Polyolefin waste and CO2 are among the most pressing sustainability issues. Microwave catalysis offers a promising platform for co-converting polyolefin waste and CO2 into light olefins and syngas. Here, a 40 wt% CeO2/alpha-Fe2O3 catalyst enables a balanced coupling of polyolefin cracking and CO2 reforming at 400 degrees C under microwave irradiation, achieving 36.5 mol% CO2 conversion, similar to 70 wt% gas yield, and 57.7 mol% light olefin selectivity. This performance arises from microwave-stimulated oxygen dynamics, wherein CeO2 activates CO2 and mitigates carbon deposition via lattice oxygen cycling, while alpha-Fe2O3 promotes selective hydrocarbon cracking and serves as a microwave susceptor. Mechanistic studies and DFT calculations confirm that microwave fields enhance lattice oxygen mobility, direct product selectivity, and sustain catalyst stability. Techno-economic analysis yields a net present value of +36.74 MM USD, and life-cycle assessment reveals a GHG footprint of 0.0667 kg CO2-eq/kg product-substantially lower than conventional steam cracking routes.

Ethylene is a critical feedstock in industrial processes, serving as a raw material in the petrochemical industry to produce plastics and commodity chemicals. Conventional ethylene production routes are energy-intensive and contribute substantially to the carbon footprint of chemical manufacturing. In this study, an industrial-scale novel microwave process was simulated using ASPEN Plus to assess its economic viability. Technoeconomic analysis confirmed the economic competitiveness of the novel microwave process, with a levelized cost of ethylene of USD 0.51/kg compared to USD 0.56/kg for the conventional base case. Key economic drivers of the process were identified, and sensitivity analyses were conducted to evaluate their impact on project economics. Furthermore, 87.7% of the total utility consumption in the novel microwave process is electricity, highlighting its potential to contribute to the electrification of the chemical industry. The findings of this study confirm the economic feasibility of both industrial-scale microwave reactors and modular plant configurations for the production of ethylene from methane, offering a promising alternative to conventional processes.

The rapid accumulation of plastic waste, particularly post-consumer polyolefins (POs), poses severe environmental and economic challenges worldwide. Recycling of post-consumer POs remains inefficient due to difficulties in separating mixed plastics, complex additive compositions, and high processing costs, resulting in recycling rates of less than 9%. To address these critical issues, this study utilized an innovative microwave-assisted catalytic upcycling approach for the efficient upcycling of complex post-consumer POs mixtures into valuable light olefins. Using the microwave-assisted catalytic upcycling approach, gas yields reached up to 80 wt.% from post-consumer POs mixtures, accompanied by a high selectivity (> 70 wt.%) toward valuable light olefins. The upcycling of POs under microwave conditions is fully investigated, including additives in real-world plastics, mixtures of different POs, reusability of catalyst, and more. Techno-economic analysis (TEA) and life-cycle assessment (LCA) further indicate that the process is economically viable, with a positive net present value (NPV) of +$81.67MM, and environmentally favorable, with a gate-to-gate greenhouse gas footprint of only 0.0468 kg CO2 eq/kg ethylene-equivalent product, substantially lower than conventional steam cracking. The microwave-assisted catalytic upcycling approach offers an efficient, scalable, and cost-effective solution for upcycling post-consumer plastic mixtures, thereby advancing the principles of a circular economy.

