مصطفی کیانی ده کیانی

In recent years, due to its availability and low environmental pollution, the use of Earth-Air Heat Exchanger (EAHE) has been developed as an efficient energy system in heating and cooling residential buildings and agricultural greenhouses. In this system, air is circulated by a fan through a pipe buried deep in the ground. Depending on the geographical location and soil type, the soil temperature at a depth of 2-3 meters remains unchanged throughout the season. Of course, this depth varies throughout the year and according to climatic changes. The heat exchange between the soil and the air inside the pipe depends on the type of soil and its moisture content, the length and diameter of the air transmission pipe, the depth of burial and the velocity of the air flow (air velocity). Air circulation can be done in an open-loop or closed-loop circuit.

A factorial experiment was conducted in the form of a completely randomized block design with two factors (pipe length at three levels (34, 17 and 52 meters) and air velocity at two levels (5 and 10 m/s)) in three replications, to investigate the effect of these factors on the coefficient of performance (COP), system efficiency and outlet air temperature. The experiment was conducted in a greenhouse in Arak city, Iran, in Joune 2022. This 150 square meter greenhouse was equipped with geothermal equipment. Air was circulated through a 200 mm diameter PVC pipe buried three meters deep in the ground. Air was circulating through an open loop circuit. Dependent variables were measured during the hot hours of the day (from 12:00 to 18:00) for one week at the end of July. The air temperature at the fan inlet and at 17, 34 and 52 meters along the pipe was measured by a single-channel data logger. Hourly changes in outlet air temperature, COP and efficiency were measured in a 24-hour period and plotted using Excel software.

The outlet air temperature for the pipe length of 34 and 52 m did not change when the air velocity decreased from 10 m/s to 5 m/s. But for the pipe length of 17 m, the maximum temperature, COP and efficiency were observed at an air velocity of 5 m/s. Regardless the air velocity, the average temperature of the outlet air for the three levels of the pipe length was 28.5, 25.5 and 25.3°C, respectively. The outlet air temperature was almost the same for the 34 and 52 m pipe lengths. In other words, the optimal length of the pipe is about 34 meters. The mean efficiencies for these two pipe length levels were 0.69 and 0.66, but the COP depended on the air velocity. The average COP for air velocity of 5 and 10 m/s was obtained 1.4 and 2.5, respectively. Based on these results, the best performance of the system in terms of output temperature reduction, cooling efficiency and COP is obtained in situation that the length of the pipe is 34 m and the air velocity is 10 m/s. when the length of the pipe is 17 meters, the temperature of the air outlet at two velocities of 10 and 5 m/s was 29.9 and 27 °C, respectively. The cooling efficiency and COP at two velocity of 10 and 5 m/s, were 0.34, 0.54; and 2.1, 1.7 respectively. If the desired temperature is 28-30 °C, pipe length of 17 m and the air velocity of 5 m/s is recommended. The results of hourly performance analysis showed that the highest difference between inlet and outlet air temperatures, is obtained at middle hours of the day. The higher the ambient temperature, the higher the efficiency of the EAHE system.

This system successfully met the cooling needs of a model greenhouse in the weather conditions of Markazi Province in June. Based on the results, the optimal pipe length and air velocity were obtained as 34 m and 10 m/s, respectively. The average air outlet temperature and cooling efficiency were 25.5, 0.66 and 2.5 respectively. The higher the ambient temperature, the higher the EAHE efficiency. This is mainly due to the higher temperature difference between the outgoing and incoming air during the hottest hours of the day. As a result, system efficiency and COP increase at the hottest hours of the day.

The reason for drying is the long-term storage of food, minimizing the need for storage, packaging and reducing transportation costs. In this research, the aim is to use a combination of solar dryer with heat recovery system (MCHP) which, while storing energy, also makes temperature control possible. In the present study, the MCHP (Micro-scale Simultaneous Power and Heat Generation System) system consists of a single-cylinder diesel engine with a power of 4.5 hp and a maximum engine speed of 2,500 rpm, which runs on biodiesel fuel. The solar dryer also has a flat collector, inside which a heat exchanger is designed and built. A vacuum cleaner was used to direct hot air from the collector to the dryer chamber. The results showed that by increasing the gas valve (25%, 50%, 75% and 100%), the temperature of the exhaust gas before entering the heat exchanger increases. The second converter was designed and built in the collector. Outlet water temperature of the collector converter in different throttle positions (25%, 50%, 75% and 100%) respectively (37.5 ± 2.5, 43.3 ± 2.3, 49 ± 2 and 55 ± 2 ° degrees Celsius) was. Also, the drying time of barberry crop for temperature (70 ° C and a speed of 1.5 m / s) was shorter than the temperature and other velocities in this study.

