Method of producing carbonates and recycling energy by cyclically capturing and mineralizing CO2

Abstract

A method of producing carbonates and recycling energy by cyclically capturing and mineralizing CO2 includes the following steps: 1) adding water to calcium-containing or sodium-containing waste residues to prepare a calcium-containing or a sodium-containing alkaline water solution, or employing calcium-containing alkaline waste water from steel industry as the calcium-containing alkaline water solution; 2) feeding the solution through a pressurizing pump into a multi-stage jet-flow complete stirred reactor, and feeding CO2 flue gas into the multi-stage jet-flow complete stirred reactor in a counter flowing direction to perform a gas-liquid two-phase mineralizing absorption reaction to capture and mineralize CO2; and 3) performing heat exchange and filtration to generated mineral slurry or solution, wherein the filtrate is recycled. The method high-effectively captures and mineralizes low-concentration CO2 waste gas through the alkaline waste residue / waste water, and meanwhile mineralizes and converts the CO2 to obtain a high-additional-value by-product containing carbonate. Reaction heat generated during the capturing and mineralizing process is comprehensively recycled through heat exchangers, thereby achieving low-carbon environment protection treatment of the whole process.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and environmental protection, in particular to a cyclic capture mineralized CO 2 Method for producing carbonate and recovering energy. Background technique [0002] According to the forecast of the International Energy Agency, in 2030 China's energy-related CO 2 Emissions (carbon equivalent) will rise to 11.615 billion tons, an increase of 91.3% over 2007, accounting for 48.6% of the new increase in global carbon emissions (11.4 billion tons of carbon equivalent) during the period from 2007 to 2030. The metallurgical industry is one of the major industrial fields that emit greenhouse gases in my country. Only the ferrous metal industry may emit more than 600 million tons of greenhouse gases (equivalent to CO 2 ). Taking the electrolytic aluminum industry as an example, as a large energy consumer, the direct emission of CO per 1 ton of electrolytic aluminum is 2 More than 1.5 tons, 17 tons o...

AI Technical Summary

Problems solved by technology

There is also the Bayer process red mud in the alumina industry, which is also a strong alkaline waste residue. The annual discharge in my country is more than 50 million tons, and it is currently being stockpiled; this not only causes a huge waste of resources, but also causes serious environmental pollution.

In addition, there are nearly 10 billion tons of alkaline calcium-containing wastewater in the iron and steel industry every year. Due to the high calcium hardness and unstable water quality, it also brings serious pipeline scaling, which seriously affects normal production.

[0004] At present, low-concentration CO 2 There are few reports on the research on energy saving and emission reduction by direct treatment of flue gas

At the same time, there are still a large amount of calcium carbide waste residue, red mud, boron mud, magnesium slag and other waste residues in the industry, as well as high-alkaline calcium-containing wastewater that cannot be cleaned and utilized.

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