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ClearRefining Process Upgrades ULSD to Lighter, Cleaner-Burning Fuel; Nevada Designates it an Alternative Fuel

Nevada-based Advanced Refining Concepts, LLC, (ARC) has developed a process—called ClearRefining—for the upgrading of ultra-low sulfur diesel to a lighter, cleaner burning, higher quality fuel. The GDiesel product was recently designated as an alternative fuel by the Nevada Division of Environmental Protection (NDEP) due to the reduction in criteria emissions stemming from GDiesel use.

The low-temperature (295 °F, 146 °F), low-pressure (<10 psi, 69 kPa) ClearRefining process combines ULSD with natural gas in a catalytic system that essentially smoothes out the spike of the heavier molecular weight alkanes in conventional diesel, resulting in a heavy concentration in the C10 to C14 range, says Peter Gunnerman, co-founder and director of Advanced Refining Concepts. GDiesel still meets all the ASTM D975 specifications.

We’re moving the [alkane] concentration to the lower molecular weight product. In theory, if you have a fuel that has that characteristic, you see improved responsiveness, less smoke, with efficiency increases. It burns a little bit quicker and more completely than the initial product. That’s theory. In practice, our customers, have come back with reports of improved mileage, responsiveness and less odor.

—Peter Gunnerman

The ClearRefining process combines ULSD with natural gas in a tank at 295 °F (below the diesel boiling point) and low pressure. A fog of diesel vapor and natural gas is generated at the top of the tank; this mixture is passed through a series of four catalytic plates, then a series of chillers, then a series of condensers. The result is GDiesel fuel.

Gas not used is circulated and ultimately several units offgas into another unit. ARC is trying to have no gas remaining at the end of the process, Gunnerman said.

The ClearRefining units are “zero-emission” at the refinery, Gunnerman said. ARC takes all of the power required from the electric grid. At the ARC refinery there are no emissions, no solid byproducts and no liquid effluents. Because of that, Gunnerman said, the permitting process for a ClearRefining unit can be extremely rapid; their first refinery completed permitting in 43 days. Construction time is also very short. ARC broke ground on its first refinery on 27 Sep 2009, and it came online in August 2010.

ARC envisions the potential for small, inexpensive, low-capital refineries in a distributed model that provides another quality control steps between the large refiners and the consumer’s tank.

ARC is currently selling GDiesel at the same price as regular diesel through five local and regional Nevada distributors, including Golden Gate Petroleum, one of the largest fuel distributors in Northern Nevada and Northern California. ARC recently began the start-up phase at its Peru Heights refinery, which will produce up to 100,000 gallons of GDiesel per day when fully operational. The site is on 10 acres owned by the company at the Tahoe Reno Industrial Center, located 10 miles east of Reno, Nev.

Although the company (which is a small business with 30 employees) is concentrating immediately on the Nevada diesel market, the ClearRefining process could be applied to other end products (such as jet fuel), and use other inputs, such as kerosene, Gunnerman said.



What a crock. It still comes from petroleum. It still has to be refined to ULSD...and THEN use electricity to create this new "alternate fuel".

How much electricity? The average on the US grid is still 600g/kWh so how much electricity?

So let's recap:
1) It still comes from petroleum
2) it still has to be initially refined
3) it has to be further refined using more electricity
4) some company is making BIG money to sell this and providing lots of campaign contributions to politicians in Nevada so they can get this classified as an "alternative" fuel.

Sounds great guys...keep up the *good* work.


DaveD, great to see you have in interest in this area. I guess that you are now going to tell us all that EV's and fuel cells are the way of the future - let me know when the technology is affordable/emission free and l will jump on board as well. However, until that day comes any new technolgy that reduces emissions from refined fossil fuels is a great start.


Then go with ethanol, methanol, butanol or one of the other alcohols.

You are not reducing emissions if you just do more refining on existing petroleum and you use more electricity to do it. Did you not read that part of my post or did you just want to argue?

And you are certainly not reducing the amount of petroleum used which means more money is still bleeding out of our economy and we still have more excuses to fight in the middle east.


DaveD, l think that the use of an alcohol blend fuel increases the safety risk when using as a transport fuel. Surely the use of NG as a blend, 98% of supply produced in North America, will be a good start to reduce imports? Thanks for the chat.


True, I agree with the NG idea and forgot that one. I'm not familiar with the issue of alcohol blends being more dangerous. Is that a transport issue or something else?


Take for example E diesel (20% alcohol, 80% diesel), the flash point is lowered from 126 degree F to 50 degree F, which stored on trucks in the large volumes that they do is a significant fire risk if fuel tanks are ever ruptured. So l believe the use of alcohol blend fuel is not the best alternative for transport in terms of safety.


They used methanol at Indy for decades and now use ethanol because both are safer than gasoline. The one issue is low visibility flame which can be remedied with a bit of additive. M85 and E85 both have gasoline, so the flame is more visible.


I would say methanol was chosen back in the 60's because it has a higher octane rating than gasoline (more power) and then they relised that it had a lower flashpoint than gasoline. Ethanol was introduced in 2007 to make a renewable fuels statement, ie; if it is good enough for Indy it's good enough for mum and dad. The V8 supercars racing in Australia now use ethanol as well. So in the case of gasoline it raises the flashpoint from -45 degree F, not so good when talking diesel blends.


Diesel is also more efficient, and if it can be developed with lower emissions, Diesel powered cars may become more mainstream in the US, as it is in Europe. Normally you can expect diesel engines to get a good 50% more mileage than gasoline. As I have said in previous posts, I have a large old 1997 Audi A6 with a 140bhp 5cyl 2.5TDi. I can get up to 50 USmpg highway mileage on long motorway journeys, or let me put it another way, 900 miles on an 18 US Gallon tankful from mostly highway driving.


