SOFC-MGT hybrid power plants fuelled by methane and methanol

In this paper the use of methane and methanol in SOFC-MGT hybrid power plants has been compared. As a matter of fact, SOFC-MGT hybrid plants are a very attractive near term option, as they can allow to achieve efficiencies of over 60-65%, even for small power outputs (200-400 kW). The SOFC systems currently developed are fuelled with natural gas, which is reformed inside the same stack at about 800-900 °C. However, the use of alternative fuels with low reforming temperature (for example, methanol reforms at about 250-300 °C), can lead to enhanced hybrid plant performance. In particular, this paper reports a comparative performance analysis of internally reformed SOFC-MGT power plants fuelled by methane and methanol. Moreover, in the case of methanol use, both internal and external reforming have been compared. The performance analysis has been carried out by considering different values for the most important operating parameters of the fuel cell. The comparative analysis has demonstrated that simply replacing methane with methanol in SOFC-MGT power plants slightly reduces the efficiency. However, the use of methanol in SOFC-MGT power plants with external reforming enhances efficiency significantly (by about 4-5 percentage points). The study shows that the use of methanol with external fuel reforming raises stack efficiency thanks to the improved heat management and to the higher hydrogen partial pressur