Optimization of a compressed natural gas station operation to minimize energy cost

Abstract

Compressed natural gas (CNG) is one of the growing alternatives to liquid petroleum fuels for propulsion of motor vehicles. Lower greenhouse gas emissions as well as increased durability of vehicle engines are the main properties of CNG that make it a better alternative to petrol and diesel. CNG refueling infrastructure is vital to the expansion of consumer adoption of CNG vehicles. The economical operation of CNG fueling stations is beneficial to the station operators and consumers, by reducing cost of fuel delivery. The present study is concerned with the optimal scheduling of compressor operation in a CNG fueling station to achieve reduced cost of energy in a time-of-use electricity tariff environment. The cascade fast fill station is modelled as a single storage mass flow system with storage refilling optimally controlled to achieve minimum cost of electricity in supplying a typical day gas demand profile. The open loop optimization strategy shows the potential to achieve savings of 59.28% in cost of electricity for operating the compressor, while also minimizing compressor wear and tear.