Hydrothermal Treatment of Base Hydrolysis Products

Hydrothermal Treatment of Base Hydrolysis Products Hydrothermal treatment has been investigated by LANL as a possible secondary treatment for base hydrolysis products from explosives destruction. Small-scale experiments offered promising results. Larger-scale experiments were required to look more carefully at the feasibility for such a treatment approach. More product analysis and parameter studies were also required. 

The reaction is carried out in a 0.478 cm i.d. Inconel 625 reactor at 960 to 1,100 bar and 380° to 450°C with approximately one minute of residence time. Treatment at these conditions is often called supercritical water oxidation (SCWO) however, since the critical parameters of the PBX-9404 hydrolysis product mixture are unknown, the treatment may or may not be above the critical parameters for the hydrolysate. Therefore, the more general term hydrothermal treatment is used in this case. 

Since the effluent was basic (pH between 9 and 10), carbon dioxide produced in the reaction was converted to sodium carbonate/sodium bicarbonate. No plugging was observed at pressures near 1,000 bar. Plugging typically occurs at lower pressures when sodium carbonate precipitates out of solution. 

A conceptual design for a demonstration base-hydrolysis/hydrothermal processing unit would consist of two 210-L batch reactors for hydrolysis treatment followed by a 38-L/hr continuous hydrothermal processing unit. The unit is sized to treat an excess HE stream from Pantex of 36 kg/day. 

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