Browsing by Author "Aldemir, Adnan"

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Adsorption of Malachite Green Dye Using Pinus Sylvestris: Isotherm, Kinetics and Thermodynamics Studies
(Parlar Scientific Publications (p S P), 2019) Kul, Ali Riza; Aldemir, Adnan; Elik, Hasan
In this study Pinus sylvestris shavings powder (PiSP) was utilized as an adsorbent for the removal of Malachite Green (MG) which is one of the common basic dyes, from aqueous solution. The adsorption experiments were carried out in a batch system and effects of initial dye concentration, interaction time and temperature were investigated. Langmuir, Freundlich and Temkin adsorption isotherms have been used to model equilibrium data. Freundlich isotherm model becomes more convenient option compared with Langmuir and Temkin models. Freundlich model coefficients are raise as the temperature rises, showing that the adsorption process becomes favorable higher temperature. Kinetic parameters were determined by pseudo first order (PFO), pseudo second order (PSO) and intraparticle diffusion (IPD) models. Results indicated that experimental and calculated qe values close to each other explained that this process fits PSO kinetic model with higher R-2 values than other two models. Kinetic constants become closer to both temperatures and initial concentrations and qe values are increases with increasing concentration of MG. Initial dye concentration elevates from 10 to 60 mg/L, dye adsorption capacity onto PiSP from 3.28 to 22.88 mg/g, 3.58 to 24.06 mg/g and 3.88 to 25.78 mg/g for 298, 308 and 318K, respectively. Thermodynamic parameters for instance free energy (Delta G), enthalpy (Delta H) and entropy (Delta S) of this separation process are determined from -2757,7 J/mol, 6550,68 J/mol and 12,73 kJ/cool, respectively. The negative values of Delta G degrees showed that this separation process was endothermic and natural. The research results demonstrate that PiSP may be an alternative material than costly adsorbents for dye removal.
Alcohol Electrooxidation Study on Carbon Nanotube Supported Monometallic, Pt, Bi, and Ru Catalysts
(Taylor & Francis inc, 2018) Caglar, Aykut; Aldemir, Adnan; Kivrak, Hilal
In the present study, carbon nanotube supported Pt (Pt/CNT), Bi (Bi/CNT), and Ru (Ru/CNT) catalysts are prepared via NaBH4 reduction method for ethanol (C2H5OH), ethylene glycol (C2H6O2), and methanol (CH3OH) electrooxidation. The physical characterization of these as-prepared catalysts is performed by X-ray diffraction (XRD). Furthermore, electrochemical measurements are conducted via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and linear sweep voltammetry (LSV). Pt/CNT catalyst exhibits the highest catalytic activity and stability compared to Bi (Bi/CNT) and Ru (Ru/CNT) catalysts. It is observed that the electrocatalytic activity of Pt/CNT catalyst for ethylene glycol (C2H6O2) oxidation is higher than its electrocatalytic activities for ethanol (C2H5OH) and methanol (CH3OH) oxidation. Maximum current density of C2H6O2 of Pt/CNT catalyst is about 4 and 5.7 times lower than C2H5OH and CH3OH. Furthermore, electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and linear sweep voltammetry (LSV) results are in good agreement with CV results in terms of stability and electrocatalytic activity of Pt/CNT. The Pt/CNT catalyst is believed to be a promising anode catalyst for the alcohol fuel cells.
Application of Machine Learning Methods To Removal Percentage Prediction for Malachite Green Adsorption on Kaolinite
(desalination Publ, 2022) Canayaz, Murat; Aldemir, Adnan; Kul, Ali Riza
In this study, the removal percentage was estimated using machine learning methods, such as artificial neural network, radial basis function neural network, support vector regressor, and random forest regressors, for data obtained during Malachite green adsorption on kaolinite as an adsorbent in an aqueous solution. Important process parameters, including initial dye concentration, sonication time and temperature, were investigated. Statistical evaluation metrics such as R2, mean squared error, and root mean square error were used to evaluate the performance of the models. Among these models, the artificial neural network was more successful compared to other models with 0.98 R2 values for three temperatures. Radial basis function neural network and random forest regressors were observed to achieve successful results. In this study, the results obtained from the machine learning methods are given comparatively. The initial dye concentrations increased from 10 to 60 mg L-1, the removal percentage of Malachite green on kaolinite increased from 68.71% to 79.61% for 298 K, 72.26% to 82.58% for 308 K and 78.75% to 85.91% for 318 K, respectively. Isotherm, kinetic and thermodynamic calculations for Malachite green removal by kaolinite were completed. The equilibrium of Malachite green adsorption onto kaolinite was best described by the Langmuir isotherm and the kinetics of the process followed the pseudo-second-order model, which had the highest correlation values. Thermodynamic analysis of experimental data suggests that the adsorption process is spontaneous and endothermic in nature.
