It is not recommended but, yes you can. But beware of the CO2 (and CO if your burner is really badly adjusted) and leaking gas is a REAL DANGER! it is heavier than air so it can flow down and collect somewhere, then ignite when you least expect it!
Yes, it is possible to barbecue indoors with the proper indoor grill equipment. An outdoor grill should not be used indoors, even in a garage because it can produce carbon monoxide that can harm people even in the smallest amounts.
A Barbecue takes either butane or propane.
Butane
Propane
For those who dream of enjoying delicious barbecue meals without battling the elements, pesky insects, or curious wildlife, an indoor barbecue grill could make those dreams reality. Consumers can choose from a variety of grill styles from traditional free-standing models to compact countertop options. Indoor grills usually function on either electrical or gas power versus charcoal. Indoor grilling provides the traditional barbecue taste and appearance and enhances these experiences by bringing the great outdoors indoors.
conduction and convection..
chemical energy
There are many place that we can get gas barbecue grills. Just go to this website (http://www.barbecuegrillsandmore.com/) to check more information about gas BBQ grill.
Butane
Carbon monoxide.
Propane which is C3H8
well depending on what barbecue you have... if you light it with a lighting torch it is full of gas... if you light it with a match it contains nicotine! so gas barbecues contain nicotine ! =)