IRANICA JOURNAL OF ENERGY AND ENVIRONMENT
Year:2025 | Volume:16 | Issue:2|Papers Count:17

One of the main problems facing humanity today is the use of fossil fuels. To solve this problem and worry about the energy crisis due to the lack of these resources, renewable energies can be replaced. One of the biggest sources of clean energy is solar energy, which can be used in solar thermal power plants. In this study, aluminum oxide nanofluid with water has been used in linear parabolic solar combined thermal power plant with Rankine cycle, and the energy efficiency and exergy of this power plant have been investigated by the nanofluid used and the storage tank. Also, this power plant has an energy storage tank with molten salt so that the amount of energy needed at night can be provided in the absence of sunlight. Energy and exergy analysis equations of this power plant have been done with the help of EES software. The result of this analysis is that the exergy efficiency of the solar system is 16.27% and the energy efficiency is 59.72%.

Thermal diode solar water heaters (SWHs) are novel, promising tools that address an inherent problem in SWHs: significant heat losses. Thermal diodes SWHs use heat transfer fluids (HTFs) to carry out this crucial task, or in other words, to improve the heat transfer rate during the collection period and reduce its retention period. This study investigates how HTFs affect the performance of thermal diode SWHs. To this aim, a thermal diode SWH was fabricated and tested outdoors using two common HTFs: pure water and ethanol-water azeotrope. Ethanol-water azeotrope has a lower boiling point and latent heat than pure water; hence, it goes through the phase change process sooner and faster than pure water. The results reveal that the maximum reserved water temperature in the SWH using azeotrope is nearly 17.7% higher than in the SWH using pure water. Furthermore, the reserved water in the SWH using azeotrope loses its thermal energy in a gentler gradient than the water in the SWH using pure water during the retention period. The collection and retention efficiencies of the SWH using azeotrope are nearly 37.83% and 130.2% higher than those using pure water. Hence, ethanol-water azeotrope is a suitable material, serving as HTF in thermal diode SWHs.

The adsorption process is an economical, low-energy, and environmentally friendly approach to purify water contaminated with polycyclic aromatic hydrocarbons (PAHs). Clay (CL), as a natural adsorbent, represents a class of materials particularly well-suited for this adsorption purpose. This study aims to assess the viability of utilizing chemically modified clay, organoclay (OCL), for the removal of PAH contaminants compared to unmodified clay. The synthesis of modified clay involved the use of CTAB surfactant with cationic exchange capacity. To create water-based PAH solutions, the required amount of PAH was first dissolved in methanol and then diluted to the final concentration with deionized water. To estimate the adsorption mode, Freundlich, Langmuir, and Temkin models were fitted with the experimental isotherm data. Additionally, to investigate the basic process of the PAH adsorption mechanism, pseudo-first-order, pseudo-second-order, and Roginsky-Zeldovich models were applied, with the results best fitting the pseudo-second-order model. The kinetic results indicated that the pseudo-second-order kinetic model, with high correlation coefficients, was more suitable than the other kinetic models. The maximum change in entropy (ΔS) obtained was equal to -53.25 J (mol K) −1. Furthermore, the negative values of the change in enthalpy (ΔH) indicate that both physical and chemical adsorption play a role in the adsorption process. Overall, the prepared modified clay is highly effective in removing PAHs and demonstrated an improved ability to adsorb this organic contaminant compared to other conventional methods.

In this research, thermodynamic and thermoeconomic analysis of a new multigeneration system based on the Parabolic trough collector and the photovoltaic-thermal solar collectors is carried out to produce power, cooling, hot water, hydrogen and freshwater. The proposed system includes an organic Rankine cycle, double-effect absorption refrigeration system, PEM electrolyzer and the reverse osmosis desalination unit. Analysis of energy, exergy, thermoeconomics, as well as analysis of various parameters was done by using the EES software. The results show that the energy and second law efficiency of the system is 33.49% and 13.31%, respectively. The net power produced by the system is 1271.48 kW in which ORC turbine has the maximum share. Moreover, the coefficient of performance of the cooling system is achieved to be 1.097 by considering the basic assumptions. The hydrogen and freshwater production rates are 542.3 kg/day and 4.55 kg/s, respectively. Finally, the rate of exergy destruction in each part of the system shows that the highest rate of exergy loss occurs in the PTC collector and the organic Rankine cycle with the amount of 53575 kW and 1624 kW, respectively, and in the organic Rankine cycle, the thermoelectric generator unit and evaporator have the largest share of exergy losses.