Combined Statistical Analysis of Water Quality for Determination of Relationships Between Parameters: Case Study of Akkopru Stream, Van/Turkey
(Elsevier Science inc, 2022) Turan, Aysenur; Aldemir, Adnan; Hapoglu, Hale
Today, water is affected negatively in terms of its characteristics and quality due to many factors. Necessary measures should be taken to control environmental pollution by analyzing the conditions and parameters that cause pollution and monitoring the water quality in water bodies such as lakes, streams, rivers and ponds. Akkopru Stream is one of the rivers flowing into Lake Van and it has great importance within the borders of Van/Turkey. The data in this study were used to perform water quality analysis based on the physicochemical parameters obtained from Akkopru Stream. A total of 22 water quality parameters were used to determine water quality at the discharge into Lake Van. Evaluation of these parameters was made according to the regulation about water pollution control (Turkey). As a result, Akkopru Stream has Class I water quality in terms of seasonal conditions and water parameters. Among the parametric analysis methods, trend distribution, normality, correlation, matrix table, regression and normal distribution of the data set were examined and the relationships between parameters were interpreted statistically. According to the results, most of the parameters were within the normal range, solid matter and hardness effects were correlated, and matrix relations and regression equations were related to other parameters.
Comparative Research of Isotherm, Kinetic, and Thermodynamic Studies for Neutral Red Adsorption by Activated Carbon Prepared From Apple Peel
(Springer int Publ Ag, 2023) Kul, Ali Riza; Koyuncu, Huelya; Turan, Aysenur; Aldemir, Adnan
In this study, activated carbon (AC) obtained with apple peel was used for removal of Neutral Red (NR) from aqueous solutions. The characterization of AC was evaluated with the Brunauer-Emmett-Teller (BET), Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analyses. Isotherm, kinetic, and thermodynamic parameters were determined for NR removal with AC. Eighteen isotherm models and eight kinetic models were analyzed for three temperatures and six initial dye concentrations. The experimental data best agree with the Langmuir model among the isotherm models, and the maximum adsorption capacity (q(m)) was calculated 142.857 mg/g at 318 K. It was determined that the pseudo-second-order (PSO) model was the best choice among the kinetic models with the highest correlation coefficients. The removal percentage of NR dye with AC obtained 82.13%, 84.79%, and 87.20% for 120 mg/L initial dye concentration at 298 K, 308 K, and 318 K, respectively. The negative free energy, enthalpy, and entropy values of adsorption obtained - 6386 J/mol, 46280 J/mol, and 165.48 J/mol.K for 20 mg/L NR concentration at 318 K, respectively. The results of this separation process shown spontaneous essence, and workability coinciding with the negative free energy and activation energy was found 13.651 kJ/mol. The assessment of the isotherm, kinetic, and thermodynamic results were evaluated with error functions. The highest correlation coefficient (R-2) values and the lowest sum of squares (SS), sum of the square of error (SE), and mean square of error (MSE) values were determined with Langmuir isotherm and PSO kinetic models. This research showed that AC prepared from biomass can be used effectively for wastewater treatment using adsorption technique.
Comparison of Acid Blue 25 Adsorption Performance on Natural and Acid-Thermal Co-Modified Bentonite: Isotherm, Kinetics and Thermodynamics Studies
(Pamukkale Univ, 2020) Aldemir, Adnan; Kul, Ali Riza
In the present study, natural bentonite and acid-thermal co-modified bentonite were utilized for Acid Blue 25 (AB25) removal. The adsorption experiments were executed at the temperature values of 298K, 308K and 318K. According to the results, Freundlich isotherm becomes more convenient model compared with Langmuir and Temkin model. Freundlich model coefficients rise when the temperature increases. Kinetic coefficients were calculated by pseudo first order (PFO) and pseudo second order (PSO) models. Coefficients of R2 evaluated were higher than 0.99 with experimental and obtained qe values close to each other explained that this process fits PSO kinetic model. The concentration of AB25 elevates from 30 to 80 mg/L adsorption capacity onto natural, acid-thermal co-modified bentonite increases from 8.36 to 27.00 mg/g and 9.30 to 29.09 mg/g for 298 K, respectively. Absolute values of free energy of AB25 onto natural and acid-thermal co-modified bentonite changes from 4.065 kJ/mol to 8.586 kJ/mol, respectively. Enthalpy values of AB25 onto natural and acid-thermal co-modified bentonite changes from 5.483 kJ/mol to 11.249 kJ/mol and entropy values of AB25 on natural and acid-thermal co-modified bentonite changes from 4.759 J/mol K to 8.940 J/mol K, respectively. It was also found that modified bentonite has higher adsorption capacity than natural bentonite.
