Method for separating high molecular weight gases from a combustion source

Abstract

High molecular weight (HMW) gases are separated from an exhaust gas of a combustion source using a blower and an interior vent within the exhaust stack. The interior vent includes a vent wall having a top portion attached to the interior surface of the exhaust stack along the entire inner perimeter of the exhaust stack and a lower portion that extends downward into the exhaust stack to form an annular space or gap between the vent wall and the interior surface of the exhaust stack, and at least one opening in the interior surface of the exhaust stack between the top and bottom portions of the vent wall. The blower creates a tangential flow of the exhaust gas with sufficient centrifugal force to concentrate substantially all of the HMW gases along the inner surface of the exhaust stack. A transfer pipe removes the HMW gases from the interior vent.

What is claimed is: 
     
       1. A method for separating high molecular weight gases from an exhaust gas of a combustion source comprising the steps of:
 providing (a) a blower attached to an intake of an exhaust stack to receive the exhaust gas from the combustion source, (b) an interior vent within the exhaust stack comprising (i) a vent wall having a top portion attached to the an interior surface of the exhaust stack along the entire inner perimeter of the exhaust stack and a lower portion that extends downward into the exhaust stack to form a gap between the vent wall and the interior surface of the exhaust stack, and (ii) at least one opening in the interior surface of the exhaust stack between the top and bottom portions of the vent wall, and (c) a transfer pipe connected to the at least one opening in the interior surface of the exhaust stack; 
 concentrating the high molecular weight gases along the inner surface of the exhaust stack by creating a tangential flow of the exhaust gas within the exhaust stack using the blower, wherein the blower imparts sufficient centrifugal force on the exhaust gas to concentrate substantially all of the high molecular weight gases along the inner surface of the exhaust stack; 
 collecting the high molecular weight gases concentrated along the inner surface of the exhaust stack using the interior vent; and 
 removing the high molecular weight gases from the interior vent using the transfer pipe. 
 
     
     
       2. The method as recited in  claim 1 , further comprising the steps of:
 storing the removed high molecular weight gases in a tank connected to the transfer pipe; 
 compressing the removed high molecular weight gases; or 
 injecting the removed high molecular weight gases into a below-ground storage. 
 
     
     
       3. The method as recited in  claim 1 , wherein the high molecular weight gases have a molecular weight greater than 35. 
     
     
       4. The method as recited in  claim 1 , wherein the high molecular weight gases comprise CO 2 . 
     
     
       5. The method as recited in  claim 4 , further comprising the step of flowing the removed CO 2  up through one or more bubble trays containing sodium hydroxide which causes the removed CO 2  to combine with the sodium hydroxide to produce sodium carbonate. 
     
     
       6. The method as recited in  claim 1 , wherein;
 the sufficient centrifugal force is provided by the blower in combination with a stationary tabulator, spin vanes, or in-stack centrifuge; and   the blower is located inside or outside of the exhaust stack.   
     
     
       7. The method as recited in  claim 1 , further comprising providing a bustle attached to or integrated into the exhaust stack between the at least one opening in the inner surface of the exhaust stack and the transfer pipe. 
     
     
       8. The method as recited in  claim 1 , wherein the lower portion of the vent wall is substantially parallel to the interior surface of the exhaust stack, curved, or is angled with respect to the interior surface of the exhaust stack. 
     
     
       9. The method as recited in  claim 1 , wherein the concentrating the high molecular weight gases along the inner surface of the exhaust stack comprises concentrating at least 85% of the high molecular weight gases are concentrated along the inner surface of the exhaust stack. 
     
     
       10. The method as recited in  claim 1 , wherein the gap comprises an area of approximately 10% of a cross-sectional area of the exhaust stack. 
     
     
       11. The method as recited in  claim 1 , wherein the at least one opening is positioned such that the high molecular weight gases have spun around the exhaust stack approximately fifteen to twenty times prior to reaching the at least one opening. 
     
     
       12. The method as recited in  claim 1 , wherein the blower causes the exhaust gases to spin around the exhaust stack at least five times within a height approximately equal to one diameter of the exhaust stack. 
     
     
       13. The method as recited in  claim 1 , wherein the at least one opening is positioned at a height above the a bottom of the exhaust stack approximately equal to three diameters of the exhaust stack. 
     
     
       14. The method as recited in  claim 1 , wherein the bottom lower portion of the vent wall extends down to a height above the a bottom of the exhaust stack approximately equal to one half diameter of the exhaust stack. 
     
     
       15. The method as recited in  claim 1 , further comprising a motor attached to moving the vent wall that adjusts to adjust a size of the gap. 
     
     
       16. The method as recited in  claim 15 , wherein the motor step of moving is used to adjust the size of the gap based on one or more parameters comprising temperature, humidity, velocity, gas composition, fuel type, or exhaust gas mixture. 
     
     
       17. The method as recited in  claim 15 , further comprising:
 one or more sensors attached to the blower, exhaust stack, interior vent or transfer pipe; and   a controller communicably coupled to the motor and the one or more sensors, wherein the controller to adjusts the size of the gap using the motor based on one or more parameters detected by the one or more sensors.   
     
     
       18. The method as recited in claim 9, wherein concentrating the high molecular weight gases along the inner surface of the exhaust stack comprises concentrating substantially all of the high molecular weight gases along the inner surface of the exhaust stack. 
     
     
       19. The method as recited in claim 16, further comprising:
 sensing the one or more parameters of the exhaust gas at the blower, exhaust stack, interior vent, or transfer pipe; and   controlling the step of moving the vent wall to adjust the size of the gap based on the sensed one or more parameters.   
     
     
       20. A method for removing high molecular weight gases from an exhaust stream, comprising:
 introducing exhaust gas tangentially into an exhaust stack;   concentrating high molecular weight gases toward an inner surface of the exhaust stack by spinning the exhaust gas and imparting centrifugal force; and   removing gases from along the inner surface of the exhaust stack;   wherein the spinning the exhaust gas and imparting centrifugal force comprises accelerating exhaust gas that is spinning within the stack; and   wherein the accelerating exhaust gas comprises removing exhaust gas tangentially from one side of the exhaust stack and blowing it tangentially back into the exhaust stack on a side opposite the one side.