Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Thermodynamic Analysis of a Polygeneration Plant Based on LNG-regasification for CO2 Capture and Air Liquid Storage
Submission Author:
José Vicente Dangelo , SP
Co-Authors:
Pedro Otávio de Carvalho Ramos, José Vicente Dangelo
Presenter: José Vicente Dangelo
doi://10.26678/ABCM.COBEM2023.COB2023-2215
Abstract
The long-distance transport of natural gas is made in the liquid form due to its much lower volume with respect to its gas phase. In this cryogenic liquid form, LNG (liquefied natural gas) presents not only the advantage of being easier to transport by ships, but also a great potential to work as a cold source in a regasification plant. This regasification process consists basically of heating LNG from its storage temperature up to ambient temperature using a heat source and this process involves a large amount of thermal energy (approximately 240 kWh/t-LNG). This huge thermal potential may be used in many different ways considering plants with different configurations designed for: power production, air liquefaction, cryogenic CO2 capture, refrigeration, hydrogen production and so fourth. This work has performed a thermodynamic analysis considering both energetic and exergetic approaches of a polygeneration plant combining both air liquefaction for liquid air storage as a cold source and CO2 capture from a flue gas stream produced in an Allam cycle. The reduction of CO2 emissions is increasingly urgent given the concern about global warming, while the technology of energy storage in liquid air presents itself as an excellent source of energy, which can be released according to the demand, having a high efficiency when the process is integrated with LNG regasification. In order to evaluate the thermodynamic performance of the system, the following parameters were calculated: net power output of the global system; round-trip efficiency of the energy storage subsystem; net electrical power of the LNG oxy-combustion subsystem; exergy efficiency of the energy storage subsystem and exergy efficiency of the LNG oxy-combustion subsystem. Aspen HYSYS v.10 software was used to simulate the polygeneration plant and perform a parametric analysis investigating the influence of some key variables, such as pressure, temperature and mass flow over both energetic and exergetic efficiencies of the polygeneration plant. The integrated system proposed in this work combining both applications (liquid air storage and CO2 capture) in an LNG regasification plant has shown a greater efficiency then the individual processes, presenting a net electrical efficiency of 74.3% for the Allam cycle, a global exergetic efficiency of 71.3% for the air liquid storage system and a global exergetic efficiency for the Allam cycle of 53.4%.
Keywords
liquefied natural gas, Computational simulation, CO2 capture, Air liquid storage, thermodynamic analysis, polygeneration plant
