MEP002 CNG conversion

[CDR]

Has anyone ever tired this? From what I understand you could run 10% diesel 90% CNG look like the garbage trucks in my area are doing this

 

[gimpyrobb]

Dunno why you would waste time on something like that. Where do you get your CNG from? What pressures does it run at? How is it bought, by the gal? How much is it?

 

[Westech]

I would convert a gas engine to propane before I mess with cng. Very limited around here on cng stations

 

[Isaac-1]

Onan made high compression natural gas only J series engines, with a bit of work you might be able to swap one in, but it would probably just be easier to get an Onan JB generator already set up for natural gas.

 

[Keith_J]

What CDR is talking about is hybrid diesel and natural gas. How it works is simple, natural gas is mixed with the intake air at concentrations less than the lower flammable limit, the small amount of diesel needed to induce combustion then burns the natural gas, releasing the heat equivalent to a much larger injected quantity.

now, in simple terms, it just isn't possible with indirect injected engines. On the technical side, the governor would not have the authority to run at such wide range of control lever positions. You might use 10% natural gas, hardly worth the expense. Larger, electronically controlled direct injected engines are possible and it is done on a large scale, from garbage/delivery trucks to peak load electric generation plants. And yes, 10 % of the total fuel load is diesel! the rest natural gas.

 

[CDR]

I have natural gas service at my house wondering how feasible it would be to use sounds like a got my Anwser thank you!

 

[rustystud]

It seems as if you already got your answer, but I'll add my 2 cents worth. At my work (municipal transit) they where considering going to CNG. The cost was out of this world ! The mods to the engine was in the thousands ! and the cost of infrastructure (piping, safety valves, fire suppression systems ) was staggering ! So if you tried this at home without getting all the proper gear and permits and an accident happened ( like at the Texas transit building in Dallas I believe) you would not be covered by insurance and the resulting damage to your and other homes would all be out of your pocket. For me this alone would put a end to the topic.

 

[rustystud]

I would convert a gas engine to propane before I mess with cng. Very limited around here on cng stations

My backup to my backup generator is a "Vanguard" 16HP Briggs&Stratton 10KW unit (actually only 7KW) and it runs on propane from our 500 gallon tank.

 

[CDR]

http://www.tri-fuel-generator.com

 

[Keith_J]

For stationary applications, you don't need to compress the natural gas, making it far more economical than compressed. This is what makes CNG expensive.

 

[NDT]

The inexpensive MEP-17A is super simple to convert to regular house natural gas. So is the PE-95.

 

[Keith_J]

This thread is far more complex than spark ignition engine modification to natural gas, it is bi-fueled diesel. This is more efficient than spark ignition because of thermodynamics, Diesel engines have higher compression ratio and lower pumping losses.

Yes, it could be done but the cost is too great.

 

[rustystud]

For stationary applications, you don't need to compress the natural gas, making it far more economical than compressed. This is what makes CNG expensive.

I didn't know that about the stationary application. Thanks Keith for the Illumination ! (get it, lights, generator ? well I thought it was funny !)

 

[Keith_J]

CNG is the buzz word in stretching diesel supplies, only thing is the range is highly limited. Diesel is dense and requires gossamer thin tanks to safely store.

Beware of those pitching buzz words, that is the hallmark of a politician in need of retirement.

 

[steelypip]

The gotcha in running your generator on municipal low-pressure natural gas is that you have to have constant availability of municipal low pressure natural gas. Basically, you're protecting your dwelling against an outage of a utility supply by depending on a different utility supply.

It is generally harder to disrupt municipal natural gas than electricity, but I've seen both go out if things are bad enough, sometimes for days. (Hurricane Fran in Raleigh did disrupt some Nat gas supplies. Whether or not you had gas the morning after depended on random luck in your choice of neighborhoods).

I'd stick with fuel stored on premises for that reason. Propane is good if you think through the use scenario carefully. I stuck with diesel because of the ease of getting more after a disaster versus getting a propane truck up the hill on the narrow, tree-lined road to refill the buried tank.

 

[CDR]

The idea was to run on tri fuel diesel NG CNG Propane. Just more options

 

[Isaac-1]

Another problem with propane in an extended outage is that residential customers are the very last in line for resupply. My inlaws that lived about 40 miles from the coast in SW Louisiana used propane for heat, water heating, and cooking. When Hurricane Rita (at one point the second strongest hurricane ever recorded in the Gulf of Mexico) hit SW Louisiana 3 weeks after Hurricane Katrina hit New Orleans , they were unfortunately running low on propane. They had placed an order about a week before the storm hit, but had not yet received delivery due to all the commercial customers topping off supply with a hurricane in the gulf and the recent memory of what happened to New Orleans. The short version is the propane supplier was shut down for almost 2 weeks after the storm as most of their employees had evacuated, and my inlaws, whose house survived with only moderate damage (needed new siding and a new roof, plus some interior repair from water damaged ceilings) finally received their propane delivery on a Sunday afternoon 3 weeks and 1 day after Rita made landfall.

Ike

p.s. even conserving it, their propane for cooking ran out about 2 weeks after the storm hit, just about the time their electricity was restored.

 

[CDR]

I never been a fan of bottled propane to much headaches involved with it

 

[rustystud]

The gotcha in running your generator on municipal low-pressure natural gas is that you have to have constant availability of municipal low pressure natural gas. Basically, you're protecting your dwelling against an outage of a utility supply by depending on a different utility supply.

It is generally harder to disrupt municipal natural gas than electricity, but I've seen both go out if things are bad enough, sometimes for days. (Hurricane Fran in Raleigh did disrupt some Nat gas supplies. Whether or not you had gas the morning after depended on random luck in your choice of neighborhoods).

I'd stick with fuel stored on premises for that reason. Propane is good if you think through the use scenario carefully. I stuck with diesel because of the ease of getting more after a disaster versus getting a propane truck up the hill on the narrow, tree-lined road to refill the buried tank.

Good point !!! I wasn't even thinking about that when I responded to the CNG option. I have a propane generator since I have a 500 gallon tank ( back-up for my back-up ), but I always go to my diesel MEP units when the power go's out ! As far as long term storing of fuels go, propane is "king", but diesel is right there behind it.

 

[Keith_J]

Propane isn't as desirable in a fogging style bifuel as it's auto ignition temperature is lower than that of natural gas. And gasoline is even lower.

now, a spark ignition engine can use all three since sparks are pretty high temperature ignition sources.