Hasan MERDUN - Academia.edu (original) (raw)

Papers by Hasan MERDUN

Research paper thumbnail of Temporal Variation of Soil Moisture Under Alley Cropping System in Pistachio in Semi Arid Region of Turkey

Friends Science Publishers, 2010

ABSTRACT Alley cropping is practiced to produce grain and forage crops, reduce soil and nutrient ... more ABSTRACT Alley cropping is practiced to produce grain and forage crops, reduce soil and nutrient losses by surface runoff and improve nutrient availability. Growing barley and legumes for grain and forage in pistachio, olive and vineyards is a common alley cropping ...

Research paper thumbnail of Çokdeğişkenli Analiz Ile Katalitik Hızlı Pirolizin Biyoyağ Bileşenlerinin Değerlendirilmesi

Pamukkale University Journal of Engineering Sciences, 2019

Katalitik hızlı piroliz yöntemi ile üretilen biyoyağdaki kimyasalların varlığı ve verimleri prose... more Katalitik hızlı piroliz yöntemi ile üretilen biyoyağdaki kimyasalların varlığı ve verimleri proses parametreleri tarafından etkilenmekte, dolayısıyla, kimyasallar ve proses parametreleri arasındaki ilişkiler çokdeğişkenli analiz teknikleri ile detaylı bir şekilde araştırılmalıdır. Bu çalışma temel bileşenler analizi (PCA) ve hiyeraraşik sınıflama analizini (HCA) kullanarak belediye katı atıklarının katalitik hızlı piroliz deneylerinin 24 örneğine (konusuna) bağlı olarak biyoyağ içerisinde en fazla bulunan 11 kimyasal maddeyi sınıflandırmaktadır. Üç temel bileşen oluşmuş, fakat bunların ilk ikisi toplam değişkenliğin %74'ünü açıklamıştır. PCA'inde örnekler ve değişkenler (kimyasallar) sırasıyla 4 ve 2 farklı grupta toplanmıştır. HCA'inde ise örnekler ve değişkenler 2 ana grup ve birkaç alt grupta toplanmıştır. PCA ve HCA'nin her ikisinin sonuçları da örneklerde ve değişkenlerde açık bir gruplanmanın olduğunu göstermiştir.

Research paper thumbnail of Comparison of Irrigation Performance Based on the Basin, Crop Pattern, and Scheme Sizes Using External Indicators

Turkish Journal of Agriculture and Forestry, 2004

A comparative assessment allows screening of irrigation systems based on the key issues relative ... more A comparative assessment allows screening of irrigation systems based on the key issues relative to performance and indicates where improvements should be made, such as in type of management, infrastructure, crop pattern and intensity, and system size. The objective of this study was to assess the performance of 239 irrigation schemes (57 DSI-operated and 182 transferred to Irrigation Associations) based on the basin, crop pattern, and scheme sizes using 6 external indicators for 2001. The basins that grow mostly orchard and industrial crops have higher output per unit land and water than that of the basins that mostly grow cereals. ANOVA test results indicated that the differences in all the indicators except for the relative water supply among the crops in all schemes were statistically significant (P = 0.05). However, the differences in all the indicators except for the irrigation ratio among the size groups of all schemes were not statistically significant. Although more water t...

Research paper thumbnail of Factors Affecting Preferential Flow

Preferential flow concept is important because it is related to a variety of subjects such as agr... more Preferential flow concept is important because it is related to a variety of subjects such as agricultural applications, urbanization, environmental pollution, and industrial production. Any kind of wastes left on the environment by means of any of these activities rapidly reaches groundwater by flowing through cracks, earthworm holes, plant root channels, openings developed due to the factors such as soil textures and structures. Soil factors such as soil texture and structure and rainfall factors such as amount and intensity of rainfall are important factors which affect the extent of preferential flow and transport.

Research paper thumbnail of Modeling of pyrolysis product yields by artificial neural networks

Artificial neural network (ANN) needs to be applied to the complex, multivariate, and highly vari... more Artificial neural network (ANN) needs to be applied to the complex, multivariate, and highly variable biomass and pyrolysis data to define optimum input variables and develop effective models. In this study, two different ANN methods, the feed-forward network (FFN) and the cascade-forward network (CFN), were applied to model pyrolysis product yields (biochar-BC, bio-oil-BO, and gas mixture-G) from 11 biomass and pyrolysis variables through hierarchical modeling approach. Both methods were supplied with two subsets of data, with two-thirds being used for training and one-third for testing the performances of the methods, after normalizing all data (72 samples). The performances of both ANN methods were evaluated by using three statistical parameters. In general, FFN and CFN methods had very similar performances in training and testing. Both methods had mean R 2 of 0.91, 0.96, and 0.95 for training BC, BO, and G, respectively. For testing of all FFN and CFN models, the R 2 value...

Research paper thumbnail of Pedotransfer functions for point and parametric estimations of soil water retention curve

Plant, Soil and Environment, 2011

A water retention curve is required for the simulation studies of water and solute transport in u... more A water retention curve is required for the simulation studies of water and solute transport in unsaturated or vadose zone. Unlike the direct measurement of water retention data, pedotransfer functions (PTFs) have attracted the attention of researchers for determining water retention curves from basic soil properties. The objective of this study was to develop and validate point and parametric PTFs for the estimation of water retention curve from basic soil properties such as particle-size distribution, bulk density, and porosity using multiple-linear regression technique and comparing the performances of point and two parametric methods using some evaluation criteria. 140 soil samples were collected from three different databases and divided as 100 and 40 for the derivation and validation of the PTFs. All three methods predicted water contents at selected water potentials and combined water retention curves pretty well, but van Genuchten’s model performed the best in prediction. Ho...

Research paper thumbnail of Synergistic effects on co-pyrolysis and co-combustion of sludge and coal investigated by thermogravimetric analysis

Journal of Thermal Analysis and Calorimetry, 2021

Research paper thumbnail of Fast pyrolysis of greenhouse waste into bio-oil and optimization of process conditions using response surface methodology

Biomass Conversion and Biorefinery, 2021

Research paper thumbnail of Kinetic and thermodynamic analyses during co-pyrolysis of greenhouse wastes and coal by TGA

Renewable Energy, 2021

Abstract For thermal and kinetic analyses of co-pyrolysis of biomass and coal thermogravimetric a... more Abstract For thermal and kinetic analyses of co-pyrolysis of biomass and coal thermogravimetric analysis (TGA) is usually used to get valuable information for accurate design of co-pyrolysis facilities. In this study, pyrolysis mechanism of the equal mixture of tomato, pepper, and eggplant wastes as greenhouse vegetables wastes (GVW) and its blend with coal was investigated by using TGA with different heating rates. Kinetic and thermodynamic parameters were calculated by using Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. To highlight the synergistic effect between GVW and coal during co-pyrolysis, the deviation between the experimental and calculated values of mass loss and mass loss rate was calculated. The average activation energy (Ea) of 100%wt calculated by FWO and KAS models was 74.27 and 67.00 kJ mol−1, whereas Ea of 0%wt was 133.99 and 129.84 kJ mol−1, respectively. The average Ea of 25%wt was 148.34 and 145.19 kJ mol−1, while it was 57.21 and 49.40 kJ mol−1 for 50%wt. The positive values of deviation indicated the existence of synergistic effect between GVW and coal during co-pyrolysis. The blend of 50%wt with the smallest Ea and ΔS was the best combination for the simultaneous valorization of GVW and coal through pyrolysis.

Research paper thumbnail of Investigation of thermal behavior of pine sawdust and coal during co-pyrolysis and co-combustion

Energy, 2021

Abstract Nowadays, most of the recent large-scale installations are configured to use more than o... more Abstract Nowadays, most of the recent large-scale installations are configured to use more than one fuel. Thermal analysis allows us to properly design and operate especially such a large-scale co-pyrolysis and/or co-combustion process. In this study, thermal behaviours of pine sawdust (PS), coals, and their blends were investigated by using thermogravimetric analysis (TGA) under nitrogen and air atmospheres with different heating rates of 10, 20, and 40 °C min-1. Kinetic parameter such as activation energy (Ea) was calculated by using Kissenger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), and Starink models. The results showed the existence of an obvious synergistic effect between PS and coal during pyrolysis and combustion processes. The initial, maximum, and burnout temperatures of the reactions; the mass loss rate; and total mass loss were influenced by the proportions of PS and coal in the blend. For pyrolysis the average Ea of 25PS calculated by KAS, FWO, and Starink models was found as 31.57, 40.45, and 32.55 while that of 50PS was 166.80, 168.64, and 167.25 kJ mol-1, respectively. For combustion, the average Ea of 25PS calculated by KAS, FWO, and Starink models was found as 59.57, 67.74, and 60.52 while that of 50PS was 66.60, 74.20, and 67.49 kJ mol−1, respectively. According to the Ea value, the blend of 25PS was more suitable than 50PS for energy production through both pyrolysis and combustion. This synergistic effect between PS and coal may be further detailed with more different blend ratios.

Research paper thumbnail of Catalytic fast pyrolysis of Pearl Millet and Sida cordifolia L. to investigate products distribution and bio-oil quality

Fast pyrolysis is an attractive way of converting abundant biomass resources into valuable produc... more Fast pyrolysis is an attractive way of converting abundant biomass resources into valuable products such as bio-oil. Nevertheless, high oxygenated compounds and water content of bio-oil limit its direct use as fuel or chemicals. Catalytic fast pyrolysis (CFP) is able to improve bio-oil properties so that downstream upgrading processes can be economically feasible. In this study five different catalysts such as zeolite socony mobil-5 (ZSM-5), cerium dioxide (CeO2), zirconium dioxide (ZrO2), zinc oxide (ZnO), and sodium carbonate (Na2CO3) were employed due to their potential in enhancing bio-oil properties. CFP of pearl millet (PM) and Sida cordifolia (Sida) was performed to investigate the effects of catalysts on the products distribution and chemical contents of bio-oil. The results showed that bio-oil yield decreased during CFP regardless of catalyst and biomass types. Among all catalysts, CeO2 was found to be the most suitable to produce acids and alkanes from CFP of PM; and acids...

Research paper thumbnail of Optimization and characterization of bio-oil from fast pyrolysis of Pearl Millet and Sida cordifolia L. by using response surface methodology

Fuel, 2020

Abstract The objective of this study was to optimize experimental parameters to obtain the maximu... more Abstract The objective of this study was to optimize experimental parameters to obtain the maximum bio-oil yield (BOY) from fast pyrolysis of Pearl Millet (PM) and Sida cordifolia L. (Sida) by using response surface methodology (RSM) based on the central composite design (CCD). Important fast pyrolysis process parameters such as particle size (PS), reaction temperature (T), and nitrogen gas flowrate (NGF) were optimized. The most influential factor of each experimental design response was identified and an empirical model was derived in terms of factors through ANOVA. The second-order polynomial equation for the BOY was developed to correlate the parameters. The cubic and quadratic models fit the data of PM and Sida the best, respectively. The maximum BOY of 48.27 and 48.00% for PM and Sida respectively were obtained at the optimum parameters of PS of 1.5 mm, T of 400 °C, and NGF of 200 mL min−1 for both biomasses. GC–MS analysis of the optimized bio-oil samples from PM and Sida indicated the presence of many important chemical compounds such as acids, alcohols, aldehydes, aromatics, ketones, phenols, and others. Therefore, PM and Sida can be used as feedstocks for fuels and chemicals production through fast pyrolysis.

Research paper thumbnail of Kinetic analysis of Pearl Millet (Penissetum glaucum (L.) R. Br.) under pyrolysis and combustion to investigate its bioenergy potential

Fuel, 2020

Abstract Pearl Millet (Penissetum glaucum (L.) R. Br.), ranked as the sixth most grown cereal cro... more Abstract Pearl Millet (Penissetum glaucum (L.) R. Br.), ranked as the sixth most grown cereal crop in the world, is an important food crop produced in Africa and India. In this study, residues of Pearl Millet were used to evaluate its thermal decomposition characteristics through thermogravimetric analysis (TGA). TGA was made in the presence of nitrogen and air to represent pyrolysis and combustion, respectively. Thus, five different heating rates were used as 10, 20, 30, 40, 50 °C min−1 in the analyses. The kinetics and thermodynamic parameters were determined by using isoconversional models of Flynn-Wall-Ozawa (FWO) and Kissenger-Akahira-Sunose (KAS). The results showed that the average of activation energy during pyrolysis was 89.63 and 83.89 kJ mol−1, respectively, calculated by the FWO and KAS methods; while it was 57.27 and 49.47 kJ mol−1 in combustion. The low activation energies obtained from both models show that millet residues are suitable for pyrolysis and combustion.

Research paper thumbnail of Pyrolysis and combustion kinetics of Sida cordifolia L. using thermogravimetric analysis

Bioresource Technology, 2020

Sida cordifolia L. (Sida) is an annual invasive plant that remains underutilized in Niger. The go... more Sida cordifolia L. (Sida) is an annual invasive plant that remains underutilized in Niger. The goal of this study was to characterize the thermal decomposition of Sida for its valorisation as a source of energy through thermogravimetric analysis (TGA). TGA was carried out under nitrogen and air atmospheres. Thus, five different heating rates were used as 10, 20, 30, 40, 50 °C min-1. Kinetic and thermodynamic parameters were determined by isoconversional models of Kissenger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The results showed that the average activation energy (Ea) of Sida calculated by KAS and FWO in pyrolysis was found to be 74.74 and 80.74 kJ mol-1 respectively, while it was 51.08 and 58.91 kJ mol-1 in combustion respectively. Kinetic and thermodynamic parameters such as Ea, ΔH, ΔS, and ΔG obtained by KAS and FWO show that Sida is a remarkable feedstock for bioenergy.

Research paper thumbnail of Utilization of Two Artificial Neural Network Methods in Surface Water Quality Modeling

Environmental Engineering and Management Journal, 2010

Artificial neural networks (ANNs) are capable of learning the relationships between the dependent... more Artificial neural networks (ANNs) are capable of learning the relationships between the dependent and predictor surface water quality variables and have a high ability to predict from the new data set. In this study, two different ANN methods, the feedforward network (FFN) and the cascadeforward network (CFN) were applied to predict two surface water quality variables such as chlorophyll-a (Chl-a) and fecal coliform (FC) using twelve other variables as an input to the models. Both methods, for developing and training the ANN, are multilayer, leading to the same architecture of the feedforward neural network trained by back-propagation learning algorithm. The networks were supplied with two subsets of water quality data, with two-thirds being used for training and one-third for testing the performance of the networks, after pre-processing of the data set (110 samples) by normalization and moving average techniques. The performances of both ANN methods were evaluated visually by plotting and quantitatively by using five statistical parameters. The training procedures of both ANN methods for Chl-a and FC were very successful and a perfect match was obtained between the measured and predicted values with the correlation coefficient (R) of 1.00. The testing or prediction results also produced good agreements with the measured data of Chl-a and FC in terms of R values of 0.83, 0.93 (for FFN), and 0.89, 0.91 (for CFN), respectively. Results of this study show that ANN methods are able to predict Chl-a and FC with reasonable accuracy, suggesting that ANN is a valuable and powerful tool for surface water quality modeling and management.

Research paper thumbnail of Evaluation of bio-oil compounds of catalytic fast pyrolysis by multivariate analysis

Pamukkale University Journal of Engineering Sciences, 2019

The presence and amounts of chemicals in bio-oil produced by catalytic fast pyrolysis are affecte... more The presence and amounts of chemicals in bio-oil produced by catalytic fast pyrolysis are affected by the process parameters, hence, the relationships between the chemicals and process parameters need to be investigated in detail by multivariate analysis techniques. The present work classifies the most available 11 chemicals in bio-oil based on the 24 samples (treatments) of catalytic fast pyrolysis experiments of municipal solid wastes by using principle components analysis (PCA) and hierarchical cluster analysis (HCA). There were 3 principle components (PCs), but the first 2 PCs explained 74% of the total variance. The samples and variables (chemicals) were clustered into 4 and 2 different groups, respectively, in PCA. The samples and variables were clustered in 2 main groups and a few subgroups in HCA. Both PCA and HCA results showed that there was a clear grouping in the samples and variables. Katalitik hızlı piroliz yöntemi ile üretilen biyoyağdaki kimyasalların varlığı ve verimleri proses parametreleri tarafından etkilenmekte, dolayısıyla, kimyasallar ve proses parametreleri arasındaki ilişkiler çokdeğişkenli analiz teknikleri ile detaylı bir şekilde araştırılmalıdır. Bu çalışma temel bileşenler analizi (PCA) ve hiyeraraşik sınıflama analizini (HCA) kullanarak belediye katı atıklarının katalitik hızlı piroliz deneylerinin 24 örneğine (konusuna) bağlı olarak biyoyağ içerisinde en fazla bulunan 11 kimyasal maddeyi sınıflandırmaktadır. Üç temel bileşen oluşmuş, fakat bunların ilk ikisi toplam değişkenliğin %74'ünü açıklamıştır. PCA'inde örnekler ve değişkenler (kimyasallar) sırasıyla 4 ve 2 farklı grupta toplanmıştır. HCA'inde ise örnekler ve değişkenler 2 ana grup ve birkaç alt grupta toplanmıştır. PCA ve HCA'nin her ikisinin sonuçları da örneklerde ve değişkenlerde açık bir gruplanmanın olduğunu göstermiştir.

Research paper thumbnail of Evaluation of MACRO model by short-term water and solute transport simulation in Maury silt loam soil

Plant, Soil and Environment, 2011

Modeling preferential flow has been a concern of many academic fields in the past 30 years all ov... more Modeling preferential flow has been a concern of many academic fields in the past 30 years all over the world and helps to prevent groundwater contamination. A dual-porosity model, MACRO, was evaluated for short-term (less than 2 days) simulation of water flow and non-reactive solute (chloride) transport through the profile of six plots in well-structured Maury silt loam soil. Water flow in micropores is calculated by the Richards’ equation while simple gravity flow is assumed in the macropores. Solute transport in the micropores is calculated by the convection-dispersion equation (CDE) while the dispersion and diffusion in the CDE is neglected for the solute transport in the macropores. The applied water and chloride reached the bottom of the profile during the 2 and 1-hour(s) application periods in studies 2 and 3, respectively. There is a strong indication of macropore flow in this soil. Based on the statistical criteria, the model accurately simulated water flow and solute...

Research paper thumbnail of Determination of the drainage basin characteristics using vector GIS

Hydrology Research, 2006

Detailed geomorphologic characteristics need to be compiled for performing hydrologic modeling of... more Detailed geomorphologic characteristics need to be compiled for performing hydrologic modeling of a basin. Basin form and hydrologic characteristics are to be related so the basin form must also be represented by quantitative descriptors. The typical morphologic characteristics used in hydrological analyses are basin area, perimeter, mainstream length, total stream length, contour length, basin shape (form factor, circularity ratio, compactness ratio, basin elongation), slope, drainage density, relief (maximum relief, relief ratio, relative relief), effective basin width, and median elevation. The objective of this study is to propose an algorithm to automatically calculate basin characteristics using vector GIS. The results produced by the algorithm were compared to the manual method and the two methods were found statistically similar.

Research paper thumbnail of Artificial neural network and regression techniques in modeling surface water quality

Environment Protection Engineering

Research paper thumbnail of Estimation of suspended sediment concentration by acoustic equations for soil sediment

AFRICAN JOURNAL OF BIOTECHNOLOGY

Research paper thumbnail of Temporal Variation of Soil Moisture Under Alley Cropping System in Pistachio in Semi Arid Region of Turkey

Friends Science Publishers, 2010

ABSTRACT Alley cropping is practiced to produce grain and forage crops, reduce soil and nutrient ... more ABSTRACT Alley cropping is practiced to produce grain and forage crops, reduce soil and nutrient losses by surface runoff and improve nutrient availability. Growing barley and legumes for grain and forage in pistachio, olive and vineyards is a common alley cropping ...

Research paper thumbnail of Çokdeğişkenli Analiz Ile Katalitik Hızlı Pirolizin Biyoyağ Bileşenlerinin Değerlendirilmesi

Pamukkale University Journal of Engineering Sciences, 2019

Katalitik hızlı piroliz yöntemi ile üretilen biyoyağdaki kimyasalların varlığı ve verimleri prose... more Katalitik hızlı piroliz yöntemi ile üretilen biyoyağdaki kimyasalların varlığı ve verimleri proses parametreleri tarafından etkilenmekte, dolayısıyla, kimyasallar ve proses parametreleri arasındaki ilişkiler çokdeğişkenli analiz teknikleri ile detaylı bir şekilde araştırılmalıdır. Bu çalışma temel bileşenler analizi (PCA) ve hiyeraraşik sınıflama analizini (HCA) kullanarak belediye katı atıklarının katalitik hızlı piroliz deneylerinin 24 örneğine (konusuna) bağlı olarak biyoyağ içerisinde en fazla bulunan 11 kimyasal maddeyi sınıflandırmaktadır. Üç temel bileşen oluşmuş, fakat bunların ilk ikisi toplam değişkenliğin %74'ünü açıklamıştır. PCA'inde örnekler ve değişkenler (kimyasallar) sırasıyla 4 ve 2 farklı grupta toplanmıştır. HCA'inde ise örnekler ve değişkenler 2 ana grup ve birkaç alt grupta toplanmıştır. PCA ve HCA'nin her ikisinin sonuçları da örneklerde ve değişkenlerde açık bir gruplanmanın olduğunu göstermiştir.

Research paper thumbnail of Comparison of Irrigation Performance Based on the Basin, Crop Pattern, and Scheme Sizes Using External Indicators

Turkish Journal of Agriculture and Forestry, 2004

A comparative assessment allows screening of irrigation systems based on the key issues relative ... more A comparative assessment allows screening of irrigation systems based on the key issues relative to performance and indicates where improvements should be made, such as in type of management, infrastructure, crop pattern and intensity, and system size. The objective of this study was to assess the performance of 239 irrigation schemes (57 DSI-operated and 182 transferred to Irrigation Associations) based on the basin, crop pattern, and scheme sizes using 6 external indicators for 2001. The basins that grow mostly orchard and industrial crops have higher output per unit land and water than that of the basins that mostly grow cereals. ANOVA test results indicated that the differences in all the indicators except for the relative water supply among the crops in all schemes were statistically significant (P = 0.05). However, the differences in all the indicators except for the irrigation ratio among the size groups of all schemes were not statistically significant. Although more water t...

Research paper thumbnail of Factors Affecting Preferential Flow

Preferential flow concept is important because it is related to a variety of subjects such as agr... more Preferential flow concept is important because it is related to a variety of subjects such as agricultural applications, urbanization, environmental pollution, and industrial production. Any kind of wastes left on the environment by means of any of these activities rapidly reaches groundwater by flowing through cracks, earthworm holes, plant root channels, openings developed due to the factors such as soil textures and structures. Soil factors such as soil texture and structure and rainfall factors such as amount and intensity of rainfall are important factors which affect the extent of preferential flow and transport.

Research paper thumbnail of Modeling of pyrolysis product yields by artificial neural networks

Artificial neural network (ANN) needs to be applied to the complex, multivariate, and highly vari... more Artificial neural network (ANN) needs to be applied to the complex, multivariate, and highly variable biomass and pyrolysis data to define optimum input variables and develop effective models. In this study, two different ANN methods, the feed-forward network (FFN) and the cascade-forward network (CFN), were applied to model pyrolysis product yields (biochar-BC, bio-oil-BO, and gas mixture-G) from 11 biomass and pyrolysis variables through hierarchical modeling approach. Both methods were supplied with two subsets of data, with two-thirds being used for training and one-third for testing the performances of the methods, after normalizing all data (72 samples). The performances of both ANN methods were evaluated by using three statistical parameters. In general, FFN and CFN methods had very similar performances in training and testing. Both methods had mean R 2 of 0.91, 0.96, and 0.95 for training BC, BO, and G, respectively. For testing of all FFN and CFN models, the R 2 value...

Research paper thumbnail of Pedotransfer functions for point and parametric estimations of soil water retention curve

Plant, Soil and Environment, 2011

A water retention curve is required for the simulation studies of water and solute transport in u... more A water retention curve is required for the simulation studies of water and solute transport in unsaturated or vadose zone. Unlike the direct measurement of water retention data, pedotransfer functions (PTFs) have attracted the attention of researchers for determining water retention curves from basic soil properties. The objective of this study was to develop and validate point and parametric PTFs for the estimation of water retention curve from basic soil properties such as particle-size distribution, bulk density, and porosity using multiple-linear regression technique and comparing the performances of point and two parametric methods using some evaluation criteria. 140 soil samples were collected from three different databases and divided as 100 and 40 for the derivation and validation of the PTFs. All three methods predicted water contents at selected water potentials and combined water retention curves pretty well, but van Genuchten’s model performed the best in prediction. Ho...

Research paper thumbnail of Synergistic effects on co-pyrolysis and co-combustion of sludge and coal investigated by thermogravimetric analysis

Journal of Thermal Analysis and Calorimetry, 2021

Research paper thumbnail of Fast pyrolysis of greenhouse waste into bio-oil and optimization of process conditions using response surface methodology

Biomass Conversion and Biorefinery, 2021

Research paper thumbnail of Kinetic and thermodynamic analyses during co-pyrolysis of greenhouse wastes and coal by TGA

Renewable Energy, 2021

Abstract For thermal and kinetic analyses of co-pyrolysis of biomass and coal thermogravimetric a... more Abstract For thermal and kinetic analyses of co-pyrolysis of biomass and coal thermogravimetric analysis (TGA) is usually used to get valuable information for accurate design of co-pyrolysis facilities. In this study, pyrolysis mechanism of the equal mixture of tomato, pepper, and eggplant wastes as greenhouse vegetables wastes (GVW) and its blend with coal was investigated by using TGA with different heating rates. Kinetic and thermodynamic parameters were calculated by using Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. To highlight the synergistic effect between GVW and coal during co-pyrolysis, the deviation between the experimental and calculated values of mass loss and mass loss rate was calculated. The average activation energy (Ea) of 100%wt calculated by FWO and KAS models was 74.27 and 67.00 kJ mol−1, whereas Ea of 0%wt was 133.99 and 129.84 kJ mol−1, respectively. The average Ea of 25%wt was 148.34 and 145.19 kJ mol−1, while it was 57.21 and 49.40 kJ mol−1 for 50%wt. The positive values of deviation indicated the existence of synergistic effect between GVW and coal during co-pyrolysis. The blend of 50%wt with the smallest Ea and ΔS was the best combination for the simultaneous valorization of GVW and coal through pyrolysis.

Research paper thumbnail of Investigation of thermal behavior of pine sawdust and coal during co-pyrolysis and co-combustion

Energy, 2021

Abstract Nowadays, most of the recent large-scale installations are configured to use more than o... more Abstract Nowadays, most of the recent large-scale installations are configured to use more than one fuel. Thermal analysis allows us to properly design and operate especially such a large-scale co-pyrolysis and/or co-combustion process. In this study, thermal behaviours of pine sawdust (PS), coals, and their blends were investigated by using thermogravimetric analysis (TGA) under nitrogen and air atmospheres with different heating rates of 10, 20, and 40 °C min-1. Kinetic parameter such as activation energy (Ea) was calculated by using Kissenger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), and Starink models. The results showed the existence of an obvious synergistic effect between PS and coal during pyrolysis and combustion processes. The initial, maximum, and burnout temperatures of the reactions; the mass loss rate; and total mass loss were influenced by the proportions of PS and coal in the blend. For pyrolysis the average Ea of 25PS calculated by KAS, FWO, and Starink models was found as 31.57, 40.45, and 32.55 while that of 50PS was 166.80, 168.64, and 167.25 kJ mol-1, respectively. For combustion, the average Ea of 25PS calculated by KAS, FWO, and Starink models was found as 59.57, 67.74, and 60.52 while that of 50PS was 66.60, 74.20, and 67.49 kJ mol−1, respectively. According to the Ea value, the blend of 25PS was more suitable than 50PS for energy production through both pyrolysis and combustion. This synergistic effect between PS and coal may be further detailed with more different blend ratios.

Research paper thumbnail of Catalytic fast pyrolysis of Pearl Millet and Sida cordifolia L. to investigate products distribution and bio-oil quality

Fast pyrolysis is an attractive way of converting abundant biomass resources into valuable produc... more Fast pyrolysis is an attractive way of converting abundant biomass resources into valuable products such as bio-oil. Nevertheless, high oxygenated compounds and water content of bio-oil limit its direct use as fuel or chemicals. Catalytic fast pyrolysis (CFP) is able to improve bio-oil properties so that downstream upgrading processes can be economically feasible. In this study five different catalysts such as zeolite socony mobil-5 (ZSM-5), cerium dioxide (CeO2), zirconium dioxide (ZrO2), zinc oxide (ZnO), and sodium carbonate (Na2CO3) were employed due to their potential in enhancing bio-oil properties. CFP of pearl millet (PM) and Sida cordifolia (Sida) was performed to investigate the effects of catalysts on the products distribution and chemical contents of bio-oil. The results showed that bio-oil yield decreased during CFP regardless of catalyst and biomass types. Among all catalysts, CeO2 was found to be the most suitable to produce acids and alkanes from CFP of PM; and acids...

Research paper thumbnail of Optimization and characterization of bio-oil from fast pyrolysis of Pearl Millet and Sida cordifolia L. by using response surface methodology

Fuel, 2020

Abstract The objective of this study was to optimize experimental parameters to obtain the maximu... more Abstract The objective of this study was to optimize experimental parameters to obtain the maximum bio-oil yield (BOY) from fast pyrolysis of Pearl Millet (PM) and Sida cordifolia L. (Sida) by using response surface methodology (RSM) based on the central composite design (CCD). Important fast pyrolysis process parameters such as particle size (PS), reaction temperature (T), and nitrogen gas flowrate (NGF) were optimized. The most influential factor of each experimental design response was identified and an empirical model was derived in terms of factors through ANOVA. The second-order polynomial equation for the BOY was developed to correlate the parameters. The cubic and quadratic models fit the data of PM and Sida the best, respectively. The maximum BOY of 48.27 and 48.00% for PM and Sida respectively were obtained at the optimum parameters of PS of 1.5 mm, T of 400 °C, and NGF of 200 mL min−1 for both biomasses. GC–MS analysis of the optimized bio-oil samples from PM and Sida indicated the presence of many important chemical compounds such as acids, alcohols, aldehydes, aromatics, ketones, phenols, and others. Therefore, PM and Sida can be used as feedstocks for fuels and chemicals production through fast pyrolysis.

Research paper thumbnail of Kinetic analysis of Pearl Millet (Penissetum glaucum (L.) R. Br.) under pyrolysis and combustion to investigate its bioenergy potential

Fuel, 2020

Abstract Pearl Millet (Penissetum glaucum (L.) R. Br.), ranked as the sixth most grown cereal cro... more Abstract Pearl Millet (Penissetum glaucum (L.) R. Br.), ranked as the sixth most grown cereal crop in the world, is an important food crop produced in Africa and India. In this study, residues of Pearl Millet were used to evaluate its thermal decomposition characteristics through thermogravimetric analysis (TGA). TGA was made in the presence of nitrogen and air to represent pyrolysis and combustion, respectively. Thus, five different heating rates were used as 10, 20, 30, 40, 50 °C min−1 in the analyses. The kinetics and thermodynamic parameters were determined by using isoconversional models of Flynn-Wall-Ozawa (FWO) and Kissenger-Akahira-Sunose (KAS). The results showed that the average of activation energy during pyrolysis was 89.63 and 83.89 kJ mol−1, respectively, calculated by the FWO and KAS methods; while it was 57.27 and 49.47 kJ mol−1 in combustion. The low activation energies obtained from both models show that millet residues are suitable for pyrolysis and combustion.

Research paper thumbnail of Pyrolysis and combustion kinetics of Sida cordifolia L. using thermogravimetric analysis

Bioresource Technology, 2020

Sida cordifolia L. (Sida) is an annual invasive plant that remains underutilized in Niger. The go... more Sida cordifolia L. (Sida) is an annual invasive plant that remains underutilized in Niger. The goal of this study was to characterize the thermal decomposition of Sida for its valorisation as a source of energy through thermogravimetric analysis (TGA). TGA was carried out under nitrogen and air atmospheres. Thus, five different heating rates were used as 10, 20, 30, 40, 50 °C min-1. Kinetic and thermodynamic parameters were determined by isoconversional models of Kissenger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). The results showed that the average activation energy (Ea) of Sida calculated by KAS and FWO in pyrolysis was found to be 74.74 and 80.74 kJ mol-1 respectively, while it was 51.08 and 58.91 kJ mol-1 in combustion respectively. Kinetic and thermodynamic parameters such as Ea, ΔH, ΔS, and ΔG obtained by KAS and FWO show that Sida is a remarkable feedstock for bioenergy.

Research paper thumbnail of Utilization of Two Artificial Neural Network Methods in Surface Water Quality Modeling

Environmental Engineering and Management Journal, 2010

Artificial neural networks (ANNs) are capable of learning the relationships between the dependent... more Artificial neural networks (ANNs) are capable of learning the relationships between the dependent and predictor surface water quality variables and have a high ability to predict from the new data set. In this study, two different ANN methods, the feedforward network (FFN) and the cascadeforward network (CFN) were applied to predict two surface water quality variables such as chlorophyll-a (Chl-a) and fecal coliform (FC) using twelve other variables as an input to the models. Both methods, for developing and training the ANN, are multilayer, leading to the same architecture of the feedforward neural network trained by back-propagation learning algorithm. The networks were supplied with two subsets of water quality data, with two-thirds being used for training and one-third for testing the performance of the networks, after pre-processing of the data set (110 samples) by normalization and moving average techniques. The performances of both ANN methods were evaluated visually by plotting and quantitatively by using five statistical parameters. The training procedures of both ANN methods for Chl-a and FC were very successful and a perfect match was obtained between the measured and predicted values with the correlation coefficient (R) of 1.00. The testing or prediction results also produced good agreements with the measured data of Chl-a and FC in terms of R values of 0.83, 0.93 (for FFN), and 0.89, 0.91 (for CFN), respectively. Results of this study show that ANN methods are able to predict Chl-a and FC with reasonable accuracy, suggesting that ANN is a valuable and powerful tool for surface water quality modeling and management.

