Optimising Compressed Natural Gas filling stations reservoir pressure based on thermodynamic analysis

A theoretical analysis has been developed to study the effects various parameters on the Compressed Natural Gas (CNG) filling process and the conditions. The analysis is based on first and second laws of thermodynamics, conservation of mass and the AGA8 Equation of State (EOS). Based on AGA8 EOS and thermodynamics relationships, the required properties of natural gas mixtures have been calculated. It is found that, the compositions of natural gas have big effects on the CNG filling process and final in–cylinder values. For various Iranian natural gas compositions, the optimised filling stations' reservoirs pressure has been found.