This study investigates the development and economic analysis of a modular integrated system for carbon-neutral methanol synthesis, leveraging direct air capture (DAC) and solid oxide electrolysis cells (SOEC) for carbon dioxide and hydrogen production, respectively. The proposed system integrates a novel building-based DAC process, functionalized solid sorbents, and low-energy SOEC technology, aiming to minimize operational and capital costs. A comparison between the base case system (1,000 t methanol/year) and a scaled-up model (14,758 t methanol/year) reveals significant improvements in efficiency and economic feasibility. The scaled-up system achieves a levelized cost of methanol (LCOM) of $740/t, a 7.5% reduction compared to that of conventional DAC-based systems, while utilizing existing building HVAC infrastructure for air handling. Detailed sensitivity analyses were conducted, evaluating the effects of plant capacity and air flow rate on the LCOM, demonstrating the scalability of the building-based DAC system. The cradle-to-gate life cycle analysis shows that the proposed process using renewable-sourced electricity achieves a 38% reduction in greenhouse gas (GHG) emission compared to reported values of green methanol production technologies that use a conventional DAC and a conventional methanol synthesis catalyst. When fossil-sourced electricity is used in the proposed process, it leads to about a 37.5% reduction in GHG emission in comparison to reported values for conventional methanol production technologies using steam methane reforming technology and fossil-sourced electricity.

Ammonia production has traditionally been done by using the Haber-Bosch process, that operates at extremely high pressure (200-300 bar), has a large carbon footprint, and requires significant energy. For ammonia to be used as a hydrogen carrier, it is desired that it is produced by using modular technologies under benign conditions, yet the economics remain commercially viable. This paper investigates a novel technology for ammonia synthesis by using a microwave-assisted low-pressure reactor. Microwave reactors are compact and can be readily modularized and started/shutdown thus making them ideal to be integrated with the electric grid or with regional/local renewable-based electric generation facilities. For separation of unreacted reactants from the product ammonia, if the traditional condensation separation technology used in the high-pressure Haber-Bosch process is used, then the separation process needs to be operated under cryogenic condition thus adversely affecting the economics. A solid sorbent based separation technology is investigated in this paper. A kinetic model for the microwave-catalytic synthesis process is used. An isotherm model is developed for MgCl2-Si adsorbent and used for modeling the dynamic adsorption-desorption cycle. A plant-wide model with heat and mass integration is developed. An economic model is developed and used for economic optimization by using an equation-oriented approach. Since the adsorption-desorption process is dynamic, for techno-economic optimization, a reduced order model for the key performance measures of the adsorption-desorption process as a function of its input and decision variable is developed under cyclic steady-state conditions. For the optimized MW-assisted process, the levelized cost of ammonia is $772/mt as opposed to $808/mt for the conventional Haber-Bosch process for a hydrogen price of $2.07/kg. The MW-assisted process is found to be economically viable in the US market if the hydrogen price is below $4/kg.

Novel carbon capture systems are necessary to help natural gas power plants approach net zero CO2 emissions. We propose a hybrid carbon capture system attached to a natural gas combined cycle (NGCC) power plant that consists of a membrane system and a solid sorbent system, with this work focusing on the design of the solid sorbent system. We modeled fixed bed adsorbers that are packed with metal-organic framework (MOF) solid sorbents that adsorb CO2 and undergo temperature swing desorption using steam from the power plant. Parametric simulation of adsorber conditions showed that ten 5-m diameter beds adsorbing in parallel with 4.9 bars inlet gas pressure and 1.5 bars of steam pressure at a flow rate of 0.15 kmol/s led to optimized performance. This study enabled us to determine that the MOF bed adsorber can attain 86.6 % and 85.4 % carbon capture during peak and off-peak operation, respectively. When combined with the membrane capture system, this results in overall capture rates of 98.4 % and 98.9 % during peak and off-peak operation, respectively. Although we were unable to attain net-zero or net-negative emissions in this study, we are confident that net-negative operation could be obtained in future work by selecting a solid sorbent better suited to direct air capture conditions so that more air could be processed by the solid sorbent system.

