http://prod.sandia.gov/techlib/access-control.cgi/2007/078012.pdf
Herein, a United States Department of Energy scientist urges us to "adopt revolutionary thinking about energy and fuels", asserting that, if we do, then, "it may be possible to the meet the future fuel challenges while maintaining our traditional hydrocarbon fuel framework".
Further, he says that we "must recognize that hydrocarbon fuels are energy carriers, not energy sources. The energy stored in a hydrocarbon is released for utilization by oxidation to form CO2 and H2O. Furthermore, just as H2O can be 'reenergized' by applying energy to split water back into H2 and O2, hydrocarbons can be recycled by capturing CO2 (and H2O) and 're-energizing' them back into hydrocarbon form".
And, he goes on to emphasize, that "there is a hydrocarbon analogy to the envisioned hydrogen economy that realizes the benefits of hydrogen while capitalizing on much of the existing liquid fuel infrastructure".