OTEC Gas Desorption Studies

Abstract

Seawater deaeration is a process affecting almost all proposed ocean thermal energy conversion (OTEC) open-cycle power systems. If the noncondensible dissolved air is not removed from a power system, it will accumulate in the condenser, reduce the effectiveness of condensation, and result in deterioration of system performance. To explore ways to mitigate these effects, a test loop was constructed and experiments were carried out in three areas: (a) vacuum deaeration in a packed column using Raschig rings or plastic pall rings, (b) deaeration in a barometric water intake system, and (c) noncondensibles disposal through hydraulic air compression. Preliminary subsystem analyses based on the experimental data have shown that, as compared to the previous baseline study, a 10 percent reduction both in deaeration cost and pumping power can be realized with a combination of barometric intake and packed column deaeration. The design and operation of the gas desorption loop and the experimental and computer simulation results are presented. The implications for OTEC open-cycle power systems are discussed.