Comparison of Methylene Blue Adsorption Performance on Natural, Thermal and Acid Modified Kaolin: Isotherm, Kinetics and Thermodynamics Studies
(Parlar Scientific Publications (p S P), 2019) Kul, Ali Riza; Aldemir, Adnan
Dyes in the industrial wastewaters such as textile, food and cosmetic are the one of major water pollution source. In this study natural, thermal and acid modified kaolin have been utilized as adsorbent for the removal of methylene blue (MB) which is one of the widely used dye in the industry, from aqueous solution within a batch process. Adsorption experiments were performed at three different temperatures (298, 308, 318K). Based on the experimental data Freundlich isotherm model better than the Langmuir model. Freundlich model coefficients increase as the temperature increases, indicating that adsorption is favorable at higher temperature. The kinetic data were analyzed using pseudo first order and pseudo second order models. Adsorption of the MB on kaolin at the different conditions was best fit the pseudo second order model. Kinetic constants are closer to the both temperatures and initial concentrations and qe values are increases with increasing concentration of MB. The values of activation parameters such as free energy (Delta G), enthalpy (Delta H) and entropy (Delta S) were determined. Thermodynamic parameters indicates that the adsorption process is physisorption, endothermic and increased randomness at the solid-solute interface with the high affinity of the kaolin for the MB. Initial dye concentration increases from 25 to 75 mg/L, the adsorption capacity of dye onto natural, thermal modified and acid modified kaolin from 5.03 to 20.29 mg/g, 6.66 to 23.89 mg/g and 7.16 to 25.57 mg/g, respectively. It was also found that acid modified kaolin has a higher adsorption capacity compared to that of natural or thermal kaolin. The results indicate that kaolin could be interesting alternative material with respect to more costly adsorbents used for dye removal.
Comparison of Wireless Temperature Profiles With Generalized Predictive Control
(Gazi Univ, 2016) Aldemir, Adnan; Hapoglu, Hale
In this study, Generalized Predictive Control (GPC) algorithm is applied to a process simulator which wireless temperature experiments were achieved and the results of the experiments were compared under the same conditions obtained. To achieve the data transfer between computer in Process Control Laboratory and the process simulator in Unit Operations Laboratory, wireless communication system was established and wireless experiments were performed on-line by means of MATLAB/Simulink program. Wireless data transfers during the experiments were carried out by using radio waves at a frequency of 2.4 GHz. In wireless temperature control experiments which are conducted using with algorithm of GPC, all L (control weighting) values which are bigger than 1.0 are not suitable for temperature control because the heater made very big oscillatory behaviour and consequently temperatures also made very big oscillatories at any Nu (control costing horizon), N1 (minimum costing horizon) and N, (maximum costing horizon) values. Therefore GPC experiments were carried out in L values smaller than 1.0. Changes of temperature profiles were observed with time as a result of experiments carried under the same conditions, using the Nu, N-1 ve L parameters in the GPC algoritm to the N-u=1.0; N-1=1.0; N-2=2.0; N-U =1.0; N-1=1.0; N-2=4.0; N-U=2.0; N-1=1.0; N-2=2.0 ve N-U=2.0; N-1 1.0; N-2 =4.0 values for the L=0.001; 0.005; 0.01; 0.05; 0.1 and 0.5 values. According to the experimental results analyzing the temperature profiles, the temperatures the N-1=1.0 and N-2=2.0 values of control was closer to the set point and oscillations were found to be less than according to the values of N-U=1.0; N-1=1.0; N-2=4.0; N-U=2.0; N-1=1.0; N-2=2.0 ve N-U=2.0; N-U=1.0; N-2=4.0. Also by increasing the value of Nu and N, temperatures are begin to move away from the set point and the oscillations are increased. Wireless experiments conducted under the same conditions for Tset=50 degrees C and Tset 60 degrees C which using the best temperature control parameters with the L=0.001; 0.005; 0.01; 0.05; 0.1 and 0.5 values were determined with the integral of the square of the error (ISE) and the integral of the absoluteof the error (IAE) values. According to the experiments carried out at the lowest values of ISE and IAE were determined that the value L 0.01. In addition, lower and higher values of L= 0.01 calculated ISE and IAE values were higher and that can be seen the temperature away from set point. In conclusion, the best temperature control is obtained N-U=1.0; N-1=1.0; N-2=2.0 and L=0.01 values.
