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Öğe Alkali catalyzed transesterification of safflower seed oil assisted by microwave irradiation(Elsevier, 2011) Duz, M. Zahir; Saydut, Abdurrahman; Ozturk, GulsenThe safflower (Carthamus tinctorius L) oil was extracted from the seeds of the safflower that grows in Diyarbakir, SE Anatolia of Turkey. Biodiesel has been prepared from safflower seed by transesterification of the crude oil under microwave irradiation, with methanol to oil molar ratio of 10:1, in the presence of 1.0% NaOH as catalyst. The conversion of C. tinctorius oil to methyl ester was over 98.4% at 6 min. The important fuel properties of safflower oil and its methyl ester (biodiesel) such as density, kinematic viscosity, flash point, iodine number, neutralization number, pour point, cloud point, cetane number are found out and compared to those of no. 2 petroleum diesel, ASTM and EN biodiesel standards. Compared with conventional heating methods, the process using microwaves irradiation proved to be a faster method for alcoholysis of triglycerides with methanol, leading to high yields of biodiesel. (C) 2010 Elsevier B.V. All rights reserved.Öğe Altın nanomalzeme sentezi ve karekterizasyonu(Dicle Üniversitesi Mühendislik Fakültesi, 2019) Baran, Mehmet Fırat; Saydut, AbdurrahmanNanobiyoteknoloji, nanobilim ve teknolojide çarpıcı ve en hızlı gelişen alanlardan biridir. Altın nanopartikülleri (AuNP'ler), yeşil sentez ile herhangi bir yüzey aktif madde, stabilizatör ve kimyasal madde kullanılmadanbıttım(Pistacia terebinthus) yaprak özütü kullanılarak elde edilmiştir. Elde edilen AuNP’lerin karekterizasyonu UV-vis, SEM-EDX, XRD, FTIR ve TGA-DTA ile yapıldı. SEM-EDX, analizi incelendiğinde sentezlenen nanomalzemelerin kristal boyutunun 100 nm’nin altında olduğu ve kristal yapısının küresel olduğu anlaşılmaktadır. UV-vis, analizi verileri gösterdiki oda koşullarında farklı zaman aralıklarında yapılan ölçümler sonucunda renk değişimi ile maksimum dalga boyunun 335 nm’de karesteristik pik verdiği görüldü. XRD analizi verilerinden kristal yapılarının boyutu 14.37 nm büyüklükte olduğu hesaplandı. Ayrıca çalışmamızda sentezlenen nanomalzemenin TGA-DTA analizi yapılarak nanoparçacıkların 1000 oC ‘ye kadar dayanıklı olduğu rapor edildi.Öğe Application of Modified BCR Sequential Extraction Method for the Fractionation and ICP-OES Determination of Copper in Asphaltite Combustion Waste(Atomic Spectroscopy Press Ltd, 2013) Aydin, Firat; Gunduz, Beniz; Aydin, Isil; Akba, Osman; Saydut, Abdurrahman; Hamamci, CandanAsphaltite is derived from petroleum-origin solid fossil fuel. It contains many elements in different forms which may change during the combustion process. This study presents a modified BCR sequential extraction method for the fractionation of copper (Cu) in asphaltite combustion waste (ACW) into four forms (exchangeable, reducible, oxidizable, and residual) and determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The 327.393 nm line was used because it offers highest detectability and is free from major spectral interferences. A two-stage microwave acid digestion program was used for preparation of the samples. The total Cu concentration in the ACW was 104.56 mg kg(-1) dry weight (d.w). The most abundant copper fraction in the studied ACW samples was found as residual fraction of Cu (59.94 mg kg(-1) d.w.). The relative abundances of the remaining Cu fractions in ACW were as follows: exchangeable + water- and acid-soluble (19.07 mg kg(-1) d.w.) > oxidizable (17.49 mg kg(-1)' d.w.) > reducible (7.65 mg kg(-1) d.w.). The results were found to be in good agreement with the certified values. The advantages of the technique include a high degree of automation, good reproducibility, and short analysis time, which makes it the method of choice for the fractionation of Cu.