The energy generates from the combustion of fossil fuels has
simultaneously created several environmental concerns which can
threaten the sustainability of our ecosystem. One of the primary
concerns will be the emissions of greenhouse gases and other types
of air pollutants such as hydrocarbons, nitrogen oxide and volatile
organic compounds [3]. The major contributor of the greenhouse
gas is carbon dioxide emissions and the trend has been increasing
every year since 1982 as shown in Fig. 1 [1]. It is shown that the
global carbon dioxide emission has risen significantly from
19,380 million tons in 1980 to 31,577 million tons in 2008. It is
predicted that carbon dioxide emission will increase to 40 billion
tons in year 2030 if no tremendous effort are thrown in to mitigate
it [4]. It is inevitable that CO2 emission will continue to climb as
long as fossil fuels remain as the main contributor in the energy
mix. Huge accumulation of those gases in our atmosphere will
eventually lead to drastic climate changes, acid rain and smog.