Letter Re: Low Sulfur Diesel and Refinery Shutdowns

Dear Jim,
I wanted to provide a technical article to explain to your readers why refineries have to shut down more often than they used to. There’s a good reason for this, and its not greed.
 
A few years ago I went to welding school. I wanted a post-oil survival skill that would make me money and have real value. During the course of my education I learned how to weld stainless steel, and one of the key components of welding stainless is something called the Heat Affected Zone. It turns out that when welding stainless steel you can crystallize out a crucial element which is key in making stainless steel resistant to corrosion. This band of rust-able steel can be reduced in size, but not removed altogether. Agricultural tanks, for things like wine, get around this by adding a coating of stainless steel powder over this Heat Affected Zone and greatly improves its acid/corrosion resistance, but you can’t really do that with refinery pipes.
 
Light Sweet Crude has low sulfur, so produces little sulfuric acid. Heavy Sour Crude, which we get from Mexico and Saudi Arabia these days, is so loaded with Sulfur that its a resellable byproduct that goes to fertilizer plants and industrial processes, since its good for that. Unfortunately, refining it out means that sulfuric acid rushes through the refinery pipes and attacks the heat affected zone, eating them away until there’s a leak. We had a big leak of exactly that about a year ago in Richmond, California at a Chevron refinery, one that sickened hundreds of residents and shut down the refinery, causing a temporary fuel shortage and 50 cent/gal increase in fuel price until repairs were completed and production started again. It will happen again if maintenance isn’t done promptly. There’s really no escaping this problem so long as we use high sulfur oil and mostly all we’ve got anymore.
 
Someday we’ll be growing algae in reactor vessels or inclined glass tubes and harvesting the biodiesel waste, then burning that in diesel engines for fuel. It will require us to have diesel engines, but Hayes has proven that common rail diesel motors can be miniaturized and reliable in their motorcycle, and Ford is bringing their 1.0 L 3-cylinder diesel to the USA from the EU, a clean burning and reliable powerplant which would work for either a hybrid or a very light weight vehicle and run on synthetic biodiesel. This has no sulphur so gets around the whole issue of SO2 emissions that current diesels have to face.
 
The alternatives to diesel are the following:
1. Ethanol fuel made with stills from various source materials. Engines must be designed to burn this to get full efficiency. Current engines are a hodgepodge of compromises. They will have to be modified to run best. We can import cheap ethanol from Brazil, but what can we pay for it with that they will accept?
2. Natural gas, which UPS has their delivery vans running on. Many countries run their vehicle fleets on this. The natural gas will run out, but it can be made from various sources, like manure, and provide secondary income to sewage plants and dairies.
3. Electric cars, which are limited by both battery materials and battery capacity. If you can live with a 20 mph golf cart, you might as well get one soon. Lithium powered cars are like the ransom money in “Way of the Gun”: A motive. A new battery chemistry is needed, but does not yet exist.
4. Fischer–Tropsch process: coal converted to gasoline. Works till you have no more coal. And you have to mine the coal.  
In the short term the answer to high gasoline prices is minimize consumption with fewer and shorter trips using the most efficient vehicle you have, and carpooling when possible. Here in the Sierras, I see more and more Geo Metros at commute times and fewer 4WD SUVs and Trucks. People are adjusting to the Post (Cheap) Oil reality.
 
Links:
Heat-Affected Zone
Fischer–Tropsch synthesis 
Synthetic Fuel definition and history
Diesel Motorcycles
OPOC Diesel Engine

Note: I am unclear why this engine was not released on schedule two years ago. There are no published reports on reliability or maintenance, and none from users in the real world.