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#1 Farming guy

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Posted 03 January 2018 - 07:45 AM

It's been a struggle keeping the farm tractors running in the extreme cold weather.  It used to be that when we got diesel fuel delivered in November, it was mixed with kerosene so it would not gel, or worse turn waxy in times such as these.

 

Anyway, a diesel mechanic friend of mine told me that the modern refining process for diesel fuel now uses water to remove the sulfur.  I would like to know how this works, and why anyone would thing it a good idea to put fuel through water.  It just seems like asking for trouble to me.

 

Also, we have been avoiding purchasing new diesel engines because the modern legal emissions regulations (at least in the U.S) are concerned with NOx (is that nitrous oxide?) and use urea (mostly nitrogen, to my understanding), which can freeze, and cause other problems for operators. Can someone explain how the urea reacts with the diesel exhaust fluid, please?

 

Someone told me that in Europe, they are more concerned with carbon dioxide emissions, and don't require the systems that use diesel exhaust fluid.  Is this true?  If so, why are the Americans so much more concerned with NOx?

 

 



#2 exchemist

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Posted 03 January 2018 - 09:43 AM

It's been a struggle keeping the farm tractors running in the extreme cold weather.  It used to be that when we got diesel fuel delivered in November, it was mixed with kerosene so it would not gel, or worse turn waxy in times such as these.

 

Anyway, a diesel mechanic friend of mine told me that the modern refining process for diesel fuel now uses water to remove the sulfur.  I would like to know how this works, and why anyone would thing it a good idea to put fuel through water.  It just seems like asking for trouble to me.

 

Also, we have been avoiding purchasing new diesel engines because the modern legal emissions regulations (at least in the U.S) are concerned with NOx (is that nitrous oxide?) and use urea (mostly nitrogen, to my understanding), which can freeze, and cause other problems for operators. Can someone explain how the urea reacts with the diesel exhaust fluid, please?

 

Someone told me that in Europe, they are more concerned with carbon dioxide emissions, and don't require the systems that use diesel exhaust fluid.  Is this true?  If so, why are the Americans so much more concerned with NOx?

I suspect your friend may be confusing water with hydrogen!

 

Hydrodesulphurisation is the method generally used to reduce sulphur in hydrocarbons. It relies on adding hydrogen, which, with the action of a suitable catalyst, takes sulphur out of the fuel, turning it to hydrogen sulphide, which can be further reacted to produce elemental sulphur or sulphuric acid, which has industrial applications. More here: https://en.wikipedia...desulfurization

 

I think you friend saw "hydro" and thought "water". Understandable, but not correct.   :)

 

On the exhaust treatment side, I was surprised you are adding urea. That implies SCR, selective catalytic reduction: https://en.wikipedia...lytic_reduction  which I had understood was more commonly used on large diesels in power gen and marine. For most automotive diesels I had thought this was too cumbersome. But your question has prompted me to look this up and indeed it seems that from 2010 in the US SCR became one route to achieving the new standards that came into force at that time.  I think in Europe the method was to reduce peak combustion temperatures so that less NOx was formed and also to use EGR (exhaust gas recirculation) to reduce the amount of free oxygen available in the cylinders to convert nitrogen to NOx.

 

But these technologies are evolving all the time. The regulatory authorities in the US and Europe often follow different routes and play leapfrog, which is probably a good thing for the planet as it forces the exploration of a variety of technical routes.


Edited by exchemist, 03 January 2018 - 09:57 AM.


#3 pzkpfw

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Posted 06 January 2018 - 01:21 PM

... which I had understood was more commonly used on large diesels in power gen and marine. For most automotive diesels I had thought this was too cumbersome. ...


Just a side point, but adblue has become very common on diesel engines here (New Zealand), in the utes (small trucks) etc. These are generally 4 cylinder engines in the 2.4 to 3 litre range.

https://en.wikipedia...l_exhaust_fluid

(They don't do this just for us, so I expect it's a global thing.)

Edited by pzkpfw, 06 January 2018 - 01:22 PM.


#4 exchemist

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Posted 06 January 2018 - 01:57 PM

Just a side point, but adblue has become very common on diesel engines here (New Zealand), in the utes (small trucks) etc. These are generally 4 cylinder engines in the 2.4 to 3 litre range.

https://en.wikipedia...l_exhaust_fluid

(They don't do this just for us, so I expect it's a global thing.)

Yes indeed, it seems that I am already getting out of date, having left the oil industry in 2011! Seems that SCR is now quite widespread in automotive diesels. Well, that's partly why I come to these forums: there's always something to learn. 



#5 Deepwater6

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Posted 06 January 2018 - 02:52 PM

Is there any possibility the diesel fuel has been diluted down to create more product for them to charge for? We have our own gas and diesel stations in one of my more busy plants. I'm friends with the mechanic that services it. He explained it is now required to preform monthly inspections along with documenting usage amounts.

