As a major development direction of modern coal chemical industry, coal-to-ethylene glycol (coal-to-syngas and then syngas to ethylene glycol) has always been a competitive place for the industry. By 2014, Shanghai Wuzheng Engineering Technology Co., Ltd. had already heard that it had completed the medium and high pressure carbonylation process for the first time in the world and realized the pilot test of the large-scale whole process technology development of syngas to ethylene glycol.

A stone stirs up a thousand waves. Considering the extension of the industrial chain into the field of coal-to-ethylene glycol, coal enterprises, polyester production enterprises, iron and steel, coking and other industrial enterprises are very concerned about this news. And many developers of syngas to ethylene glycol technology will also face the competition brought by the birth of this new technology. So, how did the pilot-scale technology of carbonyl synthesis of ethylene glycol under medium and high pressure complete? The reporter interviewed Wang Baoming, chairman of Shanghai Wuzheng Engineering Technology Co., Ltd.

'The process of carbonyl synthesis of ethylene glycol under medium and high pressure was developed by Wuzheng Company after more than two years of scientific and technological research. We call it the second generation synthesis gas to ethylene glycol technology, and declare the PCT patent. Wang Baoming told reporters that the second generation technology is innovated on the basis of the first generation technology.

The first generation technology mentioned by Wang Baoming is the technology that the enterprise has patent right to apply to the project of 50,000 tons/year ethylene glycol production from synthetic tail gas of Shandong Hualu Hengsheng Group. The project was completed and put into operation in July 2012. Up to now, the device has been running steadily, and more than 90% of the product quality meets the requirements of polyester grade.

According to Wang Baoming, by contrast, the second generation of syngas to ethylene glycol technology has achieved three innovations.

First, the carbonylation process is re-innovated. Wuzheng Company increased the pressure of carbonylation reaction from 0.3-0.5 MPa to 2.0-3.0 MPa, increased the pressure by 5-7 times, and reduced the diameter of main equipment and pipeline by 2-2.5 times.

The second is the re-innovation of large-scale core reactor. The plate reactor used in the technology is completely different from the tubular reactor before. This makes it possible to increase the production capacity of a single reactor to 300,000 tons per year, increase the heat transfer intensity by more than one time, and increase the catalyst loading coefficient by more than 60%. It is easy to adjust the flow field distribution. The plate reactor can reduce the equipment investment cost by more than 25%, the system compression power consumption by more than 20%, the main material consumption by about 5% and the energy consumption by more than 10% compared with the existing series and parallel tubular reactors.

Thirdly, the third generation catalysts with better performance have been developed through the re-innovation of catalysts.

The second generation of medium and high pressure carbonylation process uses the newly developed third generation of highly efficient catalysts. The third generation of highly efficient catalysts have the characteristics of better selectivity, higher conversion and longer life. The carbonylation catalyst adopts unique compound gel dispersing technology, which improves the activity of the catalyst and the effective utilization rate of precious metals. The loss rate of precious metals is greatly reduced, and the selectivity and time and space yield of oxalate ester are greatly improved. At the same time, in order to avoid the disadvantage of hydrogenation catalyst which is easy to be poisoned and deactivated and has a short life, Wuzheng Company creatively introduced pre-hydrogenation catalyst, which can extend the life of hydrogenation catalyst to more than two years. The third generation of highly efficient carbonylation and hydrogenation catalysts are 1%-2% more selective than the original catalysts. Their service life is longer than 2 years. The cost of producing ethylene glycol products consumes about 150 RMB per ton of catalyst.

So, as a technology supplier, why does Wuzheng Company introduce the second generation technology when the first generation technology has been successful?

'Mainly recognizing that the first generation of technology can not meet the requirements of large-scale.' Wang Baoming pointed out the most important reason.

Originally, with the production of 50,000 tons of ethylene glycol plant in Hualu Hengsheng and the requirement of 200,000 tons and 300,000 tons of ethylene glycol project put forward by subsequent owners, Wuzheng Company felt great pressure. For a long time, due to the restriction of the first generation technology, the so-called large-scale reactor in the industry is to connect the multi-tube reactor in series and parallel. Most of the 20-300,000-ton/year scale ethylene glycol plant reactors constructed are in series, parallel and matching systems of 50,000-ton/year one-line reactors with 10-14 sets. This is essentially the accumulation of multiple sets of low productivity and low efficiency. Obviously, this will result in large reactor, high energy consumption, large investment and other shortcomings, which is not conducive to the competition after the mature market.

The emergence of a customer inspired the innovation courage of Wuzheng Company. Zhejiang Rongsheng Holding Group, the world's largest terephthalic acid enterprise, has a polyester production capacity of 7 million tons per year. To make ethylene glycol, the company is looking for China Global Engineering Company, which recommended the technology of syngas to produce ethylene glycol from Wuzheng Company.

In November 2012, Rongsheng Group plans to build an annual production of 1.8 million tons of ethylene glycol project in Kuqa, Xinjiang, according to its own needs. In order to improve the competitiveness of enterprises, the owners hope that a single unit can best reach the scale of petroleum ethylene glycol, and the annual output of a single series can reach 300,000 to 500,000 tons. In the process of Rongsheng project, Wuzheng found that the first generation of process conditions can not meet the large-scale. The conventional process pressure of carbonylation section is 0.3-0.5 MPa, which is relatively low, and the matching production is twice as much as that of hydrogenation section. If a conventional tubular reactor is to be used, it needs parallel connection of multiple lines or tubular reactors, which also leads to the over-specification of power compression equipment and the over-specification of pipelines, which seriously restricts its large-scale.

With the deepening of basic research and engineering research, especially after cooperation with China Global Engineering Corporation in 2012, experts from Global Corporation