Ammonia, essential for agriculture, chemical industries, and energy storage, is traditionally synthesized through the Haber-Bosch (HB) process. This established process requires high pressures (up to 300 bar) and temperatures (400-500 degrees C), thus generally limiting its feasibility to large-scale operations with high capital investment. This study investigates a novel low-pressure (6.5-35.5 bar) microwave-assisted ammonia synthesis process as an alternative to the HB process. Since the ammonia reaction is equilibrium-limited, single-pass conversion is limited, thus requiring separation of ammonia from the unreacted reactants for recycling. However, conventional condensation separation used in the HB process is not suitable for this novel process due to the low operating pressure. This work evaluates four potential separation technologies: cryogenic distillation, cryogenic flash separation, absorption with water as the solvent, and membrane separation. A model of the microwave reactor is developed with kinetic parameters estimated from in-house experimental data. Different configurations of plant- wide models with production capacity of 60,000 t_NH3/year are developed using Aspen Plus. Economic performance is assessed by using two economic measures- minimum selling price (MSP) and levelized cost of ammonia (LCOA). The cryogenic flash separation is found to result in the best economic performance. Optimization results show that the catalyst cost significantly impacts the optimal number of reactors needed. Interestingly, it is observed that the highest single-pass conversion does not necessarily yield the best process economics. The range of MSP improvement through optimization spanned from 0.84% to 16.2% for various case studies. Notably, the optimized case achieved an MSP of $0.113/kWh, that is close to $0.111/kWh obtained using the conventional thermo-catalytic HB process under same boundary conditions for the feed.

Carbon capture & storage (CCS) with high capture rates (90-99%) will be necessary to keep natural gas around in a low-carbon future. Furthermore, as intermittent renewable energy expands, natural gas power plants will have to operate at low-load conditions more frequently. To meet these demands, we propose a natural gas combined cycle (NGCC) power plant with a hybrid CCS system that can attain high capture rates and easily cycle between high-load and low-load conditions. More specifically, we propose an integrated system where natural gas exhaust is first processed by a membrane CCS system and then by a solid sorbent CCS system. We integrated models of an NGCC plant, a membrane carbon capture system and a solid sorbent carbon capture system into a single optimization platform to maximize the net present value (NPV) and carbon capture rate of the integrated system. The optimization results indicate a 99.3% carbon capture rate from the inlet natural gas stream at high-load conditions, and a 99.6% carbon capture rate from the inlet natural gas stream at low-load conditions. Compared to a baseline NGCC system without carbon capture, the integrated system has a higher NPV, which indicates that performing carbon capture is more profitable than operating an NGCC system without carbon capture in a future with CO2 taxes. Compared to a baseline NGCC system with an amine-based CCS system that performs 90.7% carbon capture, the proposed integrated system captures more carbon and emits less CO2, while still maintaining a competitive CO2 capture cost.

To address the rising electricity demand and greenhouse gas concentration in the environment, considerable effort is being carried out across the globe on installing and operating renewable energy sources. However, the renewable energy production is affected by diurnal and seasonal variability. To ensure that the electric grid remains reliable and resilient even for the high penetration of renewables into the grid, various types of energy storage systems are being investigated. In this paper, a compressed-air energy storage (CAES) system integrated with a natural gas combined-cycle (NGCC) power plant is investigated where air is extracted from the gas turbine compressor or injected back into the gas turbine combustor when it is optimal to do so. First-principles dynamic models of the NGCC plant and CAES are developed along with the development of an economic model. The dynamic optimization of the integrated system is undertaken in the Python/Pyomo platform for maximizing the net present value (NPV). NPV optimization is undertaken for 14 regions/cases considering year-long locational marginal price (LMP) data with a 1 h interval. Design variables such as the storage capacity and storage pressure, as well as the operating variables such as the power plant load, air injection rate, and air extraction rate, are optimized. Results show that the integrated CAES system has a higher NPV than the NGCC-only system for all 14 regions, thus indicating the potential deployment of the integrated system under the assumption of the availability of caverns in close proximity to the NGCC plant. The levelized cost of storage is found to be in the range of 136–145 $/MWh. Roundtrip efficiency is found to be between 74.6–82.5%. A sensitivity study with respect to LMP shows that the LMP profile has a significant impact on the extent of air injection/extraction while capital expenditure reduction has a negligible effect.

