Petroleum-Based Fuels – An Outlook
Petroleum-based fuels have been used to power automotive vehicles and industrial production for well over 100 years [1–2]. Petroleum is one of the most important fuels derived fossil energy sources.
Currently, global annual energy consumption is about 12.2 × 109 tons of crude oil. Energy consumption is expected to increase to 17.5 × 109 tons of oil by 2035 [3–9]. Southeast Asia’s energy demand alone will expand by about 75% by 2030 based on the strong economic growth trends in China and India [8–11]. The reserves of oil, gas, and coal that we depend on are therefore declining, and oil production is becoming ever more expensive, and causing significant environmental impact as well.
The industrial sector uses more energy than any other end-user sector, and currently it consumes about half of the world’s total delivered energy . Huge amounts of energy are consumed in manufacturing, mining, and construction, mainly by processing and assembly equipment but also by air conditioning and lighting. Worldwide, industrial energy consumption is expected to grow by 1.75 × 109 tons from 2010 to 2030, while transportation by about 0.6 × 109 tons and other energy consumption by about 0.8 × 109 tons during the same time period .
Industrial energy demand varies across countries depending on the level and mixes of economic activity and technological development. About 90% of the increase in world energy consumption is projected to occur in the non-OECD countries, where rapid economic growth is taking place. The key countries—Brazil, Russia, India, and China—will account for more than two-thirds of the growth of non-OECD industrial energy use by 2030 [7,9]. The transportation sector follows the industrial sector in world energy use, and it is of particular inte
rest worldwide, as extensive improvements are being continually made in the quality of engine fuels.
To comply with climate change regulations, the energy sector is required to limit the long-term concentration of greenhouse gases to 450 ppm (mg/kg) of carbondioxide equivalent in the atmosphere so that the global temperature rise can be contained to about 2 °C above the pre-industrial level . In order for this target to be met, energy-related carbon dioxide emissions need to fall to 26.4 gigatonnes (ca. 26.4 × 109 tons) by year 2050 from the level at 28.9 Gt in 2009 [7,13]. Even given this outlook, fossil fuel demand will peak by year 2020.
The projected growth of energy consumption is based on the fast increase in the world population and in the standard of living. The world population was estimated to increase to about 7.03 billion (7.03 × 109) by April 2012 . The fastest population growth rate (about 1.8%) were witnessed during the 1950s and then for a longer time period during the 1960s and 1970s. At this rate the world population is expected to reach about 9 billion (9 × 109) by year 2040 [4,14].
In North America and Western Europe, the automobile population has been growing roughly in parallel to the human population growth. But in the developing world, the automobile population growth is becoming almost exponential, due to effect of faster economic growth .
Globally, the number of vehicles on the road may reach 1 billion (109) by 2011 . The growth is being fueled primarily by the rapidly expanding Asian market, which will see 5.7% average compound annual growth in vehicles in operation in the next three years. Asia will account for more than 23% (231 million vehicles) of global vehicles in use by 2011 . Thus every seventh person in the world will have a vehicle by 2011. Europe and the Americas will account for 34% and 36% of the global share of automobiles by 2011, respectively. The America
s and Western Europe will continue to see approximately 1.3% and 2.0% compound annual growth in the next three years respectively, while Eastern Europe’s vehicle population growth rate is forecasted to be 4.3% .
With the growth in the number of vehicles, especially passanger cars with internal combustion engines, fuels consumption has gone up significantly [9,16,17]. This has had a deleterious effect on the environment.
A large part of energy consumption is in form of engine fuels. Fuels for internal combustion engines produced from primarily sources are composed of combustionable molecules. Heat energy is a derivative of fuel’s oxidation, which is converted to kinetic energy. Different gas, liquid, and solid (heavy diesel fuel, which is solid below 20 °C) products are usable as engine fuels [8,9,18–20]. These fuels are classified as crude oil based—namely gasoline, diesel fuels, and any other gas and liquid products [18–21]—and non-crude oil based—namely natural gas based fuels—compressed natural gas (CNG) and dimethyl-ether—biofuels, like methanol, ethanol, any other alcohols and different mixtures of them; biodiesel; biogas oil (mixtures of iso- and n-paraffins from natural tryglicerides). Liquefied petroleum gases (LPG), which can be crude oil or natural gas based, and hydrogen are derivatives from different fuel sources [22–38].
