Method for reducing flue gas carbon dioxide emissions

Abstract

Plants, devices, and methods are presented which economically and effectively reduce carbon dioxide (CO2) emissions from flue gases by converting heat derived from one or more sources of flue gas to drive a heat engine, which generates power, energy, and / or work that is utilized by a CO2 capture unit coupled to the stream of flue gas. CO2 captured from the flue gas stream may be sequestered and / or utilized for commercial purposes.

Description

FIELD OF THE INVENTION[0001]The field of the invention is capture of CO2 from plant emissions or waste gases. In particular this invention relates to the capture of CO2 from flue gases, especially those produced in chemical or petrochemical plants, power plants, and refineries.BACKGROUND[0002]Flue gases are waste gases typically produced as exhaust from turbines, furnaces, boilers, ovens, steam generators, and similar installations, and are often produced in large quantities by power plants and chemical, petrochemical, and refinery installations. As a combustion product, the composition of flue gas is dependent on the fuel source, however, it will usually comprise nitrogen and unconsumed oxygen from the combustion air, carbon dioxide (CO2), carbon monoxide (CO), trace components like argon, and water vapor. It may further contain volatile organic carbon compounds, nitrogen oxides, and sulfur oxides. Release of many of these compounds (CO2 in particular) to the atmosphere has become ...

AI Technical Summary

Benefits of technology

The invention provides a way to economically and effectively reduce CO2 emissions from multiple sources by combining flue gases and using heat from the combined stream to power a CO2 capture unit. This can be done by collecting hot flue gas streams from one or more sources and combining them to form a cooled flue gas stream. The recovered heat can be used to generate power, which can then be used to capture CO2 from the flue gas stream. The invention also includes a flue gas treatment unit with a duct and heat recovery unit, which can be connected to different sources of flue gas. The heat recovery unit can transfer heat to a heat engine, which can then be used to power the CO2 capture unit. The invention has various technical benefits, such as reducing CO2 emissions and improving energy efficiency.

Problems solved by technology

A significant barrier to removal of CO2 from flue gases is the expense associated with the removal process.

These costs can be very substantial, both in terms of equipment and operations costs and in reduction of plant efficiency.

It is estimated that CO2 capture from emissions generated by a coal-fired power plant increase overnight power generation costs by about 75% when amine-containing solvent based methods are used (Finkenrath).

Even though such methods have the advantages of recycling key materials and capture and subsequent use of CO2 at high efficiency, power requirements (and hence the energy costs) for such processes remain significant.

In addition, such costs increase with the scale of the CO2 capture operation.

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