Thermodynamic characteristics of the processing of gaseous hydrocarbons in the SOFC reforming system

This paper presents calculations of the thermodynamic functions (enthalpy, entropy, Gibbs energy) for hydrocarbon fuel reactions occurring in the reformer of a solid oxide fuel cell (SOFC) power plant. More than forty possible chemical interactions between hydrogen, carbon, oxygen, hydrocarbons, carbon dioxide, water and carbon monoxide were analyzed. During the reforming of complex hydrocarbons, unsaturated hydrocarbons are converted into saturated ones, then split to lower hydrocarbons (up to methane) due to interaction with hydrogen. During the reforming process, soot formation reactions from carbon monoxide and methane can occur. In the temperature range of 600 – 1000°С, reactions of steam interaction with higher hydrocarbons and methane are possible. The efficiency and consumption of hydrocarbons for the SOFC with a reformer on various types of fuel were also calculated. Complex hydrocarbon fuels may require the use of external and internal reforming for more complete processing in the SOFC. Reforming of natural gas and gaseous wastes from petrochemical industries shows sufficiently high efficiency and requires low fuel consumption.