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Low efficiency is the main stumbling block preventing the widespread adoption of small-scale gas turbines in distributed energy production. The evaporative gas turbine cycle has been proposed as a way to improve efficiency, but the large number of components required make the configuration complex and expensive. The condensing evaporator is a component that simplifies the evaporative gas turbine cycle. The heat and mass exchanger device is designed for an externally fired application, which means that the flue gas stream is replaced by moist air. The air-water mixture condenses inside a tube bank, releasing heat to the evaporating water film on the other side of the tubes. Similar inventions include the tubular humidifier and the Maisotsenko compressed air saturator, which also aim to make the evaporative gas turbine cycle more economically feasible. Available theory focuses on either humidification towers or evaporative condensers in HVAC applications. The tubular humidifier has been analyzed in a similar manner as humidification tower since the flow configurations of the two components are similar. However, the theory of humidification towers is not directly applicaple to the condensing evaporator. This study proposes a method of analysis of the condensing evaporator in power generation.

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Consequent to the importance of crude palm oil (CPO) to global food processing industries, and the need for quality assurance of CPO. A kinetic model that describes changes of free fatty acid (FFA) in industrially stored CPO has been developed. CPO FFA is a well-known indicator of the deterioration of CPO. The effect of initial moisture content, storage temperature, and time on CPO FFA has been investigated in this work. Specifically, statistical multi-regression models for changes in FFA and moisture content (MC) were developed at P-value < 0.05 or 95% confidence interval fence. It was found that CPO FFA increases with an increase in moisture content, temperature, and time in their linear term and in respect to decreases in their quadratic term, and interaction between moisture content and temperature. The CPO MC was also found to decrease with an increase in temperature and time and increases in the quadratic term of temperature. Although while the model for CPO FFA, based on Fisher's F-test: \({\text{F}}_{\text{m}\text{o}\text{d}\text{e}\text{l}}\left(6.80\right)<{\text{F}}_{95\text{\%}}\left(19.30\right)\), showed no lack-of-fit; that of CPO MC showed lack-of-fit, \({\text{F}}_{\text{m}\text{o}\text{d}\text{e}\text{l}}\left(13.67\right)\nless {\text{F}}_{95\text{\%}}\left(4.39\right)\). Furthermore, based on inference from the statistical model, their kinetic models were also developed. While the CPO FFA kinetic, found to be a half-order kinetic model and its other auxiliary models showed a very good fit (R2 {0.9933–0.8614} & RMSE {0.0020–3.6716}); that of CPO MC was a poorly fitted first-order kinetic model (R2 {0.9885– 0.3935} & RMSE {0.0605– 17.8501}).