Using renewable energy is an efficient method for addressing the drawbacks of utilizing fossil fuels. The study focuses on a multigeneration system that integrates PTC solar collector and geothermal energy, along with two ORC cycles, a single-effect absorption refrigeration cycle, a PEM electrolyzer, and a dryer. A TEG unit is utilized in the ORC cycles to increase power production. The system is analyzed from energy, exergy, and exergoeconomic perspectives using EES software. Parametric analysis is conducted to assess the impact of crucial parameters on the system's performance. The examination of overall results reveals that the energetic and exergetic efficiencies of the multigeneration system are 41.58 and 25.61%, respectively. The power generated by ORC1 turbine and ORC2 turbine are 461.9kW and 227.6kW, respectively. Introducing TEG units in place of condensers in the ORC cycles results in increased power production to 138.2kW and 328.2kW for ORC1 and ORC2 cycles. The energetic and exergetic COPs of the system are 0.8103 and 0.3484, respectively. Additionally, the multigeneration system is capable of producing 493.1 kg/day of hydrogen. Lastly, six different working fluids in the ORC cycle were investigated. It is demonstrated that among the 6 working fluids, n-pentane exhibited the best performance.

The negative environmental effects of cow dung disposal and the limited supply of conventional gas sources call for innovative approaches to address both problems at the same time. The production of biogas from cow dung presents a viable solution for reducing environmental deterioration and providing a source of renewable energy. This study explores the complexities of producing biogas in a novel kind of plastic digester system over a period of fourteen days to clarify how effective it is in resolving these related issues. The result of this study reveals separate phases of biogas production: a latency period that is followed by a progressive increase in pressure readings that indicates the start of gas generation. But by day fourteen, 520 kPa of pressure was measured, and optimal gas yield is hindered by temperature swings between 27°C and 32°C as well as possible leaks. To overcome these obstacles, the plastic digester is buried underground, which maintains environmental conditions and encourages vital microbial activity that is necessary for the production of biogas. When comparing above-ground and underground setups, it was found that the latter significantly improves biogas generation efficiency by keeping the surrounding temperature at 34°C, speeds up biogas production, and produces noticeably higher pressure readings—up to 1200 kPa, which is more than twice as high as in non-buried setups. The environment is stabilized, which promotes microbial metabolism and increases the breakdown of organic waste and the production of methane. The result of the study also revealed that methane (CH4) has 63% while carbon dioxide (CO2) has 32% and other gases account for 5%. This strategy not only provides a viable means of managing waste but also supports the production of renewable energy, highlighting the revolutionary potential of biogas produced from cow dung in resolving related environmental and energy issues most cost-effectively.

Combining wind and solar technologies with reverse osmosis (RO) desalination offers a novel solution to combat water scarcity in Shahrekord, Iran. This innovative approach harnesses renewable energy sources to power the desalination process, potentially resulting in reduced energy expenses and carbon emissions compared to traditional fossil fuel-based methods. Furthermore, this study has the potential to shed light on the feasibility and effectiveness of integrating multiple renewable energy sources for water desalination in mountainous regions. The present work is the first study of its kind aimed at minimizing the energy consumption of the RO system pump and then finding the optimal configuration of a microgrid based on renewable energy in off-grid and on-grid modes. Comparing with traditional methods of using the power grid and diesel generators to supply the required power for the RO system prompts decision-makers and investors in this field to better advance the industry based on the energy-economic-environmental analyses of this work. In this research, the initial phase involved an examination using WAVE V.1.82q software to assess the viability of purifying surface water to provide a daily water supply of 3220 m3, employing BW30-400 modules. Subsequently, efforts were made to minimize operational pressure and thus lower the operational costs of the system through the utilization of low-energy modules like XLE-440i. Lastly, the evaluation of the power supply for the RO pump system was carried out across six different scenarios using HOMER V.2.81 software. The simulation results indicated that in the most favorable scenario, the energy required per m3 of water treatment stands at approximately 0.53 kWh. When a diesel generator serves as a backup, the lowest electricity production cost is associated with the solar system at $0.355 per kWh, with solar energy contributing to 91% of electricity generation. On the other hand, when grid electricity is the backup source, the lowest electricity production cost amounts to $0.024 per kWh, with only 1% of electricity generated from solar energy. Comparing different scenarios, it was found that employing renewable energy sources for desalination purposes has manifold benefits.