Future wireless communication is expected to be a paradigm shift from three basic service requirements of 5th Generation (5G) including enhanced Mobile Broadband (eMBB), Ultra Reliable and Low Latency communication (URLLC) and the massive Machine Type Communication (mMTC). Integration of the three heterogeneous services into a single system is a challenging task. The integration includes several design issues including scheduling network resources with various services. Specially, scheduling the URLLC packets with eMBB and mMTC packets need more attention as it is a promising service of 5G and beyond systems. It needs to meet stringent Quality of Service (QoS) requirements and is used in time-critical applications. Thus through understanding of packet scheduling issues in existing system and potential future challenges is necessary. This paper surveys the potential works that addresses the packet scheduling algorithms for 5G and beyond systems in recent years. It provides state of the art review covering three main perspectives such as decentralised, centralised and joint scheduling techniques. The conventional decentralised algorithms are discussed first followed by the centralised algorithms with specific focus on single and multi-connected network perspective. Joint scheduling algorithms are also discussed in details. In order to provide an in-depth understanding of the key scheduling approaches, the performances of some prominent scheduling algorithms are evaluated and analysed. This paper also provides an insight into the potential challenges and future research directions from the scheduling perspective.

Monoethylene glycol (MEG) is used to produce polyester fibers and polyethylene terephthalate resins. It is also utilized in antifreeze, pharmaceuticals, and cosmetics applications. In this research, we consider the development of a novel process plant that produces MEG from ethylene. The proposed ethylene-to-ethylene oxide (EO) plant is integrated with an EO-to-MEG plant to reduce utility costs and recover high-value products. Energy-saving opportunities are analyzed via heat integration tools. Furthermore, a multitube glycol reactor is used in conjunction with a novel MTO catalyst in the ethylene-to-EO reactor. Our results demonstrate that the integrated EO/EG plant produces ethylene glycols with that same purity and product recovery as conventional designs. A comparative economic assessment based on a 200,000 t/y plant indicates that process integration techniques can reduce costs significantly.

An e-health monitoring system with wearable sensors, smart phone and an intelligent web server is proposed in this paper in cloud environment. An adaptive data collection technique is included in the system to investigate the patient's health condition interactively. In the system the sensors gather the patient's physiologic parameters (e.g., heart rate, body temperature etc.) periodically and transfer the data to the smart phones via Bluetooth module. The patient data are then uploaded to the cloud server database using an android application. The server monitors the database intelligently to find abnormality in the database. If the server finds abnormality, then it sends a notification to the doctor android application to notify the condition of the patient. Based on the patient condition the doctor may ask anything about the disease symptom or suggest anything. We propose periodically data collection and monitoring the database adaptive to the patient condition. Moreover an on-demand real-time investigation technique is integrated in the system for doctor to check real time patient health condition. The proposed system is evaluated with the patients of Medical Center of University of Rajshahi. The results show the effectiveness of the proposed system.

Propylene glycol is an important member of the glycol group and is widely used in the industry as a raw material particularly for producing polyester compounds, food additives, and antifreeze. In this research, a novel integrated plant is developed for the production of propylene glycol from shale gas. This integrated approach has the benefit of safer operating conditions because the intermediate propylene oxide, which is explosive, does not need to be stored and transported. Furthermore, there are potential economic benefits from integration. The overall plant is simulated in the Aspen Plus environment, and a variety of process conditions are tested at the steady state to optimize the production of propylene glycol. Heat-integration tools are utilized for energy-saving and capital cost reduction opportunities. A comparative economic assessment based on the existing plant information indicates that the use of process integration techniques has the potential to reduce costs significantly.