 

It was explained to him the reason for this was, many unscrupulous inner-city gas stations were adding water to their tanks. As soon as the city figured it out it would shut the stations down. The problem was, many times the station would re-open the next week when a relative was shown as the new owner. Especially when the original offending relative was a foreigner and could go back to his/her country to avoid the fines.

 

I'm not nearly as versed as Exchemist on the processing procedure, but I know I now have tight controls on my plant generators. We have {5} 2000hp generators to power the primary plant complex to keep the water on and provide fire hydrant protection in case of a power outage. A few years ago we were forced to spend $80,000 for exhaust scrubbers on them. Every month we must record run-time, fuel usage and other readings to our states DEP.

 

In recent years the generators which were installed as being only for emergencies has morphed into a moneymaker for the company. During extremely hot high power usage days the electric company will ask us to get off the grid to help them out. The company makes money every time we do this for them including $250,000 just to be in the program. Since they are not regarded as "emergency generators" in this role and they run more often these catalytic systems had to be installed and the gens fell under much tighter regulation.

 

I'm not sure what is more concerning, all the regulations we fall under for so many different things these days, or the fact that the grid is so under-sized and fragile that it needs our help.

 

FG, Do you get any sort of purity paperwork with your diesel deliveries? It must be tested and regulated at some stage from the processing plant to your tractor. It may be getting diluted from one of the chain of companies that supply your supplier. Just a thought.



#6 exchemist

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Posted 06 January 2018 - 04:15 PM

Is there any possibility the diesel fuel has been diluted down to create more product for them to charge for? We have our own gas and diesel stations in one of my more busy plants. I'm friends with the mechanic that services it. He explained it is now required to preform monthly inspections along with documenting usage amounts.

 

It was explained to him the reason for this was, many unscrupulous inner-city gas stations were adding water to their tanks. As soon as the city figured it out it would shut the stations down. The problem was, many times the station would re-open the next week when a relative was shown as the new owner. Especially when the original offending relative was a foreigner and could go back to his/her country to avoid the fines.

 

I'm not nearly as versed as Exchemist on the processing procedure, but I know I now have tight controls on my plant generators. We have {5} 2000hp generators to power the primary plant complex to keep the water on and provide fire hydrant protection in case of a power outage. A few years ago we were forced to spend $80,000 for exhaust scrubbers on them. Every month we must record run-time, fuel usage and other readings to our states DEP.

 

In recent years the generators which were installed as being only for emergencies has morphed into a moneymaker for the company. During extremely hot high power usage days the electric company will ask us to get off the grid to help them out. The company makes money every time we do this for them including $250,000 just to be in the program. Since they are not regarded as "emergency generators" in this role and they run more often these catalytic systems had to be installed and the gens fell under much tighter regulation.

 

I'm not sure what is more concerning, all the regulations we fall under for so many different things these days, or the fact that the grid is so under-sized and fragile that it needs our help.

 

FG, Do you get any sort of purity paperwork with your diesel deliveries? It must be tested and regulated at some stage from the processing plant to your tractor. It may be getting diluted from one of the chain of companies that supply your supplier. Just a thought.

Well you can't dilute diesel fuel with water as they are immiscible. You will get a layer of water below the diesel fuel.

 

But there could perhaps be a scam whereby the diesel level in a tank is raised by means of adding a water layer beneath and then somehow the operator is credited on the basis that the level of the tank represents just diesel fuel.

 

With marine heavy fuel oil (which is basically a residual waste product from the refinery) there used to be a spec that permitted up to 1% water to be present. In practice most supplies would have far less than that, but some operators would deliberately add water to get up to just below the 1% limit. Since fuel oil delivery runs on wafer-thin margins, a bit of money for water can make all the difference. But with diesel fuel supplies on land this sort of thing should not be an issue. 



#7 Farming guy

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Posted 06 January 2018 - 05:45 PM

Is there any possibility the diesel fuel has been diluted down to create more product for them to charge for? We have our own gas and diesel stations in one of my more busy plants. I'm friends with the mechanic that services it. He explained it is now required to preform monthly inspections along with documenting usage amounts.

 

It was explained to him the reason for this was, many unscrupulous inner-city gas stations were adding water to their tanks. 

Since all of the fuel lines on the tractors come out of the bottoms of the tanks, any water would settle and plug the fuel line upon freezing.  What I saw as soon as it got to -10 degrees F was a jelling of the fuel.  When I opened the bleed screw next to the filter housing and manually pumped the supply pump, the fuel would still flow, but I it had a thicker consistency than normal.  I think it's a bigger problem on the newer tractors because they run the fuel at a much higher pressure and have a "better" filter since any impurities would cause more problems at the higher pressures.  I think the slightly jelled fuel can flow through the older style filters, but clog up the new ones.  

 

From what the feed sales lady tells us, nearly every other farm in our area has been struggling with the same problems, so it isn't just us, for what little comfort that provides us.

 

 

.

 

 

 

FG, Do you get any sort of purity paperwork with your diesel deliveries? It must be tested and regulated at some stage from the processing plant to your tractor. It may be getting diluted from one of the chain of companies that supply your supplier. Just a thought.

