a b s t r a c tThis study is for the technoeconomic analysis of an integral facility consisting of wind energy-based electrolytic hydrogen production, bioethanol-based carbon dioxide capture and compression, and direct methanol synthesis. ASPEN Plus was used to simulate the facility producing 97.01 mt (metric tons) methanol/day using 138.37 mt CO 2 /day and 18.56 mt H 2 /day. A discounted cash flow diagram for the integral facility is used for the economic analysis at various hydrogen production costs and methanol selling prices. The feasibility analysis is based on a multi-criteria decision matrix consisting of economic and sustainability indicators comparing renewable and non-renewable methanol productions. The overall energy efficiency for the renewable methanol is around 58%. Fixation of carbon reduces the CO 2 equivalent emission by around À1.05 CO 2 e/kg methanol. The electrolytic hydrogen production cost is the largest contributor to the economics of the integral facility. The feasibility analysis based on multi-criteria shows that renewable methanol production may be feasible.

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This study presents the assessment of energy and environmental sustainability metrics for a crude oil refinery consisting of three distillation columns. The assessments of the current operation and the retrofits for possible improvements are suggested by the thermodynamic analysis and energy analyzer. The main objective is to explore the scope of reducing the thermal energy consumption and CO 2 emissions for a more sustainable refinery operation. Thermodynamic analysis is carried out by using the thermal analysis capability of 'column targeting tool' to address the 'energy intensity metrics' and the 'energy analyzer' to design and improve the performance of the heat exchanger network system for process heat integration. Environmental pollution impact metrics are estimated from the 'carbon tracking' options with a selected CO 2 emission data source of US-EPA-Rule-E9-5711 and using crude oil as a primary fuel source for the hot utilities. The results indicate that column targeting tool, energy analyzer, and carbon tracking can estimate the energy and environmental sustainability metrics of an existing design and determine the scope of considerable improvements for reducing the costs of thermal energy required and emissions of carbon dioxide in a crude oil refinery operation.

This study presents metrics of energy intensity and environmental impact of the back-end separation of ethylene plant consisting three interacting distillation columns by thermodynamic analysis. The objective is to explore the scope of reducing the energy for utilities and CO 2 emissions. Thermodynamic analysis is carried out using the column targeting tool (CTT) to address the sustainability metrics of 'Energy Intensity.' CTT is based on the 'Practical Near-Minimum Thermodynamic Condition' representing a close to practical reversible column operation. Environmental impact metrics are estimated from the carbon tracking options. The carbon tracking are estimated by the CO 2 emission data source of US-EPA-Rule-E9-5711 using natural gas as the primary fuel. The results show that the total reductions in exergy loss and the total hot and cold utility are around 44 and 10 %, respectively; the total reductions in carbon dioxide are around 14 %. These improvements lead to considerable reductions in the operating costs. Thermodynamic analysis helps estimating and improving the energy and environmental sustainability metrics and hence can lead to a more sustainable separation by distillation columns.