Or chop the dead trees in abandoned Jebel Ali Village (that if you're allowed to enter the premise). Seriously, I passed this place and I saw many dead trees lying down which can be good for BBQ firewood
I usually order it from 800 FIREWOOD (80034739663) and they deliver to my villa in Dubai . Oak and birch fire wood imported from Europe. Oak is of same quality as charcoal, if not better. 40-50 aed for a 15kg bag. Very happy with service and its free delivery !