In this study, the performance of solar desalination by humidification-dehumidification of closed air and water in Ahvaz city was investigated. This desalination includes a collector, condenser, salty water, freshwater tanks, air blower, and water pump. The evaluation of the system was done at three levels of air velocity (3, 4, and 5 m/s) and at three pump discharge levels (2, 4, and 6 liters/min). The results showed that the lowest daily average of evaporative efficiency was about 56%, which obtained at air velocity of 3 m/s and water discharge of 2 liters/min, and the highest value of that was about 79%, which obtained at air velocity of 5 m/s and water discharge of 6 liters/min. Also, the highest daily average of condenser efficiency was 21.52%, which was obtained at the air velocity of 3 m/s and discharge water of 6 liters/min. The lowest freshwater was obtained at air velocity of 5 m/s and 2 liters/min, and the highest value was obtained at air velocity of 3 m/s and 6 liters/min.

According to the importance of energy and the impact of this input on the final price of a product, selection of materials and components of poultry saloons is very important.  Poultry saloons are divided into two types: open saloons and closed saloons. In closed saloons, the choice of materials and components of the saloon (door, window, etc.) are more sensitive than the open type. Due to the climatic conditions of Khuzestan province, all of the used saloons in this province are almost closed. Poultry farms in Khuzestan province have a lot of cooling load in the warm seasons. If the materials and components of the saloons are not chosen properly, energy losses increase, and as a result, the price of meat increases. Therefore, investigating of heating and cooling loads of saloons and use of suitable components to prevent energy losses is necessary. Energy modeling of saloons and buildings is done by various software (Plast Energy, Design Builder, Trnsys, etc.). One of the most efficient and precise of this software is Carrier.

This study was conducted to calculate heating and cooling loads in different climates of Khuzestan province. In this research, the cities of Izeh, Shoosh, Abadan and Andimeshk were selected as corresponding to different climates in the province.Required data  for software was collected in three categories: (a) Weather data (geographic information, location of the saloon, local time zone and local soil specifications), (b) Data  about the physical properties of the building (general specifications of the space, internal sources of heat production (personslabors, poultry, equipment), (c) Specifications of walls, floor, windows and doors, ceiling and lighters, (d) Infiltration of air, (e) Systems, and (f) Information on power and fuel consumption.In this research, a rectangular saloon with dimensions of 85×16 meter was considered for all three types of conventional saloons in the province (block, brick and panel), which are the common dimensions and the capacity of these saloons is 20,000 broiler chickens. In this study, Carrier software was used to calculate heating and cooling loads. The results of software were verified by the amount of fuel and power consumption.

The sand and soil floors had the highest cooling load by 48828 and 53012 kJ h-1, respectively, while concrete and mosaic floors had lower cooling load than them. The heating load of these two floors (3906 kJ h-1) was less than that in the sand and soil floors. Concrete floor had better conditions to choose because of the less cost than the mosaic floor.Comparison of heating and cooling loads in different types of walls made of various materials showed that the block wall had the highest heating load of 429356 kJ h-1 and the highest cooling load by 658356 kJ h-1, while the sandwich panel wall had the lowest heating load by 116873 kJ h-1 and the lowest cooling load by 123618 kJ h-1.Three types of doors are commonly used in poultry houses: iron, fiberglass and aluminum. The results showed that the iron and fiberglass doors had the highest and lowest heating and cooling loads, respectively. The investigation of the effect of different types of windows on heating and cooling loads showed that iron and plastic windows had the highest and lowest heating and cooling loads, respectively. The results showed that Irannait ceiling had the highest heating and cooling loads by 371416 kJ h-1 and 787535 kJ h-1, respectively, while the ceiling made of sandwich panel had the lowest heating and cooling loads by 72756 kJ h-1 and 72429 kJ h-1, respectively, because of low heat transfer coefficient.Comparison of heating load of the saloons showed that the block saloon had the highest heating load by 891525 kJ h-1 and the suggested saloon in this study had the lowest heating load by 309068 kJ h-1. The block and suggested saloons also had the highest and lowest cooling loads by 1604828 kJ h-1 and 330795 kJ h-1, respectively.

