4.1 COALS AND COKE

Approximately 2930 MMtoe/y (toe=tonnes of oil equivalent, approximately 42 GJ or 1.5 t hard coal or 3 t lignite) of coal is consumed each year (BP, 2006). Of this, about 35 MMt/y is gasified to produce 150 million Nm ³/d of synthesis gas (Simbeck and Johnson, 2001). Roughly half of this gas is generated in the Sasol synfuels plants in South Africa, where the synthesis gas is used for the production of liquid hydro carbons and other chemicals. Most of the remainder of this gas is used for ammonia production and in China for the production of town gas.

The total proven reserves of coal amount to 909 10 ⁹t world wide. Coal consumption was stable over the period 1991-2001, but has increased at about 6% per year since then, predominantly in China (27% annual rate of increase 2001-2005) and India (6%). Coal consumption in North America and Europe has continued to remain stable over this period. Nonetheless, it plays an important part in the thinking of many long-term energy strategies, despite its contentious role in the production of CO ₂as a greenhouse gas. The reason for this can be seen from the figures in Table 4.1. The ratio of reserves to current production (R/P ratio) is 155. In other words, at current consumption rates the world's reserves will last 155 years. Compare this with 65 years for natural gas and 41 years for oil. Furthermore, the reserves are more evenly distributed...