(36c) Design and Analysis of Cryogenic Air Separation Processes Integrated with Liquefied Natural Gas Gasification

Liquefied natural gas (LNG) is a major source of natural gas supply for long-distance
transport. After the long travel, the LNG is vaporized in a receiving terminal in order to supply natural gas at desired conditions through domestic pipeline networks. Due to the extremely low temperature LNG regasification plant can provide, ASU unit can benefit significantly from the cold exergy.

However, in the heat integration, highly flammable hydrocarbons in the presence of oxygen pose a risk. Advanced equipment fabrication techniques minimize the risk, however there is always a possibility of leak in the equipment and it is desirable to have inherently safer equipment.

The main object of the project is to analyze the conventional integrated Heylandt system using inherent safety index. Based on the safety analysis, stage to identify the equipment which needs improved design. Two designs are proposed which minimize the hazards by introducing an intermediate fluid for the heat transfer. Mixed Refrigerant (MR) is used as the heat transfer fluid in Design 1. Propane is used as the heat transfer fluid in Design 2. A comparative safety analysis of the proposed designs is done, indicating that the new designs are safer as compared to the conventional design.