"Strong Combination" Energy Conservation and Carbon Reduction——Key technologies and industrial application projects of energy conservation in chemical separation and purification processes under the background of carbon neutrality

Mass transfer and separation is an important part of
the chemical production process.
The project of "Key Technologies and Industrial Applications of Energy Saving in Chemical Separation and Purification Process under the Background of Carbon Neutrality" completed by Professor Li Qunsheng's team of Beijing University of Chemical Technology has broken through the problems of large energy consumption in the single distillation process of isomers or substances with similar boiling points, reduced energy consumption and carbon dioxide emissions in the process of chemical separation and purification, and realized large-scale industrial applications
.
The project recently won the first prize of scientific and technological progress of
the Chinese Society of Chemical Industry.

Conventional separation technology consumes a lot of energy

According to relevant data from the National Bureau of Statistics, China's GDP energy consumption is about 3 times that of OECD countries and 1.
5 times the world average, and there is still much room
for decline.
In the chemical industry, separation systems are a major energy consumer
.
According to incomplete statistics, the energy consumption of the separation and purification process accounts for about 60%
of the total energy consumption of chemical production.
The traditional chemical separation and purification process, especially the rectification process, has problems such as backward energy-saving technology and low equipment efficiency, which has become one of the bottlenecks restricting the green development of
China's chemical industry.

With the economic and social development, higher requirements for chemicals have been put forward in various fields, and the demand for high-purity and ultra-pure chemicals is increasing
.
The production of high-purity chemicals faces the separation of trace impurities with similar boiling points, and every grade of purity increases, the number of theoretical plates and energy consumption of the distillation column increases sharply, and purification is extremely difficult, so the separation of high viscosity and easy self-polymerization systems and energy conservation and emission reduction have become the focus
of attention of industries and academia at home and abroad.

Independent development of key technical equipment

The development of key energy-saving technologies for chemical distillation process is of great significance
for improving the overall level of China's chemical industry.
With the support of the Ministry of Science and Technology and the Ministry of Education, Li Qunsheng's team has spent 15 years researching key problems, carried out a large number of chemical energy-saving related research, pioneered the key technologies of distillation - other separation (crystallization, extraction, membrane separation, etc.
) combined with energy conservation with independent intellectual property rights, and realized large-scale industrial applications
.
The technical achievement has passed the appraisal of scientific and technological achievements organized by the Chinese Chemical Industry Society, and is considered to have reached the international advanced level as a whole, and the key technologies such as rectification-other separation combined energy saving have reached the international leading level
.

Yue Han, a member of the project team, said that the key technologies of distillation and other separation combined energy saving can "strongly combine" the advantages of multiple separation technologies to achieve the effect
of significant energy saving and consumption reduction.
For example, the distillation-continuous multi-stage countercurrent step-by-step crystallization combined energy-saving technology applied in the separation and purification project of Anshan coking fine naphthalene, taking advantage of the high difference in the melting point of this material, a continuous countercurrent crystallization column is added to the distillation column, thereby reducing the reflux ratio of the distillation process and achieving significant energy-saving effects
.

"We have also developed core distillation components such as high-efficiency large-flux wire mesh corrugated packing, packing-type guide tower, high-efficiency separation of bulk packing and high-efficiency guide sieve plate, established a data model for energy-saving optimization of the whole system of the distillation process, developed key technologies for comprehensive energy saving and thermal integration optimization in the distillation operation process, improved the heat exchange efficiency, reduced energy consumption and equipment investment, and realized the green production
of the separation process.
" Yue Han introduced
.

Help the green and high-end development of the industry

Talking about the industrial application status of the project, Li Qunsheng said that the purpose of the project team's research and development of key technologies for the separation and purification process is to reduce the energy consumption of the chemical process and contribute to
the realization of the national "dual carbon" goal.
At present, the project has achieved industrial application in 15 large and medium-sized enterprises, reducing energy consumption and carbon dioxide emissions
in chemical separation and purification projects.
According to statistics, projects applying related technologies have increased profits by 1.
13 billion yuan in the past three years, energy saving equivalent to 113,600 tons of standard coal, and reducing carbon dioxide emissions by 329,000 tons
.

In addition, the application of key technologies of separation and purification and energy saving has also improved the purity of domestic high-purity chemicals to meet the demand
for key high-end basic chemical materials in the fields of electronic information, aerospace, and medical health.
At present, the distillation-membrane separation coupling process developed by the project team has been applied to the production of electronic chemicals
.
It has been verified that the process can remove by-products such as unsaturated hydrocarbons, water, nitrogen, oxygen, etc.
on a large scale through the distillation process, and then reduce the metal ion content to less than 0.
1 mg/L through membrane separation technology, producing 5N grade (99.
999%) pure electronic grade hydrogen
chloride.

"The production of high-end materials has high energy consumption, and it is more necessary to use advanced distillation technology to achieve energy saving and consumption reduction, on the one hand, to achieve carbon neutrality, on the other hand, it can also reduce the production cost of products and expand production, thereby promoting the large-scale development
of high-purity and ultra-pure chemicals in China.
" Li Qunsheng said
.