Design and Two Step Process Optimization of a Reactive Distillation Column for Improving Production Amount of Ethyl Acetate and Water
(Elsevier Science inc, 2024) Ersingun, Dilan; Aldemir, Adnan
In this study, two step optimization was performed for operating conditions of a reactive distillation (RD) column using simulation outputs. The effects of the operating parameters of the RD column, on the ethyl acetate (EtAc) amount as a result of the reaction between ethanol (EtOH) and acetic acid (HAc) were assessed. The response surface methodology (RSM) was applied to determine the optimum operating conditions for the RD column. The two step experimental design used in RSM was created with the Design Expert (DE) program. The Plackett-Burman (PB) design was used to determine the most important parameters affecting on the designed RD column for production of EtAc amount. The most important parameters were determined as HAc feed rate (kmol/h), EtOH feed rate (kmol/h), reflux ratio and temperature (degrees C). After PB design Central Composite Design (CCD) was applied to determine the optimum operating conditions of these most important parameters for the RD column. ANOVA was used to investigate the interaction between the response and independent variables with the obtained data and 3 dimensional (3D) plots created by the program were interpreted. A second order regression model according to the independent variables for the EtAc amount (response) was developed with DE program. The optimum operating conditions for the designed RD column were obtained as HAc feed rate 149.86 kmol/h, EtOH feed rate 99.99 kmol/h, feed temperature 70 degrees C and reflux ratio 2.50. The production of EtAc amount which determined with model coefficients and recommended by the program were compared and relative errors between the model results and the predicted values were less than 1%. The obtained results were showed that RSM may be a suitable method for optimization of operating parameters in RD columns.
Determination of Optimal Pid Control Parameters by Response Surface Methodology
(2020) Sadaralddin, Mohammed; Aldemir, Adnan
Proportional–Integral–Derivative (PID) controllers are the most widely used systems in industrial applications and in academic research regarding control engineering. In this study, the optimal PID control parameters of a liquid level control system were determined with Response Surface Methodology. Dynamic analysis was carried out on the liquid level control system to prepare the reaction curve. Accordingly, dead time, time constant and process gain values were determined as 16s, 261s and 0.842, respectively. Based on the dynamic analysis, PID parameters were calculated in accordance with the Cohen-Coon, Ziegler-Nichols, Yuwana-Seborg methods, which are the commonly used tuning methods. The Kp, τI, τD parameters were calculated as 30.77, 29.15 and 5.4 with the Cohen-Coon method, as 0.453, 30.0 and 7.5 with the Ziegler-Nichols method and as 1.63, 686.3 and 117.7 with the Yuwana-Seborg method, respectively. The PID control parameters applied for the 40cm, 50cm and 60cm set points and ISE and IAE control performance values after experiments were calculated. The Kp, τI and τD values were selected as the independent parameters, while the ISE and IAE values were chosen as the dependent variables. The numerical values of the responses for the runs in the design matrices were determined with a closed-loop PID controller with the liquid level system block diagram that was designed in MATLAB/Simulink. The simulations proposed by the trial version of Design Expert 7.0 program were performed in order and the IAE and ISE values were calculated after the simulations were processed. In this study, minimum ISE and IAE values were selected to determine the best PID parameters of a liquid level control system. The optimal PID control parameters of the liquid level system required to obtain the lowest ISE and IAE values were determined as 23.14, 28.31 and 11.50 for Kp, τI and τD, respectively.
Determination of Optimum Operating Conditions With a Dynamic Simulation of a Reactive Distillation Column by Response Surface Method
(2019) Ersingün, Dilan; Aldemir, Adnan