Over the years fuel specifications have evolved considerably to meet the changing demands of engine manufacturers and consumers [20,39–42]. Both engines [43–45] and fuels [9,20,39,41,42] have been improved due to environmental and energy efficiency considerations. New processes have been developed to convert maximum refinery streams into useful fuels of acceptable quality at reasonable refinery margins [8,9,46,47].
Gasoline and diesel fuels have been preferred  in the development of engine technology. The price of crude oil is
also often at a level that makes petroleum–based fuels in engines desirable for economic reasons [46,47,53–54]. Whenever crude oil prices do rise, the issue of alternative fuels comes up [9,22–27,48–51], but the discussions and investigations get dropped out soon after crude oil prices settle down . The oil crises of the 1970s and 2008 reflect this tendency. However, oil is not going to last forever, and it is also not going to be exhausted in the near future [5,7,9,10]. So, while the use of petroleum-based fuels and lubricants may continue in the current century, it is likely that a significant decrease will occur after crude oil usage peaks [3,7,10,11,52].
The application of alternative fuels will find a place wherever cost–benefit analyses permit or wherever regulations force their use. (The use of compressed natural gas in all of New Delhi’s city transportation vehicles is an example. This was decreed by the Supreme Court of India and is now being enforced in the other cities of India as well.)
While world gasoline demand is expected to be static and possibly to decrease in future, the consumption of diesel and kerosene, the rail and water transport fuel, will likely expand 1,3% to 15% by 2030 [9,16,17]. With the demand for heavy fuel oil expected to decrease [9,16,17], heavy fuel oil is being converted into lighter products such as LPG, gasoline, and diesel [53–55].
The world demand for middle distillate fuel, mainly diesel oil and heating fuel, will grow faster than that for any other refined oil products toward 2030 [9,56]. Globally, new car fleets are shifting to diesel from gasoline, and therefore the demand for middle distillates will grow and account for about 60% of the expected 20 million barrels per day (bpd) (2.66 × 106 t/day) rise in global oil production by 2030. In 2008, the difference in demand between gasoline and diesel was around 3 million bpd (0.4 × 106 t/day). By
2020, the projected gas oil/diesel demand is 6.5 million bpd (0.9 × 106 t/day), higher than for gasoline, and by 2030, the difference exceeds 9 million bpd (1.2 × 106 t/day). The expected global demand for diesel and gas oil (mainly used for heating) will grow to 34.2 million bpd (4.5 × 106t/day) by 2030 from 24.5 million bpd (3.3 × 106 t/day) in 2008. Gasoline demand will rise to about 25.1 million bpd (2.9 × 106 t/day) by 2030 from 21.4 million bpd (2.5 × 106 t/day) in 2008. Jet fuel/kerosene demand will rise to 8.1 million bpd (1.0 × 106 t/day) from 6.5 million bpd (0.8 × 106 t/day), while residual fuel demand, used as a refinery feedstock and as marine fuel, will fall to 9.4 million bpd from 9.7 million bpd.
The United States accounts for most of the world’s gasoline demand, whereas in Europe the demand for diesel is increasing [4,9,42] due to the rising number of diesel vehicles . India and several other Asian countries also consume more diesel fuel than gasoline [4,49]. With the development of more fuel-efficient diesel vehicles, the demand for diesel will increase significantly and its use might have to be restricted to meet future demand. However, gasoline-powered engines seem still to be favorable for hybrid vehicles.
Among the primary energy carriers, in absolute terms, coal demand will increase to the highest rate, followed by gas and oil over the projected time period . Nevertheless, oil still remains the largest single fuel source by 2030, even if its share drops from the present 34% to about 30% (in 2010 ca. 92.3% and in 2030 ca. >85% fuels from petroleum) [4,11].
The projected worldwide crude oil demand reflects the leading role of crude oil in engine fuel production. The global total crude oil demand in 2011 was 4.05 × 109 t, and this is expected to increase to 4.4 × 109 t/year by 2015, and to 5.25 × 109 t/year by 2030...