Charging water oxidation reactor using recovered reactor energy

A charging system for charging a reactor with gas, using energy produced by the reactor, the charging system comprising:

• an oxidation reactor configured for reacting fuel;
• a vessel having one or more walls that define a hollow interior cavity configured to be partially filled with a liquid slug, a first air pocket within the hollow interior cavity on a first side of the liquid slug, and a second air pocket within the hollow interior cavity on a second side of the liquid slug, wherein the liquid slug forms a water trap seal against the one or more walls that define the hollow interior cavity between the first and second air pockets;
• a plurality of valves configured to control admission of charge gas into the first air pocket at a pressure lower than an operating pressure of the oxidation reactor and to extract charge gas from the first air pocket at a pressure higher than the operating pressure of the oxidation reactor and to control the admission of gas from the oxidation reactor into the second air pocket and to control a release of gas from the second air pocket;
• and
• a controller configured to control the operation of one or more of the plurality of valves to cause the liquid slug to move within the vessel in a cycle in which charge gas is loaded into the first air pocket in a first stroke of the liquid slug and gas in the first air pocket is compressed in a second stroke of the liquid slug, wherein movement of the liquid slug during the second stroke is caused by an increasing pressure in the second air pocket due at least in part to introduction of gas from the oxidation reactor into the second air pocket, and wherein the movement of the liquid slug during the first stroke is caused by a decreasing pressure in the second air pocket due at least in part to the release of gas from the second air pocket.