Crude oil distillation is one of the most energy-intensive processes in petroleum refining, consuming up to 20% of total refinery energy. Improving the energy efficiency of crude distillation units (CDUs) is essential for reducing costs, lowering emissions, and achieving sustainable refining. Current studies often examine energy savings, operational flexibility, or renewable energy integration separately. This review brings these aspects together, focusing on heat integration, advanced control systems, and renewable energy options such as solar-assisted preheating and green hydrogen. Advanced column designs, including dividing-wall and hybrid systems, can cut energy use by 15–30%, while AI-based optimization improves process stability and flexibility. Solar-assisted preheating can reduce fossil fuel demand by up to 20%, and green hydrogen offers strong potential for decarbonization. Our findings highlight that integrated strategies, including advanced simulation tools and machine learning, significantly improve CDU performance. We recommend exploring hybrid algorithms, renewable energy integration, and sustainable technologies to address these challenges and achieve long-term environmental and economic benefits.

Distillation is a critical separation process widely used in various industries, especially in petroleum refining, where efficient separation significantly influences product quality and energy consumption. This study evaluates the performance of a crude distillation unit located in Upper Egypt, with the aim of enhancing its energy and exergy efficiencies by addressing region-specific operational challenges and inefficiencies. A comprehensive thermodynamic and exergy analysis was conducted using Aspen HYSYS, based on the first and second laws of thermodynamics. The simulation model was validated against actual plant data, demonstrating strong agreement and confirming its reliability. The analysis focused on key process units, including the preflash unit, fired heater, heat exchanger network (HEN), pumps, coolers, and particularly the distillation tower, which showed the highest exergy destruction. The distillation tower alone accounted for 41.8% of total exergy destruction (44.5 GJ h⁻¹), primarily due to irreversibilities associated with phase separation. In contrast, the preflash unit exhibited high performance, with an exergy efficiency of 97.1% and minimal destruction (459 MJ h⁻¹). The fired heater and HEN also demonstrated strong efficiencies 92.7% and 91.6%, respectively, though both contributed to non-negligible thermal losses. Coolers, however, had the lowest exergy efficiency (55.2%), responsible for 33% of total exergy destruction. Parametric studies revealed that increasing overhead pressure improved overall exergy efficiency by 4.3%, while excessive pump-around flow rates led to higher irreversibilities and reduced efficiency. These findings offer valuable, localized insights for improving energy recovery and operational performance in refining processes, particularly in developing regions with limited operational data. The study supports efforts to enhance sustainability and implement energy-efficient control strategies in crude oil refining.

Crude oil distillation is a crucial separation process in the petroleum refining industry, where crude oil is fractionated into various components based on their boiling points. This energy-intensive industrial process significantly contributes to global energy consumption and greenhouse gas emissions. Given the magnitude and environmental implications of crude distillation operations, there is an urgent need to analyze energy usage patterns rigorously and identify opportunities for enhancing efficiency. This review explores the extensive efforts made by researchers to develop advanced models and techniques for the techno-economic evaluation of crude distillation systems. It begins by highlighting the considerable energy demands and emissions associated with conventional crude distillation units (CDUs). Emphasizing the necessity of comprehensive energy analysis, the paper discusses how optimization strategies can improve CDU operations and enable retrofits aimed at reducing both energy consumption and environmental impacts. Various modeling approaches are examined, including rigorous process simulations using tools like Aspen HYSYS and innovative exergy-based analyses, which provide deeper insights into the thermodynamic principles and operational factors influencing CDU performance. The review focuses on key areas such as distillation tower configurations, operating conditions, and heat exchanger network designs, all aimed at identifying energy-efficient modifications. Additionally, the paper discusses advancements in process intensification techniques, including Dividing Wall Columns, Hybrid Distillation, and reactive distillation. These methods not only enhance separation efficiency but also contribute to significant reductions in energy usage. The findings from numerous case studies are synthesized, demonstrating their effectiveness in improving overall efficiency.

Steam boilers are widely used in power generation and industrial processes. Improving their efficiency is crucial for enhancing sustainability and reducing operating costs. This study conducts a comprehensive bibliometric analysis to map the evolving research landscape on steam boiler efficiency improvement from 2014 to 2023. A literature search in the Scopus database retrieved 3574 publications. This study employs bibliometric analysis using Bibliometrix R packages and VOSViewer software to examine research trends, focusing on publication growth, key journals, influential authors, and emerging themes in steam boiler efficiency improvement. The results indicate a significant increase in annual research output, reflecting sustained global efforts in the field. China leads in both the volume and impact of contributions. Key research themes include materials development, innovative designs, heat recovery, and sustainable solutions. Notable publications emphasize eco-friendly approaches such as solar and organic thermoelectrics. Prolific authors from China, the United States, and Europe have shaped the discourse through influential collaborations. Emerging trends highlight a growing focus on renewable energy integration, advanced thermal management, and computational methodologies. This study consolidates knowledge on enhancing steam boiler efficiency through both quantitative and qualitative analyses, showcasing remarkable progress driven by dedicated international efforts. These insights can inform future strategies and inspire innovation in optimizing this critical energy conversion process.

