Arc-plasma process

Residuals Produced The plasma arc process produces ash which may require post treatment to make it suitable for disposal. The wet, scrubber blowdown may require treatment prior to disposal. 

Acetylene production. Hydrogen is produced as a by-product in the production of acetylene by high-temperature thermal cracking in a plasma arc process. In a simplified form,... 

As part of a technology test program for non-stockpile CWM, the NSCMP hired Stone Webster to conduct tests of the MGC/PLASMOX plasma arc process on simulated H and GB neutralents with MEA. MGC conducted these tests from January 8 through January 19, 2001, under a subcontract to Bums and Roe Enterprises at the MGC/PLASMOX facility in Switzerland. 

The key public concern about plasma arc processes for the destruction of non-stockpile CWM in the United States centers on whether plasma arc offers a true alternative to incineration. Depending on the type of plasma gas used and the configuration of secondary oxidation zones, quench, and scrubber processes, plasma arc systems may produce gas volumes and reaction products that are quite similar to or quite different from those associated with incinerators. 

An important feature of acetylene production is the high energy requirement due to the formation of a triple bond. In the Hiils plasma arc process, the energy is supplied by an electric arc. Hydrocarbons are fed to the electric arc reactor in gaseous form and are pyrolyzed at high temperature (>2000 K). At these temperatures, acetylene is formed in preference to other hydrocarbon compounds. To suppress further reaction to carbon and hydrogen, the hot crack gas must be cooled rapidly (a few microseconds) to low temperatures. 

Finally, significant amounts of single shell carbon nanotubes were obtained by adding metal catalysts such as Co, Fe, or Ni [15] [34] to the plasma arc process. The addition of metal catalysts seems to facilitate a controlled process by a VLS phase transformation. For example, the addition of cobalt was achieved with a modified positive carbon rod (electrode) into which a hole had been drilled that was filled with cobalt powder [34]. 

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