LIQUID AND GASEOUS FEEDSTOCKS
In 2002 some 154 million Nm3/d of synthesis gas was produced by partial oxidation of liquid or gaseous feeds (Simbeck and Johnson 2001; SFA Pacific 2001). If fed to state-of-the-art IGCC units, this would have generated some ll,500MWe. By far the largest portion of this synthesis gas (about 80%) is generated from refinery residues, typically visbreaker vacuum bottoms or asphalt. The most important product from these plants is ammonia. Methanol is also important, but refinery hydrogen and power applications via IGCC are rapidly increasing (Figure 4-2). Most plants with gaseous feed are small units for the production of СО-rich synthesis gases, particularly for the production of oxo-alcohols. The largest single gas-fed plant is the Shell unit at Bintulu, Malaysia, which serves as the front end for a synfuels plant using Fischer-Tropsch technology. The number of projects recently announced indicates that this type of application is likely to gain increasing importance in the near future. However in the long term one must recognize that neither oil nor natural gas availability is as great as that of coal. The reserves-to-production ratios are 40 and 62 years, respectively, compared with 216 years for coal.