Öğe Chemical speciation of vanadium in coal bottom ash(Wiley, 2012) Aydın, Fırat; Saydut, Abdurrahman; Gündüz, Beniz; Aydın, Işıl; Hamamcı, Candan; 0000-0002-6112-9209; 0000-0002-0868-2769; 0000-0002-7802-4251; 0000-0001-6571-6032Chemical speciation of vanadium is important to understand the true nature of this element in the environment as well as its biochemical pathways. Sample pretreatment, preparation, and chemical speciation methods were applied for vanadium in coal bottom ash here. Two-stage microwave acid digestion was used to preparation of samples. Determination of vanadium was performed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Speciation of vanadium was carried out using a seven-step sequential extraction procedure of the coal bottom ash each releasing species of vanadium: Water soluble, exchangeable, carbonate, reducible, oxidizable, sulfide, and residual fractions. Total vanadium concentration in the coal bottom ash is 701?mg?kg-1 d.w. The most abundant form of vanadium in coal bottom ash is residual fraction of vanadium (196?mg?kg-1 d.w.). Relative abundances of the remaining vanadium fractions in coal bottom ash are as follows: Reducible (176?mg?kg-1 d.w.)?>?sulfide (176?mg?kg-1 d.w.)?>?carbonate (85?mg?kg-1 d.w.)?>?oxidizable (50?mg?kg-1 d.w.)?>?water soluble (10.6?mg?kg-1 d.w.)?>?exchangeable (9.0?mg?kg-1 d.w.).Öğe Comparison of the biodiesel quality produced from refined sunflower (Helianthus annuus L) oil and waste cooking oil(Multi-Science Publ Co Ltd, 2010) Saydut, Abdurrahman; Kafadar, Aylin Beycar; Tonbul, Yalcin; Kaya, Canan; Aydin, Firat; Hamamci, CandanA major hurdle in commercialization of biodiesel from vegetable oil, in comparison to petroleum-based diesel fuel, is its cost of manufacturing, primarily the raw material cost. Waste cooking oil is one of the economical sources for biodiesel production. NaOH and KOH catalyzed processes for prepared of biodiesel expressed of fatty acid methyl ester were comparatively studied for refined sunflower (Helianthus annuus L) oil and waste cooking oil. Transesterification was carried out using 100% excess methanol; i.e. molar ratio of methanol to oil is 6:1 and catalyst concentration of 0.5% at 60 degrees C. Fuel properties and specifications such as viscosity, flash point, cloud point, pour point, density, cetane number, and acidic value are determined and compared to each other and petroleum diesel. This study characterizes the fuel properties of biodiesel produced from refined sunflower oil and waste cooking oil using two different catalysts (NaOH and KOH) to provide a comprehensive understanding of biodiesels.Öğe Content and Mobility Behavior of Iron and Manganese in Asphaltite Burning Residue Using ICP-OES(Atomic Spectroscopy Press Ltd, 2014) Aydin, Isil; Gunduz, Beniz; Aydin, Firat; Akba, Osman; Saydut, Abdurrahman; Hamamci, CandanThe determination of inorganic pollutants leaching from solid waste, such as coal, asphaltite, oil shale, and ash, is an important topic for industrial applications and solid waste management. This study presents the concentration and fractionation of iron (Fe) and manganese (Mn) in asphaltite burning residue (ABR) and their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). A modified Tessier sequential extraction method was used for the fractionation of Fe and Mn in four forms (exchangeable, carbonates, bound to organic and sulfide, and residual content). Investigations on the Fe and Mn chemical fractions and their environmental mobility in ash solution systems were carried out. It was found that Mn in ABR (from Harbul-Silopi, Turkey) occurs in the following fractions: exchangeable (13.56%), associated with carbonates (28.94%), associated with organic matter and sulfides (17.48%), and residual content (40.08%). Fe occurs in the following fractions: exchangeable (11.11%), carbonates (27.68%), organic matter and sulfides (23.39%), and residual content (37.82%). Among these fractions, the exchangeable and carbonate-bound fractions are unstable and prone to leach out, while the organic matter-bound fractions and the residual fractions are considered to be relatively stable and of low bioavailability. Thw mobility fractions of Fe contain 38.79% and of Mn contain 42.50% of their total concentration in ABR under normal environmental conditions.