1. Industry status, market demand and application prospects
The use of energy-saving and environmentally friendly separation technology to remove CO2 from gas streams has become a research hotspot in the fields of environment, energy, and chemical industry. Traditional CO2 separation methods, such as chemical absorption, adsorption, and cryogenic distillation, have been used in industry. However, these methods have some disadvantages in industrial applications. For example, chemical solvents may corrode equipment and pollute the environment. Physical adsorbents have high costs, low recovery rates, and a small range of applications. In addition, cryogenic distillation equipment is large in size and consumes a lot of energy. Considering these advantages of traditional methods, membrane technology has received attention in recent years for its high energy efficiency, easy operation, and environmental protection.
The separation performance of current membrane materials is limited by the “Robenson upper bound”, which means that it is extremely challenging to improve the balance between gas permeability and selectivity. Therefore, it is of great significance to develop new materials for the preparation of high-efficiency membranes.

2. Potential market size
The fifth assessment report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) of the United Nations pointed out that CO2 emissions from fossil fuel combustion and industrial processes accounted for about 78% of the total increase in greenhouse gas emissions from 1970 to 2010. In the past, 95% of the causes of global average temperature rise may be related to greenhouse gases produced by human activities, and greenhouse gases such as CO2 produced by traditional fossil energy consumption are the main cause of the global greenhouse effect. In 2019, global CO2 emissions from energy were about 34.169 billion tons, an increase of 0.5% over 2018. China is a major energy consumer and carbon emitter. In 2020, China’s total carbon emissions accounted for 32% of the global total emissions, of which CO2 emissions in the industrial sector accounted for the main reason. In order to achieve China’s goal of reaching carbon peak by 2030 and achieving carbon neutrality by 2060, reducing CO2 emissions from industry at the source has great potential value. Membrane technology can be used to efficiently capture carbon dioxide from sources such as industrial waste gas and power plant emissions. Its excellent separation performance makes it one of the key technologies for reducing greenhouse gas emissions, and is expected to play an important role in addressing climate change and environmental protection.

3. Potential benefits of application
Compared with the polysulfone membrane sold on the market, the composite membrane prepared by the present invention has a CO2 permeability performance improved by about 350%, and a CO2/N2 separation factor improved by 20%. In addition, the preparation method is simple and environmentally friendly, saving labor costs and chemical pollutant treatment costs, thereby improving product benefits.

4. Promotion of social value
The composite membrane prepared by the present invention has structural adjustability, thermal stability, high CO2 affinity and high hydrophilicity, which is of great significance for the capture of CO2 emitted in industries such as electricity, steel, cement, and petrochemicals.