The amount of heating and cooling loads for suggested saloon were 29.6% and 18.24% lower than that of brick and block saloons, respectively. The difference in the cost of constructing suggested and brick (the most common saloon in the province) saloons was 28.9 million tomans. By considering the difference in the cost of energy consumption of them (11.726 million tomans), this amount will be compensated after 2 years and 5 months and then will be returned on investment.

Introduction:

 The limitation of fossil fuels and environmental pollution by using them have encouraged researchers toward renewable fuels.  The most important renewable fuels are bioethanol, biodiesel and biogas. Biogas is a gas that is produced from biodegradable fermentation, agricultural products and wastes, animal waste and urban waste by anaerobic digestion.  One of the products that has a significant amount of waste is sugar cane. This plant is widely cultivated in Khuzestan Province and annually produces a lot of waste which is currently not useful. One of the most important wastes is bagasse. Bagasse is the solid residues after crushing sugar cane and extracting it. Bagasse is composed of cellulose (45%), humiculus (27%), lignin (21%), extract (5%) and a small amount of inorganic salts (2%). A lot of bagasse is produced in sugar cane production process (about 240 kg with a moisture content of 50% per ton of sugar cane). Every year, a lot of bagasse is wasted. One of the most useful ways is to convert it into biogas and provide the percentage of the required thermal and electrical energy of the plant. Therefore, in this study, the effect of temperature and percentage of cow manure as an additive on biogas production from bagasse sugar cane was investigated.

Materials and Methods:

 The used bagasse in this research was provided from Farabi industry and Cultivation, located 48 km from Ahwaz, and a cow manure was provided from a livestock farm in Hamidieh, Ahwaz. In order to increasing the production efficiency of biogas, sugar cane bagasse was milled. Batch reactors of 4 liters was used to produce biogas from sugar cane bagasse.  To control and maintain the working temperature, the reactors were placed in a water bath and the temperature of the bath was kept constant by using the thermal element and the thermostat. Cow manure was used to provide source of microorganisms. Cow manure with 5, 10, 15 and 20% weight percentages (B5, B10, B15 and B20) was blended with bagasse (numeric index of B indicates the percentage of cow manure in the blends). Sodium bicarbonate was used to control the pH of the reactors. Stirring was carried out manually in order to homogenize the materials and prevent the formation of hard layer at the top of the reactors. The amount of produced biogas was daily measured by water displacement method. Another measured parameter was the total Solid Index (TS), which represents the percentage of organic and inorganic matter for materials of the reactors. The experiments were carried out by using eight reactors for 30 days and the results were analyzed by completely randomized factorial design.

Results and Discussion:

 The results of variance analysis of biogas production in terms of bagasse to cow manure ratio and temperature changes showed that they had a significant effect at 1% level on biogas production. Considering the interaction effects of temperature and bagasse to cow manure ratios have a significant effect on the produced biogas at a 1% level. The results showed that with increasing in the percentage of cow manure in the materials, the amount of biogas production increased at both temperatures, so that by increasing the ratio of cow manure in the blends from 5 to 20% at 35 and 45 ° C, the produced biogas increased by 27.78% and 81.83%, respectively. By increasing the percentage of cow manure in the blends, the number of microorganisms in the digestion increased, and as a result of their activity, the amount of produced biogas increased. It was also observed that with increasing the temperature of digestion from 35 ° C to 45 ° C, the biogas production for B5, B10, B15 and B20 blends increased by 19.82%, 22.5%, 15.85% and 80.8%, respectively. The highest amount of cumulative production of biogas was obtained 0.3 m3.kg.VS-1 for 45 ° C and 20% cow manure to bagasse ratio.