Öğe Desulfurization and demineralization of asphaltite using combination of froth flotation and aqueous caustic leaching(Sage Publications Inc, 2008) Saydut, Abdurrahman; Duz, M. Zahir; Aydin, Isil; Hamamci, CandanThe mineral matter and Sulfur, which are present in varying amounts in asphaltites, are a major problem in utilization of asphaltites as a fuel. The effect of leaching asphaltites from Simak and Silopi, SE Anatolia, Turkey, with froth flotation following aqueous sodium hydroxide oil desulfurization and deashing was investigated. Froth flotation reduced the ash content of asphaltite by 35.8 % and 35.3 %, pyritic Sulfur 22.55 % and 8.7 % (wt %) and its volatile matter content by 28.9 % and 28.9 %. The asphaltite flotation yield was 79.1 % and 85.3 %. Never organic sulfur could be removed by froth flotation. The asphaltite concentration obtained from flotation was leached using aqeous sodium hydroxide and its organic sulfur content was reduced by 60.8% and 61.9 %. Hence using combination of the two methods, the total sulfur, ash and volatile matter contents was reduced by 76.4% and 71.4 %, 38.1 % and 38.3 %, 44.1 % and 47.2 %. respectively.Öğe Determination of mineral phosphate species in sedimentary phosphate rock in Mardin, SE Anatolia, Turkey by sequential extraction(Elsevier Science Bv, 2009) Aydin, Isil; Imamoglu, Sefik; Aydin, Firat; Saydut, Abdurrahman; Hamamci, CandanThe importance of the effect of phosphate rock depends on the chemical form of phosphorus in which this element is combined. The paper presents the results of inorganic and organic forms of phosphorus in the phosphate rock from Mazidag-Derik, Semikan deposit located at Mardin city at SE Anatolia of Turkey. Total phosphorus concentration in the rock is an average 18.5%. The inorganic phosphorus mean % contents were 99.98% for studied sedimentary phosphate rock. Speciation of inorganic phosphorus was carried out using a method based on sequential extractions of the sedimentary phosphate rock each releasing four forms of inorganic phosphorus: loosely sorbed phosphorus, phosphorus bound to aluminium (P-Al), phosphorus bound to calcium (P-Ca) and phosphorus bound to iron (P-Fe). Calcium bound phosphorus is the dominant form of inorganic phosphorus in the studied sedimentary phosphate rock. Aluminium bound phosphorus is the second, iron bound phosphorus is the third most prevailing form. Loosely bound phosphorus is present in the lowest amounts. Analyses of phosphorus forms in sedimentary phosphate rock using a UV spectrophotometric method and ICP-AES are reported here. For the phosphorus the two methods give the same results and the concentrations are in good agreement with the reference values. (C) 2008 Elsevier B.V. All rights reserved.Öğe Froth flotation pretreatment for enhancing desulfurization of coal with sodium hydroxide(Natl Inst Science Communication, 2007) Saydut, Abdurrahman; Tonbul, Yalcin; Baysal, Akin; Zahir Duz, M.; Hamamci, CandanFroth flotation (FF) pretreatment of coal from Hazro, Turkey, for enhancing desulfurization with sodium hydroxide was investigated. FF reduced following contents of coal: ash, 58.54; pyritic sulfur, 79.34; and volatile matter, 56.98%. The coal flotation was 69.59%. FF could not remove organic sulfur Coal concentration obtained from flotation was leached using aqueous NaOH and its organic sulfur content was reduced by 59.27%. Hence using combination of two methods, total sulfur, ash and volatile matter, contents was reduced by 88.06%, 63.13% and 77.32%, respectively.Öğe Gümüş nanomalzeme sentezi ve antimikrobiyal uygulamaları(Dicle Üniversitesi Mühendislik Fakültesi, 2019) Saydut, Abdurrahman; Baran, Mehmet Fırat; Umaz, AdilÇevre dostu sentez yöntemlerinin her geçen gün daha etkin olması ve nanopartiküllerin (NP’lerin) kullanım alanlarının yaygınlığı bu yöntemlere olan ilginin oldukça artmasına neden olmaktadır. Biz atık durumunda ki zeytin yapraklarından elde ettiğimiz özüt ile gümüş nano partikülleri (AgNP’leri) basit, ucuz ve çevre dostu bir yöntemle sentezledik. Bu partiküllerin Ultraviyole ve Görünür Işık Absorpsiyon Spektroskopi (UVVis.), Fourıer Dönüşümlü Kızılötesi Spektroskopisi (FTIR), X-Işınları Kırınım Cihazı (XRD), Taramalı Elektron Mikroskobu- Enerji Yayılımlı X-ışını (SEM-EDX) ve Termo Gravimetrik (TGA-DTA) analizleri kullanılarak karakterizasyon işlemi yapılmıştır. Antibiyotik dirençliliği günümüz dünyasının ciddi sorunlarından biri bu sebeple elde edilen partiküllerin patojen gram pozitif Staphylococcus aureus ATCC 29213, gram negatif Escherichia coli ATCC 25922 suşları ve Candida albicans mayası üzerinde etkili bir anti-mikrobiyal aktivite gösterdiği tespit edilmiştir. AgNP’lerin MİK (Minimum İnhibisyon Konsantarasyon) değerleri sırası 0.112, 0.028, ve 0.007 olarak bulunmuştur.