Directed Catalytic Conversion Of ABE And Adipic Acid By Biological Fermentation

The long-term and large-scale exploitation and application of fossil energy lead to the increasing concentration of greenhouse gases in the atmosphere and the escalating environmental problems.Under the background of"Carbon peak and neutrality goals"goal,the conversion of lignocellulose with the largest content in biomass to biofuel has become one of the potential ways to solve environmental problems.However,the direct conversion of lignocellulose has a complex reaction system and is difficult to control.Cascade biochemical and chemical catalytic pathways provide a feasible route for the conversion of lignocellulose to biofuels.At present,the efficient and directional conversion of the lignocellulose fermentation platform compound ABE fermentation(acetone ethanol butanol mixture)into biofuels(C8?C15chain alkanes)through two steps has become the research focus of the utilization of ABE fermentation.Firstly,this dissertationsystematically studied the route of preparing C8?C15 chain alkanes from ABE fermentation,and explored the structure-activity relationship of the catalyst.In order to improve the conversion performance of ABE fermentation to biofuels,a mesoporous tantalum phosphate catalyst with super acid sites was designed and prepared to convert acetone and unilateral alkylation products(2-pentanone,2-heptanone)of ABE fermentation broth with high selectivity to prepare naphthenic hydrocarbon biofuels with high volumetric calorific value and low freezing point.In the conversion of lignocellulose to biofuel,the alcohol dehydration step in alcohol conversion(ATJ)is very important.In this paper,a copper modified SSZ-13 zeolite catalyst with high activity and stability was prepared to catalyze the dehydration of bioethanol from ABE fermentation at low temperature.Finally,in order to further develop a new path of biomass conversion to prepare high-performance fuel,the path of preparing decahydronaphthalene JP-900)from biological adipic acid was explored.The second chapter of this dissertation aims to develop an efficient catalyst to convert the fermentation of lignocellulose platform compound ABE fermentation into bio jet fuel(C8?C15 chain alkanes).It is includes two steps:(1)alkylation of ABE molecules for chain growth reaction to produce C8?C15ketones;(2)Ketone compounds are hydrodeoxygenated into bio jet fuels(chain alkanes of C8?C15).The alkylation reaction includes four steps:dehydrogenation,aldol condensation,dehydration and hydrogenation,which requires the synergistic action of metal nickel and acid-base sites.Alkylation reaction is the key step of this route.In this chapter,a multi-functional catalyst catalysis of mixed metal oxide supported nickel nanoparticles(Ni/Mg O-Al₂O₃)is constructed,in which nickel catalyzes the hydrodeoxygenation reactions and Mg O-Al₂O₃ catalyzes the condensation reactions.In this chapter,the nickel content,valence state,Mg/Al ratio and other preparation conditions of the catalyst were optimized through a large number of experiments.The optimal catalyst contained nickel loading of 6%,Ni⁰/Ni²⁺of 3.55 and Mg/Al ratio of 3.The conversion of ABE fermentation was 89.2%and the total yield of C5?C15 ketones was 79.9%,which was higher than the research results in the dissertation.In addition,the ketones obtained in this chapter can be completely converted into the corresponding alkanes through the hydrodeoxygenation process of Ni/Al-SBA-15 catalyst.In the third chapter of this dissertation,the route of preparing naphthenic hydrocarbon fuel by trimerization and hydrogenation of unilateral alkylation products(2-pentanone,2-heptanone)of ABE fermentation and acetone was explored.Mesoporous tantalum phosphate(Ta PO-1)catalyst with rich Superacid sites was synthesized.The catalyst can efficiently catalyze the trimerization of acetone:up to?80%yield of mesitylene can be obtained when the trimerization of acetone is catalyzed at 200°C,and 84.1%and68.5%yield of corresponding aromatics can be obtained when the conversion of 2-pentanone and 2-heptanone is catalyzed at 180°C and 230°C,respectively.Through kinetic study and theoretical calculation,it is found that the key step of trimerization of 2-ketones is the condensation of monomer and dimerization product,and the strong acid site in the catalyst is the active center of this step.These aromatics can be transferred to the corresponding naphthenic hydrocarbon fuel through simple hydrogenation by Pt/Al₂O₃catalyst.These aromatics can obtain the corresponding naphthenic hydrocarbon fuel through simple hydrogenation.In Chapter 4,the dehydration of bioethanol from ABE fermentation was studied.Zeolite molecular sieve shows high activity in catalyzing ethanol dehydration,but its reaction temperature often needs more than 400°C,and its activity needs to be improved at low temperature.In this chapter,Cu-SSZ-13zeolite with copper loading up to 12.9%was directly synthesized with tetraethylene pentamine copper as copper source.The yield of ethylene is greater than 99%at 212°C,which is much better than other molecular sieve catalysts.Combined with kinetic study and catalyst characterization,it is found that the introduction of copper greatly increases the acid density of the catalyst,which makes it have high activity in the key step of ethanol dehydration to ether.The fifth chapter explores the preparation of JP-900 fuel by adipic acid conversion,which includes the following steps:cyclopentanone is synthesized by decarboxylation and cyclization of adipic acid in liquid phase with barium oxide catalyst.2-cyclopentanyl cyclopentanone was synthesized by aldol condensation of cyclopentanone catalyzed by barium oxide,and then1,2,3,4,5,6,7,8-octahydrogenated naphthalene-1-one was obtained by ring rearrangement.Decahydronaphthalene was synthesized from1,2,3,4,5,6,7,8-octahydronaphthalene-1-one by hydrodeoxygenation of Rh/C,and the conversion of biological fermented adipic acid was realized by four steps.In this dissertation,the conversion of ABE fermentation components to biofuels and their intermediates was explored.It also explores a new way to prepare high-performance fuel from Biobased adipic acid.The whole path conforms to the concept of green sustainable development and contributes to the realization of the"Carbon peak and neutrality goals".