From flare to fuel

Consumption of natural gas is set to rise in the long term. One reason for the increase is the practical advantages of using natural gas, another is its more favourable environmental image. Oil company Esso is expecting to see natural gas become the second most important energy source by as early as 2020.

Almost every continent has its reserves of natural gas. The main production regions are Russia, the Near East, the Arabian Gulf and North America. The biggest reserves of all, however, are to be found under the Atlantic Ocean at depths of up to 7,000 metres. How long supplies of natural gas will last depends on the one hand on the rate of worldwide consumption and on the other on the extent of what are called the undiscovered recoverable resources. Based on the production rate of the year 2000, the Earth’s proved and economically recoverable reserves of natural gas will – in statistical terms – last for more than 60 years. If we allow for additional reserves and resources, such as natural gas extracted from oil shale deposits, scientists estimate that natural gas reserves will last for approximately 105 years.

A cheaper alternative to oil

Given the rising price of crude oil and the growing political instability of many producer countries, natural gas is becoming an increasingly popular alternative – not only as an energy source but also as a fuel. Natural gas is far more economical than petrol or diesel. Combustion of natural gas also releases less pollutants. However, switching from oil to natural gas as a primary energy source brings only a slight overall reduction in greenhouse gas emissions. The main savings in carbon dioxide emissions result from the fact that natural gas is then no longer flared – that is to say burnt off as a waste product – which is still common practice in many places. Consequently, using natural gas is above all an important step in expanding the range of energy sources and reducing dependency on oil.

Using natural gas really begins to make sense when it serves as the basis for the production of synthetic fuel or SynFuel. SynFuel is a liquid fuel with physical properties similar to those of petrol or diesel. It neither calls for new filling stations nor new means of transport, as natural gas would if it was to be used directly as a fuel. Moreover, vehicles can run on SynFuel without requiring design modifications. This is important, because it means that lower emissions can be achieved not only by new vehicles but by all vehicles on the road.

SynFuel’s properties can be made to measure

Synthetic fuels are also known as designer fuels because their properties can be influenced and determined more precisely than with the fuels produced at today’s refineries. Synthetic fuels contain neither sulphur nor aromatics and offer considerable potential when it comes to making real reductions in exhaust emissions from internal combustion engines – and of nitrous oxides (NOx) and soot particles in particular. SynFuel can also be used with optimised engine technologies such as the Combined Combustion System (CCS), which combines the lower emissions of a petrol engine with the low fuel consumption of a diesel.

Industrial-scale production of SynFuel has been underway since 1993, when companies such as Shell began producing approximately 600,000 metric tons a year in Malaysia. Given the right background conditions, the technology is already economically viable, and oil companies Shell, Sasol and ConocoPhillips have announced plans to build additional industrial-scale SynFuel plants in Qatar. Construction of a further production facility is planned in Egypt where, from 2005 onwards, drivers in the capital city of Cairo will be legally obliged to fill up on synthetic diesel on account of the smog.