Method for preparing liquid alkane fuel by upgrading bio-oil in aqueous phase catalytic mode

Abstract

The invention provides a method for preparing liquid alkane fuel by upgrading bio-oil in an aqueous phase catalytic mode. The method comprises the following steps of: 1) pretreating the bio-oil to obtain a water-soluble component and a water-insoluble component; 2) performing a pressurized acid hydrolysis process on a furan compound of the water-insoluble component to prepare the furan compound; 3) performing a reforming and hydrogen production reaction on the water-soluble component; 4) mixing the furan compound with a liquid-phase product separated from the step 3) to perform an aldol condensation reaction to increase carbon chains; and 5) performing a hydrogenation and dehydration reaction on an aldol condensation product to obtain liquid linear alkane. The method has the advantages that: an upgrading process, which is performed in a double-phase system, can effectively contribute to the desorption of an intermediate product from the surface of a catalyst and the mass transfer of an upgraded product, and can reduce the risk of carbon deposition on the surface of the catalyst; the quality of oil obtained by the method is high; the energy density and the energy grade of the bio-oil are improved greatly; and the liquid alkane fuel can be obtained from all kinds of bio-oil so as to partially substitute for the conventional widely-used fossil gasoline and diesel oil fuel.

Description

technical field [0001] The invention relates to the fields of chemical technology and biomass utilization, in particular to a method for preparing liquid alkane fuel by water-phase catalytic upgrading of biological oil. technical background [0002] Biomass is the only renewable energy that can produce liquid products. The research on producing liquid fuel oil from biomass began in the oil crisis in the mid-1970s. The main processes are fast pyrolysis, slow pyrolysis and hydrothermal liquefaction. Its liquid product, bio-oil, is a dark brown liquid with a strong smoky smell. It has the following characteristics: 1) high water content, accounting for about 15-30%; 2) high oxygen content, accounting for about 35-40% (The oxygen content obtained by hydrothermal liquefaction of biomass is low, about 20%); 3) High acid content; 4) The composition is complex. Therefore, the calorific value of bio-oil is only about 30-50% of that of gasoline. It has high solid content and poor uni...

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Problems solved by technology

This process has the advantages of mild reaction conditions and low operating costs, but the oxygen content in the product oil is about 15-20%, and the content of hydrocarbons is very low, so the quality of the oil product is poor, and the coking process on the catalyst surface is prone to occur, resulting in catalyst loss. Live and other issues, thus limiting the further development of the process

[0008] In summary, the effects of catalytic hydrogenation and catalytic cracking of bio-oil are not ideal, mainly due to the following three reasons: 1) The nature of bio-oil is unstable, and it is easy to polymerize and generate tar during the reaction to block the reactor; 2) Due to the dehydration reaction The bio-oil loses its hydrophilic groups, and the reaction products generated on the surface of the catalyst increase in a large amount, making it difficult to peel off from the catalyst surface and diffuse into the liquid phase body, resulting in carbon coking on the surface of the catalyst; 3) The bio-oil has a high oxygen content, and the dehydration reaction generates a large amount of water Changed the catalyst acid site leading to catalyst deactivation

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