Marcos Fallanza

Post-combustion amine absorption is the most mature CO₂ capture technology, while membrane separation is a promising alternative due to its modularity and operational simplicity. Process intensification through exhaust gas recirculation (EGR) has also gained attention for increasing flue gas CO₂ concentration and reducing capture energy demand. However, comprehensive techno-economic comparisons of absorption, membrane, and hybrid systems under EGR-integrated NGCC conditions remain limited. This study presents a techno-economic assessment of multiple CO₂ capture configurations for a 450 MW NGCC power plant. Process simulations were performed using Aspen Plus and Aspen Custom Modeler to evaluate absorption, membrane, and hybrid systems integrated with conventional and selective EGR. The analysis considers full steam cycle integration and compares energy consumption, net plant efficiency, levelized cost of electricity (LCOE), and CO₂ avoidance cost. The results show that EGR significantly improves carbon capture performance. Among all cases, selective EGR combined with amine absorption delivers the best performance, reducing the energy penalty by more than 30% compared with standalone absorption and by over 70% relative to membrane separation. This configuration achieves an LCOE of approximately 72 USD/MWh and a CO₂ avoidance cost of about 39 USD/tCO₂, outperforming the selective EGR–membrane system (77 USD/MWh and 51 USD/tCO₂). These findings demonstrate that integrating selective EGR with amine absorption is a highly promising strategy for improving the technical and economic feasibility of CCSU in NGCC power plants.

Oxygen and nitrogen are two valuable and widely used products in industries, medical applications, and the food sector, for instance, so they present a significant market opportunity. Traditional methods to separate these gases are very energy-intensive. Therefore, in a world moving toward energy sustainability, membrane technology offers a more sustainable alternative. The aim of this work is to develop polymeric membranes with a hollow fiber configuration using Matrimid and ZIF-8 as fillers to improve the separation performance. As a first step, planar membranes with varying ZIF-8 content (0–20 wt %) were prepared using the casting solvent evaporation technique to determine the optimal Matrimid/ZIF-8 ratio. Subsequently, hollow fiber membranes of Matrimid and Matrimid/ZIF-8 were fabricated via the spinning method. The novelty of this work lies in incorporating ZIF-8 into Matrimid membranes in a hollow fiber configuration, as it is known that the inclusion of fillers in polymeric membranes allows improvements in their performance. Nevertheless, their production is quite challenging. The flat-sheet membranes prepared have shown that inclusion of ZIF-8 in Matrimid improves its O₂/N₂ selectivity by one point and that 5 wt % loading is the optimal point to see this enhancement. The same effect was observed in hollow fiber membranes, reaching an oxygen permeance of 2.16 GPU and an O₂/N₂ selectivity of around 6 (30 °C) for the Matrimid/ZIF-8 membrane, with a dense layer thickness of around 2 μm. All of these results were compared with those reported in the literature for the O₂/N₂ separation. Additionally, the impact of feed composition variations on membrane performance was analyzed.

This study explores the application of an Adaptive Neuro-Fuzzy Inference System (ANFIS) for controlling wastewater treatment processes using ion-exchange resins. It addresses the critical challenges of water scarcity and pollution by enhancing the regulation of water hardness (H) and Total Dissolved Solids (TDS). Using a pilot laboratory device and experimental data from the mixed wastewater of the Kungrad Soda Plant in Uzbekistan, an ANFIS model was developed in MATLAB to automate process control. The model leverages water hardness and TDS as input parameters to regulate the water flow rate by servo valve opening degree, ensuring precise and efficient treatment. Compared to fuzzy logic models, ANFIS achieves a 3–4 second reduction in settling time and significantly lowers error rates. This enhanced control not only optimizes water hardness and TDS regulation but also ensures greater consistency and efficiency. Experimental results indicate that adopting ANFIS for real-time parameter adjustments can reduce energy consumption by up to 1.3%. These findings highlight the potential of ANFIS as a superior solution for controlling dynamic and nonlinear wastewater treatment processes.