1,3-Butadiene is an important feedstock in the production of rubbers and plastics, such as styrene butadiene rubber, polybutadiene rubber, and styrene butadiene latex. As the cracker feedstock around the globe is trending toward lighter feedstock from shale and natural gas, the sustained production of 1,3-butadiene in olefin plants, which is traditionally made via naphtha cracking, is facing big challenges. In this research, it is shown that 1,3-butadiene can be produced from natural gas via a novel integrated plant. The manufacturing process consists of the following steps: (1) conversion of natural gas to methanol, (2) conversion of methanol to ethylene, and (3) conversion of ethylene to 1,3-butadiene. The ASPEN Plus environment is utilized to simulate the overall plant, and the predictive capabilities of this model are tested by comparing the results from experimental data from individual plants. Then, energy-saving and capital cost reduction opportunities are explored by utilizing heat integration tools.

Bangladesh is experiencing triple burden of malnutrition among adolescents, which may be associated with inadequate dietary diversity (IDD). In the recently completed round of the national nutrition surveillance (NNS 2018–2019), we explored the prevalence of IDD and its determinants among adolescent girls and boys. A total of 4808 adolescent girls and 4761 adolescent boys were interviewed. We used minimum dietary diversity for women (MDD-W) questionnaire to collect dietary data. IDD was defined as consumption of <5 food groups out of 10 food groups in the past 24 hours. Bivariate and multivariable logistic regression were performed to identify risk factors for IDD among adolescent girls and boys. The prevalence of IDD was 55.5% and 50.6% among the adolescent girls and boys. Prevalence of IDD decreased with an increase of educational attainment among girls (no education 77.8% and grade 10 completed education 49.2%) and boys (no education 68.2% and grade 10 completed education 44.2%). The prevalence of IDD in slum, urban and rural areas was 66.4%, 55.6%, and 51.9% among girls and 61.4%, 50.5% and 52.6% among boys, respectively. Prevalence of IDD was lowest among the richest wealth quintile (girls: 45.4% and boys: 43.1%). Among adolescent girls education (e.g., for grade 10 completed, AOR: 3.42, P = 0.002), marital status (AOR: 1.24, P = 0.046), processed food consumption (AOR: 1.66, P < 0.001), television viewing time (e. g. for ≤60 min/day, AOR: 1.37, P < 0.001), and sex of household head (AOR: 0.81, P = 0.003) were significantly associated with IDD. Among the adolescent boys age (AOR: 0.82, P = 0.024), education (e.g., for grade 10 completed, AOR: 2.36, P < 0.001), sex of household heads (AOR: 0.80, P = 0.002), livestock ownership (AOR: 1.22, P = 0.012), fruits and vegetable consumption (AOR: 1.38, P = 0.004), processed food intake (AOR: 1.74, P < 0.001), physical activity (AOR: 0.76, P = 0.001), and television viewing time (e. g. for ≤60 min/day, AOR: 1.19, P = 0.021) were significantly associated with IDD. About more than half of the adolescent girls and boys consume inadequately diversified diet in Bangladesh. The study identified a number of factors associated with IDD, which should be addressed through comprehensive and sustainable public health interventions. Ministry of Health and Family Welfare, Bangladesh.

The monoethylene glycol (MEG)-based natural gas (NG) dehydration process often faces significant glycol losses at the stripper column because of vaporization and poor NG liquid recovery because of the inefficient refrigeration system. A proportional integral derivative (PID)-based regulatory control strategy can partially mitigate this problem under certain upset conditions. However, to run the plant more efficiently and economically, it is necessary to apply advanced control technologies to reduce MEG losses. Although there are several examples of industrial implementation of advanced process control technologies in the refining industry, there are very few realistic examples that demonstrate the advantages of modern control technology in NG production. In this study, a plant-wide dynamic simulation model for an NG dehydration plant is developed and examined. A hierarchical control system comprising dynamic matrix control (DMC) and basic regulatory control loops is constructed to optimize the plant operation in terms of reducing MEG losses and minimize the operating costs with ensured product qualities under various process upsets. Both standard DMC and adaptive DMC controller models are developed based on the subspace identification model in the Aspen manufacturing platform. Although adaptive DMC performs a little better than the standard DMC, both controller models are very robust and can handle +/- 25% feed and 31% chiller temperature disturbances and demonstrate significant improvement over traditional PID control methodology.

