How does one recycle used synthetic motor oil?

Synthetic oil is recyclable just as fossil (actually plant- and bacteria-derived) oil. I take mine to the nearest auto parts dealer who accepts used oil. I fill out the form, list the make and quantity in Liters and the dealer accepts (Mobil 1) without question. The only concern is that used oil not be mixed with antifreeze or other fluids.

 

used motor oil isn't re-refined into motor oil it's refined down to a heavy grease

 

Actually, according to one source that I was able to Google about 14% of used motor oil is re-refined for reuse. Kings County in Washington uses re- refined oil in their vehicles, as do a few other countys in the US. And a local auto parts store sold it for a time as well. Used it in one of our older vehicles without any issues. Problem apparently is that, because there is such a low demand, the cost is expensive enough that it can cost more than the virgin product. Sigh...

 

Here's a good link on how used oil is re-used. Click Here

 

one of the largest users of "used oil" grease is the railroads. It's used to lube the axles and piviots and such on train cars.

 

we (at work) recycle about 300 gallons of used oil, engine and hydraulic, a month some times more but seldom less and the company that picks it up also recycles oil filters and used antifreeze. The oil filters are squashed and the oil captured and recycled and then the filters are shredded and sent for remelting. The antifreeze is filtered and the additives are replenished and it's resold. The oil is re-refined into grease. Some of the oil is used to power their refinery.

 

Slightly off-thread, but I read in a transportation journal that more than one large trucking companies reuse allof their diesel drain oil by adding it, untreated, to their trucks' fuel tanks. I forget the proportion that they were successful in mixing, though at the time I was sorely tempted to use one qt. per tankful in my Mercedes 300D (just over 1%). But I worried that the fine carbon dust, that blackens crankcase oil within an hour of operation after oil and filter change, would settle in injectors and the close-tolerance pump.

 

I know lots add a quart of motor oil to the fuel tank every week or so, but like you I'd want to filter out some of the particulate matter before trying to squirt it thru the injectors. How long do you think the fuel filter would take to plug up?

 

I believe that the article to which I referred addressed filtering, perhaps only indirectly, in that total cost analysis included, as I recall, about a year of fleet data. I remember that I toyed with the idea of building a centrifugal separator, :roll: like Honda's oil filter in my CL350 bike, but bigger.

 

another question, what do you do with the sludge that comes out of the separator? I think that oil re-refining industry sells the carbon/lamp black to the tire industry.

 

Since no laundry is able to get the drain-oil-black out of my clothes, it should be valuable as a non-fading fabric dye.

 

Ha ha ha! too funny.