Bu tez kapsamında, dinamik benzetimi yapılan bir reaktif distilasyon (RD) kolonunda işletme koşullarının optimizasyonu yapıldı. Tasarımı yapılan raflı RD kolonunda işletim parametrelerinin etanol ile asetik asit arasındaki reaksiyonu sonucu etil asetat üretim hızına etkileri değerlendirildi. RD kolonunun optimum işletme koşullarının belirlenmesi için cevap yüzey yöntemi (CYY) uygulandı. CYY'de kullanılan deney tasarımı Design Expert 7.0.0 programının deneme versiyonu ile oluşturuldu. Placket-Burman (PB) tasarım yöntemi kullanılarak RD kolonunu etkileyen en önemli parametreler asetik asit besleme hızı (kmol/h), etanol besleme hızı (kmol/h), geri döngü ve sıcaklık olarak belirlendi. Daha sonra RD kolonunun optimum işletme koşullarının belirlenmesi için Merkezi Kompozit Tasarımı (MKT) uygulandı. Cevap ve bağımsız değişkenler arasındaki etkileşimi ve elde edilen verileri incelemek üzere ANOVA analizi kullanıldı. Etil asetat üretim hızının bağımsız değişkenlere göre ikinci dereceden regresyon modeli, Design Expert 7.0.0 programı kullanılarak geliştirildi. MKT'de oluşturulan üç boyutlu (3D) grafikler yorumlandı. En yüksek etil asetat üretim hızı elde etmek için optimum RD işletme koşulları sırasıyla asetik asit besleme hızı 149.86 kmol/h, etanol besleme hızı 99.99 kmol/h, geri döngü oranı 2.50 ve besleme sıcaklığı 70°C optimum değerler olarak belirlendi. Bu çalışma, CYY' nin RD kolonundaki işletim parametrelerinin optimizasyonu için uygun bir yöntem olabileceğini göstermektedir. Anahtar kelimeler: ANOVA, Cevap yüzey yöntemi, Dinamik benzetim, Optimizasyon, Reaktif distilasyon
Determination of Optimum Treatment Conditions for Paint Industry Wastewater With the Coagulation/Flocculation Method
(desalination Publ, 2021) Aldemir, Adnan; Hakkitanir, Esmanur; Ozguven, Ayse
In this study, optimum treatment conditions for paint industry wastewater were determined by response surface methodology (RSM). Wastewater treatment experiments were performed in jar test using the coagulation/flocculation method. FeCl3 center dot 6H(2)O,Al-2(SO4)(3)center dot 18H(2)O, and FeSO4 center dot 7H(2)O coagulants were used in the treatment experiments. pH, coagulant dose, and mixing speed were selected as the most important parameters for wastewater treatment and chemical oxygen demand (COD), total suspended solids (TSS), turbidity, and color analyses were examined for each coagulant. After determining the coagulant (FeCl3 center dot 6H(2)O) which provided the best treatment efficiency, a central composite design (CCD) was applied for optimization of treatment conditions by using RSM. Design Expert 7.0.0. the program was used for the design of treatment experiments and analysis of results. COD, TSS, color, and turbidity values were processed by the program after experiments. 3D graphs and statistical results created by the program were interpreted. The equations obtained using the coefficients in the model created by the program were solved and the optimum values of the independent variables were calculated. Using these values, the lowest pollution values were determined as (mg/L) COD 68.636, color 2.42, turbidity 1.79 NTU, and TSS 10.135. Optimization results from the program were examined and the optimum values of treatment parameters were suggested as pH 7.54, coagulant amount 1,080.49 mg/L, and mixing speed 146.16 rpm. The lowest pollution values under optimum conditions were (mg/L) COD 71.07, color 1.00, turbidity 2.74 NTU, and TSS 7.50. Under optimized conditions COD, TSS, color, and turbidity removal were 94.1%, 95.3%, 97.1%, and 99.5%, respectively.
Determination of Pid Control Parameters by Response Surface Methodology
(2019) Anwer, Mohammed Sadralddın; Aldemir, Adnan
PID kontrol ediciler, endüstriyel alanda halen en çok kullanılan ve kontrol mühendisliğinde en çok araştırma ve uygulama alanı bulan sistemlerdir. PID kontrol edici sinyali, oransal, integral ve türevsel olarak adlandırılan üç terimin toplanması ile kontrol çıktısı oluşturulur. PID kontrol parametrelerinin ayarlanması için bazı deneysel yöntemler geliştirilmiştir. Bu yöntemler kontrolün olmadığı açık-hat sistemlere uygulanır ancak doğrusal olmayan, değişken parametreli ve kararsız sistemlerde bu yöntemler ile belirlenen parametreler etkili olmayabilir. Bu durumda optimal PID kontrol parametrelerinin belirlenmesi gereklidir. Bu tez kapsamında, Van Yüzüncü Yıl Üniversitesi, Kimya Mühendisliği Bölümünde bulunan sıvı seviye kontrol deney sistemi kullanılmıştır. Basamak etki değişimi ile hazırlanan reaksiyon eğrisi üzerinden deney sistemine ait ölü zaman, zaman sabiti ve proses kazancı belirlenmiştir. Optimum PID kontrol parametrelerinin değerleri, Cevap Yüzey Yöntemi (CYY) ile belirlenmiştir. Kapalı çevrim PID kontrolörü ile MATLAB/Simulink'te tasarlanan sıvı seviye deney sistemi blok diyagramı kullanılarak simülasyon sonuçlarının sayısal değerleri belirlenmiştir. Bağımsız parametreler olarak Kp, τI, τD ve bunlara karşılık deney sonrası hesaplanan ISE ve IAE değerleri bağımlı değişkenler (yanıt) olarak seçilmiştir. Design Expert 7.0 programı deneme versiyonu tarafından önerilen deney listesindeki deneyler sırasıyla gerçekleştirilmiş ve deneylerden sonra hesaplanan IAE ve ISE değerleri programa işlenerek sonuçlar değerlendirilmiştir. Anahtar kelimeler: Cevap yüzey yöntemi, IAE, ISE, PID kontrol, sıvı seviye.