Öğe Güneydoğu Anadolu asfaltit ve kömürlerinin pirolizi ile sıvı yakıt eldesi ve karakterizasyonu(2017) Saydut, Abdurrahman; Hamamcı, CandanBu çalışmada Güneydoğu Anadolu Bölgesi'ndeki katı fosil yakıtlardan alman numunelerin TGA analizleri ve piroliz yöntemiyle sıvı yakıt elde edilmesi imkanları araştırıldı. Çalışmanın ilk bölümünde, Silopi -Harbul, Şırnak-Avgamasya, Şırnak-Segürük filonlarmdan ve Diyarbakır-Hazro kömür ocağından numune alma yöntemine göre örnekler alındı. Alınan bu örneklerin boyut analizleri ve kimyasal analizleri yapıldı. İkinci bölümünde, bu örneklerin tane boyutuna göre termogravimetrik analizleri (TGA) incelendi. Deneyler izotermal olmayan koşullarda ve atmosferik basmç allında gerçekleştirildi. TGA eğrilerine dayanarak numunelerin ağırlığının ısı enerjisinin ektisiyle nasıl değiştiği saptandı. Üçüncü bölümünde ise piroliz yöntemi ile sıvı yakıt elde edildi. Elde edilen artık kok, sıvı ürün, su, gaz miktarları ve piroliz dönüşümü belirlenerek, en yüksek verimin elde edildiği şartlar belirlendi. Piroliz deneylerinde kömür türünün etkisi, tane boyutu etkisi ve sıcaklığın etkisi incelendi. Çalışmanın son aşamasında, piroliz sonucunda elde edilen sıvı ürünün suyu ayrıldıktan sonra, önce n-pentan sonra toluen çözücüleri kullanılarak, sırasıyla yağ, asfalten ve preasfalten fraksiyonlarına ayrıldı. Daha sonra n-pentanda çözünen (yağ) silikajel kolon kromatografisine tabi tutuldu, n- hekzan, toluen ve metanol kullanarak yağ sırasıyla alifatik, aromatik ve polar bileşenlerine ayrılarak bu bileşenlerin yağ numuneleri içerisindeki miktarları tayin edildi.Öğe Güneydoğu Anadolu bölgesindeki asfaltit ve linyitlerin fiziksel işlemlerle kül ve kükürdün giderilmesi(Dicle Üniversitesi, Fen Bilimleri Enstitüsü, 1999) Saydut, Abdurrahman; Hamamcı, CandanTürkiye'nin Güneydoğu Anadolu Bölgesinde Şırnak (Avgamasya, Segürük), Silopi (Halbur) sınırlan içerisinde geniş asfaltit yataklan ve Diyarbakır (Hazro)' da linyit yataklan bulunmaktadır. Güneydoğu Anadolu Bölgesinde katı yakıt olarak asfaltitler ve linyitler kullanılır. Bu oluşumların yapılarındaki yüksek kükürt ve kül içerdiğinden dolayı temizlenmeden yakıt olarak kullanılması uygun değildir. Bu çalışmada asfaltitleri ve linyitleri iyileştirmek için flotasyon ve yüzdürme-batırma deneyleri yapıldı. Flotasyonda etkin parametrelerden tane boyutu, katı oram, bastına, toplayıcı, köpürtücü miktan ve kanştırma hızının kömür yapısındaki kükürdün uzaklaştınlmasındaki etkileri incelenmiştir. Yüzdürme batırma deneyleri ile değişik yoğunluklarda kül ve kükürt arasındaki ilişki incelendi. Optimum flotasyon koşullarında ve yüzdürme batırma deneylerinde Hazro linyitinde kül, piridik kükürt ve sülfat kükürdü giderilebilidi. Hazro linyitinin piritik kükürt oranı yüksek olduğundan dolayı fiziksel yöntemlerle piridik kükürdü gidermede oldukça etkilidir. Asfaltitlerin organik kükürt yüzdesi yüksek olduğundan ve piritik kükürtte organik yapıya bağlı olduğundan dolayı sonuç alınamadı. Organik kükürt yüzdesi yüksek olan asfaltitler için bu işlemlerden sonra kimyasal zenginleştirme ve desülfürizasyon işlemleri uygulanması gerekmektedir.