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Although the spotlight has been on base stocks over the past 10 years, times are changing. This is not to say base stocks will be entirely out of the limelight. But at least until gas-to-liquids products enter the market, base stocks probably wont see the same level of attention as when they made the step change from solvent-processed API Group I to hydro-cracked and catalytically dewaxed Groups II, II+ and III. This is because the spotlight is now shifting to additives.

While its certainly not the only issue, one of the hottest topics in the additives business today is zinc dialkyl dithiophosphate, ZDDP. This workhorse chemistry has been in harness for over 60 years. Its a very effective antiwear agent, multifunctional (with antioxidant and corrosion inhibiting properties), and relatively inexpensive as well. In addition, ZDDP manufacturing technology is mature, as is the formulation science around its use.

So whats not to like about ZDDP? Well, unless you are the EPA or someone who stands to benefit from ZDDP going away, there is little reason not to like it. Until the EPA started to take a look at the lifespan of catalytic converters, there seemed to be no risk this ubiquitous additive would be asked to lose some weight, let alone get the boot. But times have changed.

At issue is the fact that, in an internal combustion engine, the phosphorus in ZDDP can and does volatilize and/or slip past the rings into the exhaust system. Seemingly no big deal since phosphorus emissions are not on the EPAs bad list. But it is a big deal when you consider evidence exists that engine oil phosphorus poisons catalytic converters. This compromises the cats lifetime ability to limit the amount of NOx spewing from the tailpipe. And that does offend the ever sniffing and increasingly sensitive nose of the EPA.

So forget about the Z and the double Ds in ZDDP; the immediate challenge for additive companies is how to deal with the P, phosphorus.

This challenge is certainly not new. Additive companies have been addressing it since 1992, when ILSAC GF-1 allowed a max of 0.12 percent phosphorus (at a time when many engine oils contained 0.14 percent). But in the minds of some, subsequent efforts to ratchet back on engine oil phosphorus have been little more than baby steps. With the EPA scheduled to require that each manufacturers entire light-duty vehicle fleet be certified by 2009 to meet the more rigid Tier 2 bin 5 standard (average NOx emissions of 0.07 grams/mile), they argue that a step change will be needed in antiwear technology. Otherwise, some OEMs may have to increase the size of the catalysts (more precious metal) on some of their 2009 vehicles.

Additive companies are working hard to find solutions, and there is some good news. Not all ZDDPs are the same. After delving deeply into the chemistry of primary and secondary alcohols, additive makers have found that ZDDP synthesized from short-chain alcohols tend to volatilize more readily than those from long-chain. As such, ZDDP with long-chain alcohols carry less phosphorus into the exhaust system. Although its an over-simplification to say that using long-chain molecules will do the trick, the additive companies are keeping the details of their molecular manipulations to improve ZDDP close to the vest.

You can be sure the Big Four engine oil additive companies will figure it all out and come up with a ZDDP solution by the time ILSAC GF-5 hits the streets in three years. Some, however, say these efforts too will be nothing more than baby steps, in part because of resistance to go below todays 0.06 percent phosphorus minimum, due to concerns about timing chain wear. They say the industry really needs new and more effective chemistries which can provide a step reduction in phosphorus without compromising its antiwear properties.

More than just talking about it, some very bright minds in our industry are working on this. But its a tall order for a number of reasons – not the least of which is that ZDDP is good stuff, relatively cheap and deeply entrenched in our industry.

So the big questions are, why should the major additive companies invest in new technology, collaborate with other technology companies, or put existing depreciated manufacturing assets at risk of obsolescence by pursuing new technology? How does anyone find the money to support or get into a business where millions of dollars are put at risk to run engine, bench and field tests? And how do innovators looking to offer a step change in additive technology get such components as antiwear, antioxidants, detergents, dispersants and others into the mainstream?

Newcomers with innovative technologies and longtime stakeholders alike say a paradox clearly exists in the additives business that inhibits innovation. Next months column will examine that paradox and whether trailblazing technologies can leap over it.

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