The World Health Organization (WHO) set a target of 15% relative reduction of the prevalence of insufficient physical activity (IPA) by 2025 among adolescents and adults globally. In Bangladesh, there is no national estimates of the prevalence of IPA among adolescents. In the recently completed round of the national nutrition surveillance (NNS 2018–2019), we aimed to estimate the prevalence and risk factors associated with IPA among adolescent girls and boys. NNS was conducted in 57 rural, 15 urban and 10 slum clusters selected using multistage cluster sampling. In these clusters, we collected data from 4732 adolescent girls and 4761 adolescent boys. We used Global Physical Activity Questionnaire to collect physical activity (PA) data. The WHO recommended cut off points for IPA (5–17 years: <300 minutes of moderate to vigorous-intensity PA weekly; 18–19 years: <150 minutes of moderate intensity PA weekly or <75 minutes of vigorous-intensity PA weekly) were used to estimate the prevalence of IPA. Bivariate and multivariable logistic regression were performed to identify factors associated with IPA. Prevalence of IPA among girls and boys were 50.6% and 29.4%, respectively and the prevalence was significantly higher among early adolescents (10–14 years) than late adolescents in both boys and girls. The IPA prevalence was the highest among the adolescents living in non-slum urban areas (girls: 77.9% and boys: 64.6%). The IPA prevalence in slum areas was 36.6% for girls and 34.0% for boys; and in rural areas was 50.0% for girls and 28.2% for boys. For both girls and boys, age group, occupation and >6 hours of sitting per day were associated with IPA. Place of residence, consumption of fruits and vegetables, education and paternal occupation were associated with IPA only among the boys. On the other hand, maternal and paternal education and overweight/obesity were associated with IPA only among the girls. One in every two adolescent girls and one in every three adolescent boys do not meet the WHO recommended level of PA in Bangladesh. This study identified several modifiable factors associated with IPA among adolescent boys and girls and these factors should be addressed through comprehensive public health interventions in order to improve adolescent health in Bangladesh. Ministry of Health and Family Welfare, Bangladesh.

Ultra-Reliable and Low Latency Communications (URLLC) is one of the most important service classes of the emerging 5G and beyond communications systems. This service is used for various applications including medical and healthcare, industrial automation, transportation and robotics where both latency and reliability is of paramount importance. To ensure very low latency, most widely used method is to use short packet size. For ensuring latency and reliability requirement, designing efficient scheduling mechanism is a major challenge. In this work, we propose an efficient packet scheduling algorithm for downlink data transmission. The algorithm provides the highest priority to the packets with largest weighted delay based quantity. The performance of the algorithm is evaluated against some key performance metrics and compared with existing well known scheduling scheme such as proportional fair (PF) and exponential proportional fair (EPF) schemes. The results show the superiority of the proposed packet scheduling algorithm compared to the above mentioned existing schemes.

Advanced process control is developed for a novel oxy-fuel Allam cycle power plant integrated with an Air Separation Unit (ASU) with no greenhouse gas and NOx emissions. The Dynamic Matrix Control (DMC) controller was developed with AspenTech's DMC Technology Version 11 engineering software. The DMC controller improves nitrogen purity, carbon dioxide purity and flowrate, and power output by an average of 4%. Also, the DMC controller is able to handle disturbances in the range of 12.5% for feed flow changes and 10% for feed composition changes. Substantial enhancement was observed in upgrading carbon dioxide purity from 97% Enhanced Oil Recovery (EOR) grade to 99.9% food/medical grade. Therefore, this advanced control strategy is superior to regulatory PID controllers and the developed DMC controller can be used as a seed model in the actual plant control by combining with the actual plant test data in the calibrate mode.