Desulfurization sorbents for green and clean coal utilization and downstream toxics reduction: A review and perspectives

Abstract

The efficient utilization and clean conversion of coal have become one of the urgent tasks in the current situation of energy utilization in China. Aiming to promote the energy efficiency and sustainability, coal to gas is playing a more and more important role in the national environmental and climate change. However, the presence of harmful H2S in the syngas not only corrodes the equipment and poisons the catalyst, but also pollutes the environment seriously after it is discharged to the atmosphere, so it must be removed. The preparation of desulfurization materials with high sulfur capacity, high efficiency, good regenerability and stable performance has always been the research hotspot in this field. Based on previous works, first, newly developing desulfurization sorbents prepared with excellent performance and novel methods and materials emerging in recent years have been reviewed and highlighted in the present paper. Second, the preparation method, performance indicators and merits of various single metal oxides (Fe2O3, ZnO, Mn2O3, CuO, CaO) and composite metal oxides (Fe–Zn–O, Mo–Fe–Mn–O, Mn–Ca, etc.) have been discussed and compared. More important, the further perspectives, such as techno-economic analysis and life cycle assessment of the relating field were also proposed based on the existing understandings, which will make sense for the promotion of energy efficiency and sustainability, pollution reduction and resource recovery. The in depth development status and the state of the art of clean coal utilization sorbents for hydrogen sulfide clean-up reviewed in the present paper aiming to offer theoretical basis and experience to the accurate design and performance improvement of cost-effective desulfurization sorbent.