Biofuels
Mojtaba Malekzadeh; Reza Yeganeh; Bahram Ghamari; shaban ghavami jolandan
Abstract
Introduction: Biogas is a natural and cost-effective source of energy that leaves significant impacts on the environment and industries, widely produced and utilized in many countries. This gas is generated through the anaerobic digestion of organic materials, including animal manure, food waste, and ...
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Introduction: Biogas is a natural and cost-effective source of energy that leaves significant impacts on the environment and industries, widely produced and utilized in many countries. This gas is generated through the anaerobic digestion of organic materials, including animal manure, food waste, and sewage. Microorganisms play a crucial role in the biogas production process by feeding on biomass. The digestion carried out by these microorganisms produces methane, constituting approximately 50-70% of biogas, which is flammable and used for cooking, cooling and heating, electricity generation, methanol and steam production, waste management, and mechanical power. Given these benefits, biogas production holds special significance, and extensive research has been conducted globally in this field, yielding valuable results. In the present study, we aim to investigate and evaluate the influence of lentil skin as a biomass on the quantity and constituents of produced biogas.Materials and Methods: This research was conducted in the Biosystems Mechanics Workshop of the Faculty of Agriculture, Ilam University. The objective of this study was to investigate the effect of lentil skin on biogas production and analyze its constituent components. The workflow typically comprised four stages. In the first stage, fresh lentil skins were broken down into smaller pieces and stored in a suitable environment to be used as digester feedstock for the experiment. Shredding organic waste aids in the digestion process. The second stage involved providing optimal conditions for microbes, which require warmth. Accordingly, the temperature was maintained at an average of 28-30 degrees Celsius during the experiment.The third stage involved the actual digestion process, where anaerobic digestion took place in large tanks, resulting in real biogas production. For this purpose, materials were combined in predetermined proportions (1:1) and loaded into the digesters. In each stage, 5 kilograms of lentil skin were combined with 5 kilograms of water and added to the digester. The experiment was conducted in three repetitions, employing fixed digesters, digesters with agitation every three days, and digesters with daily agitation as influencing factors. The quantity of biogas production and its components were examined over a 30-day period. Gas sampling occurred every 10 days, while pH and gas pressure were measured every 72 hours. In the final stage, the gas underwent purification by removing impurities and carbon dioxide. The amount of gases produced from lentil skin was measured using a chromatograph with a TCD detector. This instrument employs chromatography-based separation. It's worth noting that 9 gas capsules specifically designed for automobiles were used to construct the digesters. The construction stages of the digesters included cleaning, coloring, and installing connections. Moreover, to create uniform temperature and concentration conditions inside the tank, inlet and outlet connections were carefully designed and installed. A safety valve was also installed to ensure the safety of the digesters.Results and Discussion: The obtained results, including loading conditions, pH levels, and internal pressure within the digester during the experiment, and the quantity and components of biogas, were examined across all samples. Statistical methods, including Analysis of Variance (ANOVA) and Duncan's mean comparison test, were employed for data analysis. The results indicated that digester agitation directly influences the pH levels, with the highest pH observed in digesters with daily agitation, displaying the most significant fluctuations. Furthermore, digester agitation has a direct impact on the biogas production levels, enhancing structural effects within the digester. However, frequent agitation repetition has a negligible effect on the amount of biogas produced. The average methane production rates in this process were 34.06% mol for digesters with daily agitation, 23.09% mol for digesters with agitation every three days, and 17.32% mol for fixed digesters.Conclusion: Currently, a significant portion of the world's energy demand is met through fossil fuels, the combustion of which releases carbon dioxide and various pollutants, including sulfur and nitrogen oxides, which are highly harmful. Consequently, in recent years, there has been a growing inclination towards utilizing various renewable energy sources. One crucial energy source that also provides a solution for waste reduction is biogas. Given the increasing importance of sustainable energy development and the need for waste management, anaerobic digestion technology and biogas production have rapidly grown. Therefore, the findings of this research underscore the importance of exploring innovative methods and utilizing diverse biological resources in managing and optimizing the biogas production process.
