A self-regulating system for reducing concentration of hydrocarbon vapor in a container may be performed by introducing air into the container and extracting a mixture of air and vapor from the container. The extracted mixture may be compressed with a compressor to produce a flow of compressed mixture of air and vapor. The compressed mixture may be passed through an oxidation reactor that may be either catalytic or thermal to produce a flow air and CO.sub.2. A turbine may be driven with the flow of air and CO.sub.2. The compressor may be driven with the turbine. Extraction from the container may continue until vapor concentration is low enough so that flow of CO.sub.2 and air from the reactor is insufficient to drive the turbine.