Production of gasoline fraction from bio-oil under atmospheric conditions by an integrated catalytic transformation process

Compared with bio-oil from sawdust (common lignocellulosic biomass), the bio-oil obtained by fast pyrolysis of coffee waste has a unique feature to contain a significant amount of fatty acids such as oleic acid and palmitic acid. It is necessary to conduct C-C cracking of fatty acids present in coffee-waste bio-oil to maximize gasoline fraction (C5-C12) production. In this work, catalytic cracking of oleic acid as a model compound for the fatty acids was carried out in batch reactors to understand the effect of major parameters such as zeolite type (HZSM-5, SAPO-11, MCM-41), reaction temperature (380-500 °C), and reaction time (0-50 min) on gasoline fraction production. The GC-MS analysis showed hydrocarbons and aromatics to be major compounds present in the gasoline fraction irrespective of zeolite type and reaction conditions. At 400 °C and 0 min reaction time, the yield of gasoline fraction was 18.6, 6.7, and 33.1 % with HZSM-5, SAPO-11, and MCM-41, respectively. As reaction temperature increased to 500 °C, the total gasoline fraction yield reached 43.7 and 22.7 % with SAPO-11 and MCM-41, respectively. In all the catalysts, the content of aromatic compounds in the gasoline fraction increased with the increase in reaction temperature and reaction time. Meanwhile, the formation of hydrocarbons in the gasoline fraction showed different optimum temperature with catalyst: 11.8 % yield with SAPO-11 at 500 °C and 27.0 % yield with MCM-41 at 400 °C.

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Integration of Thermal Treatment and Catalytic Transformation for Upgrading Biomass Pyrolysis Oil

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1559 ◽

2007 ◽

Vol 5 (1) ◽

Cited By ~ 14

Author(s):

Beatriz Valle ◽

Ana Guadalupe Gayubo ◽

Alaitz Atutxa ◽

Ainhoa Alonso ◽

Javier Bilbao

Keyword(s):

Thermal Treatment ◽

Thermal Degradation ◽

Fluidized Bed ◽

Catalyst Deactivation ◽

Fluidized Bed Reactor ◽

Coke Deposition ◽

Catalytic Transformation ◽

Pyrolysis Oil ◽

Bio Oil ◽

Oil Components

The upgrading of bio-oil by catalytic transformation upon acidic catalysts is aimed at adapting its composition to that of conventional fuel, or at obtaining petrochemical raw materials, such as olefins and aromatics. A further alternative of growing interest for bio-oil upgrading is catalytic reforming for obtaining H2. The viability of any of these alternatives requires minimizing both the plugging problems that arise in the reactor when the bio-oil is fed and the rapid deactivation of the catalyst, which are associated with the thermal degradation of the lignocellulosic components. In this paper, the catalytic transformation of bio-oil (obtained by fast pyrolysis of vegetable biomass) in a fluidized bed reactor upon a Ni-HZSM-5 zeolite catalyst has been studied, and special attention has been paid to the design of the feed preheating zone. Operation in a single-unit (U-shaped steel tube) for the thermal treatment of the bio-oil (in the downward zone of the U-tube) and its catalytic transformation (in a fluidized bed located in the upward zone of the U-tube) has been compared with operation in a two-unit system, where both steps are carried out in separate units connected through a thermostated line (U-shaped tube for thermal treatment, followed by a fluidized bed reactor for catalytic transformation). It has been proven that a separate step of thermal treatment prior to the catalytic transformation notably improves the global process of bio-oil upgrading. Firstly, it contributes to minimizing coke deposition on the acidic catalyst, mainly the deposition of "thermal" coke (which is associated with the thermal degradation of the bio-oil components at high temperatures), leading to an important attenuation of catalyst deactivation. Secondly, the bio-oil components degraded in the thermal treatment can subsequently be subjected to another upgrading treatment (by steam activation or pyrolysis) in order to obtain a high quality char, which involves upgrading the entire bio-oil.

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