In this two-part paper the production of synthetic natural gas (SNG) through integrated plants
featuring high temperature electrolysis and subsequent syngas methanation is analyzed.
Part one focuses on plant configuration and performance evaluation. Part two focuses on
cost for an economic assessment. Two different ways to produce SNG have been analyzed:
the first option features a plant that integrates steam electrolysis with methanation (Sabatier
reaction); the second one considers co-electrolysis of water and carbon dioxide coupled …

This part II work is built on the energy performance results of part I and focuses on the cost of
producing synthetic natural gas and sensitivity scenarios around main economic variables.
Capital costs for each plant section have been evaluated taking into account operational
parameters such as pressure and temperature of the SOEC. The costing and financial
methodology is based on a discounted cash flow analysis that was used to calculate the
specific cost of synthetic natural gas (SNG) which ensures economic profitability of the …