Kullanılmış yağların pirolizi ile organik kimyasallar ve yakıt üretimi
Başlık çevirisi mevcut değil.
- Tez No: 55748
- Danışmanlar: PROF.DR. H. AYŞE AKSOY
- Tez Türü: Doktora
- Konular: Kimya Mühendisliği, Chemical Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 1996
- Dil: Türkçe
- Üniversite: İstanbul Teknik Üniversitesi
- Enstitü: Fen Bilimleri Enstitüsü
- Ana Bilim Dalı: Belirtilmemiş.
- Bilim Dalı: Belirtilmemiş.
- Sayfa Sayısı: 182
Özet
ÖZET Dünya nüfusunun hızla artması, endüstrileşme ve hızlı şehirleşme doğal kaynakların tüketimini de hızla arttırmaktadır. Bununla birlikte, oluşabilecek enerji temini sorununu bir anda çözebilecek teknolojik bir gelişme de bulunmamaktadır. Bu durum, bilinen kaynakların en rasyonel şekilde kullanımı ve yeni enerji kaynaklarının değerlendirilmesi gibi acil önlemlerin şimdiden alınması zorunluluğunu ortaya çıkartmıştır, özellikle, biyokütle ve ürünlerinin sentetik yakıtların ve organik kimyasalların üretiminde leuUanüabilirMğinin incelenmesi alternatif kaynakların araştırılmasında geniş bir yer almaktadır. Bitkisel yağlar yüksek ısıl değerleri ve uygun özellikleri nedeniyle bu amaçla kullanılan biyokütle kaynaklan arasında önemli bir potansiyele sahiptirler. Bitkisel yağlardan alternatif yakıtların ve ham madde olarak kullanılabilecek organik kimyasalların üretiminde kullanılan en ümit verici yöntemin katalitik ve termokimyasal dönüşüm teknolojileri (piroliz) olduğu düşünülmektedir. Yapılan bu çalışma ile, atık bir madde olan kullanılmış kızartma yağının fraksiyonlama kolonu ile teçhiz edilmiş bir reaktörde 400 ve 420°C de farklı uzunluklarda fraksiyonlama kolonları (180, 360 ve 540 mm) kullanılarak katalizörlü ve katalizörsüz olarak gerçekleştirilen fraksiyonlamalı piroliz reaksiyonu incelenmiştir. Na2CÛ3, Octidyne ve HZSM-5'in katalizör olarak kullanıldığı çalışmalarda, katalizör oram yağa göre ağırlıkça % 1, 5, 10 ve 20 olarak seçilmiş ve reaksiyonlar iki farklı ısıtma hızı ve reaksiyon süresinde yürütülmüştür. Reaksiyonlarda uygulanan koşullara bağlı olarak farklı miktar ve bileşimlerde sıvı (hidrokarbon fazı, sulu faz ve asit fazı) ve gaz ürünler elde edilmiştir. Sıvı hidrokarbon fazı, asit fazı ve gaz ürün bileşimleri GC/MS ve GC cihazlarında belirlenmiştir. Sıvı hidrokarbon fazlan 5-18 karbonlu alkan, alken, aromatik hidrokarbonlar, alken ve alkanlann izomerleri ile çok az miktarda naftenik hidrokarbonlardan meydana gelmektedir. Gaz ürünler 1-6 karbonlu alkan ve alkenlerle, H2, CO ve CO2, asit fazlan ise 5-18 karbonlu doymuş ve doymamış karboksilli asitler içermektedir. Deneysel çalışmalarda sulu faz bileşimleri incelenmemiştir. Elde edilen sonuçlara göre, reaksiyon koşullarının uygun olarak seçimi ile bitkisel yağlann bileşim ve özellik bakımından yakıt alternatifi olabilecek veya organik kimyasalların üretiminde ham madde olarak kullanılabilecek sıvı ve gaz ürünlere dönüştürülebileceği görülmüştür. XX
Özet (Çeviri)
CONVERSION OF USED OIL TO OBTAIN FUELS AND CHEMICAL FEEDSTOCKS BY USING FRACTIONATING PYROLYSIS REACTOR SUMMARY Petroleum, coal and natural gas are at present the principle source of fuels and organic chemicals. These fossil fuels have high sulphur, nitrogen and metal content resulting in substantial amounts of S02 and NOx being released to the atmosphere causing 'acid rains“. The combustion of coal and crude oil also releases CO2. A continuous increase in the C02 concentration in the atmosphere has undesirable climatic consequences through global warming by the ”greenhouse effect“. It is estimated that, worldwide, over 20 billion metric tones of carbon dioxide are released into the atmosphere every year. It has been reported that a significant amount of radioactive gases are also emitted during coal combustion. Furthermore, the increase in world population, rapid industrialization and urbanization have also caused gradual decreases in fossil fuel reserves. Also, in parallel with the development of environmental consciousness, research on new energy sources which do not cause environmental pollution have gained importance. Since World War I, biomass and its products have been investigated as an alternative and renewable raw materials for fuels and organic chemicals. Biomass is formed by photosynthesis according to the reaction: chlorophyll C02 + H20 + solar radiation > (CH20) + 02 470 1J The formula (CH20) is the building block for all carbohydrate materials including cellulose (CöHioOs), which is a polymer of the carbohydrate unit and constitutes the bulk of any biomass. A large number of plant species have been reported which are also capable of converting C02 beyond carbohydrates to isoprenoid and other hydrocarbon-like compounds. The energy content of biomass is a very important parameter in its conversion to energy products and synthetic fuels. The different components in biomass would be expected to have different heats of combustion because of varying chemical structures and carbon contents. Monosaccharides have the lowest carbon content, highest degree of