Conclusion:

 In this research, the effect of cow manure in blend of sugar cane bagasse and temperature on produced biogas was investigated. The experiments were carried out at two temperatures of 35 and 45 ° C, and four blends with different weight percentages from cow manure to bagasse (5, 10, 15 and 20 percent). The results showed that with increasing the percentage of cow manure in blends, the amount of biogas production increased. Also, with increasing temperatures from 35 ° C to 45 ° C, the production of biogas in all blends increased.

Anaerobic digestion has progressed rapidly since the late 1960s. With the progress of the anaerobic fermentation process in the world, anaerobic reactors have been developed to digest different types of organic wastes in each country. So various types of reactors have been built, and that they have been in different shapes, dimensions, and operating conditions. One of these reactors is the static granular bed reactor (SGBR). SGBR with its granular bed digests a substrate in less hydraulic retention time (HRT). SGBR is a downstream reactor that consists of active anaerobic granules. The biomass contacts the granular surfaces and does not require the use of mixers, gas, solid, and a separator. The reactor startup is very short since there is no need for some operations, such as extra time to grow microorganisms in the granule. One of the most important residues in the alcohol production plant from molasses is vinesse which has become a major problem in this industry. The conversion of vinasse to biogas and using it to supply the energy of the industry is one of the basic ways to solve this problem. Several studies have been conducted in this field by using various reactors, but there is no research about SGBR. In this study, an SGBR producing biogas from vinasse has been designed and constructed. Also, the performance of the reactor was investigated at three HRTs (2, 3, and 4 days) and the thermophile temperature of 55 °C. The best diameter to height ratio (reactor volume) in the SGBR is 1:7. Accordingly, the shape of the reactor is a pipe. Based on the volume of the reactor and the maximum pressure inside it, a 4-inch polyethylene tube with a height of 1 meter was selected to carry out the testes. According to the thermophile temperature (55 °C) and the accuracy of the element (0.9 °C), the maximum temperature of the reactor is 329 K. Therefore, the minimum power for obtaining this temperature is 405.316 watts. The water displacement method was used to measure the amount of biogas. An iron sponge was used for removing hydrogen sulfide gas from biogas. Sodium hydroxide solution was used to remove carbon dioxide from biogas. The reactors were loaded daily with organic matter (86002, 28667, and 21500 mgCOD/L.d) for different HRTs (2, 3, and 4 days). For three HRTs, the amount of methane production was high during the first day which is due to the thermal shock caused by the microorganisms in the granule. Methane production in HRT of 2 days had fewer variations than HRT of 3 and 4 days, and after 13 days, it reached a nearly constant value of 4600 ml/day. For HRT of 3 days, the daily rate of methane production reached a constant value of 4800 ml/day after 12 days and for HRT of 4 days, it reached 4,900 ml/day after 10 days. For HRTs of 2 and 3 days, the rate of methane production per unit of volatile solids had less variation and remained constant approximately after 7 days. The average methane production per unit of volatile solids at HRT of 4 is days higher than the other HRTs. The average methane production for HRTs of 2, 3, and 4 was 379, 380, and 433 CH4 (L)/VS (kg), respectively. The maximum value of methane production was 582 m3/kgCOD, which was obtained at HRT of 2 days. In this study, 31 liters of methane were produced per one liter of vinasse at HRT of 4 days, which was more than other studies. In this study, the required heat power and pressure inside the SGBR laboratory have been calculated. The minimum required heat is 261 watts. Also, this reactor should be able to bear at least 4.34 bar for biogas production. The average amount of methane production per unit of volatile solids was 379, 380, and 433 CH4 (L)/VS (kg) at HRTs of 2, 3, and 4 days, respectively. The maximum amount of produced methane was 582 m3/kgCOD, which was achieved at HRT of 2 days, and the maximum percentage of COD reduction was 39%, which was achieved at HRT of 4 days. In general, the results indicated that SGBR produced higher biogas from vinasse than other reactors, but it is not suitable for reducing pollutions.

