A biofuel-based cogeneration plant in a natural gas expansion system: An energetic and economic assessment

The paper deals with an analysis of the energetic and economic performance of a City Gas Station (CGS) plant, made up of a rapeseed oil cogenerator coupled to a turbo-expansion system for the reduction of natural gas pressure, which is currently in operation in Italy. Although this kind of systems concept is well known, the plant can be considered unusual because the heat needed to pre-heat the gas before its expansion is obtained from a renewable source. The aim of the paper is to analyse the energetic efficiency of the plant and its economic viability, which is affected to a great extent by subsidizing energy policies and by the volatility of vegetable oil prices. All the evaluations have been based on a real set of experimental data.