Finished Lubricants



Riverbed to Recycling

Recently, my wife and I were driving home from one of our weekend trips to California when the subject of used oil came up. My wife has been hearing about the oil business for a long time, and she often asks some pretty interesting questions. She recalled how her dad used to go the riverbed to change the oil in one of their family cars. He would open up the drain plug and let the oil run into the sand! This prompted a discussion about how we got from dumping used oil into a riverbed to rerefining it. 

This started me thinking about how I used to drain the oil in our cars. I remember crawling under the car as far as I could reach, removing the drain plug and letting the oil drain into a round plastic hospital basin. When I was through, I carefully poured the used oil into the then-empty oil containers (fiber cans), taped the oil spout hole with duct tape and put it in the trash. OK, I plead guilty to the ignorance of the time.

An illustration from Popular Science shows the “high-tech” way to handle used oil circa 1963. It suggests digging a hole, filling it with gravel and pouring in the used oil. Don’t worry, it will be absorbed into the ground before your next oil change!

The question is, how did we get from this to the recycling processes we use today? What are the drivers that motivated the changes, and what came along in between?

The United States Environmental Protection Agency was proposed by President Richard Nixon on July 9, 1970, and began operations by executive order on December 2 of that year. Paraphrasing the EPA website, the agency was created in response to elevated concerns about environmental pollution. Its purpose was to consolidate into one agency a variety of federal research, monitoring, standard-setting and enforcement activities to ensure environmental protection. 

Some of the oil-related drivers for the EPA’s creation included used oil handling and health-related issues. First—and I hope everyone knows this—while new oil is relatively harmless (but don’t drink it), used oil is carcinogenic. Not really a surprise when you think about the combustion byproducts, oxidation, unburned fuel and other assorted junk found in it. Nasty stuff, at best.

During the time that the EPA’s efforts were getting underway, various methods were being used to dispose of used oil. One was to use it as a part of fuel oil-fired heating systems, which were great for shops and maintenance facilities but only in the winter. It could also be used year-round in boiler systems running on fuel oil. 

Do-it-yourselfers continued to discard oil in various and often unsavory ways. When I was working at Pennzoil, we were at a high school science fair sharing information on engine oil. I started asking people who came by our booth what they did with used oil. Many of them were disposing of it by taking the drained oil to their local service station (there were still service stations in the 1980s) or the newly introduced fast oil change outlets. Others were pouring it down the storm drain. 

This being in Texas, some had some more creative ways to dispose of the used oil. One said that he would pour the oil along his fence line to discourage weeds. Another suggested that it was a great way to destroy fire ant nests.

Also around the time the EPA was founded, we had our first major oil supply shock. The summer of 1973 was all about getting in line and waiting for your eight gallons of allotted fuel. Certainly, conservation was a big positive, and that included used oil. While the EPA first focused on fuel economy, some enterprising folks started looking at rerefining oil.

The state of the art in oil recycling at the time was filtration. The railroads had been filtering used oil from locomotives and either reusing it in lube applications or working it off in fuel. Very laudable on their part, although it was undeniably cost-effective. 

The next step toward used oil rerefining after filtration was solvent extraction, which came into use in the mid-1970s. It was similar to producing solvent-refined base stocks, a process that had been in use since the early 1920s. This was certainly an improvement, as it removed a lot of the sludge and other impurities from the mix. However, the quality of the used oil feed varied so much that it wasn’t possible to produce a consistent base stock that could be used to supply quality finished oils.

In the meantime, hydrotreating processes were introduced in the early 1970s for crude oil that allowed for much better quality base stocks. By the late ‘70s, it was pretty clear to the oil industry that hydroprocessing was the future of base stock refining. 

This led Phillips 66 to introduce a used oil re­refining process called PROP (Philips Rerefined Oil Process) in 1980 that involved hydrotreating the used oil. It cleaned up used oil to the point where a consistent rerefined base stock could be produced. It also produced a heavy sludge that found its way into such applications as road oil, where it could be mixed with asphalt, which was already a known application.

So, now we had a usable base stock that could be included in motor oil compositions. This led to the next great challenge: how to collect sufficient amounts of used oil in order to feed rerefining operations. If you think about it, no one site produced enough used oil to justify a major rerefining unit. By my calculation, if a fast oil change serviced about 25 cars per day, six days a week for a year, it would produce about 9,750 gallons of used oil per year, the equivalent of about 232 barrels per year. That’s not enough to justify even the smallest current rerefinery: Safety-Kleen’s Wichita, Kansas, plant, which produces about 750 barrels per day of rerefined API Group II. Obviously, you’d have to figure a way to collect a lot of used oil.

So a new business opportunity had presented itself: collecting used oil. Pennzoil, in conjunction with Jiffy Lube, which it acquired in 1989, began studying how to gather sufficient oil to make a rerefining operation feasible. We spent a lot of time determining how many trucks over how large an area would be required to justify such an operation. 

We also looked at costs to support such a system. One way was to pay those who had used oil in order to get enough for rerefining. We found that of the nearly one billion gallons of engine oil sold annually, less than half could be located as used oil. Much of it was still being dumped in the riverbed or on fire ants, or used as fuel oil. Paying for used oil seemed to be the best way to maximize recovery. Obviously, anyone changing oil would be encouraged to save it for sale. It took a while to get that ball rolling, but eventually a gathering system developed. 

Times have changed. Today, oil collectors are charging for their services, which represents a cost to those with used oil. The legal and social penalties for polluting are such that it is worth the cost to have the used oil hauled away.

The next big break came when the American Petroleum Institute added rerefined oils to the base stock category system in API 1509. That occurred sometime after the introduction of the system in the early 1990s. The PROP process, as well as other processes, was in business to supply base stocks for engine oils and other applications. The federal government as well as state and local agencies began to specify finished oils containing some portion of rerefined base stocks.

That pretty much brings us to the current situation. Most of the major oil marketers have individual brands or product lines based on rerefined base stocks. There are a number of smaller oil marketers who also market similar oils.

One concept that is gaining acceptance is a so-called “closed loop” process. It works like this: An oil is formulated with rerefined base stocks and sold. The customer—usually a shop or fast oil change—collects the used oil, which is given back to the oil marketer, which re­refines it and turns it into new oil for sale back to the customer. Less new base stock is required to meet the customer’s needs.

So, the bottom line is that rerefining has developed to the point where valuable resources like base stocks are no longer being drained into the sands of the riverbed. Fewer, if not zero, fence lines are being marinated in used oil, and the fire ants have regained their dominance of the Texas landscape, not to mention a lot of other states.

Industry consultant Steve Swedberg has over 40 years experience in lubricants, most notably with Pennzoil and Chevron Oronite. He is a longtime member of the American Chemical Society, ASTM International and SAE International, where he was chairman of Technical Committee 1 on automotive engine oils. He can be reached at