A possible refinery process with higher output of gas oil and more hydrogen
consumption than in conventional refinery processes was proposed. The CO,
emissions form the proposed processes with (case B) and without (base case,
A) outer source of hydrogen were evaluated. The possibility of combining t
he refinement and transportation of petroleum with hydrogen produced from r
enewable energy resources such as hydropower and solar cells (photovoltaic,
PV) was discussed by life cycle assessment (LCA), where hydrogen is suppli
ed to the refinery process installed overseas and the lighten and desulfuri
zed products are transported to Japan (case Q. The result was compared with
the case when liquefied hydrogen is transported to Japan and supplied to a
refinery installed in Japan (case B).
CO2 emissions from the proposed refinery processes with (case B) and withou
t (case A) outer source of hydrogen were calculated with 159 and 141 kg-CO2
/kl-produced oil, respectively. In any case with outer hydrogen supply (cas
es B and Q, the total CO2 emission was less than that for case A, when the
hydrogen is produced from hydroelectricity. On the other hand, when the hyd
rogen is produced from PV, total CO2 emissions for cases B and C were large
r than that for case A. Finally, the characteristics of case C was identifi
ed and the conditions for the product import case (case Q can show the best
one with the minimum CO2 emission were discussed. (C) 2001 Elsevier Scienc
e Ltd. All rights reserved.