Evaluation of Waste Heat Recovery in Petrochemical Refining Processes at Omega Chemicals

Thesis Abstract

In the context of increasingly stringent environmental regulations and rising energy costs, the petrochemical industry faces critical challenges in optimizing energy efficiency whilst minimizing environmental impact. Waste heat generated in refining processes represents a notable unexploited energy resource, contributing to operational costs and greenhouse gas emissions. This study aims to comprehensively evaluate the effectiveness of waste heat recovery (WHR) systems within Omega Chemicals' refining operations to enhance sustainability and economic performance. The specific objectives include quantifying heat energy losses across key refining units, assessing the technical feasibility of implementing heat recovery technologies, evaluating the potential energy savings and emission reductions, and developing an optimized model for WHR system integration tailored to Omega Chemicals’ process configuration. The research adopts a mixed-methods design, incorporating quantitative energy audit procedures complemented by qualitative assessments of operational constraints and stakeholder perspectives. The study's population comprises the entire refinery process units at Omega Chemicals, with a stratified random sample of 50 process sections selected based on heat emission profiles, process complexity, and operational variability. Data collection involves on-site measurements of temperature, flow rates, and energy consumption using portable infrared thermometers and flow meters over a continuous three-month period, supplemented by semi-structured interviews with key process engineers and energy managers. To ensure data validity and reliability, measurement instruments are calibrated quarterly, and triangulation techniques are employed to cross-verify quantitative and qualitative data. Analytical methods include the application of regression analysis to model relationships between process variables and heat losses; thermodynamic analyses grounded in the second law of thermodynamics to identify recoverable heat streams; and cost-benefit analysis to evaluate economic viability. Additionally, multi-criteria decision-making techniques, such as the Analytic Hierarchy Process (AHP), are utilized to prioritize heat recovery options. A conceptual framework grounded in the Second Law of Thermodynamics and the Theory of Constraints guides the analysis, aiding in identifying bottlenecks and maximum achievable efficiencies within existing processes. Expected findings indicate that approximately 25-30% of process heat energy is recoverable through dedicated heat exchangers, with potential reductions in fuel consumption by up to 15% and greenhouse gas emissions by 20%, contingent upon the deployment of suitable heat exchangers and organic Rankine cycle (ORC) systems. The study anticipates identifying the most promising heat streams for recovery, based on temperature profiles, flow rates, and economic considerations, thereby underpinning targeted system design recommendations. These findings are expected to contribute new insights into the practical integration of WHR systems in complex refining settings, particularly within the context of petrochemical plants similar to Omega Chemicals. This research offers a significant contribution to the body of knowledge by providing a detailed, process-specific evaluation of heat recovery potentials, integrating thermodynamic principles with economic analysis tailored to the operational realities of petrochemical refining. It advances understanding of how to leverage existing waste heat streams to achieve energy savings, cost reductions, and emissions mitigation in the refining sector. The main conclusion underscores the feasibility and substantial benefits of implementing tailored heat recovery systems in Omega Chemicals, emphasizing strategic technological upgrades and operational adjustments. The study recommends a phased implementation plan entailing detailed engineering design, pilot testing of selected WHR systems, and staff training to optimize system performance. It advocates for policy frameworks that incentivize waste heat utilization and underscores the importance of continuous monitoring to refine recovery efficiencies. Future research should explore long-term operational performance of installed systems, integration with renewable energy sources, and broader applicability across different petrochemical plants to substantiate and extend these findings.