Benzene, toluene and xylene (BTX) from in-situ gas phase hydrodeoxygenation of guaiacol with liquid hydrogen donor over bifunctional non-noble-metal zeolite catalysts
Graphical abstract
Synopsis: A series of molecular sieve supported catalysts with different modification methods were prepared and the effect on the HDO of guaiacol was investigated under the action of hydrogen donor.
Introduction
With the alarming rise in global energy consumption, there is an urgent need to replace fossil fuels with renewable and sustainable energy sources [1]. Therefore, the attention of the research community has centered on the abundant reserve of clean and renewable biomass [2]. As a raw source, biomass is subjected to the biomass-to-liquid process for conversion into liquid fuels known as bio-oils [3]. The setback with bio-oils, however, is that they contain high amounts of water and oxygen element, highly viscous and corrosive, and have low calorific value. Thus, they require upgrading to overcome such disadvantages and make them applicable as a fuel of existing engines. One effective and widely employed method for improving the quality and stability of bio-oils is hydrodeoxygenation (HDO) upgrading technology [4].
High-purity hydrogen has been often used as the hydrogen source for the HDO of bio-oil or various simulated compounds [5,6]. Nonetheless, the high combustion risk and the costly hydrogen production, makes hydrogen unconducive as a source for large-scale application of the HDO technology [7].
A strategy of adding an organic solvent to the bio-oil during the HDO reaction has been introduced in previous research [8,9]. Especially, a series of hydrogen-donating reactions have been investigated to determine the role of hydrogen donors (tetralin, isopropanol, glycerol, and formic acid) in lignin/microalgae, concluding that hydrogen donors have a significant effect on product distribution [10,11]. Zhang et al. studied the transfer hydrogenation of phenol over supported Pd catalysts with formic acid as the hydrogen donor. They obtained the highest phenol conversion of 65.6%, with almost all the converted phenol being turned into cyclohexanone [12]. Xiang et al. achieved 18.1%–53.1% conversion of phenol and up to 96.1% selectivity of cyclohexanone through the hydrogenation of phenol with methanol or ethanol, over Raney Ni or Pd/Al2O3 catalyst [13]. In certain conditions, the solvent can react as a co-reactant of bio-oil [14]. These studies provide another route for hydrogen donors for catalytic HDO of bio-oils.
However, a large number of studies on hydrogen donors mainly use a one-pot method, which is difficult to achieve continuous production. Studies on gas phase hydrodeoxygenation of hydrogen donors have rarely been found. And little is known about the interaction between the reactants and the hydrogen donor. The continuous HDO reactor under gas-phase conditions is more in line with industrial production requirements.
Isopropanol is selected as a hydrogen donor for HDO of guaiacol under the gas phase, and isopropanol has been proven to have excellent hydrogen supply capacity [15]. In industrial applications, the transport and safety performance of isopropanol is higher than pure hydrogen. At present, biomass pyrolysis oil is treated as dangerous waste materials. It costs $600/t to treated it and there are serious environmental problems. However, biomass pyrolysis oil is a raw material with a high C,H content, which can be used as a raw material to be converted into a chemical. The current international cost of benzene, toluene, and xylene raw materials is $615/t, $645/t and $670/t, respectively. Therefore, BTX prepared by continuous HDO of biomass pyrolysis oil under hydrogen donor conditions has high economic and environmental benefits.
Phenols are the main oxygenates in biomass pyrolysis oils and also one of the main causes of bio-oil instability [16]. Due to the presence of phenolic hydroxyl groups, phenols are most difficult to convert in the biohydrogenation process. In the biohydrogen hydrodeoxygenation process, the conversion of phenolic hydroxyl groups is critical. Therefore, guaiacol was selected as a model compound in this manuscript.