Determination Optimum Treatment Conditions of Paint Industry Wastewater by Coagulation Method
(2019) Hakkıtanır, Esmanur; Aldemir, Adnan
Bu tez çalışmasında, boya endüstrisi atık suyunun koagülasyon yöntemi ile optimum arıtım koşulları belirlenmiştir. Atık su karakterizasyonu ile ölçülen kirlilik değerleri deşarj standartlarının üzerinde olduğu görülmüştür. Atık su arıtım deneyleri jar test düzeneğinde gerçekleştirilmiştir. Deneylerde FeCl3.6H2O, Al2(SO4)3.18H2O, FeSO4.7H2O koagülantları ile çalışılmıştır. Arıtım koşulları olarak pH, koagülant dozu ve karıştırma hızı esas alınmıştır. Ön denemelerde herbir koagülant için KOİ, AKM, bulanıklık ve renk analizleri gerçekleştirilmiştir. En iyi arıtım verimini sağlayan koagülant (FeCl3.6H2O) belirlendikten sonra Design Expert programı kullanılarak Yüzey Yanıt Yöntemi (YYY) ile arıtım koşullarının optimum değerleri için Merkezi Kompozit Tasarım (MKT) uygulanmıştır. Deneylerden sonra KOİ, renk, bulanıklık ve AKM değerleri yanıt olarak programa işlenmiştir. MKT'de oluşturulan üç boyutlu grafikler ve ANOVA tabloları yorumlanmıştır. Program tarafından oluşturulan model katsayıları kullanılarak elde edilen denklemler çözülmüş ve seçilen bağımsız değişkenlerin optimum değerleri hesaplanmıştır. Bu değerler kullanılarak ilgili model yardımıyla en düşük kirlilik yükü değerleri KOİ 68.636 mg/L, renk 2.42 mg/L Pt-Co, bulanıklık 1.79 mg/L NTU, AKM 10.135 mg/L olarak belirlenmiştir. Ayrıca program tarafından yapılan optimizasyon sonuçları incelendiğinde arıtımda çalışılan parametrelerin optimum değerleri pH 7.54, koagülant miktarı 1080.49 mg/L ve karıştırma hızı 146.16 rpm/dk olarak önerilmiştir. Bu optimum koşullarda yanıt olarak seçilen en düşük kirlilik yükü değerleri de KOİ 71.07 mg/L, renk 1 mg/L Pt-Co, bulanıklık 2.74 mg/L NTU, AKM 7.5 mg/L olarak gösterilmiştir.
Determination Optimum Treatment Conditions of Petrochemical Industry Wastewater by Chemical Coagulation Method
(2022) Ayhan, Neslihan Nubar; Aldemir, Adnan
Yapılan tez çalışmasında, petrol endüstrisine ait atıksuyun koagülasyon yöntemi ile arıtımında Design Expert programı çalıştırılarak YYY aracılığı ile optimum arıtım koşulları tespit edilmiştir. Atıksuyun karakterizayonu yapılmış ve analiz değerlerinin deşarj standartlarının üzerinde olduğu belirlenmiştir. Atıksuyun arıtım deneyleri için koagülansyon metodu uygulanmış ve çalışmalar bu metod için tasarlanmış jar testi düzeneğinde gerçekleştirilmiştir. Ön işlemle ile en iyi koagülantın seçilmesi ve bu koagülant ile sonraki aşamaların gerçekleştirilmesi amaçlanmıştır. Bu doğrultuda Al2(SO4)3.18H2O, FeCl3.6H2O ve FeSO4.7H2O koagülantları belirlenmiştir. Arıtım koşullarında ise pH, koagülant dozu ve karıştırma hızı değerleri temel alınmıştır. Optimum arıtım koşulun tespitinde ön çalışmalar yapılarak Al2(SO4)3.18H2O koagülantı ile en iyi giderim verimi elde edilmiştir. Seçilen koagülant ile YYY ve MKT programları kullanılarak optimum arıtım değerlerinin tespiti yapılmıştır. KOİ, renk, bulanıklık ve AKM parametrelerinin değerleri yanıt olarak sisteme işlenmiştir. MKT programının çıktısı olan üç boyutlu grafikler ve ANOVA tabloları parametrelerin maksimum giderim verimleri esas alınarak değerlendirilmiştir. Design Expert programı tarafından yapılan sayısal optimizasyon sonuçları analiz edildiğinde sistemin önerdiği arıtımda kullanılan parametrelerinin optimum değerleri; pH 9.43, karıştırma hızı 145.93 rpm ve koagülant dozu 36.14 mg/L. Bu koşullarda sistemin yanıt olarak belirlediği giderim verimleri ise; KOİ % 78.75, AKM %91.21, renk %72.89 ve bulanıklık % 98.10.
