Journal of Petroleum Technology and Alternative Fuels Vol. 3(3), pp. 29-35, March 2012 Available online at http://www.academicjournals.org/JPTAF DOI: 10.5897/JPTAF11.031 ©2012 Academic Journal Full Length Research Paper Quality of commercial high speed diesel and its environmental impact Ghulam Yasin 1 *, Muhammad Iqbal Bhanger 3 , Tariq Mahmood Ansari 1 , Syed Muhammad Sibtain Raza Naqvi 2 and Farah Naz Talpur 3 1 Department of Chemistry Bahauddin Zakariya University, Multan 60800, Pakistan. 2 Hydrocarbon Development Institute of Pakistan, Multan, Pakistan. 3 National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan. Accepted 10 January, 2012 Physico-chemical characteristics such as American Petroleum Institute (API) gravity, specific gravity, pour point, kinematic viscosity, flash point, copper corrosion, conradson carbon, water and sediments, total sulphur, residue and hydrocarbon contents (saturates, aromatics and polar) of high speed diesel (HSD) collected from Multan regions of Pakistan have been evaluated using standard ASTM procedures. Results have been compared with the standards specifications of European, Indian and Pakistan to assess the quality and environmental impact. Key words: Quality, sulphur, aromatics, environmental impact. INTRODUCTION Diesel is a complex mixture of hydrocarbons. Its exact composition depends on the source of crude oil from which it is produced and the refining methods used. Substances derived from petroleum have great commercial value. The customary processing of petroleum does not involve the separation and handling of pure hydrocarbons. Indeed, petroleum derived products are always mixtures occasionally simple but more often very complex. Diesel fuel oil (Conservation of Clean Air and Water in Europe, 1998) is composed of molecules with 15 to 25 carbons atoms and a boiling range of 275 to 400°C. It consists of fractions, which distil between kerosene and lubricating oil (Glumov et al., 1997) distillates. Diesel fuel oils with higher cetane numbers have numerous benefits including reduced exhaust emissions and engine noise, improved cold starting and engine durability (Guibet, 1995). Quality of petroleum products and HSD is generally determined by measuring various Physico-chemical parameters such as specific gravity, kinematic viscosity, cetane number, distillation range, residue, copper corrosion, sediments, conradson carbon, sulphur and ash contents, flash point, etc. following standard test methods *Corresponding author E-mail: gyasinmalik@hotmail.com. (Thiault, 1995; Beer, 1995; Gad, 1991; Skryabyna et al., 1993). Due to speedy mechanization in this era, there has been a tremendous increase in the numbers of light and heavy vehicles in Pakistan, which resulted in a very high demand for good quality (Brown et al., 1999) high- speed diesel products. These petroleum products have gained prime importance in daily life. Gas oil is used as jet and diesel fuel and those fuels need the opposite specification to those of an internal combustion engine. Long chain paraffins which would cause knocking in petrol engine are much more suitable for diesel engine. Iso-octane is the standard for the internal combustion engine and n-hexadecane (cetane) is the standard for the diesel engine reference to the quality (Bureau of India Standards, 1995) measurement. What are the development trends, which attract our attention to diesel engine and what are the influences, which are pertinent to these trends. In general they can be stated as: the cost and availability of fuel and the demand for increased performance. The urge for higher horsepower per cubic inch of piston displacement, the achievement of maximum portability per brake horsepower and the lowering of maintenance coast and increase of engine life, these factors are all pertinent to fuel economics in diesel operation. The entire refinery situation in the world has changed materially within the last several years.