Derya Unlu

Fuel bioadditive production by chitosan/sulfosuccinic acid catalytic membrane

ABSTRACT Global warming is one of the biggest environmental problems of late. The use of renewable raw material resources as biomass and its conversion into alternative energy resources have attracted considerable attention during the recent years. Ethyl levulinate (EL) is a kind of fuel bioadditive for use in diesel and biodiesel engines, which is produced by the esterification of ethanol and levulinic acid. In the present study, sulfosuccinic acid (SSA) catalysts supported on chitosan catalytic membrane is used for the synthesis of EL. The effects of temperature, catalyst amount, and molar feed ratio were studied.

Review of Renewable Biofuels in the Aviation Sector

The air transport industry has a significant effect on air pollution. Usage of petroleum-derived fuels is responsible for greenhouse gas emissions. Also, these fuels have a high cost. Therefore, development of alternative biofuel from renewable feedstock gains importance. Renewable and sustainable biofuels must be produced and used for the all vehicle engines. This study is related to the synthesis of biofuels and production process. Renewable feedstocks, biofuels, and their production processes are explained.

Improvement of fuel properties of biodiesel with bioadditive ethyl levulinate

Abstract Biodiesel has poor cold flow properties due to their high saturated fatty acid content. Ethyl levulinate is used as bio-based cold flow improver additive in biodiesel. In this work, both ethyl levulinate and biodiesel were synthesized in the laboratory. Ethyl levulinate was added to the biodiesel at different rates, i.e, 5, 10, 15, 20 (vol %). The effect of ethyl levulinate addition on density, kinematic viscosity, acid value, cloud point and pour point was determined and compared to the EN 14214 and ASTM D6751 specification. Consequently, ethyl levulinate appears acceptable as a cold flow improver for biodiesel fuel.

Uçaklarda Buzlanma ve Buzlanmayı Önleyecek Yöntemler

Ucaklarin kanatlari uzerinde ki kar ve buz birikintileri ucus performansini etkileyerek ucusun elverissiz hale gelmesine sebep olur ve kalkis yapmasini engeller. Bu sebeple buzlanma havacilik sektorunde onemli bir meteorolojik tehlikedir. Ucus yuksekligi, hava kosullari, nem, sicaklik gibi cevresel faktorler buzlanmayi onemli derecede etkiler. Buzlanma yolcularin hayatini tehlikeye sokacak sonuclara sebep olabilecegi icin tehlikeli bir durumdur. Dolayisiyla buzlanma olayinin sebepleri, neden oldugu olumsuz sonuclar ve buzlanmayi engelleme veya buzlanmanin olumsuz sonuclarini ortadan kaldirma calismalari hem insan hayati bakimindan hem de teknolojik acidan onemli bir yere sahiptir. Bu calismada buzlanma olusumunu ortadan kaldirmak icin kullanilan buzlanma onleyici ve engelleyici kimyasallar, yapi malzemeleri arastirilmistir

Bioadditive Synthesis from Glycerol by Esterification Using Catalytic Chitosan Membrane

Glycerol is the main by-product in biodiesel production. The increasing production of biodiesel has resulted in significant amount of glycerol deposition. Esterification of glycerol with acetic acid is a kind of method to consume excess glycerol. The valuable chemicals like that bioadditives are produced in this method. Zr(SO4)2·4H2O loaded chitosan catalytic membrane was prepared by the solution casting method and used as catalyst for esterification of glycerol and acetic acid. The reactions were performed in a batch reactor and in a pervaporation catalytic membrane reactor (PVCMR). The structure of the membranes was investigated by means of Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results of esterification of acetic acid and glycerol show that the conversion was slightly improved with the Zr(SO4)2·4H2O content in the membrane at a fixed chitosan content. The reaction rate constant increased with increasing acetic acid/glycerol molar ratio, amount of catalyst loading in the catalytic membrane and reaction temperature. Higher conversion values were obtained by PVCMR.