Climate change (CC) has affected all parts of the world, including Iran. The effect of CC on agriculture is mainly related to crop growth, agricultural production and water resources. This paper analyzes the effects of CC on wheat, a strategic crop in Iran and the world, as changes in yield, water requirements and water productivity from scientific papers and reports. CC has had adverse effects on wheat yield, especially rain fed wheat, in Iran and other parts of the world. By changing the environmental parameters, it is estimated that CC will lead to a 10-14% decrease in wheat yield. Some studies have shown that the percentage of changes in wheat yield is even higher than these values. The most important factor is the increase in temperature and heat stress on this plant. CC can reduce the crop growth period and produce associated adverse physiological effects such as reducing the planting to flowering period, shortening the seed filling period and reducing the flowering to maturity and seed production period. The proposed adaptation measures include development of crop cultivars that are tolerant to heat stress and with low water requirements, cultivars with longer growing periods, changes to planting dates, better on-farm water management, crop residue management, and increasing the level of organic matter in the soil. It is suggested that the strategies for coping with CC in wheat production should focus more on reducing the effects of rising temperatures and heat stress on the wheat plant, especially in its critical growth stages. Therefore, it is necessary to mainstream the effects of CC on agriculture, especially on strategic crops, in terms of ensuring food security and prioritizing it in national and sub-national research studies, especially in Iran.

Using renewable energy is an efficient method for addressing the drawbacks of utilizing fossil fuels. The study focuses on a multigeneration system that integrates PTC solar collector and geothermal energy, along with two ORC cycles, a single-effect absorption refrigeration cycle, a PEM electrolyzer, and a dryer. A TEG unit is utilized in the ORC cycles to increase power production. The system is analyzed from energy, exergy, and exergoeconomic perspectives using EES software. Parametric analysis is conducted to assess the impact of crucial parameters on the system's performance. The examination of overall results reveals that the energetic and exergetic efficiencies of the multigeneration system are 41.58 and 25.61%, respectively. The power generated by ORC1 turbine and ORC2 turbine are 461.9kW and 227.6kW, respectively. Introducing TEG units in place of condensers in the ORC cycles results in increased power production to 138.2kW and 328.2kW for ORC1 and ORC2 cycles. The energetic and exergetic COPs of the system are 0.8103 and 0.3484, respectively. Additionally, the multigeneration system is capable of producing 493.1 kg/day of hydrogen. Lastly, six different working fluids in the ORC cycle were investigated. It is demonstrated that among the 6 working fluids, n-pentane exhibited the best performance.

Daylight studies on office buildings are very important due to the use of artificial lighting and their energy consumption during daytime hours and also providing visual comfort in working spaces. In compliance with the National Building Code of Iran, it is mandated that office spaces possess access to natural light and ventilation through one or more windows, constituting at least 12.5% of the total glass area in relation to the floor space. This research is devoted to the investigation and assessment of the appropriateness of this ratio in diverse climates across Iran. For this purpose, the index of Daylight Autonomy (DA), Useful Daylight Illuminance (UDI) and also Annual Sunlight Exposure (ASE) metrics were used on an office space in 5 cities of Isfahan, Mashhad, Chabahar, Tabriz and Ahvaz, in Grasshopper software and Honeybee and Ladybug plug-ins. The analysis underscores a robust, direct correlation between the ratio of glass surface area to floor space and the levels of natural illumination. Notably, the intensity of light radiation, as indicated by DA, is most favorable in Isfahan and Mashhad, and least favorable in Ahvaz. Furthermore, UDI values exhibit a proportional relationship with light behavior in the environments of Isfahan and Ahvaz, respectively. Chabahar city emerges with the most favorable ASE values. The findings underscore that the current prescribed standard may not be across the country applicable or optimal across all climates. It is advised to make climate-specific adaptations to this standard, providing designers with increased assurance in its use throughout the design process.