Mahmoud Baghbanian; shaban ghavami jolandan; Seyed Mohammad Safieddin Ardebili; Seyed Majid Sajadiye
Abstract
Introduction In recent years, Underground heating systems are one of the cleanest and best types of heating systems which these techniques have been used in many greenhouses. In this method, a source of thermal energy, which is often a gas or diesel, is used to heat the fluid. Then, the heated fluid ...
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Introduction In recent years, Underground heating systems are one of the cleanest and best types of heating systems which these techniques have been used in many greenhouses. In this method, a source of thermal energy, which is often a gas or diesel, is used to heat the fluid. Then, the heated fluid is transferred to the entire greenhouse through the pipe networks that are placed on the floor of the greenhouses and under the soil, and creates a pleasant heat. During the cold months of the year, having a proper heating system for the greenhouse is essential. A standard greenhouse heating system could improve the temperature inside the greenhouse and spread it evenly on the entire surface of the greenhouse and finally, it is very effective in the growth and quality of plants and products in all months of the year. Today, fluids play a very important role in industry, especially in heating systems. Common fluids such as water, ethylene glycol and motor oil have a limited conductivity coefficient. Therefore, using the above-mentioned fluids at high temperatures causes heat transfer problems. Nanofluids consist of very small particles (usually less than 400 nm) dispersed in a base fluid. The conducted research shows that due to the high thermal conductivity of nanofluids compared to common fluids, in the future nanofluids will become a new type of fluid used in advanced heat transfer for engineering applications. Therefore, according to the importance of this topic, in this research, the heating system of the greenhouse floor is simulated and analyzed using CFD technique.Materials and Methods In this research, in order to simplify the process of simulation, the inhomogeneity in the fluid flow is ignored and the single-phase flow is considered. In order to investigate the effect of each of the nanofluids on the fluid behavior and heat transfer of the pyramidal greenhouse, analysis and simulation of the greenhouse was performed based on three-dimensional computational fluid dynamics. First, the geometry of the control volume of a greenhouse was designed in Solidwork software, and in order to check the simulation, a pyramidal geometry was considered. The boundary conditions for the coldest day and night temperature in the year were extracted according to the environmental conditions by measuring the data of temperature, humidity and air flow. Two parameters of pressure drop value and Nusselt number were selected as target parameters in this research. The flow friction coefficient in the floor heating section was calculated through the pressure drop along the section and its hydraulic diameter. Single-phase fluid pressure drop in all pipes inside the thermal cycle was modeled in this section. Finally, the parametric analysis of the results and the comparison of the heating efficiency of the greenhouse floor for two types of nanofluid alumina and titanium dioxide in volume percentages of 1%, 2% and 3% were used. Besides, the effect of the mentioned parameters on the Nusselt number and in the flow of floor heating was investigated.Results and DiscussionBased on the obtained results, it was concluded that an increase in Reynolds number in all volume percentages leads to an increase in Nusselt number and alumina nanofluid has a higher Nusselt number than titanium dioxide nanofluid. Also, in both nanofluids assuming a constant inlet temperature of 40℃ and a diameter of nanoparticles of 5 nm, the Nusselt number also increased with an increase in the volume percentage of particles at a constant Reynolds number. According to the results obtained with the increase in the diameter of nanoparticles, the Nusselt number decreased for both alumina and titanium dioxide nanofluids, which is greater for titanium dioxide nanofluids. Considering the findings related to the pressure drop, with the increase in the volume percentage of nanoparticles in both nanofluids, the pressure drop increased, and this drop is more severe in the alumina nanofluid, and it could be attributed to the higher density and viscosity of the alumina nanofluid compared to the titanium dioxide nanofluid. The results related to the pressure drop showed that, with the increase in the volume percentage of nanoparticles in both nanofluids, the pressure drop increased, and this drop is more intense in the alumina nanofluid and this factor is attributed to the higher density and viscosity of alumina nanofluid compared to titanium dioxide nanofluid. On the other hand, the increase in Reynolds number in both nanofluids has resulted in an increase in pressure drop. The results related to the changes in the friction coefficient in terms of Reynolds number in different volume percentages show that the coefficient decreases with the increase in Reynolds number, and these changes are more intense at lower Reynolds numbers. By comparing the performance coefficient between alumina nanofluid and titanium dioxide nanofluid, it can be concluded that the average value of this coefficient is 14% higher than other nanofluids for alumina nanofluid. But, the sensitivity of the performance coefficient of titanium dioxide nanofluid compared to alumina nanofluid is more intense to the changes of Reynolds number.Conclusion Due to the production of greenhouse products in all seasons and the necessity of precise greenhouse control, it can be concluded that dealing with new and advanced methods in the management and optimization of the country's greenhouses is importance. The results of the present research show the fact that the simulation of heating from the greenhouse floor and its various aspects can be a suitable measure to check the uniformity and proper distribution of heat inside the greenhouse. In order to improve the efficiency of thermal equipment, using nanofluids with higher thermal ability is essential. Besides, comparing the performance coefficient of the system due to the use of nanofluids indicated the high efficiency of the use of nanofluids in comparison with pure water in the greenhouse floor heating system.
