Abstract: Systems and methods for pressure reduction, including a first conduit with a pressure sensor, a static restriction device, and second conduit connected therebetween. Fluid is introduced through the second conduit as a function of the pressure sensed by the pressure sensor, thereby compensating for fluctuations in sensed pressures due to restriction device degradation and other factors.

Abstract: Oxidation reactions occurring in a plug flow reactor under conditions approximating supercritical water conditions are controlled by injecting a process stream of water and two reactants in non-stoichiometric proportions into the reactor and causing the process stream to flow through the reactor. Water is injected at one or more points downstream from the inlet to lower the temperature of the process stream and additional reactant injected to re-start the reaction. The quench and re-start process is repeated until substantially all oxidizable material in the process stream has be oxidized.

Abstract: Method and apparatus for inhibiting plugging in a reactor that operates at a temperature and a pressure that are at least in the vicinity of supercritical condition for water. One or more salts are preferably added, in a controlled manner, to a stream containing a first salt, in order to allow a eutectic, molten blend with the first salt to be formed. The blend may have a melting point below the temperature of the reactor. The stream is introduced into the reactor and preferably at least a portion of the blend is in a molten state. Plugging in the reactor may thus be inhibited or prevented.

Abstract: Method/system of adding solid particles to inhibit or prevent plugging in a reactor at conditions such that the temperature and pressure are at least in the vicinity of supercritical conditions for water. Particles may be added in conjunction with a pH-adjusting material, thereby inhibiting plugging in the reactor caused by addition of the pH-adjusting material. Reactor pressure may be reduced by flowing the stream through a static restriction device.

Abstract: An apparatus for treating waste water streams is constructed by introducing a mixture of pre-heated waste water and an amount of a oxidant lower than that required to oxidize all the organic matter in the waste stream into the front port of an elongate tubular reaction chamber maintained at supercritical temperatures and pressures. The amount of oxidant is high enough, it initially raise the temperature of the stream in the reaction chamber to 750-1,200.degree. F. A first injection side port is located downstream from the front port of the reaction chamber at a distance at which the temperature has reached a maximum value, and 90-100% of the available oxidant has been consumed. Oxidant and water are simultaneously injected through the first port, in a manner that the amount of oxidant is adequate to oxidize to oxidize a specified amount of organic matter, and the amount of water is effective to counterbalance the heat produced by the ration of the co-injected oxidant with the respective organic matter.

Abstract: Systems and methods for pressure reduction, including a first conduit with a pressure sensor, a static restriction device, and second conduit connected therebetween. Fluid is introduced through the second conduit as a function of the pressure sensed by the pressure sensor, thereby compensating for fluctuations in sensed pressures due to restriction device degradation and other factors.