Distributed Wireless Liquid Level Control of a Process Simulator Over a Network
(Springer, 2018) Bayram, Ismail; Hapoglu, Hale; Aldemir, Adnan
In a process simulator, the distributed wireless liquid level control experiments have been performed by using the generalized predictive control algorithm. The wireless local area network was established with antennas between process simulator in Unit Operations Laboratory and the computer in Process Control Laboratory. We performed the online wireless experiments with MATLAB/Simulink program. Data transfer during the wireless experiments were carried out using radio waves at a frequency of 2.4 GHz. Experiments on the same conditions were achieved by three certain values of control weighting factor in the controller algorithm, whilst the changes in valve opening and liquid level with time were monitored. In all experiments performed with the distributed control system, the control valve opening is fixed with very small oscillations after a sudden increase in the beginning. We obtained the best liquid level control response to different set point changes for the same set of controller tuning values. The Integrated Square of the Error and the Integrated Absolute of the Error values were chosen as performance criteria. The distributed wireless liquid level control was effectively realized to the process simulator and it is recommended for industrial applications.
Drying Kinetics and Quality Properties of Mellaki (Pyrus Communis L.) Pear Slices Dried in a Novel Vacuum-Combined Infrared Oven
(Wiley-hindawi, 2022) Topuz, Fatma Coskun; Bakkalbasi, Emre; Aldemir, Adnan; Javidipour, Issa
In a specially designed infrared oven equipped with a two-way infrared heating and vacuum pump systems, the effects of drying parameters (100-300 W infrared powers and 100-250 mmHg vacuum pressures) on drying kinetics and quality properties of pear slices were comprehensively studied. The samples dried at 300 W had high HMF values (12.73-95.68 mg/kg d.m). The highest sensory scores were observed in pear slices dried at 300 W and 250 mmHg. Six different mathematic models were taken into account to analyze the drying characteristics of pear slices, with the Wang and Singh model (R-2 = 0.9996, chi(2) = 0.0004, and RSME = 0.0062) presenting the best prediction of the drying behavior. The effective moisture diffusivity values were 1.1829-4.6684 x 10(-8). The activation energies for 100 and 250 mmHg vacuum applications were 44.21 and 43.89 kJ/mol, respectively. It was concluded that a vacuum-combined infrared dryer (300 W, 250 mmHg) could be a fast and economic method for drying pear slices. Novelty impact statement A combination of 300 W infrared power and 250 mmHg vacuum pressure was the fastest combination for the drying of pear slices and gave the highest score in sensory evaluation. The Wang & Singh model exhibited the best results in fitting the experimental data. As a result, the vacuum-combined infrared technology was improved the drying efficiency and quality of dried pear.
Enzymatically Synthesis of Polyaniline and Optimization of the Reaction Conditions
(2008) Aldemir, Adnan; Aktaş, Nahit
Anilinin enzimatik oksidatif polimerleşme reaksiyonu sulu ortamda, oda sıcaklığında, polielektrolit bileşen varlığında, kesikli bir reaktörde gerçekleştirildi. Polimerleşme reaksiyonunu başlatmak için Trametes versicolor (ATTC 200801)'den elde edilen lakkaz enzimi kullanıldı. Reaksiyon koşullarının optimizasyonu için reaktörde başlangıç çözünmüş oksijen derişimindeki azalmaya bağlı olarak cevap yüzeyi yöntemi kullanıldı ve bu yöntemin sonuçları Design Expert 6.0 paket programının deneme sürümünde incelendi. Başlangıç reaksiyon hızını etkileyen parametreler ve başlangıç reaksiyon hızı üzerinde etkin olduğu aralıklar ortam pH'sı (3-8), monomer konsantrasyonu (10-122mM) ve sıcaklık (20-51oC) program değişkenleri olarak belirlendi. Belirlenen parametre aralıkları Design Expert 6.0 paket programına uygulanarak program tarafından önerilen 20 deney sırasıyla gerçekleştirildi. Elde edilen sonuçlar ile çalışma parametreleri arasındaki ilişki istatistiksel analiz yöntemi ile değerlendirildi.
