Six ways to deal with carbon reduction in coal chemical industry

Six ways to deal with carbon reduction in coal chemical industry

Nowadays, carbon peak and carbon neutrality have become a widespread and profound economic and social systemic change affecting China up and down. As the main industry for the production and consumption of fossil energy, the coal chemical industry may be the first to bear the brunt and become a bullseye. On the one hand, the coal chemical industry is a major carbon emitter, and the total emissions are still rising sharply year-on-year with the expansion of production capacity. In the future, it must be an industry that will be focused on. Statistics show that last year, my country's coal chemical industry contributed 4.9 billion tons of carbon emissions, an increase of nearly 50 times compared with five years ago. On the other hand, in the process of carbon neutrality, the state will introduce a series of restrictive policies and measures, and coal chemical industry may be one of the first restricted industries.

There is no doubt that if the coal chemical industry wants to continue to develop, it must start from itself to find ways to reduce carbon as soon as possible. In my opinion, there are currently two main ways to go: one is to reduce the carbon content of carbon-containing raw materials, and the other is to try to eliminate the carbon dioxide that has been emitted. Specifically, there are probably the following processing methods.

One is carbon reduction of raw materials. Coal and petroleum are both high-carbon and low-hydrogen raw materials. The hydrogen content of coal generally does not exceed 5% (weight percentage), and the hydrogen content of petroleum is 10%-15%. If natural gas, shale gas or industrial tail gas is added to the raw materials, carbon emissions can be reduced. Because the main component of natural gas is methane, 1 carbon and 4 hydrogens, the carbon content is very low and the heating value is high. Western countries mainly rely on this approach to reduce carbon emissions, especially in regions with abundant natural gas resources such as Russia, the Middle East, and the United States.

The second is garbage gasification. At present, most of the garbage in the coal chemical industry is buried, and part of it is used for power generation. If the waste is gasified with pure oxygen at medium pressure to produce synthesis gas, not only will it be free of tar and dioxins, it can also replace coal as a raw material. Replacing coal gasification with garbage is a new way out for the coal chemical industry. This method is low cost and produces less carbon dioxide than coal, and is currently under study. It is reported that if a fixed bed plus a second-stage furnace is used for gasification, it is estimated that 800 cubic meters of synthesis gas can be converted per ton of waste. However, with this method, another gasifier must be built, and investment must be considered. It is suggested that new coal chemical projects can adopt the method of co-building coal gasifier and garbage gasifier to achieve emission reduction, pollution reduction, production cost reduction, and coal saving.

    The third is to reduce emissions from existing installations. It should be noted here that the newly commissioned coal chemical plant basically uses the latest energy-saving technology in recent years, and has undergone computer system simulation and optimization. Only a certain unit or part of the technology is updated, which makes it difficult to produce the overall process. Obvious energy saving and emission reduction effect. It is recommended that the obsolete equipment that has been in operation for 20 to 30 years be systematically modified, and emission reduction is still expected.

Fourth is to attach importance to carbon dioxide recovery, that is, planting trees around coal chemical projects, using plants for green space and ecological recovery of carbon dioxide, relying on natural sunlight and water to convert carbon dioxide into organic matter under the action of photochemistry, and provide oxygen at the same time. Of course, this is also a considerable investment. Specifically, a methanol project with an annual output of 1.8 million tons requires 128 square kilometers of broad-leaved forest to accompany it, while a synthetic oil project with an annual output of 4 million tons requires 789 square kilometers of broad-leaved forest to accompany it. However, building a wood processing plant next to the coal chemical project can produce wood and at the same time carry out wood processing, and the coal chemical project also has a way out to solve carbon dioxide emissions, which can be regarded as killing two birds with one stone.

Five is to bury carbon dioxide deeply underground. According to a report in the American "Science" magazine, scientists inject carbon dioxide into underground basalt formations and use natural chemical reactions to convert carbon dioxide into solid carbonates. The storage location of this technology is usually abandoned oil and gas fields, but the safety of the technology has yet to be verified.

 Sixth is power saving. For the coal chemical industry, saving electricity means reducing emissions. This is because more than 70% of my country's power generation relies on coal, and the carbon emissions per unit of electricity from coal power are the highest of all power generation.

 Obviously, reducing emissions will be the biggest problem faced by the coal chemical industry during the "14th Five-Year Plan" period. Only by working hard in the actual links as early as possible, can the coal chemical industry not become the target of revolution in achieving the dual-carbon goal.