An Investigation of the Performance of a Hybrid Turboexpander-Fuel Cell System for Power Recovery at Natural Gas Pressure Reduction Stations

In order to supply natural gas from long-distance pipelines to local distribution systems it is necessary to reduce the gas pressure. The expansion process produces a temperature decrease which can cause problems on the low pressure side. Therefore, the gas supplied to the pressure reduction system must usually be preheated. A new type of pressure reduction system involving a hybrid turboexpander and fuel cell system has been considered here. In such a system, a Molten Carbonate Fuel Cell running on natural gas is used provide additional electrical power and to partially preheat the gas before it flows through the turboexpander. In studying such a system the natural gas supply for a typical smaller Canadian city has been considered.