As a major development direction of modern coal chemical industry, coal-based ethylene glycol (coal to syngas and then syngas to ethylene glycol technology) has always been a battleground for the military. Recently, Shanghai Wuzheng Engineering Technology Co., Ltd. reported that the company has completed the medium and high pressure carbonylation process for the first time in the world and realized the pilot test of the development of synthetic gas to ethylene glycol large-scale full-process technology.
A stone stirs up a thousand waves. Industrial enterprises such as coal enterprises, polyester producers, steel and coking, which are considering the extension of the industrial chain and preparing to enter the field of coal-based ethylene glycol, are very concerned about this news. And many developers of syngas-to-glycol technology will face the competition brought about by the birth of this new technology. So, how is the medium and high pressure carbonylation ethylene glycol pilot technology completed? The reporter interviewed Wang Baoming, chairman of Shanghai Wuzheng Engineering Technology Co., Ltd. with questions.
“The medium and high pressure carbonylation process of ethylene glycol is developed by Wuzheng after more than two years of scientific research. We call it the second generation of syngas to ethylene glycol technology and declare PCT patents.” Wang Baoming Tell the reporter that the second generation technology is based on the innovation of the first generation technology.
Wang Baoming's first-generation technology is the technology that the company has patents for the 50,000-ton/year synthetic tail gas ethylene glycol project of Shandong Hualu Hengsheng Group. The project was completed and put into production in July 2012. Up to now, the device has been running stably, and the product quality is above 90% to meet the polyester grade requirements.
According to Wang Baoming, in contrast, the second generation of syngas to ethylene glycol technology has achieved three aspects.Re-innovation.
First, the carbonylation process is re-innovation. Wuzheng Company increased the pressure of the carbonylation reaction from 0.3 to 0.5 MPa to 2.0 to 3.0 MPa, which increased the pressure by 5 to 7 times. The diameter of major equipment and pipes decreased by 2 to 2.5 times.
The second is to reinvent the large-scale core reactor. The plate reactor used in the technology is completely different from the previous tubular reactor. This makes it possible to increase the production capacity of a single reactor to 300,000 tons/year, increase the heat transfer intensity by more than one time, and the catalyst loading coefficient is more than 60%, which makes it easy to adjust the flow field distribution. The plate reactor can reduce the equipment investment cost by more than 25%, reduce the system compression power consumption by more than 20%, reduce the main material consumption by about 5%, and reduce the energy consumption by more than 10% compared with the existing multi-string and parallel tube reactor.
Third, the catalyst was re-innovated and a third-generation catalyst with better performance was developed.
The second generation of high pressure carbonylation process uses a newly developed third generation high efficiency catalyst. The third generation of high-efficiency catalysts has the characteristics of better selectivity, higher conversion rate and longer life. The carbonylation catalyst adopts a unique composite gel dispersion process to improve the activity of the catalyst and the effective utilization rate of the precious metal, the loss rate of the precious metal is greatly reduced, and the selectivity and space-time yield of the oxalate are greatly improved. At the same time, in order to avoid the drawbacks of hydrogenation catalyst deactivation and short life, Wuzheng Company creatively introduces a pre-hydrogenation catalyst to extend the life of the hydrogenation catalyst to two years or more. The third-generation high-efficiency carbonylation and hydrogenation catalysts are 1% to 2% more selective than the original ones, and the service life is more than 2 years. The cost of producing catalysts for ethylene glycol tons is about 150 yuan.
Then, as a technology supplier, why did Wuzheng introduce a second-generation technology in the case of a successful case of the first-generation technology?
'The main reason is that the first generation technology can not meet the requirements of large-scale.' Wang Baoming pointed out the most important reason.
Originally, with the annual production of 50,000 tons of ethylene glycol equipment by Hualu Hengsheng and the requirements of the follow-up owners for the annual output of 200,000 tons and 300,000 tons of ethylene glycol, Wuzheng felt a lot of pressure. All along, due to the constraints of the first generation of process technology, the so-called large-scale in the industry is to connect multi-casing reactors in series, and the reactors of 20-300,000 tons/year scale ethylene glycol plant are mostly 10 to 14 sets. The 50,000 tons/year one-line reactor string, parallel and supporting system. This is essentially the inefficient addition of multiple sets of low capacity. Obviously, this will cause shortcomings such as large reaction equipment, high energy consumption, and large investment, which is not conducive to the competition after the mature market.
The emergence of a customer has inspired the innovation courage of Wuzheng. Zhejiang Rongsheng Holding Group, the world's largest terephthalic acid company, has a polyester capacity of 7 million tons per year. The company is going to do ethylene glycol, looking for China Ryukyu Engineering Co., Ltd., and Ryukyu recommends the Ethylene Glycol technology of Urumqi.
In November 2012, Rongsheng Group plans to build an annual output of 1.8 million tons of ethylene glycol project in Xinjiang Kuche according to its own needs. In order to improve the competitiveness of the enterprise, the owner hopes that the single set of equipment can reach the scale of petroleum glycol, and the annual output of the single series reaches 300,000 to 500,000 tons. In the process of doing Rongsheng project, Wuzheng found that the first-generation process conditions could not meet the large-scale. The conventional process pressure of the carbonyl chemical section is 0.3-0.5 MPa, the pressure is relatively low, and the supporting output is doubled compared with the hydrogenation section. If a conventional tubular reactor is to be used, multiple lines or multiple tubular reactors are required to be connected in parallel, which also leads to over-limitation of the power compression equipment and over-limit of the pipeline specifications, which seriously restricts the enlargement.
With the deepening of basic research and engineering research, especially after the cooperation with China Ryukyu Engineering Co., Ltd. in 2012, the experts of Ryukyu Company put forward a lot of opinions on technological innovation. To this end, Wuzheng has carried out secondary development of the carbonylation and hydrogenation processes, in which increasing the pressure of the carbonylation reaction and changing the performance of the catalyst are the key problems to be solved. At present, the medium and high pressure carbonylation process developed by Wuzheng has more than doubled the catalyst yield of the low pressure carbonylation process, which has a reasonable arrangement with the hydrogenation section, which creates the necessary conditions for the large-scale installation.
After more than two years of technical research, in April 2014, the 50-ton/year medium-high pressure carbonylation process was successfully tested and achieved the expected results. For the future of coal-based ethylene glycol, Wang Baoming is very optimistic: 'After the successful pilot test, the large-scale coal-based ethylene glycol is only a matter of time.' At present, Wuzheng has completed the transfer of several sets of this technology.
Finally, Wang Baoming reminded the project owners not to repeat the mistakes of investing in light operation costs, heavy-duty light weight, low-end and low-capacity simple, light, efficient, large-scale, high-capacity technology applications, and will look long-term, waiting to see Look at the real synthesis gas glycol large-scale project!