CO2 to Products - Cement,Plastics,Gasoline,Urea,Methanol
Researchers are working on finding solution to tackle the problem of capturing and storing the CO2 emitted into the atmosphere. One of the promising and emerging technologies is to convert the captured CO2 into useful products. Converting the captured CO2 to useful products is an important aspect of carbon capture and storage technology and reduces the carbon emission in those areas where long term storage of CO2 is not practical. As an alternative to storing captured CO2 in geological formations, in the oceans, or in mineral form as carbonates, this section assesses the potential for reducing net CO2 emissions to the atmosphere by using CO2 either directly or as a feedstock in chemical processes that produce valuable carbon containing products. It is expected that large volumes of CO2 will be available to source the raw materials for these industries as the fossil fuel backed power plants and other carbon intensive industries are equipped with emission control technologies to trap the emitted CO2.
CO2 has many industrial uses. Carbon dioxide is a valuable industrial gas with a large number of uses that include production of chemicals, for example urea, refrigeration systems, inert agent for food packaging, welding systems, fire extinguishers, water treatment processes, horticulture, precipitated calcium carbonate for the paper industry and many other smaller-scale applications. Large quantities of carbon dioxide are also used for enhanced oil recovery, particularly in the United States.
Carbon dioxide finds use in many industries like food industry for freezing food, keeping food cold during transport (dry ice) and for adding carbonation to beverages. In the electronics industry, carbon dioxide is used in manufacturing applications, including semiconductor device manufacturing, surface cleaning, and circuit board assembly. The chemical industry uses carbon dioxide to produce fertilizers, plastics, and polymers. It is also used to purge, pressurize and cool equipment. As a supercritical fluid, carbon dioxide can be used to replace organic solvents. In water treatment plants, carbon dioxide is safer to handle than mineral acids for pH control. Carbon dioxide can also be found in many fire extinguishers as it prevents oxygen from fuelling the fire, and it does not leave any residue.
The utilization of CO2 establishes an inventory of stored CO2, primarily in the form of carbon-containing fuels, chemicals and other products. The production and use of these products involve a variety of different ‘life cycles’ (i.e., the chain of processes required to manufacture a product from raw materials, to use the product for its intended purpose and ultimately to dispose it or to reuse it in some fashion). Depending on the product life-cycle, CO2 is stored for varying periods of time and in varying amounts. As long as the recycled carbon remains in use, this carbon pool successfully stores carbon. Withdrawal from this pool, by decay or by disposal typically re-injects this carbon into the atmospheric pool.
In a greenhouse gas-constrained world, it is likely that the industrial sector could reduce its own CO2 emissions by identifying processes that produce relatively pure CO2 streams and then either capturing and sequestering CO2 or strategically linking it to another processing operation requiring CO2 as a feedstock. There are numerous specific opportunities to reuse CO2 in industrial processes, and certain processes such as ethylene and ammonia production produce high concentration CO2 streams that are often currently released to the atmosphere.
The following products can be produced from CO2 for which research is going on and in various stages of development.
Suppose assuming that all the above mentioned products are produced from CO2 replacing the traditional feedstock, even then not all the CO2 emitted is captured and sequestered. But here is an opportunity to mitigate the long standing problem of reducing CO2 concentration in the atmosphere. This method along with algae based CO2 capture and CO2 sequestration in geological formations for enhanced oil recovery (EOR) operations provides immense potential to store all the carbon dioxide emitted into the atmosphere. A simple calculation would help us in evaluating the potential of CO2 that can be used to produce products which is summarized in the below table.Products Global Annual production Amount of CO2 used in the production process using the novel method Plastics 240 Mt (2008) 240 Mt Cement 3.04 Gt (2009) 1.5 Gt Gasoline 4 Gt (2009) 1 Gt Urea 146 Mt (2008) 146 Mt