Thailand has decided to proceed with a plan to require local refineries to slash the sulfur content of diesel oil to 0.05% from 0.25% by Jan. 1, 1999, although it acknowledged that doing so may cause some engine problems.
Deputy Commerce Minister Pothipong Lamsam stressed the need for Thailand to have more environmentally friendly fuel and said the planned reduction in the sulfur content of high-speed diesel will be enforced.
Lubricity issues
Reducing the sulfur content of Thailand's diesel oil to 0.05 wt %-the level commonly considered "low-sulfur"-will mean less black smoke and sulfur dioxide emissions from vehicles. But reports from some countries that use ultralow-sulfur diesel (0.001-0.005 wt %) have indicated that the fuel can cause lubricity problems in engines (OGJ, Apr. 22, 1996, p. 75).
A study conducted by the Petroleum Authority of Thailand (PTT) found that low-sulfur diesel with a lubricity standard of not more than 460 micrometers, measured as wear scar diameter, will not cause engine problems. PTT concedes, however, that some low-sulfur fuels may need lubricity enhancing additives to solve problems such as high engine wear rates, failure of fuel injection pumps, and build-up of gums in fuel pumps.
The ministry, which sets fuel specifications in Thailand, plans to go ahead with the reduced sulfur specification but is considering waiving a proposed requirement that refiners add detergent additives to low-sulfur diesel oil beginning Jan. 1.
All of Thailand's oil refineries have already invested in desulfurization units, to the tune of $160-200 million each, to comply with the new low-sulfur specs. And they say that reducing diesel sulfur will increase their diesel processing costs by $1-1.50/bbl.
Thailand's refineries are expected to have no problems meeting the Jan. 1 deadline. In fact, Caltex Oil (Thailand) Ltd. has been marketing 0.05% sulfur diesel oil in Thailand for several months, well ahead of the legal deadline.
Copyright 1998 Oil & Gas Journal. All Rights Reserved.