Energy efficiency Energy efficiency in buildings is a critical aspect of sustainable development (SD), especially in developing countries with significant construction volumes like Iran. The National Housing Project (NHP) in Iran aims to provide affordable housing for the middle class, with a strong emphasis on energy efficiency and sustainable development. This study examines the combined impact of orientation and configuration on visual and thermal comfort (VC, TC) using multi-objective optimization (MOO) techniques. By simulating thermal behavior in EnergyPlus and applying optimization with the Wallacei-x plugin in Grasshopper, this study identifies optimal solutions using the weighted sum method (WSM). The research consists of two parts: analysis of isolated buildings and Multi-family buildings. The linear configuration, with a 0º angle, showed a 4.9% reduction in Energy Use Intensity (EUI), a 3.9% increase in Useful Daylight Illuminance (UDI), and a 2.6% improvement in Predicted Mean Vote (PMV). In the second part, it was found that, overall, increasing the distance between blocks reduces energy consumption, enhances daylight efficiency, and improves thermal comfort conditions. The impact of horizontal distance changes in linear and U-shaped configurations is greater than that of vertical changes. In the courtyard, this trend is reversed, with vertical distance changes having a greater impact. However, in the L-shaped organizer, the effects of these distances on various parameters vary. These data offer the potential to create sustainable cities in the future.

The depletion of fuel resources, increased greenhouse gas (GHG) emissions, and energy limitations highlight the need for renewable energy. Solar energy is a cost-effective choice globally, including in Iran, due to its abundance. This paper presents the design and economic analysis of an on-grid solar system at the University of Abhar, Iran. Installing photovoltaic (PV) systems on unused university rooftops can enhance electricity reliability, reduce load shedding, and offer flexibility during peak demand, making it a valuable investment. The system was simulated in PVsyst, evaluating energy losses, output power, and power injection into the grid. Energy and exergy efficiencies of the solar system were assessed, and an economic comparison with a diesel generator (DG) system was conducted. The solar system showed an annual output of 411.5 MWh, decreasing to 355 MWh/year over 25 years, and could reduce CO2 emissions by 193 tons annually. The energy and exergy efficiencies of the selected panels were 17.02% and 19.63%, respectively. Economically, the solar system's cost of energy production was approximately $0.008 /kWh, compared to $0.01 /kWh for the DG system. The solar system also achieved a higher IRR of 26.4% and a faster DPP of 9.2 years. In conclusion, PV systems offer lower GHG emissions and better cost efficiency compared to diesel generators.

Lavender has garnered interest because of its potential therapeutic effects. The objective of this research was to examine the healing properties of corn starch nanoparticles that contain lavender extract on skin wounds in Wistar rats. The scanning electron microscope, atomic force microscopy, and dynamic light scattering techniques were utilized. The analysis revealed that the nanoparticles have a diameter of around 60 nm and exhibit a spherical morphology. Furthermore, a histological investigation was conducted by procuring tissue samples from the wound site on days 3, 7, 14, and 21 after the surgical procedure. Statistical studies were performed to ascertain the mean wound area, rate of wound healing, and percentage of wound healing among the different treatment groups. The data were analyzed using the TUKEY and Duncan multiple range tests in the SAS statistical software to discover statistically significant differences and evaluate intergroup variances across different time points. In addition, the group that received the 5% nanoformulation treatment showed healing percentages of approximately 60%, 86%, and 100% on the 7th, 14th, and 21st days, respectively, as compared to the day the wounds were formed. The results indicate that maize starch nanoparticles containing lavender extract have beneficial and efficient capabilities for enhancing wound healing.

