compressed gas conversion for diesel engine

[Ken]

A neighbor drove in with a compressed natural gas converted Suv. and in talking to him is going to get his Cummons diesel truck with a conversion also.Says it requires a computer to pulse the CNG gas into engine along with the injectors for diesel.
I have never read where this is possible and what does it take to get this conversion.
so that it is reliable to run.
I have seen propane conversion to put into manifold line and just bleed into engine.air intake.
Anyone here know of this CNG and diesel conversion ? How much is original cost.
ken

 

[rsewill]

I can't answer your question but a couple of months ago I saw the CEO of Cummins on CNBC predicting that in five years new Class 8 trucks will be compressed natural gas powered.

 

[Gary Fowler]

Why would they want to use compressed natural gas? LNG would be more appropriate and much easier to store, just like propane. The company I work for is the world leader in building LNG plants all over the world for ease of transport from producer to user. I am working on one now. They also have to build gasifier plants at unloading facilities to put it into pipelines for domestic distribution. With a demand for LNG for trucks and cars, it could easily be moved just like propane to service stations rather than turned back to a gas. At least some of it could be used that way and more and more diverted as demand grows.
This would make more sense to use natural gas than high pressure hydrogen for example.

The best use of excess natural gas is to convert it to a gas oil to be turned into diesel. The last plant I worked in was a gas to liquids plant in Nigeria that did just that. They had no use for the natural gas but plenty of use for diesel for all their cars and trucks.

 

[Ken]

Gary
There is SWN that is buying in Conway compressed gas pick-ups and cars.and also some one is converting there Dodge Cummons diesel to compressed gas with a 30/70 ratio wih a computer controlling the flow. and taping into injector to mix the gas diesel fuel this is not the manifold method of using like gas engine use.
Don't myself know more than looking for information.
With natural gas selling 1.60 pump price it would be nice to use.
Realized when more using it will increase.
ken

 

[timster2]

I have investigated this conversion when I was running a fleet of alternative fuel vehicles, CNG , Methanol, M85, E85 and electric. These were classified as co-fueled engines as opposed to dual fueled engines that could switch from one fuel to another eg. gasoline and NG. The fleet I was working with were mostly class 8 trucks, however, we did have smaller vehicles. When the first technology was introduced a unit similar to a throttle body was put into the intake system and metered NG into the intake which was ignited by a Diesel "spark". Later systems used a PWM signal to a NG fuel injector mounted in the intake system. The systems worked well but were best suited for vehicles under a heavy load, at idle or low power most of the fuel used was still Diesel. It works and given the right application could work very well.

LNG is an alternative storage method but problematic due to its cryogenic storage requirements. Still not practical for the average consumer to manage. Cryogenic fluid training is required for safe handling and storage. The engines for CNG and LNG are the same only the fuel storage system is different.

 

[buickanddeere]

Cryogenic storage in mobile applications is a problem. A LP hose jammed into an intake manifold is just hillbilly behind the barn engineering. A diesel will operate just fine with pilot injection of an idle quantity of fuel. NG is added to increase power output. Even if all vehicles and equipment were converted to LP, NG etc. the green weenies in the EPA, CAFE and CARB will just invent more regulations to virtually ban them too. The green weenies visualize a perfect world with no roads, factories, refineries etc. With them all wearing white robes on the hill side singing Kumby-Ya. Then dine on a tofu and lettuce buffet.

 

[Ken]

The compressed gas being used as fuel has a CO2 less than gas or diesel powered trucks
With same safety standreds as gasoline. meets the Nat. Fire Protection standreds
Looking for some one who has converted there diesel truck to CNG and diesel for every day use.
There is all kinds of information on gas vehicles and the conversion so far over looked any on diesel engines.
ken

 

[buickanddeere]

The compressed gas being used as fuel has a CO2 less than gas or diesel powered trucks
With same safety standreds as gasoline. meets the Nat. Fire Protection standreds
Looking for some one who has converted there diesel truck to CNG and diesel for every day use.
There is all kinds of information on gas vehicles and the conversion so far over looked any on diesel engines.
ken

The range of a compressed NG machine is short unless it's towing it's own fuel tanker.

