Petrol in Nigeria : a fuel or a killer ? “ Is shift to hydroisomerisation not overdue ? ”

Introduction Since the discovery of the high efficiency properties of automobile engines fed with “anti-knocks” by the automotive industry in the early 90s, the search for the most appropriate of these additives has been intensified. This focused primarily on striking a balance between enhancing the octane properties of the fuel, economic viability and environmental sustainability. Tetraethyl lead (TEL) was the first key gasoline anti-knock that received rapid global acceptance since the discovery of its application by Thomas Midgely in 1921 (Nadim et al., 2001), especially due to relatively cheap cost of production. However, although TEL is still in used in many developing countries, either due to government negligence or capital and infrastructural challenges, health and environmental threats necessitate its phase-out towards the end of 20 th century by developed nations. Subsequently other measures were developed as replacement. These include the addition of methylcyclopentadienyl manganese tricarbonyl (MMT), oxygenates such as methyl tertiary butyl ether (MTBE) and ethanol and aromatic compounds. MMT combustion involved the emission of manganese dioxide (MnO2), a serious pollutant that causes severe respiratory problems and hypertension. Oxygenates and aromatics produce carcinogens. The aromatics have also recorded destruction to catalytic converters in the automobile engines (Mokaya et al., 1997; Lincoln, 2000; Moushey and Smirniotis, 2009). The only alternative option that remains most acceptable and is increasingly gaining global attention is the “isomerisation” of the linear alkanes in the gasoline feed to their corresponding isomers by a process called hydroisomerisation. While numerous studies have been carried out in many parts of the world on the process and its economic feasibility to petroleum refineries, little is available in Nigerian records despite the global ranking of the country in terms of oil production, consumption and environmental and health challenges. The paper therefore tailors key issues of why a shift to the hydroisomerisation process is necessary and how it can promote sustainable human development in Nigeria. Leaded Gasoline in Nigeria While several other octane enhancers are used in different parts of the world, Nigeria is one of the global countries that recorded the used of highest TEL concentration as the only gasoline octane promoter (Table 1). However, subsequent to the “Clean Air Act” of 1996 and beyond that saw complete phaseout of TEL in UK, USA, New Zealand and Canada, the Nigerian government promulgated an initiative titled “Phasing-out leaded gasoline in Nigeria, 2002” as a response to the World Bank Clean Air Initiative in sub-Saharan African cities in 2001. Leaded gasoline in Nigeria contain lead in the concentration range of 0.65 to 0.74 g/L, the initiative proposed to reduce the concentration to 0.15 g/L and finally to zero level. However, numerous studies revealed that, the initiative is just on paper (Orisakwe, 2009) due to government negligence. The consequences have been severe environmental problems. Lead pollution from automobile emissions in Nigeria had been extensively studied and documented in various Nigerian and international publications. Nriagu et al. (1997) investigated blood lead levels in 87 children aged 1-6 years from Kaduna state. An average of 10.6 μg/dl was found, with some children having up to 30 μg/dl. The values exceed the maximum allowed limit of 10 μg/dl recommended by Centre for Disease Control (CDC) and correlated linearly with the distance of house from highly trafficking roads, as well as, whether a family owns a car or not. At the beginning of 21 st century Federal Environmental Protection Agency (FEPA) of Nigeria examined the lead concentrations in soils from roads, markets and motor parks of Lagos, Aba, Abuja, Ibadan, Kaduna and Port Harcourt.