The in-situ continue HDO of real bio-oil into a BTX and hydrocarbon is promising, compared with the one-pot method. Especially, studies on gas phase hydrodeoxygenation of hydrogen donors have rarely been found, and little literature is known to the interaction between the reaction of the substrate with the hydrogen donor. The effect of dual carriers on in situ HDO of guaiacol was discussed in this manuscript. And isopropanol was selected as a hydrogen donor, and a series of catalysts were prepared to study the mechanism of guaiacol HDO. The hydrodeoxygenation reaction characteristics of real bio-oil under the condition of hydrogen donor were described, which can provide scientific basis for high-quality utilization of bio-oil. Effect of hydrogen donor isopropanol on guaiacol HDO was discussed. Furthermore, the physicochemical characteristics of the liquid-phase products of the catalyst and hydrogen donor were compared and analyzed, the role of hydrogen donors in the HDO of guaiacol was investigated, and the possible reaction mechanisms were discussed.
Section snippets
Experimental materials
Lanthanum (III) nitrate hexahydrate (AR, 99.0%), isopropanol(AR,≥99.5%), and guaiacol(GC,>99.0%) utilized in the experiments were purchased from Shanghai Macklin Biochemical Co., Ltd. Nickel (II) nitrate hexahydrate (AR, 98.0%) and copper (II) nitrate hydrate(AR) compounds were purchased from Tianjin Fuchen Chemical Reagent Factory. HZSM-5 (SiO2/Al2O3 = 54) and SBA-15 were bought from Nankai University Catalyst Co., Ltd.
Preparation of catalysts
Firstly, the zeolite carriers were calcined at 550 °C for 180 min, using a
Characterization of the catalysts
The N2 adsorption-desorption curve of the catalyst samples were shown in Fig. 1, while the specific pore structure parameters for the different catalysts were listed in Table 1. Two different types of isotherm features could be seen from Fig. 1. The specific surface area of the HZSM-5 carrier was 374.17 m2/g and had discernible type-II isotherm characteristics. Deviation from the Y-axis of the adsorption potential curve in the micropore indicated that the force against N2 was weak [22]. The
Conclusion
A series of nickel-based zeolite supported catalysts were prepared for the in-situ HDO of bio-oil. The addition of La changed the pore structure distribution on the surface of the catalyst, and improved the dispersion of the active metal Ni. The highest HDO rate(97.79%) and BTX selectivity(34.25%) were obtained via the catalyst Ni/HZSM-5&La due to the combined role of the strong acid site and better metal dispersion. When the real bio-oil was introduced, the main products form the light oil and
Authors’ contributions
En-chen Jiang and Xi-wei Xu conceived and designed the study. Pei-Dong Zhong, Ren Tu, and Yan Sun performed the experiments. Xu-dong Fan and Yu-jian Wu wrote the paper. Xi-wei Xu, and Zhi-Yu Li reviewed and edited the manuscript. All authors read and approved the manuscript.
Declaration of competing interest
There are no conflicts of interest to declare.
Acknowledgement
Supported by National Natural Science Foundation of China (Grant No.51706075); National Natural Science Foundation of China (Grant NO.51576071); Science and Technology Planning Project of Guangdong Province, China (Grant No.2016A020210073), Science and Technology Planning Project of Guangdong Province, China (Grant No.2015B020237010); Science and Technology Planning Project of Guangzhou City, China (Grant No.201906010042).
References (52)
- et al.
Catalytic cracking of bio-oil to organic liquid product (OLP)
Bioresour. Technol.
(2010) Review of fast pyrolysis of biomass and product upgrading
Biomass Bioenergy
(2012)- et al.
Solvent effects on improvement of fuel properties during hydrodeoxygenation process of bio-oil in the presence of Pt/C
Energy
(2016) - et al.
Catalytic hydrodeoxygenation of rubber seed oil over sonochemically synthesized Ni-Mo/gamma-Al2O3 catalyst for green diesel production
Ultrason. Sonochem.
(2019) - et al.
Hydrodeoxygenation of phenol over zirconia supported Pd bimetallic catalysts. The effect of second metal on catalyst performance
Catal. B-Environ.
(2018) - et al.
In-situ hydrogen generation from 1,2,3,4-tetrahydronaphthalene for catalytic conversion of oleic acid todiesel fuel hydrocarbons: parametric studies using Response Surface Methodology approach
Int. J. Hydrogen Energy
(2019) - et al.
Catalytic hydroconversion of a wheat straw soda lignin: characterization of the products and the lignin residue
Appl. Catal. B Environ.
