Exergy, Economic, and Life-Cycle Assessment of ORC System for Waste Heat Recovery in a Natural Gas Internal Combustion Engine

Abstract

In this article, an organic Rankine cycle (ORC) was integrated into a 2-MW natural gas engine to evaluate the possibility of generating electricity by recovering the engine’s exhaust heat. The operational and design variables with the greatest influence on the energy, economic, and environmental performance of the system were analyzed. Likewise, the components with greater exergy destruction were identified through the variety of different operating parameters. From the parametric results, it was found that the evaporation pressure has the greatest influence on the destruction of exergy. The highest fraction of exergy was obtained for the Shell and tube heat exchanger (ITC1) with 38% of the total exergy destruction of the system. It was also determined that the high value of the heat transfer area increases its acquisition costs and the levelized cost of energy (LCOE) of the thermal system. Therefore, these systems must have a turbine technology with an efficiency not exceeding 90% because, from this value, the LCOE of the system surpasses the LCOE of a gas turbine. Lastly, a life cycle analysis (LCA) was developed on the system operating under the selected organic working fluids. It was found that the component with the greatest environmental impact was the turbine, which reached a maximum value of 3013.65 Pts when the material was aluminum. Acetone was used as the organic working fluid.

Economic and Exergo-Advance Analysis of a Waste Heat Recovery System Based on Regenerative Organic Rankine Cycle under Organic Fluids with Low Global Warming Potential

“…The ORC uses an organic working fluid such as hydrocarbons and refrigerants, which have better performance than water, allowing to reduce the heat source temperature [16]. However, due to the high contamination rates, environmental protection has been chosen as the main criterion, and numerous investigations report the negative impact on the atmosphere of the chlorofluorocarbon (CFC), which makes the selection of the working fluid for the ORC a complex task [17]. Therefore, different methods have been established in ICE to achieve greater energy efficiency with less environmental impact such as waste to energy technologies based on the ORC cycle operating with environmentally friendly fluids [18].…”

Performance assessment and economic perspectives of integrated PEM fuel cell and PEM electrolyzer for electric power generation

“…Considering that efficiency improvements in hydrogen-power devices have been relatively slow in the last decade, the outcomes reported in this section are promising. For instance, in other applications, extensive proposals have been implemented to improve the overall efficiency in combustion engines by 1–4% [ 60 , 61 ]. In practice, the overall efficiency can be optimized by analyzing different membrane parameters such as construction materials, thickness, porosity, permeability, among others, which can be integrated into a multi-objective optimization methodology [ 62 ].…”

Life Cycle Sustainability Analysis of Resource Recovery from Waste Management Systems in a Circular Economy Perspective Key Findings from This Special Issue

“…In all contributions, the authors explored several relevant aspects connected with this SI's research theme, so enriching the current state-of-the-art in the field of sustainable waste recovery systems for production of value-added commodities under a CE perspective. Some of the sectors where CE can be beneficial for enhancement of their sustainability performance were explored in this SI's paper collection: post-use plastics end-of-life [11,30]; waste heat recovery [31]; waste management [32,33]; electrics and electronics [34]; and olive oil [35].…”