31 January 2001

A new research consortium being formed by the Southwest Research Institute (SwRI) in San Antonio, TX aims to perform a parametric study to discover whether, how, and how much of certain common lube oil components can poison or degrade diesel emission control systems. The new research follows on the heels of upcoming regulations that aim to protect advanced emission control systems by slashing sulfur levels in diesel fuel.

Fuel desulfurization alone might not be enough to solve the catalyst poisoning problem. SwRI’s “Diesel Aftertreatment Sensitivity to Lubricant” (DASL) consortium intends to compliment government-funded R&D on lubes impact on diesel emission control systems, and hopes to get started as soon as possible. DASL not only aims to probe the impact of sulfur in lubricants, but also other lubes components including zinc, calcium, barium, magnesium, boron, and phosphorus. Lube oils may contain sulfur from crude oil origin as well as from anti-oxidant and anti-wear additives. Some low-phosphorous additive packages are said to contain exceptionally high sulfur levels. Any of these components might degrade the performance of diesel NOx traps, urea- or ammonia-SCR systems, continuously regenerating traps, and catalyzed soot filters. But the researchers could discover that some of these systems might tolerate some minimum or maximum level of these lube components/additives, while others might be especially susceptible to poisoning.

An earlier research consortium at SwRI investigated lubes impacts on diesel oxidation catalysts, so the latest consortium in effect becomes "Part 2" of that study. The new study could accelerate "aging" of the emissions control systems with extra-high doses of the lube components, then compare results with lubes using normal additive concentrations. Results should give engine and emission control system manufacturers insights into potential problems - or allay worries - while giving oil additive/component makers help in formulating future additive packages. Government agencies also might use the study results to determine whether or not modifications to standards are necessary. Cost-sharing pre-competitive research through the consortium should help companies reduce internal research costs and potentially avoid future product recalls or redesigns.

Formation of the DASL consortium follows a recent symposium on non-thermal catalyst deactivation (N-TCD), which was held at SwRI on January 18 & 19, 2001. Forty two attendees representing petroleum products, catalyst manufacturers, OEM, and SwRI researchers participated in presentations, panel discussions, and a question and answer period primarily discussing the poisoning mechanisms of lubricating oil additives (i.e., phosphorus, calcium, sulfur) on catalyst deterioration.

For more information, contact SwRI’s Gordon Bartley, (210) 522-5871, GBartley@swri.edu.

Source: SwRI