C N G

[C 5 Estate]

Compressed natural gas is one alternative to diesel fuel but the conversion cost will be a deciding factor when having to decide whether to get rid of the good condition eight year old motor or shell out for some sort of fuel conversion.

 

I have not read up on Diesel to CNG conversions and wondered if its possible to inject the CNG through the diesel fuel system and achieve successful ignition without the addition of spark plugs.

Edited May 4, 2015 by C 5 Estate

[paul.h]

Diesel works by compressing the gas/vapour until it gets hot enough to auto ignite. An internet search on auto ignition temperatures (AIT) gave 'For common hydrocarbon fuels, the minimum AIT ranges between 600C (1350 F) for methane (CH4) to 200C (472F) for dodecane (C12H26)' - so possibly you may need to compress methane (natural gas) to higher pressures than diesel to auto ignite.

 

This link gives a quick summary of what is needed to change a diesel engine in to a methane one. The fuel injector is replaced with a spark plug. http://www.afsglobal.com/faq/diesel-to-natural-gas-conversion.html

 

I would think though if you are going to spend many 100s or 1000s of pounds on a conversion of an approx 10 year old car, you would be better off just buying another one. You would also need to consider where you could fill up with CNG and plan any trips around this since I would think the range on a tank of CNG will be a lot less than a tank of diesel, unless you could compress it enough or refrigerate it to condense it to liquid. Insurance might also be difficult to get.