Investigation of Options for Harnessing Energy Losses at Pressure-Reducing Stations of High-Pressure Natural Gas Pipelines

In this study, the possibility of installing turboexpanders instead of throttle valves was investigated and analyzed using Aspen HYSYS and Aspen Capital Estimator version 12.1. The optimization and energy saving cases were studied for maximum power or electrical energy generation as well as liquefied natural gas (LNG) production. Three case studies with various refrigeration cycles were evaluated according to economic considerations. It was found that the cases of power generation and LNG production were the best cases for energy recovery in gas pressure-reduction stations. The capital cost and rate of return (ROR) of this process were $232.2 million and 75%, respectively. The employed technique and developed process can be used for the optimization of energy in gas pressure-reduction stations.