(2014) - et al.
Transfer hydrogenation of phenol on supported Pd catalysts using formic acid as an alternative hydrogen source
Catal. Today
(2014) - et al.
The effects of noble metal catalysts on the bio-oil quality during the hydrodeoxy genative upgrading process
Fuel
(2015) - et al.
Catalytic transfer hydrogenolysis of lignin into monophenols over platinum-rhenium supported on titanium dioxide using isopropanol as in situ hydrogen source
Bioresour. Technol.
(2019)
Hydrogen from pyroligneous acid via modified bimetal Al-SBA-15 catalysts
Catal. A-Gen.
BTX from anisole by hydrodeoxygenation and transalkylation at ambient pressure with zeolite catalysts
Fuel
BTX from the gas-phase hydrodeoxygenation and transmethylation of guaiacol at room pressure
Renew. Energy
Effect of metal-support interaction on the selective hydrodeoxygenation of anisole to aromatics over Ni-based catalysts
Catal. B-Environ.
The role of copper species on Cu/gamma-Al2O3 catalysts for NH3-SCO reaction
Appl. Surf. Sci.
Dry reforming of methane to syngas over lanthanum-modified mesoporous nickel aluminate/gamma-alumina nanocomposites by one-pot synthesis
Int. J. Hydrogen Energy
Significant promoting effect of Ce or La on the hydrothermal stability of Cu-SAPO-34 catalyst for NH3-SCR reaction
Chem. Eng. J.
Selective catalytic reduction of NO with CO using different metal-oxides incorporated in MCM-41
Chem. Eng. J.
Hydrodeoxygenation of dibenzofuran to bicyclic hydrocarbons using bimetallic Cu-Ni catalysts supported on metal oxides
Fuel
Catalytic conversion of guaiacol as a model compound for aromatic hydrocarbon production
Biomass Bioenergy
Effect of ethanedioic acid functionalization on Ni/Al2O3 catalytic hydrodeoxygenation and isomerization of octadec-9-enoic acid into biofuel: kinetics and Arrhenius parameters
J. Energy Chem.
Effect of La(2)O(3) modification on the catalytic performance of Ni/SiC for methanation of carbon dioxide
Catal. Commun.
Oxygen-removal of dibenzofuran as a model compound in biomass derived bio-oil on nickel phosphide catalysts: role of phosphorus
Appl. Catal. B Environ.
Influence of biomass pretreatment on upgrading of bio-oil. comparison of dry and hydrothermal torrefaction
Bioresour. Technol.
Adsorption of alcohols on gamma-alumina (1 1 0 C)
J. Mol. Catal. Chem.
Enhancing selective hydroconversion of C-18 fatty acids into hydrocarbons by hydrogen-donors
Fuel
Cited by (25)
Reductive catalytic cracking of industrial phenolics mixture to selective cyclohexanols
2023, Applied Catalysis A: GeneralValue added hydrocarbons from lignin derived bio-oils: Insights from process simulations
2023, Materials Today: ProceedingsCitation Excerpt :HDO of guaiacol was conducted over a modified HZSM-5 catalyst at a pressure of 2 MPa and a temperature of 350 °C by Fan et al. The result shows the highest HDO rate over Ni/HZSM-5 & La catalyst and achieving 97.79% and 34.25% BTX selectivity, respectively [23]. Pan et al. studied the HDO of p-cresol over a series of bimetallic catalysts Ni–M/SiO2 with different binary metals M (M = Ce, Co, Sn, Fe).
Hydrodeoxygenation of lignin biophenolics to cyclohexanes over sub-nanometric Ru multifunctional catalyst
2022, Renewable EnergyCitation Excerpt :However, nonprecious metal catalysts often require harsh conditions and precious metal catalysts are expensive, thus impeding their wide use. To reduce the cost of H2 [22], syngas, that could be generated from biomass, was used as a hydrogen donor to accomplish the HDO of anisole and cyclohexanone, where high-loading metal catalysts were indispensable [23]. High-dispersed, sub-nanometric (sub-nm) metal catalysts have gained prominence because they can dramatically promote the atomic economy of catalysts [24] as well as catalytic activity and/or selectivity [25].