Check out this comparison sheet i found could be helpful:
[h=2]Comparison chart</> EMBED THIS CHART[/h][TABLE="class: zebra-striped, width: 1"]
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[TH="class: acol, align: center"]Improve this chart[/TH]
[TH="class: vcol, align: left"]CNG[/TH]
[TH="class: vcol, align: left"]LPG[/TH]
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[TD="class: acol, bgcolor: #F9F9F9, align: left"]Constituents:[/TD]
[TD="class: vcol, bgcolor: #F9F9F9, align: left"]Methane[/TD]
[TD="class: vcol, bgcolor: #F9F9F9, align: left"]Propane and Butane[/TD]
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[TD="class: acol, align: left"]Source:[/TD]
[TD="class: vcol, align: left"]Obtained from natural gas-and-condensate wells, oil wells, coal bed methane wells[/TD]
[TD="class: vcol, align: left"]Automatically generated from gas fields when natural gas is extracted from the reservoir. By-product of cracking process during crude-oil refining[/TD]
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[TD="class: acol, bgcolor: #F9F9F9, align: left"]Uses:[/TD]
[TD="class: vcol, bgcolor: #F9F9F9, align: left"]Substitute for gasoline in automobiles[/TD]
[TD="class: vcol, bgcolor: #F9F9F9, align: left"]Heating and cooking in homes, refrigeration, industrial, agricultural, catering and automobile fuel[/TD]
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[TD="class: acol, align: left"]Environmental effects:[/TD]
[TD="class: vcol, align: left"]Releases lesser greenhouse gas[/TD]
[TD="class: vcol, align: left"]Releases CO2 which is a greenhouse gas but is cleaner when compared to gasoline[/TD]
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[TD="class: acol, bgcolor: #F9F9F9, align: left"]Properties:[/TD]
[TD="class: vcol, bgcolor: #F9F9F9, align: left"]It is lighter than air and hence disperses quickly in the event of spillage.[/TD]
[TD="class: vcol, bgcolor: #F9F9F9, align: left"]Highly inflammable. It is heavier than air and on leakage will settle to ground and accumulate in low lying areas[/TD]
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[TD="class: acol, align: left"]Safety:[/TD]
[TD="class: vcol, align: left"]Easily disperses, hence risk of ignition is minimized[/TD]
[TD="class: vcol, align: left"]Since it is difficult to disperse risk of fire is more
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