Catalysis of Organic..

Snåre et al. 41546. Continuous Deoxygenation of Ethyl Stearate:A Model Reaction for Production ofDiesel Fuel HydrocarbonsAbstractMathias Snåre, Iva Kubičková, Päivi Mäki-Arvela,Kari Eränen and Dmitry Yu. MurzinLaboratory of Industrial Chemistry, Process Chemistry Centre,Åbo Akademi University,Biskopsgatan 8, FIN-20500 Turku/Åbo, Finlanddmitry.murzin@abo.fiIn this paper the continuous deoxygenation of biorenewable feeds for diesel fuelproduction is addressed. The model reactant, ethyl stearate (stearic acid ethyl ester,C 20 H 40 O 2 ) is deoxygenated by removal of a carboxyl group via decarboxylationand/or decarbonylation reactions yielding an oxygen-free diesel fuel compound,heptadecane. The reaction was carried out in a fixed-bed tubular reactor over aheterogeneous catalyst under elevated temperatures and pressures. The effect ofcatalyst pretreatment and catalyst mass as well as influence of reaction temperaturewere investigated.IntroductionCurrently significant research effort is devoted to developing environmentallyfriendly liquid fuels from renewable sources. Natural oils and fats are produced viaextraction or pressing of renewable materials such as vegetable and animal feeds.The natural oil and fats consist primarily of triglycerides (98%), which are made upof a glycerol moiety and three fatty acid moieties[1]. Typically fatty acids invegetable oils and animal fats have a straight hydrocarbon chain with carbonsvarying from C 6 to C 24 , the chain can be saturated, monounsaturated orpolyunsaturated, Table 1 [2,3]. Diesel fuel compounds derived from crude oilgenerally have 10-20 carbon atoms , thus removal of the carboxyl group from thefatty acid molecule would result in a paraffinic hydrocarbon similar to fossil dieselcompounds. The paraffinic fuel compounds, converted from fatty acids and theirderivates, would have a superior cetane number compared to both fossil dieselcompounds and the conventional biodiesel compounds, FAME, produced via thetransesterification method [4]. Furthermore, fatty acid derived fuels are veryecologically benign, e.g. they exhibit a low sulphur and aromatic content and arebiodegradable [5].