oxygenation and lowest heating value. As the carbon content increases and the degree of oxygenation is reduced, the structures become more XXIhydrocarbonlike and their heating value increases. Cellulose, the dominant polysaccharide component in most biomass, has a higher heating value. Oils derived from plant seeds are much higher in energy content than carbohydrates and approach the heating value of paraffinic hydrocarbons (such as petroleum). Because of this property, plant oils or extracts are very important biomass sources for the production of synthetic fuels and useful chemicals. Various thermochemical (combustion, pyrolysis, liquidification, etc.) and biochemical methods (fermentation, hydrolysis, etc.) can be used to produce chemicals, energy or gaseous, liquid and solid fuels from biomass. The physical and chemical characteristics of biomass are important in the selection of the conversion technology. One of the most promising ways for producing liquid fuels and chemicals from plant oils is pyrolysis. Pyrolysis (retorting, destructive distillation, carbonization) is the thermal decomposition of organic material in the absence of oxygen. The process of pyrolysis is complex, but the most accepted theory is that primary vapors are first produced, the characteristics of which are most influenced by heating rate. These primary vapors then further degrade to secondary tars and gases if held at a high temperature for long enough for secondary reactions to occur. The proportions and characteristics of these secondary materials are a function of temperature and time. For plant oils, pyrolysis starts near 300-375°C. Chars, organic liquids, gases and water are formed in varying amounts depending particularly on the biomass composition, heating rate, pyrolysis temperature and residence times in the pyrolysis reactor. As might be expected, higher temperatures and longer residence times promote gas production, whereas higher liquid and char yields result from lower temperatures and shorter residence times. No matter what the pyrolysis conditions are, with the exception of extremely high temperatures, the product mixture has a complex composition, and selectivity for specific products is low even with a single- feed component. The ratios of unconverted organic solids, ash and fixed carbon residues produced by thermal decomposition of organics are highly dependent on pyrolysis temperature. The present work reports the results of conversion of used frying oil to hydrocarbon fuels and chemicals with catalyst (Na2C03, Octidyne and HZSM-5) and without catalyst at different temperatures (400 and 420°C), different fractionating column lengths (180, 360 and 540 mm) and different catalyst contents (1, 5, 10 and 20 % based on oil weight) by using a special pyrolysis reactor (fractionating pyrolysis reactor). Used frying oil obtained from the campus cafeteria of Istanbul Technical University (Istanbul/Turkey) was filtered to remove pieces of food and used directly without any special purification. The fatty acid composition and the main characteristics of used oil are shown in Table 1. In the study, Na2C03, Octidyne and HZSM-5 were used as alternative catalysts. Na2C03 was analytical grade of XXllRiedel de Haen (Seize/Germany) product. Octidyne obtained from TÜPRAŞ (İzmit/Turkey) is a cracking catalyst. HZSM-5 was obtained from the other research team in the Chemical Engineering Department at Technical University of Istanbul (Istanbul/Turkey). All these catalysts were dried overnight at 1 10°C before use in the reaction. Pyrolysis reactions were carried out in a special reactor (#316 stainless steel tubing, 210 mm long x 75 mm i.d.) equipped with thermocouples, inert gas connection and a fractionating packed column (#316 stainless steel tubing, 45 mm i.d., packed with ceramic rings having 7 mm i.d.). This reactor was placed in a tubular furnace (220 mm long x 78 mm i.d.). Table 1. The fatty acid composition and the main characteristics of used oil. The reactor was loaded with 100 g oil and the air was purged with N2. Then, used frying oil was heated to the selected reaction temperature with a certain program. When the set temperature was reached, the product was started to be collected. Temperature was kept constant until the end of the experiments. In the reactions carried out with catalysts, the catalyst was added to the oil before heating and stirred to disperse the pellet for 3.5 min. The reaction products leaving the fractionating column were separated into liquid and gas fractions. The liquid product was collected in two glass traps, cooled with ice-salt mixture and ice respectively. The gas products were collected over a saturated solution of sodium chloride in a gas holder. In the experiments, two different run periods were applied. In the first part of experiments (the heating rate was 20°C/min), the run was continued until the gas product volume did not change in the gas-holder. In these experiments, the run period varied from 180 to 240 min