The development of dimethyl ether technology at home and abroad

The two-step process technology for dimethyl ether has been fully mastered in China. It is possible to design plants with capacities ranging from tens of thousands of tons to hundreds of thousands of tons. The Southwest Chemical Engineering Research and Design Institute (Tianyi Technology) possesses the expertise to carry out such design work and to provide technical licenses； Small-scale installations can also be developed in China by Tsinghua University, Jutai Company, and Henan Lan Tian (for capacities of less than 50,000 tons) ； Sichuan Lutianhua has independently built a 200,000-ton dimethyl ether production facility in Ordos; its technical capabilities, as well as its experience in project construction, commissioning, and production management, are clearly superior to those of Tianyi Technology. There should be no technical obstacles to scaling up production from 200,000 tons to 400,000–600,000 tons. The main issue arises from the fact that at such a large scale, the dimensions of individual equipment become too large, which poses serious constraints due to China’s road and bridge infrastructure – a problem that coastal companies do not face. New Energy Group has also mastered the large-scale two-step production technology for dimethyl ether; since it produces dimethyl ether just like Lutianhua, it possesses extensive experience in this area as well. The two-step dimethyl ether production technologies developed by companies abroad such as Luchi, Topso, and Dongyang Engineering are also mature and reliable. For companies interested in entering the dimethyl ether industry, there are many potential technical partners available, and the technical risks are relatively low. The main challenges lie in investment, project timeline management, commissioning services, and staff training; success depends on which partner is chosen, with the decision ultimately resting with the company’s executives. There are many researchers at home and abroad working on the production of dimethyl ether using the one-step synthesis method, and significant progress has been made; however, the industrialization process is quite slow. It will be difficult to develop a truly industrialized technology within the next 5 years. Those who wish to enter the dimethyl ether industry as soon as possible might consider skipping the one-step method.

Sichuan Tianyi Company (formerly Southwest Institute) was the first in China to carry out research and development on the production of dimethyl ether from methanol. “The research on the production of dimethyl ether from methanol was a **\"Eighth Five-Year Plan\" science and technology project**, and it passed expert technical evaluation and acceptance in Beijing in January 1994. The company holds 2 Chinese invention patents for its methanol-to-dimethyl ether technology, with the key technologies included in the patent claims. The production technology for converting methanol into dimethyl ether has undergone numerous improvements and optimizations; it features low energy consumption, low investment costs, high product quality, and no pollution. This technological process is leading in China and advanced on the international stage. Technical features: ① The catalyst is independently researched, developed, and produced; it boasts good performance, high activity, excellent selectivity, and a long service life. ②Using crude alcohol as a raw material significantly reduces costs. ③The reactor uses a multi-stage quench-type fixed-bed design; it features a large catalyst loading capacity, low investment costs, an appropriate reaction temperature, few side reactions, and is easy to scale up. ④The structure and separation process of the vaporization distillation tower simplify the process, reduce investment, and effectively lower energy consumption. ⑤When using crude alcohol as the raw material, it is possible to produce both fuel-grade and aerosol-grade products simultaneously. ⑥The ‘three wastes’ are properly treated, ensuring no pollutants are discharged from the facility.

Ningbo Far East uses the methanol vapor dehydration method to produce dimethyl ether. By leveraging its advantages and characteristics in terms of reactors, as well as through process optimization, it manages to recover the heat generated during the dimethyl ether production process, thereby reducing the consumption of utilities such as steam. The methanol vapor dehydration process is considered the main method for dimethyl ether production at present, thanks to its simple production process, low equipment investment, and ease of dimethyl ether purification. The advanced and unique methanol dehydration process technology for synthesizing dimethyl ether, developed through innovation and optimization by Far East Company, represents significant improvements and innovations compared to existing methanol gas-phase catalytic dehydration methods both domestically and internationally. Its technical features include: (1) a simple process flow and convenient operation. (2) The catalyst layer has a small footprint, resulting in fewer by-products. (3) With a low temperature at the inlet of the tower and a high temperature at the outlet, the reaction heat generated in the production of fuel-grade dimethyl ether can be used in place of steam for heating the dimethyl ether reboiler, requiring a lower steam pressure level. (4) Heat recovery from the reaction is efficient, resulting in low steam consumption. (5) Reactor technology. Far East Company uses a single-tube baffled methanol dehydration reactor with a gas distribution box. The advantages are: a. An insulating layer can be installed on the bed layer, resulting in a more reasonable temperature distribution within the bed layer, especially when it is necessary to raise the temperature of the upper part of the bed layer rapidly. b. The cold tube structure is more reliable. In this structure, the cold tube bundles are divided into several separate clusters, with no interaction between these clusters. Thermal compensation is achieved between the upper and lower cold tubes within each cluster through upper elbows; its reliability is much higher than that of the double-ring tube design, where a single tube with baffle rings is buried within the catalyst. c. It has a simple structure, which reduces the requirements for manufacturing and installing the internal components; it also effectively prevents accidents caused by filler leakage from the catalyst basket cover, resulting in large temperature differences across the bed layer, and it is easy to replace the internal components. d. The catalyst is easy to load and unload, and the pressure drop across the bed is low. (6) The modified catalyst possesses appropriate acidity, enabling high conversion and selectivity in the reaction of methanol dehydration to dimethyl ether at lower temperatures, while also preventing carbon deposition at higher temperatures. (7) Dimethyl ether distillation technology. The internal components of the distillation tower utilize wire mesh corrugated packing and liquid distributors produced using the company’s proprietary technology; these features confer a large specific surface area, strong ability to distribute liquid evenly, low pressure loss in the tower, as well as high efficiency in mass and heat transfer.

Does Ningbo Yuandong also produce dimethyl ether?