Multifactor performance evaluation of an energy-saving methanol production process coupled refrigeration-power system driven by waste heat.

[Display omitted] • A new waste heat recovery process was proposed in this work. • 6E analysis was conducted for the proposed process. • The proposed process can purify methanol and recover waste heat efficiently. • 34.87% energy-saving and 34.15% TAC- saving can be realized from component to system. The post-COVID-19 resurgence in industry and employment necessitates increased energy consumption, particularly in methanol production—a sector known for being energy-intensive. This research presents a novel methanol purification method that integrates energy conservation with thermal management. The refined process yielded a methanol recovery rate of 99.82% and product purity of 99.99 wt%. Energy analysis indicates a 34.87% reduction in steam consumption compared to the basic process, underscoring its energy-saving merits. Exergy analysis reveals a 1.88% decrease in exergy destruction of the proposed process relative to the basic process. Economic analysis demonstrates that the proposed method cuts operating costs by 46.66% and total annual costs by 34.15% than that of the basic process. Moreover, environmental analysis shows a 30.30% reduction in both exhaust gas emissions and associated costs. Exergoeconomic and exergoenvironmental analysis also prove the remarkable effect of the proposed process, T105 has the highest cost of exergy destruction at 414.52 $/h, which is attributed to the higher operating load of T105 compared to other towers, resulting in more significant exergy destruction. Consequently, this refined process not only ensures optimal methanol purification but also significantly energy reduction, positioning it as a benchmark in carbon reduction initiatives. [ABSTRACT FROM AUTHOR]