tons per year p-xylene production facility was held in Luoyang, marking the official start of industrial development for this technology. In August 2017, the Shaanxi Coal Chemical Technology and Engineering Center’s new technology for p-xylene passed the evaluation of achievements organized by the China Petroleum and Chemical Industry Federation. This new p-xylene production technology utilizes a circulating fluidized bed process, and when combined with aromatic compound production units, it can significantly increase the output of p-xylene, the main product of such units. In existing aromatic compound production facilities, by introducing this new p-xylene production technology through technical upgrades, it is possible to increase p-xylene production by more than 20% without making major changes to the other components of the facilities ； In the newly built aromatic complex, a new technological unit for p-xylene production is planned to make full use of the benzene and toluene resources available in the complex, thereby reducing the investment required for the facility while increasing p-xylene production by approximately 30% ； Furthermore, this technology produces p-xylene while simultaneously generating ethylene as a by-product; both of these products are basic raw materials for polyester production, which helps improve the economic efficiency of the industrial chain. Over the next five years, a number of large-scale aromatic compound production facilities with advanced technology, low energy consumption, and low emissions will come online in the Asia-Pacific and Middle East regions. How to transform existing aromatic compound plants to enhance their competitiveness has become a prominent issue at present. It is predicted that in the long term, the growth rate of market demand for PX will be twice that of benzene ； With the promotion of ethanol gasoline, MTBE will soon be phased out of the market. For existing refineries, finding a new product route by methylating toluene into benzene and methanol is a good approach. UOP’s new toluene methylation process features high methyl utilization, low energy consumption, and low investment costs; it is a powerful tool for enhancing the capacity of existing aromatic compound production facilities and improving their competitiveness. UOP’s toluene methylation technology, built on years of fundamental research and a thorough integration of aromatic compound processing technologies, can be implemented with minimal investment; it enables an increase in PX production capacity by 30–50% while reducing energy consumption by 20%. At the same time, benzene production can be flexibly adjusted according to market demand. The 2018 China p-xylene industry chain technology and market forum will be held in Chengdu, Sichuan on April 28, 2018. Experts from UOP will deliver an excellent presentation introducing “UOP’s new toluene methylation technology”.