Study and Economic Evaluation on the Process of Calorific Value Adjustment in the LNG Receiving Terminal

摘要

In recent years, large quantities of LNG sources have occured in international trade, which have also presented themselves with vary compositions and contain more than 10 mol % light hydrocarbons components (such as ethane and propane).This paper takes a certain typical Chinese liquefied natural gas receiving terminal as an example. For the exchange and economic issues caused by high C2+ components in the feedstock of the above mentioned LNG terminal, an adjustion of the calorific value in products by adopting LH recovery, nitrogen gas injection and liquid nitrogen injection is advised. In order to evaluate profits in LNG receiving terminal, three kinds of processes have been simulated by using of the Aspen HYSYS to realize the consumption analysis. Further more, economic benefits of three schemes are analyzed based on energy measurements. It was shown that the after-tax net profit of the receiving terminal which adds liquid nitrogen to adjust calorific value is 6.17% higher than that which extracts C2+ components under the volume measurement system. Under the system of energy measurement, the after-tax net profit of three processes is respectively increased by 8.96%, 12.51% and 12.47% compared to the original measure modes. The results suggest that the proposed liquid nitrogen injection processes is the most effective one which injects at the exit of high-pressure efflux pump, and an economical way to adjust heat value, which has the highest net profit and the lowest consumption cost and capital cost in the current Chinese LNG industry chain and economic situation.