Method for reducing exhaust carbon dioxide

Abstract

A method for effectively absorbing and removing CO 2 in an exhaust gas generated during an industrial process for reducing the amount of CO 2 that is exhausted into the atmosphere. The exhaust gas containing CO 2 is blown into an agglomerate of solid particles containing CaO and/or Ca(OH) 2 so that the CO 2 is in contact with the agglomerate for fixing the CO 2 in the exhaust gas as CaCO 3 , thereby reducing the CO 2 concentration in the exhaust gas. Preferably, the solid particles contain water, and more preferably, the solid particles contain surface adhesive water.

1 . A method for reducing an exhaust carbon dioxide comprising: 
 preparing agglomerates of solid particles containing at least one compound selected from the group consisting of CaO and Ca(OH) 2 ;    contacting an exhaust gas containing CO 2  with the agglomerates of the solid particles in a reaction chamber, the solid particles having a film of adhesive water on a surface of the solid particles; and    fixing CO 2  in the exhaust gas as CaCO 3  in the solid particles to reduce CO 2  in the exhaust gas.    
     
     
         2 . The method according to  claim 1 , wherein the agglomerates of the solid particles are obtained by pulverizing materials containing CaO and/or Ca(OH) 2  into grain and/or rough grain.  
     
     
         3 . The method according to  claim 1 , wherein the step of contacting the exhaust gas comprises contacting an exhaust gas containing CO 2  with the agglomerates of the solid particles by blowing the exhaust gas into the agglomerates of the solid particles.  
     
     
         4 . The method according to  claim 3 , wherein the exhaust gas containing CO 2  is blown into the agglomerates of the solid particles from one direction.  
     
     
         5 . The method according to  claim 1 , wherein the water content in the agglomerates of the solid particles is from 3 wt. % to 20 wt. %.  
     
     
         6 . The method according to  claim 1 , wherein a grain size of the solid particles is substantially 5 mm or less.  
     
     
         7 . The method according to  claim 1 , wherein the exhaust gas introduced into the reaction chamber is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber.  
     
     
         8 . The method according to  claim 1 , wherein the reaction chamber is at a temperature corresponding to the boiling point of water or lower.  
     
     
         9 . The method according to  claim 1 , wherein a temperature of the agglomerates of the solid particles is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber.  
     
     
         10 . The method according to  claim 1 , wherein the step of contacting the exhaust gas containing CO 2  with the agglomerates of the solid particles comprises contacting a pressurized exhaust gas with the agglomerates of the solid particles.  
     
     
         11 . The method according to  claim 1 , further comprising saturating H 2 O in the exhaust gas, prior to contacting the exhaust gas with the agglomerates of the solid particles.  
     
     
         12 . The method according to  claim 1 , wherein the water content in the agglomerates of the solid particles is a range of from 3 to 20 wt. %, and the exhaust gas is blown into the agglomerates of the solid particles, to contact the exhaust gas with the agglomerates of the solid particles.  
     
     
         13 . The method according to  claim 12 , wherein the exhaust gas introduced into the reaction chamber is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber, the reaction chamber is at a temperature corresponding to the boiling point of water or lower, and the agglomerates of the solid particles to be contacted with the exhaust gas is at a temperature corresponding to the boiling point of water or lower, within the reaction chamber.  
     
     
         14 . The method according to  claim 13 , further comprising saturating H 2 O in the exhaust gas prior to contacting the exhaust gas with the agglomerates of the solid particles.  
     
     
         15 . The method according to  claim 1 , wherein the agglomerates of the solid particles are at least one material selected from the group consisting of a slag generated in an iron and steel making process and a concrete.  
     
     
         16 . The method according to  claim 1 , wherein the solid particles of the agglomerates are at least one material selected from the group consisting of a slag generated in an iron and steel making process and a concrete.  
     
     
         17 . The method according to  claim 1 , wherein the agglomerates of the solid particles are at least one material selected from the group consisting of a slag generated in an iron-steel making process, a concrete, a mortar, a glass, an alumna cement and a CaO containing refractory.  
     
     
         18 . A method of creating a seaweed bed comprising: 
 temporarily immersing a heavy material in an existing seaweed bed so that marine algae adhere and grow on a surface of the material;    recovering the heavy material and transporting the heavy material as a seed material in a place for creating the seaweed bed; and    arranging an adhering material for adhering the marine algae around the seed material so that the marine algae on the seed material is proliferated onto another seed material.