No abstract

To further enhance the development of the supercritical water oxidation (SCWO) process, a concentric-tube reactor model has been developed. Because of the heat generation and transfer processes within the reactor, both reaction kinetics and heat transfer rate factors are incorporated in the model. The simulation model treats the reactor as a number of segments, and each segment is assumed to be isothermal.The model was validated by pilot-plant tests involving the destruction of acetic acid, phenol, and n-cctanol. These tests were conducted in a pilot-scale SCWO facility that is equipped with a 6.1-meter long concentric-tube reactor and capable of treating waste water at a rate of 150 liter per hour. All simulation results, using pseudo-first-order kinetic models, agreed favorably with the pilot-plant data. The simulated reactor temperature profiles agreed well with the measured profiles.The supercritical water oxidation process (SCWO) is an environmentally attractive method for the safe and economical treatment of toxic organic waste waters and sludges. The SCWO process is capable of destroying undesirable organic compounds, converting the waste into non-noxious materials, accomplishing this task within an essentially enclosed environment. The key unit in the SCWO process is the reactor that generally operates at temperatures and pressures ranging from 400°C to 650°C and 25 MPa to 35 MPa, respectively. The exothermic heat can be sufficient to sustain the reaction. It has also been demonstrated that byproducts such as reusable water, heat, and usable inorganic substances can be produced by the SCWO process.After more than a decade of research and development, the process is now poised for potential wide-spread application (1), especially with the first commercial unit in operation.To further enhance the development of the SCWO process for industrial-scale applications, it is necessary to understand the reactor performance and develop reliable 1