One of the most important sources of the sugar production is sugarcane.Sugar is one of the eight human food sources (wheat, rice, corn, sugar, cattle, sorghum, millet and cassava). Also sugarcane is mainly used for livestock feed, electricity generation, fiber and fertilizer and in many countries sugarcane is a renewable source for the biofuel. The efficient use of inputs in agriculture lead to the sustainable production and help to reduce the fossil fuel consumption and greenhouse gases emission and save financial resources. Furthermore, detecting relationship between the energy consumption and the yield is necessary to approach the sustainable agriculture. It is generally accepted that many countries try to reduce their dependence to agricultural crop productions of other countries. The being Independent on agricultural productions lead to take more attention to modern methods and the objective of all these methods is increasing the performance with the efficient use of inputs or optimizing energy consumptions in agricultural systems. Energy modeling is a modern method for farm management that this model can predict yield with using the different amount of inputs. The objective of this study was to predict sugarcane production yield and (greenhouse gas) GHG emissions on the basis of energy inputs.
This study was carried out in Khouzestan province of Iran. Data were collected from 55 plant farms in Debel khazai Agro-Industry using face to face questionnaire method. In this study, the energy used in the sugarcane production has considered for the energy analysis without taking into account the environmental sources of the energy such as radiation, wind, rain, etc. Energy consumption in sugarcane production was calculated based on direct and indirect energy sources including human, diesel fuel, chemical fertilizers, pesticides, machinery, irrigation water, electricity and sugarcane stalk. Energy values were calculated by multiplying inputs and outputs per hectare by their coefficients of energy equivalents. Input energy in agricultural systems includes both direct and indirect energy and renewable and non-renewable forms. Direct energies include human labor, diesel fuel, water for irrigation and electricity and indirect energies consisted of machinery, seed (cultivation of sugarcane has been done with cutting of sugarcane instead of seed), chemical fertilizer. Renewable energies include machinery, sugarcane stalk, chemical fertilizer while non-renewable energy consisted of machinery, chemical fertilizer, electricity and diesel fuel. Energy values were calculated by multiplying inputs and outputs per hectare by their coefficients of energy equivalents. The amounts of GHG emissions from inputs in sugarcane production per hectare were calculated by CO2 emissions coefficient of agricultural inputs. Energy modeling is an attractive subject for engineers and scientists who are concerned about the energy management. In the energy area, many different of models have been applied for modeling future energy. An artificial neural network (ANN) is an artificial intelligence that it can applied as a predictive tool for nonlinear multi parametric. Artificial neural network has been applied successfully in structural engineering modeling ANNs are inspired by biological neural networks.
The total energy used in the farm operations during the sugarcane production and the energy output was 1742883.769 and 111000 MJha_1, respectively. Electricity (52%) and chemical fertilizers (16%) were the most influential factors in the energy consumption. The electricity contribution was the highest due to the low efficiency of energy conversion in electric motors which were used for irrigation in the study area. In some areas, inefficient surface irrigation wastes a lot of water and energy (in forms of electricity). Another reason is that electricity energy equivalent for Iranian electricity production is higher than developed countries because Iran’s electricity grid is highly dependent on fossil fuels, so that 95% of the electrical energy in Iran is generated in thermal power plants using fossil fuels sources. In addition, the electricity transmission system is too old. GHG emissions data analysis indicated that the total GHG emissions was 415337.62 kg ha-1 (CO2eq) kgCO2eq ha-1 in which burning trash with the share of 62% had the highest GHG emission and followed by electricity (32%), respectively. The ANN model with 7-5-15-1 and 5-5-1 structure were the best model for predicting the sugarcane yield and GHG emissions, respectively. The coefficients of determination (R2) of the best topology were 0.98 and 0.99 for the sugarcane yield and GHG emissions, respectively. The values of RMSE for sugarcane production and GHG emission were found to be 0.0037 and 4.52×10-6, respectively.
The statistical parameters of R2 and RMSE demonstrated that the proposed artificial neural networks results have best accuracy and can predict the yield and GHG emission. It is generally showed that artificial neural networks have good potential to predict the yield of the sugarcane production.

In this study, the production of biogas from vinasse by using three SGBR reactors with the same volume of 5.6 liters for three hydraulic retention times (2, 3 and 4 days) and organic loading rates of 86002, 28667 and 21500 mgCOD/L.d was investigated. The water bath method was used to provide the temperature of mesophyll reactors at 35, and NaOH solution was used for buffer. The biogas volume was measured using the water displacement method. The results showed that the methane production was almost constant with HRT of 4, 3, and 2 days after 11, 13, and 16 days, respectively. Methane gas production with HRT of 2, 3, and 4 days was 6.66, 16.66 and 27.38 LCH4(STP)/L.day per liter of vinasse, respectively. For three reactors, methanogen and acidogenic bacteria were in the equilibrium state at pH 5.57 after 2 days. The amount of methane gas production per volatile solids with the HRT of 2, 3, and 4 days was 244, 345 and 434 m3CH4/gvs, respectively.

IntroductionThe extensive use of diesel engines in agricultural activities and transportation, led to the emergence of serious challenges in providing and evaluating alternative fuels from different sources in addition to the chemical properties close to diesel fuel, including properties such as renewable, inexpensive and have fewer emissions.
Biodiesel is one of the alternative fuels. Many studies have been carried out on the use of biodiesel in pure form or blended with diesel fuel about combustion, performance and emission parameters of engines. One of the parameters that have been less discussed is energy balance.
In providing alternative fuels, biodiesel from waste cooking oil due to its low cost compared with biodiesel from plant oils, is the promising option. The properties of biodiesel and diesel fuels, in general, show many similarities, and therefore, biodiesel is rated as a realistic fuel as an alternative to diesel. The conversion of waste cooking oil into methyl esters through the transesterification process approximately reduces the molecular weight to one-third, reduces the viscosity by about one-seventh, reduces the flash point slightly and increases the volatility marginally, and reduces pour point considerably (Demirbas, 2009). In this study, effect of different percentages of biodiesel from waste cooking oil were investigated. Energy distribution study identify the energy losses ways in order to find the reduction solutions of them.
Materials and MethodsRenewable fuel used in this study consists of biodiesel produced from waste cooking oil by transesterification process (Table 1). Five diesel-biodiesel fuel blends with values of 0, 12, 22, 32 and 42 percent of biodiesel that are signs for B0, B12, B22, B32 and B42, respectively.
The test engine was a diesel engine, single-cylinder, four-stroke, compression ignition and air¬cooled, series 3LD510 in the laboratory of renewable energies of agricultural faculty, Tarbiat Modarres University. The engine is connected to a dynamometer and after reaching steady state conditions data were obtained (Fig. 1).
In thermal balance study, combustion process merely as a process intended to free up energy fuel and the first law of thermodynamics is used (Koochak et al., 2000). The energy contained in fuel converted to useful and losses energies by combustion. Useful energy measured by dynamometer as brake power and losses energy including exhaust emission, cooling system losses and uncontrollable energy losses.
Variance analysis of all engine energy balance done by split plot design based on a completely randomized design and the means were compared with each other using Duncan test at 5% probability.
Results and DiscussionResults showed that, in general, biodiesel use has a significant impact on all components of energy balance. Of total energy from fuel combustion, the share of energy losses to form of exhaust emissions the maximum value in all percentages allocated to biodiesel (Average 51.715 percent) with the maximum and minimum amount of B42 (55.982 percent) and B0 (46.481 percent), respectively (Fig. 2). Also, fuel blend with 12% biodiesel was diagnosed the best blend because of having the most useful power, having the lowest energy losses through the exhaust and cooling system.
ConclusionsUsing biodiesel produced from waste cooking oil by transesterification process, lead to increase the useful power. The addition of biodiesel to pure diesel cause to significant reduction in the waste energy due to friction. In higher amounts of biodiesel increase energy losses especially through the exhaust and cooling system due to higher viscosity.

