ABSTRACT

Development and performance analysis of compressed natural gas (CNG) as a transportation fuel for automobiles in Nigeria are presented. The study involved compositional analysis of natural gas obtained from the product sales point at a treatment plant about 10km off the Port Harcourt-Onitsha route chosen to ensure standard sales gas specifications, design of the gas pipeline network and the refuelling stations requirement and locations. Using field investigations and developed physical equations, the number of CNG automobiles plying the route per day and their total gasoline gallon equivalent (GGE) requirement per day was estimated. The number of CNG automobiles plying the route and their total GGE requirement were estimated as 400 vehicles/day and 3856 GGE/day respectively. It was found that a single pipeline arrangement was adequate/required to transport the gas from the sales point to the estimated five (5) refuelling stations with an average dispensing rate of 800 GGE/day. Computer modelswere applied based on HYSYS process simulation software to estimate the compressor duty required by compression stations to boost the pressure of the gas from 14.70 psia at the sales point to 32.62 psia pipeline flow pressure and 3600 psia standard outlet/dispensing pressure of CNG stations and also evaluate flow assurance parameters of condensate dropout prevention, hydrate formation prevention, erosion prevention, slug formation tendency and leak detection. Pertinent findings for optimum gas flow/delivery to the CNG refuelling stations were reported. This study developed novel CNG computer model software with capability for comprehensive techno-economic analysis of CNG as transport fuel for automobiles hitherto undertaken manually. The results from the software were in agreement with results obtained through manual calculation. The algorithm is a useful guide to engineers and investors in the field of CNG automobiles usage, to take appropriate technical, economic and investment decisions.