ULTRA-LOW SULFUR DIESEL WITH THE PRIME-D TECHNOLOGY PACKAGE

Description:

Virtually every refiner is wrestling with the issue of decreasing sulfur in transportation fuels. Sulfur has been identified as a major poison to catalytic converters, and the automotive industry has required severe sulfur fuel specifications (i.e., sulfur < 15 ppm) to meet low vehicle emissions requirements. Taxation policies coupled with high fuel efficiency has resulted in an ever-growing popularity of diesel powered automobiles in the European Union (EU). As a result, many EU countries have seen transportation diesel demand surpass that of gasoline. Although on-road diesel enjoys a lower popularity in North America, diesel engine improvements along with low CO2 emissions have resulted in renewed interest among US car manufacturers for diesel powered vehicles. Critical properties to reduce diesel fuel emissions have been widely debated during the last five years. The current focus will be limited to a sulfur reduction to the 10-15 ppm level; however, certain properties such as polynuclear aromatics content and increased cetane requirement may be reviewed in the future. Finally, stringent off-road diesel sulfur specifications are also considered as very likely in the near future. US and Canadian refiners are now studying the most economical means to produce 7-10 ppm S on-road diesel to meet the 2006 requirement of 15 ppm S fuel. Meanwhile, although the EU has limited diesel sulfur to 50 ppm by 2005, most European refiners consider that there will be a strong demand for 10 ppm S before the 2009 target. Middle distillate HDS has been practiced by refiners for decades and is considered by many as an open-art technology. Although additional reactor volume coupled with higher activity catalyst goes a long way in helping meet the fuel sulfur target, such solutions may prove insufficient or uneconomical. Axens has identified key parameters to economically respond the low sulfur diesel challenge. The following criteria are among the key differentiating factors: