Abstract: A storage system and method for storing a valuable liquid in a subterranean cavity with a displacing liquid such as brine. The valuable liquid, which normally has a density above or about that of the displacing liquid, is modified by dissolving therein small amounts of a light fluid such as alkanes and alkenes of up to 4 carbon atoms, hydrogen, nitrogen, carbon monoxide or combinations thereof. The amount of the light fluid dissolved in the stored liquid is sufficient to maintain the density of this phase below that of the displacing liquid so that the valuable liquid is stored over the displacing liquid.

Abstract: An improved method for reducing the content of water in aqueous sulfuric acid solutions by electrolysis is provided wherein a sufficient amount of a chlorine containing oxidizing agent is provided in the solution in the vicinity of the cathode to prevent the build-up of sulfur deposits thereon. In an integrated system, drying of a wet fluid stream on a continuous basis is effected by contacting it with concentrated sulfuric acid and purifying and recycling the sulfuric acid by the method of this invention, only a small inventory of the sulfuric acid being required.