shayan hajinajaf; shaban ghavami jolandan; Hassan Masoudi
Abstract
Investigation of effective factors on water production system using land coolingAbstractIntroduction Water scarcity has been a worrying issue and one of the obstacles to economic growth of countries, despite various water supply sources such as groundwater, seas, rivers and rainfall. Today, in many parts ...
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Investigation of effective factors on water production system using land coolingAbstractIntroduction Water scarcity has been a worrying issue and one of the obstacles to economic growth of countries, despite various water supply sources such as groundwater, seas, rivers and rainfall. Today, in many parts of the world, due to the scarcity of water resources, disputes over access to water resources have crossed national borders and access to these resources has become a strategic goal in the interaction between countries. According to statistics released by the World Resources Institute in recent years, about 35 countries will face water stress in 2040, of which Iran ranks 13th. Considering the average rainfall in Iran and also considering the amount of water resources and per capita consumption in the country, Iran is considered among the countries that are at risk of lack of physical water resources. The purpose of this study was to provide safe water for domestic use and drinking water without using fresh water sources and only with the benefit of the air humidity. In fact, the goal is to provide fresh water from the humidity, especially for remote areas and villages with small populations that do not have access to water. In this method, there is no need to use fossil and electrical energy and only wind energy, air humidity and depth of the earth are the factors of its production, and so it is also economically viable. The system considered in this research reduces the air temperature and cools it until the saturation phase by blowing the outside hot air into a buried pipe underground. In this way, some part of the air moisture is separated and appeared in the form of water droplets on the pipe wall; then the obtained water is stored in a tank and used. Materials and Methods In this research, a system was used that was partly underground and partly out of the soil. Buried sections include the copper pipes, the circuit breakers and connections, and a water tank and the sections on the ground include a cubic chamber with dimensions of 2×2 m, temperature and humidity sensors, fans, inlet air supply section, valves control levers, air conditioners, heaters and humidifiers. During the tests, the temperature and humidity inside the chamber were controlled by a microcontroller board and the effect of changes in air humidity (30, 50, 70 and 90%), air temperature (20, 30, 40 and 50 °C), inlet air flow (2.5, 5 and 7.5 m3/h , equal to the speeds of 1, 2 and 3 m/s , respectively) and the pipe effective length (2 and 4 m with a fixed diameter of 30 mm and a thickness of 1 mm) on the amount of extracted water was evaluated. The burial depth of the pipe was about 1 m and the soil temperature was measured by a sensor next to the buried pipes. The used statistical design was the split plots design in the form of completely randomized blocks and the results were analyzed and compared using SPSS software. In order to create and control different atmospheric conditions inside the chamber, it was necessary to consume electrical energy, while in the open space water can be produced from this system without the need for electrical energy.Results and Discussion the studied factors, including the pipe length, air humidity, air temperature and air flow rate (inside the pipe), affected on the amount of produced water significantly. By increasing of the air humidity, the air flow rate, the chamber air temperature and the pipe length, the amount of produced water was increased. The air temperature of 50 °C, the air velocity in 3 m/s, the humidity of 90% and 4 m length of the copper pipe had the maximum water production in a certain period of time.Conclusion The results of the present study show that water production from air humidity can be used as a method to produce fresh water, especially in remote and low populated areas with high air humidity that do not have access to the fresh water. Although the volume of water production by this method is not comparable with methods such as the multi-stage distillation, but it is economical and does not require any energy.
