Muhammad Kashif Khan

A carbon-circular refinery must do more than place CO₂ capture, biomass conversion, and catalytic upgrading in the same flowsheet: it must connect them at integration nodes where carbon losses, feed composition, catalyst durability, hydrogen demand, and separation duty can be evaluated together. This critical review therefore focuses on four nodes: recovery of biogenic CO₂ from biomass processing; coupling of captured CO₂ with biomass-derived methane or syngas; co-processing of CO₂-derived intermediates with biomass-derived oxygenates; and allocation of residual carbon between fuels, chemicals, biochar, and geological storage. For each node, we compare feed conditioning, catalyst function, realistic impurities, deactivation and regeneration, product separation, demonstrated operating evidence, and system-level carbon consequences. Thermochemical routes are distinguished from electrochemical and photoelectrochemical routes rather than treated as interchangeable alternatives. The analysis shows that integration is most credible when a concentrated biogenic CO₂ stream or a compatible biomass-derived co-reactant is available, the catalyst is tested with water and heteroatom-containing feeds, and renewable hydrogen and separation requirements are reported explicitly. High conversion or Faradaic efficiency alone does not establish climate benefit. Reactor-level carbon conversion, plant-wide carbon retention, life-cycle greenhouse-gas reduction, and carbon permanence must be reported separately. A unified set of benchmarking metrics, screening-level carbon and energy balances, and an indicative technology-readiness assessment are used to compare the routes; for example, electrolytic-hydrogen-based CO₂ products deliver a climate benefit only when the electricity used has a low carbon intensity, whereas biomass-derived carbon requires about one-third of the hydrogen per mole of retained carbon. The resulting framework identifies the evidence needed to move integrated CO₂–biomass pathways from conceptual coupling toward durable, scalable operation.

Carbon capture is more and more often seen as a component of an integrated carbon-management system than as a stand-alone separation phase. The practical utility of capture technology depends on the chemical state in which the carbon dioxide is held, the energy and material needs for regeneration, the compatibility of the caught species with downstream catalysis and the lifetime of the resulting carbon-containing product. This paper offers an in-depth framework for integrated CO₂ capture and circular carbon use, including catalytic conversion, bio-integrated processes, biomass-derived materials and fuels, hydrogen-enabled routes, mineralization, and artificial intelligence-assisted process design. Reactive capture techniques that convert carbonate, bicarbonate, carbamate, dissolved CO₂ or surface-bound intermediates without first generating a purified gas stream are contrasted with sequential capture, purification, compression, transport and conversion. The thermocatalytic, electrochemical, photoelectrochemical and biological conversion pathways are compared against common parameters such as working capacity, conversion rate, selectivity, carbon efficiency, regeneration energy, stability and life-cycle greenhouse gas performance. Special emphasis is given on dual-functional materials, interfacial reactors, bio-integrated methanation, carbon mineralization in construction materials and coupling with renewable hydrogen. The review also discusses how machine learning, molecular screening, process simulation, graph-based data architecture, and digital monitoring could speed up material selection and system optimization. Across all pathways, the central design requirement is not maximum capture capacity alone, but a balanced match among binding strength, transport, catalytic reactivity, product separation, durability, and carbon permanence. A reporting framework and research agenda are proposed to guide credible scale-up and comparison of integrated carbon-management technologies.

The rapid expansion of battery technologies in electric vehicles, renewable energy storage, and consumer electronics demands comprehensive safety strategies across all system levels. This review assesses the safety aspects of battery management systems (BMS), with a focus on lithium‐ion batteries, while also addressing emerging concerns in sodium‐ion, lead‐acid, and nickel‐based chemistries. Thermal runaway, a primary hazard in rechargeable batteries, is examined through electrochemical degradation, thermal abuse, and mechanical failure modes. The effectiveness of passive thermal management, utilizing phase change materials (PCMs) and composite PCM structures, is evaluated against active air cooling under high‐power and overuse scenarios. Results show that passive protection can reduce propagation temperatures by more than 60°C and delay or prevent thermal events in adjacent cells, while smart BMS algorithms improve the State of Health (SoH) by up to 20% compared to conventional protocols. This study also explores innovative BMS architectures that integrate real‐time monitoring, predictive diagnostics, and embedded control systems. Particular attention is given to the estimation and use of SoH, which quantifies battery degradation based on capacity loss, resistance growth, and electrochemical response. While lithium‐ion systems remain the primary focus, the review highlights how BMS approaches must adapt to the unique failure mechanisms, thermal behavior, and design constraints of sodium‐ion, lead‐acid, and nickel‐based batteries. This comprehensive assessment offers insight into developing scalable, chemistry‐specific safety solutions that are critical for next‐generation energy storage technologies.

The seismic analysis of ground-supported cylindrical steel tanks subjected to lateral harmonic displacement loadings has been carried out. This paper numerically evaluates the structural response of various tank geometries due to resonant seismic sloshing. The numerical investigation is performed using a two-way fluid structural interaction approach that couples computational fluid dynamics analysis with finite element transient structural analysis. The results of the analysis have been validated using Seismic Design Code (Eurocode 8, part 4). Regarding tank aspect ratio (H/D), five geometries covering slender, medium, and broad structures are analyzed under ten harmonic base excitations. All the geometries are excited at their first convective frequency, whose shape and magnitude are evaluated using modal analysis. The seismic response curves have been developed for each tank model, which reveal the complex and peculiar structural response. It is observed from the tanks’ seismic response that they undergo three transitional stress zones named safe, yielding, and failure zones. The critical loadings and failure duration have also been evaluated for each tank model. This will help to avoid future structural damage by designing liquid-containing structures based on evaluated seismic failure loads.

Forecasting energy demand and supply is the most crucial concern for energy policymakers. However, forecasting may introduce uncertainty in the energy model, and an energy policy based on an uncertain model could be misleading. Without certainty in energy data, investors cannot quantify risk and trade-offs, which are compulsory for investments in energy projects. In this work, the energy policies of Pakistan are taken as a case study, and flaws in its energy policymaking are identified. A novel probabilistic model integrated with curve fitting methods was proposed and was applied to 17 different energy demand and supply variables. Monte Carlo simulation (MCS) was performed to develop probabilistic energy profiles for each year from 2017 to 2050. Results show that the forecasted energy supply of Pakistan in the years 2025 and 2050 would be 70.69 MTOE and 131.65 MTOE, respectively. The probabilistic analysis showed that there is 14% and 6% uncertainty in achieving these targets. The research shows the expected energy consumption of 70.33 MTOE and 189.48 MTOE in 2025 and 2050, respectively, indicating uncertainties of 65% and 31%. Based on the results, eight energy policy guidelines and recommendations are provided for sustainable energy resource management. This study recommends developing a robust and sustainable energy policy for Pakistan with the help of transparent governance.