The first law of thermodynamics expresses the conservation of energy in all processes and does not apply any restriction on the transfer of energy. However¡ in recent years¡ in order to quantify the quality of energy¡ the concept of exergy has been defined widely used in design¡ simulation and evaluation of various thermal and thermochemical systems. In this study¡ the impact of the fuel and compression ratio on fuel chemical availabilities¡ thermomechanical and total availability in a spark ignition engine was examined. The results showed that by increasing the compression ratio¡ the shift process of the fuel chemical availability graph change. The parameter (a_th) at a compression ratio of 12 for the fuels E_0¡ E_20¡ E_40¡ E_60 and E_85increase to 9.2¡ 11¡ 10.9¡ 10.9 and 10.9% respectively¡ in comparison with compression ratio of 8. Also¡ total availability (a) at compression ratio of 12 is faster. exergy efficiency at compression ratio of 12 for fuels E_0¡ E_20 〖 ¡E〗_(40 )¡E_60 and E_85 increase to 11.7¡ 13.8¡ 11.3¡ 8.9 and 9.9% respectively¡ in comparison with compression ratio of 8%. It should be noted¡ that by increasing the amount of ethanol¡ terms exergy (thermo-mechanical¡ chemical fuel¡ and total) reduced. The efficiency of the second law of thermodynamics increased with increasing volume percent of ethanol.

This study was carried out in Khouzestan province of Iran. Data were collected from 113 ratoon farms in Debel Khazai Agro-Industry with face to face questionnaire method. The objective of this study was to predict sugarcane production yield and GHG (greenhouse gas) emissions on the basis of energy inputs. Accordingly¡ several ANN (artificial neural network) models were developed and the prediction accuracy of them was evaluated using the quality parameters. The results illustrated that average total input and output energy of sugarcane production were 145117.7978 and 87096.42 MJ.ha-1¡ respectively. Electricity¡ chemical fertilizers and water for irrigation were the most influential factors in energy consumption. The ANN model with 6-7-19-1 and 5-5-1 structure were the best for predicting the sugarcane yield and GHG emissions¡ respectively. The coefficients of determination (R2) of the best topology were 0.96 and 0.99 for sugarcane yield and GHG emissions¡ respectively. The values of RMSE for sugarcane production and GHG emission were found to be 17763522 MJ.ha-1 and 528¡ respectively.

In this paper, the effect of bioethanol- gasoline fuel blends on exhaust emissions of a four-cylinder spark ignition (SI) engine was investigated experimentally. Pure gasoline fuel was blended with various percentages of bioethanol (0, 20, 40, 60 and 85%), and the HC, CO, CO2 and NOX exhaust emissions were measured at different engine speeds and two throttle valve positions (full throttle and 50% throttle valve).The experimental results showed that as the ratio of bioethanol fuel is increased in the blend, the CO and HC emissions are decreased but CO2 and NOX are increased at two throttle valve positions. Also when the speed of engine was increased, the HC and CO2 emissions were decreased but CO and NOX emissions were increased. The statistical analysis indicated that the effect of bioethanol percentage in fuel blends on emissions at 5% level was significant.

In this paper، a model is described to predict performance parameters and emissions of a spark ignition (SI) engine using genetic programming (GP). To acquire data for training and testing of proposed GP، a four-cylinder engine was fueled with ethanol-gasoline fuel blends. The pure gasoline fuel was blended with various percentages of bioethanol (0، 5، 10، 15 and 20%)، and the engine brake power، the torque and exhaust emissions (CO، HC، CO2 and NOX) were measured at different engine speeds and loads. Experimental results showed that as the ratio of the ethanol fuel was increased in the blend، CO and HC emissions were decreased but the brake power، the torque، CO2 and NOX were increased. Numerous runs were performed with the GP model and the performance of developed equations was evaluated. Optimum models were selected according to statistical criteria of the root mean square error (RMSE) and the coefficient of determination (R2). Simulation results demonstrated that the GP model was a powerful tool to predict engine pollutant emissions.

Increase in environmental pollutions due to application of fossil fuels has encouraged researchers to investigate the renewable and clean fuels. One of the most important renewable fuels is bioethanol which makes a suitable fuel when it has with gasoline. The lower percentage volume of bioetanol blended with gasoline is called gasohol. In the present paper, the effect of gasohol which is a clean fuel on a spark ignition exhaust emissions of: CO, CO2, HC and NOX at 25, 50, 75 and 100% loads and speeds of 2000 and 4000 rpm was investigated. Bioethanol fuel was added to gasoline with different volume percentages (E0, E5, E10, E15 and E20). A gas analyzer was used for measuring exhaust emissions. Results of this study showed that increasing the percentage of bioethanol in gasoline fuel blends decreased CO and HC, while CO2 was increased. Also, for 25, 50 and 75% loads, NOX was decreased, but it was increased in full load conditions.