Öğe Hazardous metal geochemistry of sedimentary phosphate rock used for fertilizer (Mazidag, SE Anatolia, Turkey)(Elsevier, 2010) Aydin, Isil; Aydin, Firat; Saydut, Abdurrahman; Bakirdere, E. Gulhan; Hamamci, CandanComposition of phosphate rocks mostly depend on their type and origin. Sedimentary rocks contain high concentration of heavy metals. Phosphate rocks are mainly used for the manufacturing of phosphate fertilizers. The contents of heavy metals Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn, as well as rare earth elements Ce, La, and Th were determined in sedimentary phosphate rock used for production of fertilizer in Turkey. The Kasrik-Semikan, Mazidag (Mardin, SE Anatolia, Turkey) high-grade phosphate rock used in this study is situated near the border with Syria and was deposited during the Turonian and Senonian (Cretaceous) ages. Total phosphorus (P) concentration in the rock is 18.5% on the average. Microwave acid digestion (MW-AD) followed by inductively Coupled Plasma-Optical Emission Spectrophotometry (ICP-OES) was carried out for the determination of all the elements of interest in phosphate rock. The results revealed that hazardous metal content of the phosphate rock was lower in Mazidag phosphate than that in samples imported from other countries and were within the safety limits. (C) 2010 Elsevier B.V. All rights reserved.Öğe High-Performance Liquid Chromatography Analysis and Assessment of Benzoic Acid in Yogurt, Ayran, and Cheese in Turkey(Springer, 2012) Yildiz, Aydin; Erdogan, Sait; Saydut, Abdurrahman; Hamamci, CandanAmong food sources, particular attention is paid to milk and dairy products, due to its nutritional importance. Benzoic acid is extensively used in the preservation of foods. A reliable method for the determination of benzoic acid in some dairy products, such as yogurt, ayran, and cheese using high-performance liquid chromatography and UV detection was validated. The peak of benzoic acid was measured at a wavelenght of 226 nm. Samples were purchased from supermarkets in Turkey in the period 2009-2010. All dairy product samples were produced from cow's milk. The levels of benzoic acid in cheese, yogurt, and ayran samples were in the range of 3.17 to 56.77 mg kg(-1), 8.94 to 28.30 mg kg(-1), and 1.54 to 16.57 mg L-1, respectively. The results show that benzoic acid widely occurs in milk products in Turkey at the low levels.Öğe Influences of temperature on flash pyrolysis products of asphaltite(Natl Inst Science Communication, 2008) Saydut, Abdurrahman; Hamamci, CandanSeguruk (Sirnak, Turkey) asphaltite by flash pyrolysis in a fixed bed reactor with a heating rate 40 degrees C min(-1) at 400-800 degrees C (optimum 550 degrees C) under nitrogen atmosphere gave: solid residue (char), 67.68; oil, 13.28; and water, 0.99%. Seguruk asphaltite contained: asphaltene, 28.72; preasphaltene, 10.43; aliphatics, 52.54; aromatics, 5.05; and polar aromatic Compounds, 3.26%. Oil obtained from asphaltite is mainly aliphatic according to FTIR spectrum.Öğe Liquefaction of Harbul (Silopi SE anatolia, turkey) asphaltite by flash pyrolysis(Sage Publications Inc, 2008) Saydut, Abdurrahman; Tonbul, Yalcin; Hamamci, CandanAsphaltite, being petroleum originated solid fossil fuel, can be converted into a variety of secondary products such as light hydrocarbon gases, liquid product and high quality fuel char by means of pyrolysis. Liquefaction of Harbul (Silopi, Turkey) asphaltite, -0.60+0.25 mm particle size, and using flash pyrolysis was performed in a fixed bed reactor with a heating rate 40 degrees C min(-1) at a temperature ranging from 400 to 800 degrees C under nitrogen atmosphere. The effect of temperature on conversion and liquid yield was examined. The flash pyrolysis temperature resulted in a large increase in the oil yield, tar, gases, large increase in the yield of hydrocarbon gases occurred as a result of temperature at 550 degrees C which was attributed to an increase thermal cracking of pyrolysis vapours. The yield of asphaltite liquid at the condition of 550 degrees C reached a maximum 19.66 wt %. The asphaltenes of the pyrolytic oils were precipitated by addition of n-pentane. Pentane solubles were fractioned by column chromatography into aliphatic, aromatic and polar fractions using n-hexane, toluene and methanol, respectively. The composition of these fractions from silica gel column chromatography of oil obtained by nitrogen pyrolysis was characterized by FTIR.Öğe Methyl ester of peanut (Arachis hypogea L.) seed oil as a potential feedstock for biodiesel production(Pergamon-Elsevier Science Ltd, 2009) Kaya, Canan; Hamamci, Candan; Baysal, Akin; Akba, Osman; Erdogan, Sait; Saydut, AbdurrahmanThe peanut (Arachis hypogea L.) seed oil was extracted from the seeds of the peanut that grows in SE Anatolia of Turkey. Oil was obtained in 50 wt/wt.