 

[rsewill]

if all vehicles and equipment were converted to LP, NG etc. the green weenies in the EPA, CAFE and CARB will just invent more regulations to virtually ban them too.

Care to provide evidence for your statement?

 

[tracter]

CNG verges on being useless as the range from a 60 litre tank is woeful , enough to get you to the next filling point of which there are very few.
We have a fleet of CNG buses here in OZ and they had to strengthen the chassis to carry the additional weight of all the gas bottles so as to get a decent range
Further they take an eternity to refuel i.e. a 60 litre tank about 5 minutes at best
LPG injection in a diesel now thats a different matter works exceptionally well and produces significant gains in power and economy
Do not recommend CNG at all , run and run fast away from it

 

[Gary Fowler]

That was my point exactly, trying to carry all that compressed gas to run an engine. It would have to be really high pressure on a full tank to be able to get any volume at all. Take a 240 cu ft compressed gas tank that is over 5 feet high and 8" in diameter (approx. dont need someone to look it up and post figures that is if 59" tall etc). Anyway those tanks are quite heavy and to get any range at all would require lots of them even at 70/30 split, you are talking liquid vs vapor ratio.
Liquid storage would be the only way to go on that. As for problematic, shouldnt be any different that storing liquid oxygen, argon, nitrogen. Any pressure releases just route them to a stack above the truck and it floats away due to lighter than air weight.
We have over abundance of natural gas but no good way to use it in vehicles without converting it.
The best way as far as user convenience would be to convert it to diesel and then just pump it in the tank of any diesel vehicle. You would still have the same CO and gases released via standard diesel engines when doing that. I guess the whole thing is trying to decrease air pollution but they are going about it bassakwards.

 

[TCowner]

The move to compressed natural gas is moving ahead in Minnesota and Wisconsin. Kwik Trip, which is large operator in the fuel/convenience store business, is now to going to offer CNG at three of their stations. They also are converting their own fleet of trucks to CNG.

There is is a lot of information on the cngnow.com website about their plans.

 

[timster2]

Running trucks on CNG is not new, its been around for more than twenty years. The technology for fuel management is getting better. Engine manufacturers are working hard to make this a real world option. The problem lies in fuel storage. Payload and volume are sacrificed to carry enough fuel to be practical for over the road applications. Fleets that go short distances and return to the same place every night are ideal. Things like delivery trucks, school buses, transit buses, trash trucks are all good candidates. Now that lots of natural gas has been found here there is a renewed interest switching to CNG as a motor fuel.

 

[Ken]

Thanks for all the replys Think will use the metal tool box for cash for the diesel on longer trips.
Cost of conversion and then no real improvement in mileage .
Reason was asking I see several types of cars and SUV's some Dodge trucks with sign on rear that there using CNG fuel for there power .
This last trip with load of cattle and fuel in the 4 buck + area customers kind of got there hackles up at the hauling charge. Even explaining only the first loaded costs the money all others ride free wasn't good advice.
Will keep looking but not willing to yank out the cummons for a gasser either.
ken

 

[PoorMansCat]

We have been testing something similar on Cat Frac engines here in Texas.... This is also being used on diesel-electric rigs... Typically, they are plumbing into wellhead gas from a nearby site.. Usually just runs thru a filtering system and into a fuel header, then up to the engines...
The engine ECM still fires the injectors on diesel... just a smaller quantity as the NG is being bled in... In some applications, the compressor wheel on the turbos is acutally used as the mixer to blend the air/fuel. Advantages to this setup include a major fuel savings since diesel is 3.50 or more a gallon at bulk prices where the n.g. is free. This setup also helps with the emissions output...
Chesapeake Energy, JW Operating, and several others are now driving natural gas powered 1/2 ton trucks... with the new emissions diesels getting horrible fuel mileage, something like this could be made into a viable option with enough R&D..