Hamed Hashemi

Process simulations serve as an efficient and cost-effective method for evaluating the performance of various amine solvents and their blends in CO₂ capture technologies. This study utilized a performance indicator model to assess the effectiveness of n-methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) blends, supplemented with the activator piperazine (PZ). Key parameters such as solvent flow rates, equipment heat duties, and associated costs including energy consumption and carbon taxes were incorporated into the analysis. Among the tested formulations, a binary blend consisting of 25 wt% AMP and 5 wt% PZ demonstrated superior performance, achieving a 35% improvement over the baseline 30 wt% AMP solvent. Further enhancement was realized through the implementation of absorber intercooling (ICA) within the simulation design, which elevated the performance rating by an additional 9%. These results highlight the significant potential of optimizing solvent compositions and incorporating innovative process configurations to improve the efficiency of post-combustion CO₂ capture systems. The findings provide valuable insights for developing more effective and sustainable approaches to reducing carbon emissions in large-scale industrial applications.

Mining activities in sub-tropical regions are one of the major contributors to environmental contamination and therefore require monitoring and mitigation methodologies. The study investigated the composition of the real-world wastewater from mine explosions and explored the potential of graphene oxide as an adsorbent. Heavy metals, namely, Fe (12.10 ppm), Cu (40.70 ppm), Cr (148 ppm) and Pb (0.03 ppm) were present. The optimal pH, adsorbent dose, temperature, and contact time for heavy metal removal were 12.08, 0.5 g, 25 °C and 0.5 h, respectively. The basic conditions were favourable for efficient removal through the adsorption method. Kinetic modelling indicated adsorption via pseudo-second-order kinetics, insinuating the influence of oxygen moieties of graphene oxide. Furthermore, the Langmuir isotherm revealed favourable removal of Fe, Cu, and Cr. The study indicated potential hazards of current mining activities, especially unmonitored illegal mines in sub-tropical regions. These findings highlight the prospects of graphene oxide as a practical and effective adsorbent for water resource recovery facilities. Therefore, the study demonstrated the capability to adopt pristine graphene oxide in a simple protocol using simple setups for wastewater recovery in the sub-tropical regions in a natural matrix.

Gas hydrate inhibition using chemicals has been under continuous investigation, and several modelling studies have been published since its inception. Since it is not always feasible to conduct experimental research, it is especially crucial to forecast the conditions under which gas hydrates may form and dissociate in the presence of chemical inhibitors. As a result, a reliable forecasting tool is vital. This article provides an exhaustive review of various modelling methodologies in the context of gas hydrate chemical inhibition. The key aspects of empirical models, thermodynamic models, kinetic models, artificial intelligence-based models and quantum chemistry-based models are presented. Critical analysis of each modelling approach has been performed, highlighting strengths, limitations, and areas where further investigations are still crucial. Rapid progress has been made with respect to gas hydrate modelling approaches in the context of chemical inhibition; however, further research is still vital to bridge the gaps that have been identified in this review. Potential improvements to existing models have been proposed, particularly in terms of integrating experimental data and utilizing hybrid approaches, which could serve as valuable future directions for the field.

Process simulations serve as an efficient and cost-effective method for evaluating the performance of various amine solvents and their blends in CO₂ capture technologies. This study utilized a performance indicator model to assess the effectiveness of n-methyldiethanolamine (MDEA) and 2-amino-2-methyl-1-propanol (AMP) blends, supplemented with the activator piperazine (PZ). Key parameters such as solvent flow rates, equipment heat duties, and associated costs including energy consumption and carbon taxes were incorporated into the analysis. Among the tested formulations, a binary blend consisting of 25 wt.% AMP and 5 wt.% PZ demonstrated superior performance, achieving a 35% improvement over the baseline 30 wt.% AMP solvent. Further enhancement was realized through the implementation of absorber intercooling (ICA) within the simulation design, which elevated the performance rating by an additional 9%. These results highlight the significant potential of optimizing solvent compositions and incorporating innovative process configurations to improve the efficiency of post-combustion CO₂ capture systems. The findings provide valuable insights for developing more effective and sustainable approaches to reducing carbon emissions in large-scale industrial applications.

In this work, a thermodynamic consistency test method was used to investigate the reliability of isobaric experimental data on the sulfur content of hydrogen sulfide. The test was applied to literature data. A thermodynamic model based on the Peng-Robinson equation of state with conventional mixing rule was used for prediction of sulfur (S8) deposition from hydrogen sulfide vapor phase. The data considered was analyzed to determine whether it was thermodynamically consistent (TC), not fully consistent (NFC), or thermodynamically inconsistent (TI). The results show that the experimental data for the sulfur content of hydrogen sulfide are thermodynamically consistent.