Integrated solar organic Rankine Cycle and Direct Air Capture System for sustainable automotive manufacturing plants

• Integrated Solar Organic Rankine Cycle and Direct Air Capture System reduces CO 2 emissions in automotive paint shops. • The system uses solar energy and wasted heat to generate electricity and remove CO 2 from the atmosphere. • Scalable solution for energy-efficient, low-carbon industrial applications. • Combination of Solar Organic Rankine Cycle and wasted heat additional energy source with and Direct Air Capture in one energy system. • Demonstration of a sustainable design approach for decarbonizing industrial energy use. The automotive industry faces increasing pressure to reduce its carbon footprint and improve energy efficiency, yet energy-intensive paint shops remain underexplored targets for innovation. This work proposes a novel integrated energy system combining a Solar Organic Rankine Cycle (SORC) with Direct Air Capture (DAC) technology within an automotive paint shop, leveraging solar energy and waste heat recovery to generate electricity and heat while simultaneously removing atmospheric carbon dioxide. Unlike prior studies that examine these technologies in isolation, this research demonstrates for the first time how low-grade heat recovered from paint shop operations and solar thermal input can jointly power electricity generation and atmospheric CO 2 capture in a single plant-level configuration. The system is designed to reduce reliance on traditional grid energy and fossil fuels, promoting sustainability. A 4E analysis (energy, exergy, economic, and environmental) assesses the system’s viability, incorporating DAC system impacts and refining prior research. Simulations demonstrate the integrated system can achieve a CO 2 adsorption rate of 261 kg/h. The integrated system can generate 611 KW on average while supplying a power consumption for the DAC unit of 105 KW with an overall energy efficiency of 26.82 %. Waste heat recovery from the Regenerative Thermal Oxidizer provides a stable baseline of approximately 2000 kW, insuring sufficient and continuous thermal input for DAC regeneration. An economic analysis estimates a simple payback period of 8 years and 5 months, with a benefit-to-cost ratio of 1.29, assuming a carbon credit price of $30/ton CO 2 . The novelty of this research lies in establishing a carbon-negative manufacturing model tailored for automotive paint shops. The findings benefit the scientific community by providing validated thermodynamic model, revealing exergy bottlenecks in turbines and heat exchangers, and illustrating how renewable integration with DAC can be scaled to other energy-intensive industries. The proposed system presents a replicable pathway for achieving sustainability targets across industrial sectors, advancing the broader agenda of decarbonized manufacturing