%, by solvent extraction. Peanut (A. hypogea L) seed oil was investigated as an alternative feedstock for the production of a biodiesel fuel. Biodiesel was prepared from peanut by transesterification of the crude oil with methanol in the presence of NaOH as catalyst. A maximum oil to ester conversion was 89%. The viscosity of biodiesel oil is nearer to that of petroleum diesel and the calorific value is about 6% less than that of diesel. Peanut seed oil have about 8.3% less heating value than that of diesel oil due to the oxygen content in their molecules. The quality of biodiesel is most important for engine part of view and various standards have been specified to check the quality. The important properties of peanut oil and its methyl ester (biodiesel) such as density, kinematic viscosity, flash point, iodine number, neutralization number, pour point, cloud point, cetane number are found out and compared to those of no, 2 petroleum diesel, ASTM and EN biodiesel standards. The comparison shows that the methyl ester has relatively closer fuel properties to diesel than that of raw peanut seed oil. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Microwave Acid Digestion for the Determination of Metals in Subbitumnious Coal Bottom Ash by ICP-OES(Sage Publications Inc, 2010) Saydut, AbdurrahmanThe development of precise and easy determination method for the metals in fossil fuel is the essential factor for the study of problems which are caused by the existence of metals in fuel. Coal contains many kinds of mineral matter elements including metals derived from its generation. The sample preparation method developed for metal determination in coal by spectroanalytical technique is dry ashing, and wet acid microwave digestion. Microwave-acid digestion (MW-AD) followed by inductively coupled plasma-optical emission spectrometry (ICP-OES) was examined for the determination of metals (Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Zn) in coal bottom ash (CBA). Subbitumnious coal from Hazro deposits in SE Anatolia of Turkey has been used in this study. Metals in coal gave good recoveries for their certified or reference values.Öğe Microwave assisted transesterification of maize (Zea mays L.) oil as a biodiesel fuel(Sage Publications Inc, 2010) Ozturk, Gulsen; Kafadar, Aylin Beycar; Duz, M. Zahir; Saydut, Abdurrahman; Hamamci, CandanMaize (Zea mays L.) oil is a highly valuable agricultural commodity for the Turkey. Transesterified maize oil has the global better properties because it has the greater monounsaturated content. Biodiesel has been prepared from maize by transesterification of the crude oil under microwave irradiation, with methanol to oil molar ratio of 10:1, in the presence of 1.5% NaOH as catalyst and 5 minutes time, the conversion of maize oil to methyl ester was over 98%. Compared with conventional heating methods, the process using microwaves irradiation proved to be a faster method for alcoholysis of triglycerides with methanol, leading to high yields of biodiesel.Öğe Phosphorus Speciation in Coal Bottom Ash(Atomic Spectroscopy Press Ltd, 2011) Aydin, Firat; Saydut, Abdurrahman; Aydin, Isil; Hamamci, CandanCoal, coal bottom ash (CBA), and coal fly ash contain many elements in different forms which may change during the coal combustion process. A true understanding of the dynamics of phosphorus (P) in the natural environment requires an expanded knowledge of its oxidation-reduction (redox) cycling. This study presents a sequential extraction method for the speciation of phosphorus from CBA in seven forms and their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The total P concentration in CBA was found to be 651.48 mg kg(-1). The most abundant form of P in CBA is the sulfide fraction of P (40.42%). The relative abundances of the remaining P fractions follow the order: Residual 38.63% > Reducible 15.12% > Carbonate 3.42% > Oxidizable 1.10% > Exchangeable 0.94% > Water soluble 0.37%.