In highly populated cities, the close spacing of buildings often results in interaction effects, including structure–soil–structure interaction (SSSI) and seismic pounding (SP), which occur because of the limited gaps left between adjacent structures. In most seismic design and structural analyses, the soil–structure interaction effects are frequently ignored, even though the foundation–soil system can significantly alter the structural behaviour and response demands. Moreover, the vibration characteristics and seismic performance of a building cannot be considered independent from those of neighbouring structures. This study aims to examine SSI, SP and their combined effects (SSSI) on the performance of adjacent buildings. Three-dimensional finite element models were developed using ETABS program of single and three adjacent multi-story buildings with identical floor levels, supported on shallow raft foundations over soft soil. These models were analyzed and compared with fixed-base models to evaluate the influence of SSI. Furthermore, the seismic responses of the adjacent buildings under both fixed-base and soft soil conditions were compared with those of single-building models to assess the effect of SP. The combined influence of SSI and pounding (SSSI) was investigated by comparing the adjacent building model with SSI to the corresponding single-building fixed-base model. Seismic demands are evaluated using nonlinear time history (TH) analyses with nine earthquake records. Variations in period of vibration, story lateral displacement, story drift ratio, story shear force, story moment, story acceleration and pounding force are 

Seismic pounding between adjacent buildings has been frequently observed during past earthquakes. This phenomenon can significantly increase seismic demands, often leading to severe global or local damage and even partial or total collapse. This study investigates the seismic response and both inter-story and story-story pounding behavior of adjacent RC buildings with different dynamic characteristics by ETABS software using nonlinear time-history analyses. Eleven recorded earthquake ground motions are employed to capture comprehensive excitation characteristics. The numerical model includes nonlinear flexural and shear plastic hinges and contact elements to simulate impact interaction between the structures. Global response parameters including inter-story drift ratios, displacement demands, and acceleration demands, and local response parameters including impact force, column shear force demands and plastic hinges behavior are obtained and analyzed to identify the critical stories and gap separation levels associated with pounding occurrence. The results indicate that increasing the gap distance does not necessarily guarantee a reduction in localized damage resulting from story-column pounding. This is due to non-monotonic relationship between separation gaps and impact velocity while intermediate gaps producing high relative velocities at impact which induced and may lead to greater contact forces and a more rapid degradation in stiffness.

Urban road networks in megacities face increasing vulnerability to disruptions that can severely impair mobility and accessibility. Assessing the resilience of such systems requires identifying critical links whose congestion/failures disproportionately degrade network performance. However, conventional link-criticality analysis (LCA) approaches often require exhaustive traffic reassignment, making them computationally impractical for large-scale applications. This study introduces a scalable, data-driven framework for LCA that integrates deep learning (DL) and global sensitivity analysis (GSA) to efficiently quantify link-level vulnerability in metropolitan road networks. The framework formulates LCA as a mapping from network topology, geometric attributes, and traffic-demand features to a composite criticality index that captures both operational degradation and accessibility loss. A DL model is trained on simulation-based disruption scenarios to approximate the impact of network performance, thereby replacing computationally intensive traffic assignment procedures. Subsequently, GSA is applied to interpret the influence and interactions of the underlying factors that drive criticality predictions. The proposed approach is demonstrated on the Greater Cairo road network using a detailed, multi-class model calibrated with observed traffic data. Results show that the DL surrogate accurately reproduces network efficiency and travel-time loss metrics while achieving orders-of-magnitude reductions in computation time compared with traditional LCA. GSA results highlight a limited subset of topologically central and highly loaded corridors as primary drivers of system vulnerability, revealing non-linear interactions among capacity, redundancy, and demand patterns. These findings underscore the potential of combining DL with GSA for interpretable, scalable, and policy-relevant LCA supporting resilient transport planning, investment prioritization, and emergency response in complex urban systems.

Improving the operational effectiveness of water structures requires effective hydraulic design. Significant changes in water levels, velocity distribution, heading up, and energy loss occur at the entrance zone of these structures because of the interaction between the canal inside slope and upstream wing walls geometry. However, prior research has not adequately assessed the integrated hydraulic effects of these characteristics. This study experimentally examines the interplay between wing wall type and canal inside slope on the hydraulic performance of water structures. A total of 360 laboratory experiments were conducted using four upstream wing wall configurations (box, broken, curved, and splayed) and three canal inside slopes (Z = H:V = 1:1, 3:2, and 2:1), representing common conditions in Egyptian irrigation canals. The findings show that hydraulic behavior is strongly influenced by both parameters. When compared to the box type, the splayed configuration exhibited the lowest energy losses and afflux, with reductions of up to 84.12% and 30.01%, respectively. Furthermore, steeper slopes were linked to higher afflux and energy losses, while the 1:1 canal inside slope continuously exhibited maximum hydraulic efficiency. New empirical relationships were developed to enable the prediction and optimization of irrigation structure performance. The outcomes support sustainable water management by increasing operational dependability, lowering maintenance requirements, and increasing hydraulic efficiency. For both new construction and rehabilitation projects, the study suggests giving priority to splayed wing walls in conjunction with a 1:1 canal inside slope, considering the soil conditions.