Method for quality improvement of biological oil through catalytic esterification-deoxidize reforming in subcritical alcohol system

Abstract

The invention discloses a method for the quality improvement of biological oil through catalytic esterification-deoxidize reforming in a subcritical alcohol system. The method utilizes a double-effect supported catalyst with the functions of catalytic esterification and deoxidize reforming and adopts the one-step method to solve the problems of corrosivity and low heating value caused by the strong acidity and high oxygen content of the biological oil simultaneously, so that the pH value of oil products can rise to above 6.5 and the heat value can achieve above 35 MJ / kg; the method can effectively avoid the problem that the catalyst is coked and inactived by contacting heavy components of the biological oil in the traditional catalytic cracking and deoxidizing process. The method for the quality improvement and the modification of the biological oil has the advantages that the operation process is convenient, the quality improving yield of the biological oil is high and can reach above 84%, the modifying cost is lower, and the large-scale quality improvement of the biological oil can be easily achieved, so that the method of the quality improvement of the biological oil has potential for generalization.

Description

technical field [0001] The invention relates to the field of biomass energy, in particular to a method for catalytic esterification-deoxygenation reforming and upgrading bio-oil in a subcritical alcohol system. Background technique [0002] Converting biomass raw materials such as crop straws into liquid fuels-bio-oil through various pyrolysis and liquefaction technologies has become an important method to solve the problem of the gradual depletion of fossil energy in the world. However, bio-oil can only be used as a primary fuel for thermal equipment such as industrial kilns that do not require high fuel requirements. For automobile engines such as internal combustion engines, bio-oil is relatively acidic (pH value is lower than 5). Engine parts will produce obvious corrosion. In addition, bio-oil has a high oxygen content (greater than 20%), resulting in a lower calorific value of the oil (less than 30MJ / kg), which is much lower than that of conventional fossil fuels such ...

AI Technical Summary

Problems solved by technology

We have reported the use of solid superbase KF / γ-Al 2 o 3 Can catalyze ethanol esterification of bio-oil[Xu Yufu, Hu Xianguo, Li Chuan, et al. Research on solid superbase-catalyzed ethanol esterification of bio-oil. Acta Solaris Sinica, 2011, 32(9): 1361-1364], which is helpful for reducing bio-oil Acidity helps a lot, but does not reduce oxygen content of bio-oil

Chinese patent (CN 101486953) reports the supercritical esterification modification process of bio-oil. This method uses a high-pressure pump to add bio-oil and methanol to a static mixer and mix them well. , and then exchange heat with the esterification reaction mixture through a primary heat exchanger, and then enter the supercritical esterification tower after being heated by a heating furnace; carry out catalytic esterification to obtain modified bio-oil, but this supercritical process has reaction temperature and pressure Disadvantages such as high and high energy consumption

Catalytic hydrogenation technology refers to the hydrogenation treatment of bio-oil under high pressure (10 MPa~20 MPa) in the presence of hydrogen and hydrogen-donating solvents. This method requires high equipment and processing costs, and reactors often occur during operation. Problems such as clogging and severe catalyst coking and deactivation

Catalytic cracking mainly converts the oxygen in bio-oil into CO, CO 2 、H 2 O is removed in the form of O. This method has a good pyrolysis, deoxidation and upgrading effect on the oxygen-containing organic macromolecular compounds in bio-oil, but there is still the problem of catalyst coking and deactivation, and some small-molecular oxygen-containing organic compounds such as acetic acid, etc. The cracking effect is not obvious, so it is not promoted

Images