Right off the bat, the energy cost of doing this does not warrant what is being done, in my opinion. For an ethanol plant to capture, cool and compress CO2 requires 50% of the energy equivalent of that being produced. It literally requires twice as much energy to compress, transport and bury CO2 than the ethanol manufacturing process actually produces. However, data indicates that 900 CO2 transcritical booster systems are installed in the United States, part of a global total of approximately 46,500 systems. NTH Professor Emeritus Gustav Lorentzen has reported:The first refrigeration system using CO2 actually dates back to 1879.