Method of Improving Biocidal Efficacy of Dry Ice

Abstract

A manufactured dry ice product containing ozone entrapped or absorbed on said dry ice. The dry ice product can be used to chill and preserve food products and provides the added benefit of ozonation of the food product to kill bacteria. Novel processes for ozonating liquid and solid CO 2 are provided.

1 . A manufactured dry ice product comprising ozone entrapped or physically absorbed on or within the product or both.  
   
   
       2 . The dry ice product of  claim 1  being essentially free of water.  
   
   
       3 . The dry ice product of  claim 2  optionally comprising less than 1 wt. % water.  
   
   
       4 . The dry ice product of  claim 1  optionally containing up to 5,000 ppm water.  
   
   
       5 . The dry ice product of  claim 1  in the form of shaped dry ice units.  
   
   
       6 . The dry ice product of  claim 5  wherein said dry ice units are compression molded blocks.  
   
   
       7 . The dry ice product of  claim 1  in the form of pellets.  
   
   
       8 . The dry ice product of  claim 1  in the form of powder or flakes.  
   
   
       9 . The dry ice product of  claim 1  wherein said ozone is present in amounts of at least 0.1 ppm by weight.  
   
   
       10 . The dry ice product of  claim 9  wherein said ozone is present in amounts of from 1 to 100 ppm.  
   
   
       11 . The dry ice product of  claim 10  wherein said ozone is present in amounts of 1 to 10 ppm by weight.  
   
   
       12 . The dry ice of product  claim 11  being essentially free of water.  
   
   
       13 . The dry ice product of  claim 12  wherein said dry ice product optionally contains water in an amount of less than 1 wt. %.  
   
   
       14 . A process for producing an ozonated dry ice product comprising contacting a gaseous ozone stream with liquid carbon dioxide to form a mixture, subsequently cooling the mixture of carbon dioxide and ozone to form dry ice solid containing ozone entrapped or absorbed on or in said dry ice solid.  
   
   
       15 . The process of  claim 14  wherein said liquid carbon dioxide is at a pressure of at least 70 psig.  
   
   
       16 . The process of  claim 15  wherein said gaseous ozone is at a pressure of at least 90 psig.  
   
   
       17 . The process of  claim 14  wherein said gaseous ozone stream comprises a mixture of ozone and oxygen.  
   
   
       18 . The process of  claim 17  wherein said gaseous ozone stream optionally contains an inert gas.  
   
   
       19 . The process of  claim 14  wherein said dry ice solid is in the form of a powder or flake.  
   
   
       20 . The process of  claim 14  wherein said dry ice solid is compressed into blocks.  
   
   
       21 . The process of  claim 14  wherein said dry ice solid is extruded into pellets.  
   
   
       22 . The process of  claim 14  wherein said liquid carbon dioxide is provided from a supply of liquid carbon dioxide at a pressure of from 200 to 300 psig and wherein said supply of liquid carbon dioxide is expanded to a lower pressure of at least 70 psig.  
   
   
       23 . The process of  claim 14  wherein said mixture of ozone and liquid carbon dioxide is cooled by expansion in a dry ice press, and said solid dry ice is pressed into blocks.  
   
   
       24 . The process of  claim 22  wherein said mixture of ozone and liquid carbon dioxide is cooled by expansion in a dry ice press, and said solid dry ice is pressed into blocks.  
   
   
       25 . The process of  claim 22  wherein said gaseous ozone stream is injected into said liquid carbon dioxide as said supply of liquid carbon dioxide is expanded to said lower pressure.  
   
   
       26 . The process of  claim 22  wherein said gaseous ozone stream is injected into said liquid carbon dioxide subsequent to said supply of liquid carbon dioxide being expanded to said lower pressure.  
   
   
       27 . The process of  claim 14  wherein said gaseous ozone stream comprises 10 to 15% by weight ozone.  
   
   
       28 . A method of chilling a food product comprising placing a food product in the proximity of a dry ice solid containing entrapped or absorbed ozone such that during sublimation of the dry ice, ozone is released therefrom for contact with said food product.  
   
   
       29 . The process of  claim 28  wherein said placed food product is in storage during transport.  
   
   
       30 . The process of  claim 28  wherein said placed food product is in stationary storage.  
   
   
       31 . The process of  claim 28  wherein said dry ice is in the form of blocks.  
   
   
       32 . The process of  claim 28  wherein said dry ice is in the form of powder, flakes, or pellets and said dry ice is placed in contact with said food product.  
   
   
       33 . The process of  claim 28  wherein said dry ice is essentially free of water.  
   
   
       34 . The process of  claim 28  wherein said dry ice optionally contains water up to less than 1 wt. %.  
   
   
       35 . The process of  claim 28  wherein said dry ice optionally contains water up to 5,000 ppm by weight.  
   
   
       36 . The process of  claim 28  wherein said dry ice contains at least 0.1 ppm by weight ozone.  
   
   
       37 . The process of  claim 28  wherein said dry ice contains 1 to 100 ppm by weight ozone.  
   
   
       38 . The process of  claim 28  wherein said dry ice contains 1 to 10 ppm by weight ozone.