depending on the reaction conditions. In the second part of the experiments (the heating rate was 40°C/min), the run period was kept at 3 h. At the end of the experiments, the reactor was left to cool at ambient temperature. The respective amounts of the liquid, gas and residual oil-coke were determined. XXlllThe aqueous phase of the liquid product was separated in a separately funnel from the organic phase which consisted of hydrocarbons and carboxylic acids. The aqueous phase was discarded. Using the acid value of the organic phase, as determined by base titration, a corresponding amount of base was added to the organic phase to separete it to a 'liquid hydrocarbon”and a“acid phase”, the latter being converted to methyl esters by BF3-methanol esterification procedure. The analysis of the liquid hydrocarbon and acid phase were carried out quantitatively by using two different capillary columns in a Hewlett Packard gas chromatography 5890 series II apparatus. From these results, the average molecular weight of component fatty acids was calculated and the weight of the acid phase was determined. The gas product was further analyzed by using a packed column in gas chromatography. The conditions of the three gas chromatographic analyses (of the hydrocarbons, of acid phase and of gas product) are presented in Table 2. Table 2. The conditions of the gas chromatographic analyses. 1 Flame ionization detector 2 25 m x 0.32 mm x 0.52 um film thickness % 100 dimethyl polysiloxane 3 25 m x 0.32 mm x 0.52 u,m film thickness % 5 diphenyl and % 95 dimethyl- polysiloxane 4 Thermal conductivity detector. 5 80/100 mesh, 2 m x 1/8" x 2.2 mm, Perkin Elmer. XXIVThe following conclusions were reached: - The highest conversion of oil with and without catalyst and the maximum amount of liquid hydrocarbon product were observed at 420°C using the fractionating column length of 180 mm. - Increase in the reaction temperature increased the amounts of acid phase, liquid hydrocarbon and gas product, but decreased the amount of aqueous phase. - Increase of the column length decreased the conversion. - Increase of catalyst content increased the amounts of liquid hydrocarbon and gas product and conversion of oil. Gas chromatographic analysis of liquid hydrocarbon product revealed that this pyrolysis oil consisted of alkenes, alkanes, isomers of alkenes and alkanes and aromatic hydrocarbons having 5 to 17 carbons. The liquid hydrocarbon product composition was significantly affected by temperature, catalyst content and column length. The formation of aromatic hydrocarbons increased at the reactions catalysed by HZSM-5 at 420°C using the fractionating column of 180 mm. The weight ratios of individual hydrocarbons of the liquid hydrocarbon product at the reaction catalysed by 20 % catalyst (based on oil weight) at 420°C using the column of 180 mm were as follows: The gas product, which included H2, CO, C02, saturated and unsaturated hydrocarbons having 1 to 6 carbons, consisted mostly of Ci, C2 and C3 alkanes and alkenes. The gas product yield was a strong function of the reaction temperature, high reaction temperatures favouring the gas yield. The yield and the composition of gas products were also affected by reaction conditions. All these results suggest that the used frying oil can be converted, with or without catalyst, selectively to a mixture of liquid and gas products with high yields of conversions by using a fractionating pyrolysis system, and that this product can efficiently be used as fuel and chemical raw materials. XXV
Benzer Tezler
- Styrenation of oils based on castor oil
Hintyağı temelli yağların stirenlenmesi
OSMAN SERMET KABASAKAL
Doktora
İngilizce
1995
Kimya Mühendisliğiİstanbul Teknik ÜniversitesiKimya Mühendisliği Ana Bilim Dalı
PROF.DR. AHMET TUNCER ERCİYES
- Evaluation of scrap tires and waste mineral oils hydrocarbon source
Kullanılmış lastiklerin ve atık mineral yağların hidrokarbon kaynağı olarak değerlendirilmesi
SUAT UÇAR
- Ömrü tükenmiş lastiklerden (ÖTL) piroliz yöntemi ile elde edilen pirolitik karbon ve yağın NR-SBR bazlı kauçuk karışımlarındaki etkisi
Effect of pyrolysis carbon black and pyrolsis oil obtained from end of life tires on NR-SBR based rubber mixtures
TUĞÇE GÖRMÜŞER
Yüksek Lisans
Türkçe
2022
Polimer Bilim ve TeknolojisiGebze Teknik ÜniversitesiMalzeme Bilimi ve Mühendisliği Ana Bilim Dalı
DOÇ. DR. İLKE ANAÇ ŞAKIR
- Amino reçineleri içeren odun esaslı kompozit atıkların mikrodalga destekli katalitik pirolizi
Microwave assisted catalytic pyrolysis of wood composite wastes containing amino resins
NARİN TUĞÇE GEDİK
Yüksek Lisans
Türkçe
2023
Çevre MühendisliğiKarabük ÜniversitesiÇevre Mühendisliği Ana Bilim Dalı
PROF. DR. HAMİYET ŞAHİN KOL
- Catalytic cracking of waste cooking oils using low cost catalysts
Atık yağların ucuz katalizörler kullanılarak katalitik krakingi
KAMİL SERKAN UZYOL
Doktora
İngilizce
2019
Kimya MühendisliğiMarmara ÜniversitesiKimya Mühendisliği Ana Bilim Dalı
PROF. DR. DİLEK KAZAN
DOÇ. DR. SELİM CEYLAN