Aviation gasoline has high octane and could have been used at Indy, but was not. There will be detractors of FFVs saying that it should all go another way, but it is the most viable and one that can be done in the near future at lower cost.


The problem with aviation gasoline is that it still uses lead to boost its octane: "The main petroleum component used in blending avgas is alkylate, which is essentially a mixture of various isooctanes, and some refineries also use some reformate. Avgas has a density of 6.02 lb/U.S. gal at 15 °C, or 0.721 kg/l, and this density is commonly used for weight and balance computation. Density increases to 6.40 lb/US gallon at -40 °C, and decreases by about 0.5% per 5 °C (9 °F) increase in temperature.[1] Avgas has an emission coefficient (or factor) of 18.355 pounds CO2 per U.S. gallon (2.1994 kg/l)[2][3] or about 3.05 units of weight CO2 produced per unit weight of fuel used. Avgas has a lower and more uniform vapor pressure than automotive gasoline, which keeps it in the liquid state at high-altitude, preventing vapor lock.

The particular mixtures in use today are the same as when they were first developed in the 1940s, and were used in airline and military aero engines with high levels of boost supercharging; notably the Rolls-Royce Merlin engine used in the Spitfire and Hurricane fighters, Mosquito fighter-bomber and Lancaster bomber (the Merlin II and later versions required 100-octane fuel), as well as U.S. made liquid cooled Allison engines, and numerous radial engines from Pratt & Whitney, Wright, and other manufacturers on both sides of the Atlantic. The high-octane ratings are achieved by the addition of tetra-ethyl lead (TEL), a highly toxic substance that was phased out for car use in most countries in the late 20th century.

Avgas is currently available in several grades with differing maximum lead concentrations. Since TEL is a rather expensive (and polluting) additive, a minimum amount of it is typically used to bring it up to the required octane rating and actual concentrations are often lower than the maximum."

BTW, watch this.


The point was that Indy used methanol for octane and not safety. Since Indy could have used high octane gasoline but used methanol instead, that is a less valid point. I can recall articles about methanol safety at Indy, once they put an additive in to make the flame visible. The flame burns cooler, so it is easier to get to the crash scene and put it out.


The safety of methanol has nothing to do with flame temperature. Methanol dissolves in water, so if you spray water on it it quickly dilutes to a concentration that can't produce combustible vapor.

Ethanol is used for cooking on boats for the same reason; if any gets away, it mixes with the water in the bilge and gets pumped overboard. Gasoline or propane form heavier-than-air vapors which concentrate.


I would not say nothing to do with it, it helps if someone has to pull a driver out of a car with burning debris around it before anyone can get enough water on it to put out the fire. But point taken, water dilutes methanol and that helps.


"A seven-car crash on the second lap of the 1964 Indianapolis 500 resulted in USAC's decision to encourage, and later mandate, the use of methanol. Eddie Sachs and Dave MacDonald died in the crash when their gasoline-fueled cars exploded. The gasoline-triggered fire created a dangerous cloud of thick black smoke, which completely blocked the view of the track for oncoming cars."

"Johnny Rutherford, one of the other drivers involved, drove a methanol-fueled car which also leaked following the crash. While this car burned from the impact of the first fireball, it formed a much lesser inferno than the gasoline cars, and one that burned invisibly. That testimony, and pressure from Indianapolis Star writer George Moore, led to the switch to alcohol fuel in 1965."

Thought I would supply a bit of history.

Tim Duncan

Great discussion about fuels, a complex subject.

But to the technology of this article:
1. How much NG is added, say on a BTU/Diesel gal basis? How does this copare to CNG or LNG energy inputs? NG is a secure, abundant, inexpensive, job creator in this country. Ideas that use it in safe, efficient ways to power mobility must be exploited to the n'th.
2. How much electricity, say in BTUs/Dgal is used?
3. What are the detailed effects on engine wear and emissions? ULSD is already lower in lubricity, this combines with ever higher press. fuel systems to create big costs to injector and pump systems on engine.
4. What is going on chemically? CH4 combining with the cataliticaly cracked long cabon chains to make many short chains?
5. Does this require special NG? What happens to the non-CH4 constituents of the NG?


I think this may work as a cleaner diesel program for city buses and trucks. They take low sulfur diesel and make it cleaner. Nothing special here, it is an alternative to converting trucks and buses to CNG or DME.


The claim is that GDiesel yields better fuel economy than ULSD and lowers emissions as well, both because of more complete combustion. Does the fuel economy improvement offset the the energy used in processing? Would using this new fuel decrease emissions enough to allow trucks in areas with bad air quality to avoid installing soot traps?

With lower molecular weight, this fuel should have lower pour/cloud/gel points. Would it be a more efficient fuel than #1 ULSD?

Because leaded avgas is so expensive and in some areas unavailable, several companies are now building diesel aircraft engines. Using #2 diesel in aircraft is a bad idea since one gelling incident would ruin somebody's whole day. That's why most diesel planes run on jet A. If this new fuel flows in subzero temperatures and has higher heat value than jet A or #1 (which are about the same but for purity specs and additives), it would be a good aviation fuel for diesels.


I see LNG and CNG as good alternatives to traditional diesel fuel in the medium to heavy road transport sector, however the cost of the engine technology and refuelling infrastructure is a barrier to the uptake by operators. If the life-cycle emissions (pre and post tailpipe) of GDiesel are favourable, as well as the economics, this looks like a low cost 'fill and go' alternative to traditional diesel fuel. Any viable alternative fuels/ or technologies that will reduce dependance on traditional diesel fuel and doesn't require direct funding from governments to support should be considered in my opinion.

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