Considering the crisis of increasing greenhouse gases due to excessive consumption of energy as well as rising temperature and disrupting thermal comfort conditions in urban contexts, it will be significant to carry out more investigations in this field. This study has been carried out to investigate the mutual effects of design in reaching buildings with efficient energy consumption and providing thermal comfort conditions in external spaces. For this purpose, the dominant patterns of urban blocks and open spaces in a cold and mountainous region have been identified. By combining these models and simulating the amount of energy consumption in them with Design Builder software and measuring thermal comfort using Envi-met software, it is tried to introduce a model to establish a balance between these components. These evaluations were done for 12 months. Optimal scenarios show that they can save up to 2/3 of energy in buildings. Morphology with linear and wide blocks and open space with considerable width between buildings can improve energy efficiency inside and thermal comfort outside the buildings.

In the present work, a double-pass solar air-water heater has been designed for the first time to provide both hot air and hot water for using in many engineering applications. The proposed solar collector can be a useful device for the purpose of heating spaces and providing domestic hot water, simultaneously. It is like a conventional solar air heater but five water tubes are installed under the absorber plate with a large common surface area with the heated surface. The two-dimensional numerical simulation with the assumption of quasi-steady condition was done on a rectangular-shaped collector with a length of 1 m and a height of 0.128 m including five water tubes by solving the continuity, momentum, and energy equations for the turbulent airflow by the COMSOL Multi-physics. The effect of forced convection water flow inside the parallel tubes installed below the absorber plate is employed as a convection boundary condition in solving the air energy equation. Also, the convection boundary condition was employed on the boundary surfaces of the glass cover and insulation layer adjacent to the surroundings. Numerical simulations are carried out for the air and water mass flow rates of 0.01 kg/s and 0.03 kg/s, respectively. While the solar heat flux lies in the range of 5001100 W/m2. In several test cases, high thermal efficiencies (69% to 74%) are computed for the proposed collector, whose value is much higher than a smooth duct solar air heater operating under the same condition. A comparison is also made between the performances of double-pass and single-pass solar air-water heaters and a percentage of efficiency increase about 6% was found. This value reached to 75% when this solar collector is compared with a conventional solar air heater.

One of the most basic human needs is access to safe and sanitary water. The effects of surface and groundwater pollution on public health are one of the most important human concerns. The basis for judging the health and potability of any water is its physical, chemical and microbial characteristics. This study aimed to evaluate the quality of urban drinking water in the eastern, western, and central regions of Mazandaran Province, Iran, and to compare it with international standards. Water samples were collected from various outlets and consumption points in three cities across different seasons and were subjected to a range of physical, chemical, and microbiological tests. The results indicated that all parameters fell within healthy limits and met the basic standards for drinking water, both in Iran and globally. However, fluoride levels were found to be below the standard, which may pose risks to oral health, and water hardness was somewhat high. In conclusion, while the drinking water in the eastern, western, and central regions of Mazandaran Province is deemed safe, ongoing monitoring is essential to maintain long-term safety and quality, particularly concerning fluoride and hardness levels.

The study investigated the water quality, wetland area, and dust storm impacts on the Shadegan wetland in Iran from 2018-2023 using satellite data. The results highlight the severe challenges the wetland has faced in recent years. Key water quality indices, including water temperature, turbidity, and CDOM levels, indicate increasing pollution, particularly in 2022-2023. Water temperatures were highest in 2018 and 2021, peaking at 52°C, while turbidity and CDOM levels reached their maximum in 2022, affecting the northern, western, and southern parts of the wetland. The study also revealed a significant reduction in the wetland area, with considerable drying observed in the northern, eastern, and western sections during 2018, 2021, and 2022, with critical implications for the wetland's ecological health. Dust storm frequency and intensity have escalated, peaking in 2022-2023, correlating with periods of poor water quality and reduced wetland area. The highest dust pollution levels were recorded in 2018, 2021, 2022, and 2023, with over 214 dust days in the northern parts and over 146 dust days in the southern and southeastern parts of the wetland in 2022. Wind analysis and HYSPLIT show the pollution from the drying wetland affects a broad regional area, including Khuzestan province and the western, northwestern, and southwestern regions of Iran. The findings emphasize the urgent need for wetland conservation and restoration, as well as regional cooperation to rehabilitate the ecosystem and implement effective water resource management strategies.