KETEN TOHUMU YAĞININ SÜPERKRİTİK AKIŞKAN EKSTRAKSİYON KİNETİĞİNİN DİFÜZYON KONTROL METODU İLE MODELLENMESİ

Bu çalışmada; keten tohumu yağı, süperkritik karbondioksit ekstraksiyonu ile ekstre edilmiş ve ekstraksiyon kinetiği difüzyon kontrol yöntemi ile modellenmiştir. Basınç (20, 35, 55 MPa), sıcaklık (323 and 343 K), ve CO2 akış hızı (1 ve 3 L CO2 /dakika) gibi proses parametrelerinin etkilerinin, ekstraksiyon verimine ve etkin difüzyon katsayısına (De) etkileri araştırılmıştır. Etkin difüzyon katsayısı 2,4 x10-12 m2s-1 ile 10,8x10-12 m2s-1 arasında değişmiş, basınç ve CO2 akış hızı ile artmıştır. Model sonuçlarının deneysel sonuçlara uygun olduğu görülmüştür (OMS, %2,35-7,48)

MODELING OF SUPERCRITICAL FLUID EXTRACTION KINETIC OF FLAXSEED OIL BY DIFFUSION CONTROL METHOD

In this study, Flaxseed oil was extracted by Supercritical Carbondioxide Extraction, and extractionkinetics was modelled using diffusion controlled method.The effect of process parameters, such as pressure (20, 35, 55 MPa), temperature (323 and 343 K), and CO2 flow rate (1 and 3 L CO2 /min) on the extraction yield and effective diffusivity (De) was investigated. The effective diffusion coefficient varied between 2.4 x10-12 and 10.8 x10-12 m2s-1 for the entire range of experiments and increased with the pressure and flow rate. The model fitted well theexperimental data (ADD varied between 2.35 and 7.48%)

Optimization of Alkaline Pretreatment for Enzymatic Saccharification of Poppy Stalks

Response surface methodology (RSM) was employed to optimize dilute alkaline pretreatment conditions for the maximum glucose yield of poppy stalk, with respect to NaOH concentration (1.0 to 3.5%, w/v), pretreatment temperature (50 to 100 °C), and pretreatment time (10 to 110 min). Recovery of glucan ranged from 61.02% to 99.14%, based on the initial glucan in the raw material. The highest lignin removal (43.43%) was obtained at the pretreatment conditions of 90 °C and 3.50% NaOH for 90 min. The optimum pretreatment conditions for maximum glucose yield after enzymatic hydrolysis were found to be 2.40% w/v NaOH, 70 min, and 80 °C. Under these conditions, experimental glucose and xylose yields were 499.35 mg/g glucan and 498.66 mg xylose/g xylan, respectively

Improving lipid production capacity of new natural oleaginous yeast: Pichia cactophila firstly

Biodiesel is a useful alternative source of energy and can be used as a support for oil-source diesel. Microbial lipids are considered a promising raw material for biodiesel production. In a previously completed study, Pichia cactophila was found to be the best lipid-producing yeast by lipid screening studies among 107 yeast isolates. In this study, the lipid production conditions of P. cactophila, which was chosen as a lipid producer for the first time, were partially optimized by using response surface methodology in crude glycerol. Plackett-Burman statistical experiment design was used to determine the effect of glycerol, yeast extract, peptone, urea, (NH4)(2)SO4, NH4Cl, NH4NO3 factors on lipid production. In order to determine the optimum levels of the most effective parameters by the result of screening (glycerol, yeast extract, urea, NH4NO3), Box-Behnken experimental design method was used. The optimum production conditions were determined as 39 g/L glycerol, 20 g/L yeast extract, 5 g/L urea, and 20 g/L NH4NO3, and the result of the experiments carried out under these conditions the lipid value (%) was determined as 91.43. Lipid content was increased 1.408-fold (40.79%) by two-step optimization with the response surface methodology and reached a very high value. The fatty acid composition obtained under optimum conditions is compatible with vegetable oils. This suggests that the microbial lipid of P. cactophila can be used as a raw material for biodiesel production and is promising for further studies

Ethanol production from hazelnut shells through enzymatic saccharification and fermentation by low-temperature alkali pretreatment

Low-temperature sodium hydroxide (NaOH) pretreatment, enzymatic saccharification and ethanol fermentation were evaluated for hazelnut shell cellulose to fermentable sugars and ethanol. Maximum glucose recovery (48.33 g/100 g cellulose) was achieved with 6% NaOH for 72 h and at 1/10 solid/liquid ratio. At these conditions, 41.18% of lignin was removed. The theoretical ethanol yield (ethanol produced/potential glucose in biomass) was 40.71%, overall process efficiency was 37.73 g/kg biomass, ethanol productivity and fermentation efficiency were 0.115 g/(L h) and 96.7%, respectively. Total energy consumed for the low-temperature-long-residence-time alkali process was 34.8 Mj/kg untreated hazelnut shells. Pretreatment time has a significant effect on thermal energy consumption for the low-temperature alkali process. (C) 2017 Elsevier Ltd. All rights reserved

Lipid Production from Crude Glycerol by Newly Isolated Oleaginous Yeasts: Strain Selection, Molecular Identification and Fatty Acid Analysis

Biodiesel is a renewable alternative fuel and glycerol as a main byproduct of the manufacturing process. Lipids could be produced from crude glycerol by using yeasts. The ability of 107 yeast strains to utilize glycerol was screened and 92 of these were selected. 60 strains were determined as a potential for lipid production by Sudan Black B staining. After secondary screening 25 of them showed specific growth rates (OD 600), high biomass production and lipid content. These strains were identified as Pichia cactophila, P. fermentans, P. anomala, Rhodotorula mucilaginosa, R. dairenensis, Clavispora lusitaniae, Saccharomyces cerevisiae, Wickerhamomyces anomalus, Candida glabrata, C. inconspicua, C. albicans, Yarrowia lipolytica with molecular identifications based on ITS and D1/D2 26S rDNA sequences. The results showed that P. cactophila accumulated lipid up to 64.94%, the highest lipid content. C16:0, C18:0, C18:1 and C18:2 essential fatty acids for biodiesel production were detected by GC-MS in the lipids accumulated by all strains. P. cactophila and C. lusitaniae were reported for the first time as lipid-producing yeasts. The results suggest that selected 25 isolates have the ability to grow on crude glycerol and especially P. cactophila produce lipid that has potential use as a feedstock for second generation biodiesel production. Graphi