Thermodynamic analysis of a beer engine

Abstract

This paper shows how the heat reclaimed from the exhaust gas of a gas turbine engine can be used to convert dilute ethyl alcohol (“beer”) to a fuel that can used to power the engine. Ordinarily, there is not enough heat available to distil the weak liquor to sufficient amounts of a strong product (>90%), due to high exergy destruction. In this design, a combination of destructive distillation and ordinary distillation is used, the wet product then being sent to a reformer for an endothermic shift reaction. The high temperature gas is now ready to burn in a gas turbine engine (or high temperature fuel cell). Water in the low temperature stack gas can be reclaimed in a cooling tower, if desired, so as to have no net loss of water for the system. The exergetic (Second Law) efficiency for power production is nearly 50%.