Life cycle cost and environmental assessment of CO2 utilization in the beverage industry: A natural gas-fired power plant equipped with post-combustion CO2 capture

Abstract

Besat is a natural gas-fired steam-turbine power plant in Tehran, Iran’s only power station equipped with a monoethanolamine-based post-combustion CO2 capture unit (PCCU). The PCCU operates at a low recovery rate of 4.7% and produces 58 t-CO2/day. Captured CO2 is encapsulated and sold to beverage companies for carbonated soft drink production. Before developing this CO2 capture and utilization (CCU) route, a beverage company like ZamZam produced CO2 on-site, capturing CO2 from flue gas of diesel-fired boilers using a 95%-efficient absorption-refrigeration unit. This paper conducts an attributional, comparative life-cycle assessment/costing of applying the CCU technology to supply the beverage industry with CO2. ReCiPe, cumulative energy demand, and AWARE impact assessment methods are adopted to assess changes in the life-cycle economic, energy, and environmental impacts of electricity, liquid CO2, and carbonated water supply chains with the CCU route. As per findings, the CCU route significantly improves the sustainability profile of liquid CO2 supply for carbonated water production. Compared to on-site production, the CCU route reduces the average economic, energy, and environmental impacts of liquid CO2 supply by 55, 44, and 62%, respectively. However, the figures for carbonated-water production are reduced by only 10.1, 0.85, and 0.77%, respectively, since associated impacts primarily result from citric acid and polyethylene terephthalate value chains rather than liquid CO2. The CCU route, in comparison, increases most environmental burdens of electricity generation. With an efficiency of 4.7%, the PCCU reduces the global warming potential of electricity generation by 6.22% while increasing average toxicity- and eutrophication-related impacts by 55 and 30%, respectively, and production costs by 8%.