Theoretical study and case analysis for a pre-dried pyrolysis coupled lignite-fired power system

Lignite, a kind of low rank coal, has the characteristics of high moisture, high volatile, high ash and low heat value. The low-temperature pyrolysis technology is potential to improve the utilization efficiency of lignite. Therefore, a lignite-based energy system integrated with pre-drying and low-temperature pyrolysis was proposed in this paper. To assess the influence of pre-drying process, theoretical models were developed based on thermodynamics, and a case analysis was then performed to get the quantitative effect of pre-drying on efficiency of energy utilization. Results show that pre-drying on PPPS theoretical model can significantly improve the utilization of lignite by 1.46%.Keywords: Lignite; Pre-drying; Low-temperature pyrolysis; Energy efficiency; Case analysis.