A FULLY OPTIMIZED CASCADED LNG COLD ENERGY UTILIZATION SYSTEM UN SYSTEME PLEINEMENT OPTIMISE D'UTILISATION EN CASCADE DE L'ENERGIEDU FROID DU GNL

摘要

Osaka Gas Co., Ltd. has initiated a project to develop the world's first energy optimizing system based on the LNG cryogenic energy cascade process. This project is being conducted at an industrial complex, which consists of an oil refinery and a petrochemical plant, located adjacent to Osaka Gas's LNG receiving terminal, and it aims to improve environmental protection and achieve energy conservation. The LNG cryogenic energy cascade process utilizes LNG's cryogenic energy effectively by exchanging cold energy sequentially in multiple temperature stages ranging from low temperatures to normal temperature. There have previously been very few LNG cryogenic energy utilization systems capable of supplying cold energy for three or more applications within a single industrial complex. The project system is designed to provide LNG cryogenic energy for (1) separation of light hydrocarbons produced as a byproduct in the oil refining process (-100.C level; an energy source to separate olefin used as a raw material of polymer products at the petrochemical plant), (2) liquefaction of carbon dioxide produced as a byproduct in the manufacture of hydrogen (-55 .C level), (3) low-temperature storage of normaltemperature butane (-8.C level; making it possible to balance seasonal demand-andsupply fluctuations), and (4) chilling of water used to cool the intake air for gas turbines (10.C level; also effectively utilizing electricity and steam resulting from improved gas turbine efficiency). The technology developed in this project aims to boost the competitiveness of the industrial complex as a whole.