Addressing the escalating threat of climate change requires a global response, with significant actions from every nation. Uzbekistan, a member of the Paris Agreement, is actively pursuing sustainable development by reducing greenhouse gas emissions and promoting renewable energy. However, the country's Green Economy strategies currently lack Carbon Capture, Storage, and Utilization (CCUS) technology. A feasibility assessment is crucial to evaluating CCSU's potential for achieving net‐zero emissions, benefiting both the public and scientific communities by informing policy decisions, and providing valuable data. The primary aim of this study is to evaluate Uzbekistan's potential for carbon dioxide (CO₂) storage and utilization (CSU) in the near and mid‐term. To achieve this, this work proposes a methodology for efficient CO₂ source‐sink matching to facilitate the deployment of CCUS technologies in Uzbekistan. Resource evaluation and spatial analysis methods are used to estimate the total CSU capacity of the region and the geographical distribution of CO₂ sources in two large‐scale emitting sectors, specifically from the power and cement plants. According to the results, Uzbekistan has an annual CSU capacity of 1171 million tons CO₂, which is several times higher than the annual CO₂ emission rate. Additionally, CSU resources are primarily located in the eastern, western, and southern regions of the country, whereas CO₂ sink locations near the capital city and its surrounding areas are limited compared to their abundance of CO₂ sources. Overall, although the country has ample CO₂ storage capacity for CCUS deployment, the prospects for its chemical utilization remain limited in scale. © 2025 Society of Chemical Industry and John Wiley & Sons, Ltd.

As natural gas-fired combined cycle (NGCC) power plants continue to constitute a crucial part of the global energy landscape, their carbon dioxide (CO₂) emissions pose a significant challenge to climate goals. This paper evaluates the feasibility of implementing post-combustion carbon capture, storage, and utilization (CCSU) technologies in NGCC power plants for end-of-pipe decarbonization in Uzbekistan. This study simulates and models a 450 MW NGCC power plant block, a first-generation, technically proven solvent—MEA-based CO₂ absorption plant—and CO₂ compression and pipeline transportation to nearby oil reservoirs to evaluate the technical, economic, and environmental aspects of CCSU integration. Parametric sensitivity analysis is employed to minimize energy consumption in the regeneration process. The economic analysis evaluates the levelized cost of electricity (LCOE) on the basis of capital expenses (CAPEX) and operational expenses (OPEX). The results indicate that CCSU integration can significantly reduce CO₂ emissions by more than 1.05 million tonnes annually at a 90% capture rate, although it impacts plant efficiency, which decreases from 55.8% to 46.8% because of the significant amount of low-pressure steam extraction for solvent regeneration at 3.97 GJ/tonne CO₂ and multi-stage CO₂ compression for pipeline transportation and subsequent storage. Moreover, the CO₂ capture, compression, and transportation costs are almost 61 USD per tonne, with an equivalent LCOE increase of approximately 45% from the base case. This paper concludes that while CCSU integration offers a promising path for the decarbonization of NGCC plants in Uzbekistan in the near- and mid-term, its implementation requires massive investments due to the large scale of these plants.

With the increasing global concern regarding climate change and the need to reduce greenhouse gas emissions, carbon capture and utilization (CCU) technologies are seen as one of the primary steps toward large-scale decarbonization prospects. In this context, a thorough assessment of each CCU pathway is required from both the techno-economic and environmental perspectives. In this work, the potential of carbon biofixation through microalgae cultivation is evaluated through the preliminary technical design and calculation of plant economics in the case of the Turakurgan natural gas-fired combined cycle power plant located in the eastern part of Uzbekistan. The primary data used in this study are obtained from the open access project report of the targeted power station, along with recently published literature sources. According to the results, although the purchase and installation costs of photobioreactors require significant investments in the capital costs, the technology would still be cost competitive as long as there is a carbon tax imposition of around USD 50 per ton of CO₂ emissions. However, CO₂ biofixation can be relatively more suitable compared to benchmark absorption, particularly in low-CO₂-concentration conditions. Future research will involve a more comprehensive examination of CO₂-based microalgae cultivation and its comparison with chemical absorption and membrane-assisted separation techniques.

Cement production is one of the most energy-intensive industries. During the clinker formation and cooling processes, excess heat is lost to the atmosphere. For this reason, using waste heat to generate useful energy is considered the most promising approach to sustainable cement production. Many cement plants still face challenges in energy efficiency due to historically low energy prices and subsidies in Uzbekistan, which have deterred the adoption of waste heat recovery (WHR) technologies. This study conducts a techno-economic analysis of WHR technologies for a cement plant with an annual capacity of 1 million metric tons (Mt). It evaluates potential energy savings and economic benefits, identifying key waste heat sources, such as preheater flue gas and clinker cooling air, with a total recoverable waste heat of 60.52 MW. The implementation of WHR systems can significantly enhance energy efficiency and reduce operational costs. Results show that WHR can reduce clinker production costs by 3.81% and the levelized cost of clinkers by 7.49%, while cutting annual indirect CO₂ emissions by 63.26%. Given the legislative support and recent energy price liberalization, the first WHR projects are expected to start in 2025 in Uzbekistan. This analysis offers valuable insights for adopting WHR technologies to improve sustainability and competitiveness in Uzbekistan’s cement industry.