Yes, you^re right, syn gas also can be produced from waste. And, some of recent study show that this syn gas also could be produced using Bacterial synthesis gas (syngas) fermentation.
Hopefully as soon as possible, if this process could help people there. But, of course after the complete preliminary study is being done, and any other processes to build a plant also done.
Thanks for your question.
The syngas produced, consists primarily of carbon monoxide and
hydrogen. In the other hand, LNG or CNG is still in the form of hydrocarbon.