Assessment of renewable energy use in natural gas liquid processing by improved process integration with heat pumps

Abstract

Decarbonisation of the industrial sector is a crucial objective in new technological developments responding to global challenges. Energy-intensive industry is one of the biggest pollutants and it is mostly supplied by fossil fuels. This paper presents the methodology for the assessment of electrified options for the process industry based on systematic process integration techniques. The graphical representation was used to analyse the physical processes of the industrial unit. The improved heat recovery and electrified utility targeting were performed by using the Grand Composite Curve and analysing the main process streams and distillation column system. The electrified thermal utility system uses electric steam boilers, water coolers, heat pumps, etc. The case study analyses the natural gas liquid processing and assesses electrified thermal utility. The initial process was simulated in a UniSim environment and obtained thermophysical properties of process streams were used for the analysis. The integrated electrified scenario presumes using a low-pressure steam boiler, water coolers, propylene coolers and 3 heat pumps. Heat recovery was increased by 4 times compared to the initial process and 100% electrified thermal utilities were used. The energy cost was reduced by 41% and the carbon dioxide emissions are reduced by 512,778 tons per capita compared to existing process when using renewable energy for electrified utility. The approach can be used for further development of industry decarbonisation options and electricity targeting in process industries.

Keywords

• Process integration
• Energy saving
• Industry electrification
• Renewable energy
• Heat pumps
• Natural gas liquid