Catalytic Conversion of Used Oil to Hydrocarbon Fuels in a Fractionating Pyrolysis Reactor

Abstract

Pyrolysis of used sunflower oil was carried out in the presence of different amounts of HZSM-5 at 400 and 420 °C in a reactor equipped with a fractionating packed column, the length of which was varied. The products consisted of gaseous and liquid hydrocarbons, acids, CO, CO 2 , water, and coke. The compositions of the gaseous and liquid products were studied by gas chromatography. The product yields and compositions were affected by catalyst content, temperature, and column length. Nearly complete conversion (96.6%) of the used oil and the maximum liquid hydrocarbon yield (33%) were obtained at the highest temperature (420 °C), highest catalyst content (20%), and the lowest column length (180 mm) employed. The aromatic hydrocarbon contents of the liquid hydrocarbon products, which consisted of hydrocarbons of gasoline range, were in general lower than those obtained using fixed bed reactors but increased parallel to the increase in catalyst content. Additional thermal reactions taking place in this type of reactor increased with the increase in column length. Although the total conversion and total liquid hydrocarbon yields were influenced adversely by these reactions, liquid products with higher isomeric hydrocarbon contents were obtained with longer columns.

Optimizing the Production of Renewable Aromatics via Crop Oil Catalytic Cracking

“…The aromatic content decreased with longer columns, believed to be caused by internal thermal effects between the liquid and vapor phases [16].…”

Synthesis, characterization and use of Nb2O5 based catalysts in producing biofuels by transesterification, esterification and pyrolysis

“…For example, it has been reported the production of hydrocarbons from Tung oil in China during the Second World War. 11 Since then, numerous studies about the thermal [12][13][14][15][16][17][18] and catalytic [19][20][21][22][23][24][25][26][27][28][29] pyrolysis of triglycerides and Vol. 20, No.…”

“…The presence of these oxygenated compounds are partially or completely reduced when the reaction is carried out in the presence of a catalyst. 8 For instance, it was observed that the presence of different types of zeolites dramatically changes the reaction products, 21,[24][25][26]28 affording essentially non-oxygenated compounds, mainly aromatic and short chain hydrocarbons in the range of gasoline. 19,22 On the other hand, it was also reported that the products of soybean and babassu oils pyrolysis catalyzed by γ-alumina doped with nickel and molybdenium were completely deoxygenated when the reaction was carried out in the presence of hydrogen pressure.…”

Biocombustíveis a partir de óleos e gorduras: desafios tecnológicos para viabilizá-los

“…Por exemplo, a desoxigenação dos produtos da decomposição térmica de óleo de soja é favorecida quando a reação é realizada na presença de diferentes zeólitas, [58][59][60] sendo também observado que reações de craqueamento da cadeia dos hidrocarbonetos formados, ciclizações e aromatização levam à formação de um produto próximo à faixa da gasolina (8-10 carbonos). Já aluminossilicatos não estruturados e (γ-alumina) 61,62 são também eficientes na desoxigenação dos produtos formados, diminuindo as reações de craqueamento da cadeia carbônica e de ciclização e aromatização, gerando um biocombustível com perfil de destilação próximo ao do diesel. Por outro lado, foi relatado que alguns catalisadores, como óxidos básicos MgO e CaO 59 ou Nb 2 O 5 63 e alguns derivados, 64 estabilizam os ácidos carboxílicos formados levando a produtos com acidez superior à verificada no craqueamento térmico.…”