A novel process for small-scale pipeline natural gas liquefaction

A novel process for small-scale pipeline natural gas liquefaction is designed and presented. The novel process can utilize the pressure exergy of the pipeline to liquefy a part of natural gas without any energy consumption. The thermodynamic analysis including mass, energy balance and exergy analysis are adopted in this paper. The liquefaction rate and exergy utilization rate are chosen as the objective functions. Several key parameters are optimized to approach the maximum liquefaction rate and exergy utilization rate. The optimization results showed that the maximum liquefaction rate is 12.61% and the maximum exergy utilization rate is 0.1961. What is more, the economic performances of the process are also discussed and compared by using the maximum liquefaction rate and exergy utilization rate as indexes. In conclusion, the novel process is suitable for pressure exergy utilization due to its simplicity, zero energy consumption and short payback period.