In the meantime, Dow and Westinghouse engineers worked toward converting the two new W501D5 gas turbines that were installed at the Dow Plaquemine, LA complex in 1982/83. As a first step, in 1981, they undertook on the conversion of an old W191 located at the Dow, Freeport, Tx complex to burn low-BTU (approx. 200 Btu/scf vs. 1000 Btu/scf for natural gas.) This gas was to be produced by a protype proprietary gasifier being designed and built by Dow. They specified that the gas turbine was to be modified to be able to supply compressed air for the gasification process, and it also had to operate on natural gas (at least for startup and shut down).