USC engineers say solid particles may burn more safely and efficiently in space than gaseous fuels

An interesting research done by USC engineers described here
http://www.physorg.com/news404.html

Researchers from the USC Viterbi School of Engineering say solid fuel
particles may be safer for hazardous work environments on earth and
burn more efficiently in the microgravity of space than gaseous fuels,
which are more combustible and difficult to transport.