N Norouzi; shaban ghavami jolandan; M. J Sheikh Davoodi; S.M. Safieddin Ardabili
Abstract
IntroductionToday, with advances in all sciences, we must always look for a way to make the best use of plant residues and turn them into valuable products. A consequence of improving family life standards and consistent industrial development is a higher demand for energy usage. Nowadays, agricultural ...
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IntroductionToday, with advances in all sciences, we must always look for a way to make the best use of plant residues and turn them into valuable products. A consequence of improving family life standards and consistent industrial development is a higher demand for energy usage. Nowadays, agricultural residues are produced in huge quantities and could be considered as a promising source for renewable energy generation. Bagasse is one of the major sources of sugarcane production. The production of valuable products from Bagas, in addition to having economic benefits, can reduce the environmental damage caused by burning them. In recent years, there has been an increasing trend in the utilization of sugarcane bagasse as a major by-product of the sugarcane industry. Another very valuable substance produced from sugarcane bagasse, which we will discuss in this study, is bio compressed coal. Valorization of sugarcane bagasse to engineered biochar using hydrothermal carbonization (HTC) presents a perspective source to substitute conventional fossil fuels. HTC process offers the benefits of converting the sugarcane bagasse into biochar and bio-oil. In this process, biomass is usually conducted in the temperature range of 180–250 ◦C. HTC technique is promoted as one way of reducing carbon dioxide (CO) emissions, which mostly generated through open burning of crop residues. Besides the utilization for power/heat generation for sugarcane industries, Bagasse may find other potential applications, for instance: electricity generation, biogas production, livestock feed/compost production, and also bioethanol production. The unique features of biochar generated through HTC process are its portability, high volumetric energy density, hydrophobicity, and wear ability. Materials and MethodsIn this research, sugarcane waste was obtained from Hakim Farabi Sugarcane Cultivation and Industry Company in Ahvaz. The hydrothermal carbonization process was performed in a batch reactor at Shahid Chamran University of Ahvaz. The parameters studied in this study include the retention time of the material inside the reactor (30, 75, and 120 minutes), bagasse mass to water ratio (0.15, 0.20, and 0.30) and the pressure inside the reactor (10, 12.5 And 15 bar). In order to measure the pressure, a Nuova FiMa barometer was used, which was able to measure the pressure values up to 25 bar. A temperature control system model HANYoung ED6 was used, which was equipped with a ceramic heater with a diameter of 230 mm and a height of 230 mm to provide heat for the process. The PARR1266 calorie bomb device was employed to measure the calorific value of the samples. The moisture content of the samples was also measured using ASTM-2010a standard. In this experimental work, the response surface method was employed to investigate the effect of input parameters (i.e., pressure, residence time, and water-to-biomass) on the response parameter (i.e., HHV and energy consumption). Design Expert ver.10 software was used to predict the corresponding models. The obtained models provided a good relationship between the independent/dependent parameters. Results and DiscussionThe HTC process has been analyzed using a Response Surface Method to derive predicted models for the HHV and energy parameters. The results obtained showed that all models provided could successfully predict the HTC process. According to the results, the models developed were statistically significant at the level of 1%. The multi-regression models between the input/response variables were obtained as second-order quadratic equations. The F-value for the residence time, and water-to- bagasse, and pressure were 2417, 286, and 1185, respectively. The value of F-value of each derived model indicates the significance of the studied parameters. The parameters of water-to-bagasse and pressure had a more significant effect compared to the residence time factor. The R-square value for this study was achieved as 0.0996, indicating that the proposed model was able to evaluate the experimental data thoroughly. A multi-objective optimization technique was used to achieve an optimal HTC process condition with the maximum possible amount of desirability value. ConclusionThe optimum amount of water-to-bagasse, pressure, and residence time was calculated using the response surface techniques. A pressure of 11 bar, the residence time of 38 min, and water-to-bagasse of 0.15 were found to be optimal values. The findings of this study indicate that at optimal input variables, the value of calorific value and used energy was 21 Mj/kg and 0.09 kWh, respectively. Keywords: Hydrothermal carbonization, Sugarcane bagasse, Response surface method, Optimization
H. Mehregan; Sh. Ghavami Jolandan; M. E. Khorasani Ferdavani
Abstract
Introduction Today, in modern agriculture, the use of agricultural machines is inevitable. the tire is the last part of the power transmission system, which plays an essential role in controlling the tractor and transferring the tractor's reaction to the soil. Tires used in agricultural implements and ...
