Chapter 14 - Application of syngas in fuel cell

Abstract

The world is faced with increasing energy demand because of growing in world population and rapid progress in industry. Due to environmental issues and unsustainability, fossil fuels need to be replaced with renewable sources of energy. Among green energy sources, fuel cell technology is the most promising candidate because of its high efficiency and low greenhouse gases emission. Hydrogen is the main fuel for fuel cells; however, based on the type of fuel cells, a wide range of fuels such as methanol, natural gas, syngas, and other hydrocarbons can be used. While low-temperature fuel cells are usually fueled by pure hydrogen, high-temperature ones can be fed by other fuels. The main source of hydrogen production is the reforming of fossil fuels in which hydrocarbons are converted to syngas as hydrogen-rich gas, out of the fuel cell or internally in the fuel cell. The CO content in syngas degrades the catalyst in low-temperature fuel cells. To prevent CO poisoning, it needs CO cleaning process by using water-gas shift reaction followed by further purification processes such as preferential oxidation, selective CO methanation, pressure swing adsorption, and membrane reaction. Unlike the low-temperature fuel cells, high temperature ones can be directly fueled by syngas without any need for hydrogen purification processes which results in reducing the costs. However, presence of carbon components in the syngas causes carbon deposition on the catalyst surface which leads to reduction in fuel cell performance. To tackle this issue, an efficient anode material with high electrocatalytic activity and electrochemical stability should be used.