Research paper thumbnail of Evaluation of bio-oil compounds of catalytic fast pyrolysis by multivariate analysis

Pamukkale University Journal of Engineering Sciences, 2019

The presence and amounts of chemicals in bio-oil produced by catalytic fast pyrolysis are affecte... more The presence and amounts of chemicals in bio-oil produced by catalytic fast pyrolysis are affected by the process parameters, hence, the relationships between the chemicals and process parameters need to be investigated in detail by multivariate analysis techniques. The present work classifies the most available 11 chemicals in bio-oil based on the 24 samples (treatments) of catalytic fast pyrolysis experiments of municipal solid wastes by using principle components analysis (PCA) and hierarchical cluster analysis (HCA). There were 3 principle components (PCs), but the first 2 PCs explained 74% of the total variance. The samples and variables (chemicals) were clustered into 4 and 2 different groups, respectively, in PCA. The samples and variables were clustered in 2 main groups and a few subgroups in HCA. Both PCA and HCA results showed that there was a clear grouping in the samples and variables. Katalitik hızlı piroliz yöntemi ile üretilen biyoyağdaki kimyasalların varlığı ve verimleri proses parametreleri tarafından etkilenmekte, dolayısıyla, kimyasallar ve proses parametreleri arasındaki ilişkiler çokdeğişkenli analiz teknikleri ile detaylı bir şekilde araştırılmalıdır. Bu çalışma temel bileşenler analizi (PCA) ve hiyeraraşik sınıflama analizini (HCA) kullanarak belediye katı atıklarının katalitik hızlı piroliz deneylerinin 24 örneğine (konusuna) bağlı olarak biyoyağ içerisinde en fazla bulunan 11 kimyasal maddeyi sınıflandırmaktadır. Üç temel bileşen oluşmuş, fakat bunların ilk ikisi toplam değişkenliğin %74'ünü açıklamıştır. PCA'inde örnekler ve değişkenler (kimyasallar) sırasıyla 4 ve 2 farklı grupta toplanmıştır. HCA'inde ise örnekler ve değişkenler 2 ana grup ve birkaç alt grupta toplanmıştır. PCA ve HCA'nin her ikisinin sonuçları da örneklerde ve değişkenlerde açık bir gruplanmanın olduğunu göstermiştir.

Research paper thumbnail of Evaluation of MACRO model by short-term water and solute transport simulation in Maury silt loam soil

Plant, Soil and Environment, 2011

Modeling preferential flow has been a concern of many academic fields in the past 30 years all ov... more Modeling preferential flow has been a concern of many academic fields in the past 30 years all over the world and helps to prevent groundwater contamination. A dual-porosity model, MACRO, was evaluated for short-term (less than 2 days) simulation of water flow and non-reactive solute (chloride) transport through the profile of six plots in well-structured Maury silt loam soil. Water flow in micropores is calculated by the Richards’ equation while simple gravity flow is assumed in the macropores. Solute transport in the micropores is calculated by the convection-dispersion equation (CDE) while the dispersion and diffusion in the CDE is neglected for the solute transport in the macropores. The applied water and chloride reached the bottom of the profile during the 2 and 1-hour(s) application periods in studies 2 and 3, respectively. There is a strong indication of macropore flow in this soil. Based on the statistical criteria, the model accurately simulated water flow and solute...

Research paper thumbnail of Determination of the drainage basin characteristics using vector GIS

Hydrology Research, 2006

Detailed geomorphologic characteristics need to be compiled for performing hydrologic modeling of... more Detailed geomorphologic characteristics need to be compiled for performing hydrologic modeling of a basin. Basin form and hydrologic characteristics are to be related so the basin form must also be represented by quantitative descriptors. The typical morphologic characteristics used in hydrological analyses are basin area, perimeter, mainstream length, total stream length, contour length, basin shape (form factor, circularity ratio, compactness ratio, basin elongation), slope, drainage density, relief (maximum relief, relief ratio, relative relief), effective basin width, and median elevation. The objective of this study is to propose an algorithm to automatically calculate basin characteristics using vector GIS. The results produced by the algorithm were compared to the manual method and the two methods were found statistically similar.

Research paper thumbnail of Artificial neural network and regression techniques in modeling surface water quality

Environment Protection Engineering

Research paper thumbnail of Estimation of suspended sediment concentration by acoustic equations for soil sediment

AFRICAN JOURNAL OF BIOTECHNOLOGY