Etil Asetat Üretimi için Bir Reaktif Distilasyon Kolonunun Dinamik Simülasyonu: Cevap Yüzey Yöntemi ile İşletme Koşullarının Optimizasyonu
(2022) Bayram, İsmail; Ersingün, Dilan; Aldemir, Adnan
Bu çalışmada, etanolün (EtOH) asetik asit (HAc) ile reaktif distilasyon (RD) kolonunda, esterleştirilmesi yoluyla etil asetat (EtAc) üretimi için optimum çalışma koşullarının belirlenmesi amaçlanmıştır. Bunun için tasarlanan kolonun EtAc üretimi için simüle edilmiştir. HAc akış hızı, EtOH akış hızı, HAc besleme aşaması, EtOH besleme aşaması, geri akış oranı ve reaktif besleme sıcaklıkları değiştirilmiş ve bu parametrelerin EtAc üretimi üzerindeki etkileri gözlemlenmiştir. RD kolonu için optimum çalışma koşullarını tanımlamak için Merkezi Kompozit Tasarım kullanılmıştır. Regresyon katsayısı R2, 0.9197'ye eşittir ve bu, tahmin edilen ve simüle edilen yanıtlar arasında iyi bir ilişki olduğunu göstermiştir. Programdan elde edilen düzeltilmiş ve tahmin edilen R2 değerleri sırasıyla 0.8823 ve 0.7956'dır. EtAc üretim yanıtı için optimal koşullar, 120.00 kmol/saat HAc akış hızı, 150.00 kmol/saat EtOH akış hızı, HAc besleme aşaması 6, EtOH besleme aşaması 14, geri akış oranı 2.2 ve reaktif besleme sıcaklığı 70.28 °C olarak maksimum istenilirlik fonksiyonu ile belirlenmiştir.
Genelleştirilmiş Öngörmeli Kontrol ile Kablosuz Sıcaklık Profillerinin Karşılaştırılması
(2016) Hapoğlu, Hale; Aldemir, Adnan
Bu çalışmada bir proses simülatöründe Genelleştirilmiş Öngörmeli Kontrol (GPC) algoritmasının uygulandığı kablosuz sıcaklık kontrol deneylerigerçekleştirildi ve aynı koşullarda yapılan deneylerde elde edilen sonuçlar karşılaştırıldı. Temel İşlemler Laboratuarında bulunan prosessimülatörü ile Proses Kontrol Laboratuarında bulunan bilgisayar arasındaki veri aktarımını sağlamak için kablosuz iletişim sistemi kuruldu vekablosuz deneyler MATLAB/Simulink programı yardımıyla on-line olarak gerçekleştirildi. Deneyler sırasında kablosuz veri transferi 2,4 GHzfrekansında radyo dalgaları kullanılarak gerçekleştirildi. GPC algoritmasının kullanıldığı kablosuz sıcaklık kontrol deneylerinde, herhangi bir NU(kontrol ufku), N1(minimum öngörme ufku) ve N2(maksimum öngörme ufku) değerinde, L(kontrol ağırlık faktörü) değerinin 1.0’den büyük tümdeğerlerinde ısıtıcının çok büyük salınımlar yaptığı ve buna bağlı olarak sıcaklığında çok büyük salınımlar yaptığı görülmüştür. Bu nedenle GPCkontrol deneyleri, L’nin 1.0’den küçük değerlerinde gerçekleştirildi. GPC algoritmasındaki NU, N2 ve L parametreleri kullanılarak NU=1.0N1=1.0; N2=2.0; NU=1.0; N1=1.0; N2=4.0; NU=2.0; N1=1.0; N2=2.0 ve NU=2.0; N1=1.0; N2=4.0 değerlerinde L=0.001; 0.005; 0.01; 0.05; 0.1; 0.5değerleri için aynı koşullarda yapılan deneyler sonucunda sıcaklık profillerinin zamanla değişimi gözlemlendi. Elde edilen deneysel sonuçlaragöre sıcaklık profilleri incelendiğinde genel olarak NU=1.0; N1=1.0; N2=2.0 değerlerindeki deneysel sıcaklıkların NU=1.0; N1=1.0; N2=4.0;NU=2.0; N1=1.0; N2=2.0 ve NU=2.0; N1=1.0; N2=4.0 değerlerine göre set noktasına daha yakın olduğu ve salınımın daha az olduğu görüldü.Ayrıca NU ve N2 değerlerinin arttırılmasıyla sıcaklıkların set noktasından uzaklaşmaya başladığı ve salınımların arttığı gözlenmiştir. L=0.001;0.005; 0.01; 0.05; 0.1 ve 0.5 değerleri ile aynı koşullarda Tset=50°C ve Tset=60°C için yapılan deneyler sonucunda en iyi sıcaklık kontrolünüsağlayan parametreler, hata karelerinin toplamı (ISE) ve hata mutlak değerlerinin toplamı (IAE) değerleri kullanılarak belirlendi. Buna göreyapılan deneylerde en düşük ISE ve IAE değerleri L=0.01 değerinde olduğu belirlenmiştir. Ayrıca L=0.01’den daha düşük ve daha yüksekdeğerlerde hesaplanan ISE ve IAE değerlerinin arttığı ve sıcaklığın set noktasından uzaklaştığı görülmektedir. Sonuç olarak en iyi sıcaklıkkontrolü NU=1.0; N1=1.0; N2=2.0 ve L=0.01değerlerinde elde edilmiştir.