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Introduction Today, in modern agriculture, the use of agricultural machines is inevitable. the tire is the last part of the power transmission system, which plays an essential role in controlling the tractor and transferring the tractor's reaction to the soil. Tires used in agricultural implements and tractors should be able to transport appropriately and have sufficient adhesion and slip. Several parameters affect these abilities, including tire diameter and width, tire shape, tire tread modulus, tire pressure and load on the tire, with the last two parameters, tire pressure and load on the tire two very important factor is the tire and surface contact, the tire's contact between the tire and the ground, the tire's involvement in the direction of travel, as well as the tensile and fuel consumption of cars and motor vehicles. Given the fact that the tire pressures/load of agricultural machinery are less attractive to the users, Due to the many benefits that the use of electronic control systems. Due to the many benefits that the use of electronic control systems, Today, the use of electronic control technologies is considered as an innovation. the automatic tire pressure control system could ensure the pressure stability. Tire pressure drop is detected, and the system automatically refills the tire according to the tire pressure requirements. Therefore, the main aim of this paper is to set the tire pressure at the optimal value by designing an electronic control system for measuring and controlling tire pressure and evaluating the response speed of the system. Materials and Methods This research work is mainly aimed at designing a tire pressure control the tire pressure. BD pressure sensor, Arduino board, voltage/pressure regulator, 5-volt double-channel relay module was utilized. Moreover, Solenoid valve, rotary joint along with compressor and reservoir was employed for controlling tire pressure. In this paper, a laboratory tire pressure control system was designed which can operate in both manual and automatic modes. In automatic mode, a series of ideal pressure (P1) is defined as the soil type, and the driver selects an ideal pressure for the system. If the tire pressure (P0) differs from the set pressure point (P1), then the control unit determines a time duration (T1) for the decrease/increase the pressure level to achieve the optimal setpoint. Besides, a manual mode allows the system to provide a wide range of pressure for the driver depending on the terrain encountered. It is worthy of mentioning that the operation of the system in manual mode is the same as that of automatic mode. In this work, experiments were performed at three levels of output pressure (43.5, 65.2, 87 psi), two tire pressure reduction levels (20- 16 and 16 -12 psi), and two tire pressure increase levels (8 -12 and 12 -16 psi). The tests were laid out as a factorial in a completely randomized design with three replicates. Results and Discussion The ANOVA results indicated that the effect of reservoir outlet pressure on the timing function and tire pressure was significant at the level of 1% (p-value <0.01), while the dual and triple impacts of the factors were not significant. The results also illustrated an increase in the speed of the system response at the output pressure of the reservoir of 87 psi. Also, two different scheduling functions were conducted to evaluate the speed of the system response to reduce the tire two levels of 20 to 16 and 16 to 12 psi. For this reason, two different scheduling functions were used. The ANOVA results indicate that the timing function and tire pressure level had a significant effect on the output parameters at the level of 1%. Furthermore, an increase in the speed of the system response in the second-order scheduling function was observed. Comparison of system performance with first and second time estimation functions at different reservoir pressures, as shown in Fig. 9, showed that the use of the second-order estimation function in all cases reduced the number of steps to reaching the desired pressure significantly. Conclusion According to the obtained results, it can be concluded that the replacement of the second-order scheduling function to control tire pressure, increased the speed of the system’s response, which results in keeping the right pressure at all times very accurately.
Y. Abbaspour-Gilandeh; A. A. Khalifeh; S. Ghavami-Jolandan
