Novel Gas Turbine Cycle With Integration of CO2 Recovery and LNG Cryogenic Exergy Utilization

Abstract

In this paper we propose a new gas turbine cycle, which employs a semi-closed recuperative gas turbine with LNG utilization. Nitrogen is selected as working fluid with air induced at the inlet of compressor. The inlet temperature of the compressor is kept pretty low with LNG cooling, and turbine inlet temperature can be very high because of internal combustion, and higher average temperature of heat absorption of the cycle is achieved due to recuperation. As a result, the cycle efficiency can reach as high as 70% (TIT=1250°C). Furthermore, along the process of LNG vaporization, turbine exhaust is cooled down; CO2 in the mixture is solidified and separated without extra power consumption. Two different natural gas sendout pressures (7.0 and 3.0 MPa) are considered. Their performances are simulated and a comprehensive analysis is carried out. The performance of the new cycle, CO2 recovery, and heat transfer in LNG vaporizer are discussed in detail. The new cycle proposed here is based on the integration of carbon dioxide recovery and LNG cryogenic exergy utilization, and it will contribute to both improvement on power generation efficiency and reduction of greenhouse gas emission.