No paperwork other than a bill.  I heard that some suppliers were relying on additives (a common one is called "Power Service"), but in my experience the additives never work as well as advertised.  We use that stuff all the time to provide lubrication, but have never had much luck with the anti-jell properties.  (It seems a bit much to expect that two gallons added to a 500 gallon tank could mix thoroughly and significantly lower the jell point of diesel fuel.)  5 gallons of kerosene added to 25 gallons of diesel fuel did the trick quite nicely.  It may have less energy available for power, but it gets the cows fed!

 

This cold spell has been brutal!  I don't mind the cold so much, but oh the problems it causes!  My whole upper body is sore from carrying pails of hot water to thaw out the "frost - free" waterers in two different barns twice every day for the past 9 days!  Each watterer takes an average of six 5 gallon pails.  I'm  getting too old for this.



#8 Deepwater6

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Posted 06 January 2018 - 07:53 PM

Ugghhh in this weather that is brutal. Not sure where you are located, but here in PA the forecasts say the temps should have a low 25-35 by this coming Wednesday so hopefully you'll get some relief soon.

 

Just out of curiosity do your frost free waterers go through a wall mounted electric water heater or some sort of heat exchanger? We have collectors on cables to get the settled material out of our clarifiers. In weather like this they would often freeze the cable at the water line. We used to have guys go out and break up the area around the cable every few hours with spade bars. The plants cannot continue to run without the settled material being removed.

 

The company had spent thousands on engineers trying in different ways to prevent it. They couldn't get us a viable solution, but we managed to fix the problem in a very simple way. We went to the pet store and bought cheap aquarium bubblers to keep the water moving. With cheap plastic tubing they are placed right near the cable/ice line and we haven't had a problem since.

 

Also I'm not sure of your lay-out in the barns or the available electric you have, but we often use heat trace tape/wire to keep the water from freezing in closed lines that are outside and not being used. I hope some of this can be helpful, and I'm with you, the older I get the more I dread the winters. I now understand why so many older folks head to Florida when they retire.  :shade: 



#9 Farming guy

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Posted 08 January 2018 - 05:22 AM

 

 

Also I'm not sure of your lay-out in the barns or the available electric you have, but we often use heat trace tape/wire to keep the water from freezing in closed lines that are outside and not being used. I hope some of this can be helpful, and I'm with you, the older I get the more I dread the winters. I now understand why so many older folks head to Florida when they retire.  :shade:

We should have run some electrical wiring underground  along with the water lines when we built the barn.  The water lines are more than 4 ft deep, so they don't freeze, but the waterers are designed to rely on the livestock drinking enough water to keep it flowing enough to prevent the valve from freezing.  Most winters it is sufficient, but this isn't most winters!

 

I heard stories of  trucks stalling on the road due to jelled fuel, and I heard about one mechanic who had his service truck stall out on the way to a roadside assistance call!  A lot of people have a lot of complaints about the "diesel fuel these days."  



#10 Farming guy

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Posted 08 January 2018 - 05:20 PM

Just a side point, but adblue has become very common on diesel engines here (New Zealand), in the utes (small trucks) etc. These are generally 4 cylinder engines in the 2.4 to 3 litre range.

https://en.wikipedia...l_exhaust_fluid

(They don't do this just for us, so I expect it's a global thing.)

I believe vw started using diesel exhaust fluid in 2009, and I think those engines are only around 2 liters.  I understand that one of the ways vw cheated was to set it up so you only had to refill the DEF tank about the same time you were due for an oil change.  I know someone who had one of those cheating diesels, and he said he would never let them recall it from him, but they gave him such a good offer, he could buy a new car and have money left over!

 

  I think in Europe the method was to reduce peak combustion temperatures so that less NOx was formed and also to use EGR (exhaust gas recirculation) to reduce the amount of free oxygen available in the cylinders to convert nitrogen to NOx.

 

But these technologies are evolving all the time. The regulatory authorities in the US and Europe often follow different routes and play leapfrog, which is probably a good thing for the planet as it forces the exploration of a variety of technical routes.

My old 2002 vw uses an EGR, and I've been told that the intake manifold will need to be cleaned of the accumulated soot at around 200,000 miles.

 

Also our milk hauler was complaining not long ago that the use of EGR cuts engine life in half on the big rigs.  He says they used to be able to get a million miles out of a truck, but now you're lucky to get to 500,000.

 

My 2007 Dodge with a Cummins uses an EGR and I have to let it go through a regeneration cycle every so often, and more often in winter.  It seems that running the engine hotter reduces the need for regeneration cycles.  I have also been told that I could have a chip installed to turn the EGR off, and I could gain 5 miles per gallon or more in fuel efficiency by doing so.  

 

So is it better to burn more fuel in an effort to reduce the NOx?  

 

I still have fond memories of my father's International Scout with a Nissan diesel engine that managed to get 25 mpg on the highway.