Hydrogenation Of Bio-oil Research Articles

The in-situ formation of supported hydrous ruthenium oxide in aqueous phase during HDO of lignin-derived fractions

The in-situ formation of supported hydrous ruthenium oxide (HRO) from RuO2 over micro-mesoporous materials is reported for the selective hydrogenation of bio-oil under mild reaction conditions (200 °C, 20 bar H2) in an aqueous medium. For the first time, the phase composition of HRO was determined using a variety of characterization techniques. Using synchrotron radiation and in-situ X-ray absorption spectroscopy (XAS), we demonstrated that HRO was generated during the hydrodeoxygenation process. The hydrodeoxygenation (HDO) of real bio-oil was successfully performed at 200 °C, 20 bar H2 on RuO2-containing catalysts. The approximate composition of HRO after 3 h of catalytic hydrogenation, consisted of in approximately equal ratios metallic Ru, RuO2, and RuOOH phases.

Catalytic transfer hydrogenation of bio-oil over biochar-based CuO catalyst using methanol as hydrogen donor

The catalytic transfer hydrogenation (CTH) of bio-oil over CuO/PC (porous carbon) with the solid residue produced during biomass pyrolysis as the carrier was investigated with methanol as the hydrogen donor. The effect of carbonization temperature, activation temperature, KOH solution and metal loading on the physicochemical characteristics of CuO/PC catalystand catalytic transfer hydrogenation of bio-oil were investigated. The main alcohols formed in the CTH of bio-oil were 1, 4-butanediol, 1, 3-cyclopentadiol, 1, 3-cyclohexanediol, 2-cyclohexenol and alcohols. It was revealed that more alcohols were produced over CuO/PC using less Cu(NO3)2 than Cu2Al considering their favorable porous system. The well-developed pore structure is formed in PC at a higher calcination temperature and the concentration of activator, which was favorable for the CTH of bio-oil. Under the optimized preparation conditions, the mesopores accounting for 50% in the total pores, achieving the maximized yield of alcohols of 81%, and the well recycling performance was observed with the overall yield of alcohols decreases within 3% after five cycles because of the greater mesopores ratio. The biochar-based PC catalyst in this work enhances the effective usage of biomass to produce alcohols, fully conforming to the theme of energy conservation and low-carbon times.

Hydrogenation of bio-oil in a needle-plate dielectric barrier discharge reactor

A needle-plate dielectric barrier discharge reactor was constructed to achieve bio-oil hydrogenation under low temperature and normal pressure. According to the composition and content of rice husk bio-oil, seven model compounds were mixed up to prepare simulated bio-oil, and effects of operating voltage, gas flow rate and reaction time on the deoxygenation rate and high calorific value of simulated bio-oil were investigated. The results showed that the maximum deoxidation rate of 31.62% was achieved, with the high calorific value of bio-oil increased from 25.78 MJ/kg to 32.69 MJ/kg, and the pH value increased from 3.67 to 4.83, which confirmed the feasibility of using dielectric barrier discharge reaction to hydrogenate bio-oil under low temperature and normal pressure conditions. With energy consumption and energy conversion rate as indexes, the operation economy of bio-oil hydrogenation process in the needle-plate dielectric barrier discharge reactor was evaluated, calculation results showed that under the optimized operation conditions, energy consumption of 2.44 kW·h/kg and energy conversion rate of 40.87% were achieved.

Hydrogenation of biomass pyrolysis oil using enhanced reduction catalytic capacity cellular by expressing excavated carbonyl reductase

A biocatalytic method to achieve the hydromodification of biomass fast pyrolysis oil was implemented. Two carbonyl reductases SDR-1 and SDR-8 were excavated in the genome of Bacillus coagulans NL01, enhanced Escherichia coli ability to tolerate and reduce various toxic ketone aldehydes. 10 g/L furfural and 8 g/L acetoin as bio-oil model compounds could be transformed by the recombinant E. coli SDR-1 and E. coli SDR-8 respectively. The biphasic catalysis system was constructed to convert the keto-aldehyde compounds in bio-oil to the corresponding alcohol at 30 °C. Recombinant E. coli SDR-8 could completely consume 20 g/L glucose and consume 60% 20 g/L glucose in the diluted 50-fold and 30-fold bio-oil catalytic system, respectively. This provided a new pathway for the hydrogenation of bio-oil by biocatalytic method and laid the foundation for the low-temperature esterification in the later stage.

In-situ catalytic hydropyrolysis of lignin for the production of aromatic rich bio-oil

Catalytic hydro-pyrolysis of lignin has been investigated in the presence of ZSM-5 catalysts. Reaction was carried out at different reaction temperatures (350, 400, 450 and 500 °C) at different reaction holding time at presence of N2 and H2 gas. Non-catalytic pyrolysis was showed maximum bio-oil yield of 31.8 wt% at 450 °C for 60 min reaction condition. While catalytic pyrolysis significantly increased bio-oil yield to 46.8 wt% in presence of ZSM-5 catalyst under 10 bar hydrogen. However, under N2 with ZSM-5 catalyst bio-oil yield showed as 41.8 wt%. Catalytic hydropyrolysis produced higher amount aromatic hydrocarbon (∼49%) compared to the non-catalytic hydropyrolysis. While higher amount of H, G and S-types (Hydroxylphenyl (H), Guaiacyl (G), and Sinapyl (S)) phenols monomer were observed in case of non-catalytic reaction under nitrogen environment. Moreover in the presence of catalysts and hydrogen showed synergistic effects on hydrogenation of bio-oil which is produced BTX (Benzene, Toluene and Xylene) compounds. GPC and elemental analysis of bio-oil was indicated the breaking of lignin macromolecule into lower molecular weight bio-oil.

Highly Efficient Hydrogenation of Bio-Oil by Using Vermiculite-Supported Pd–Ni Catalyst

Highly Efficient Hydrogenation of Bio-Oil by Using Vermiculite-Supported Pd–Ni Catalyst

Two-Step Esterification–Hydrogenation of Bio-Oil to Alcohols and Esters over Raney Ni Catalysts

Fast pyrolysis bio-oil is very difficult to be used because of its acidity, instability, high degree of unsaturation, etc. Processes for property upgrading are necessary and required. In this study, three kinds of Raney Ni catalysts were prepared and used to investigate two-step esterification–hydrogenation (TEH) to upgrade the light fraction of bio-oil. The results show that the first step in esterification markedly decreased the content of active compounds such as acids and ketones and aldehydes and increased the content of alcohols and esters (from 10.53% to 47.55%), which improved the bio-oil stability and was favorable for the following hydrogenation reaction. The second step of TEH (hydrogenation) further improved the quality of the bio-oil over Raney Ni and metal-modified Raney Ni catalysts at 140 °C. In particular, the Mo-RN catalyst displayed the best hydrogenation effect, with only 5.44% of acid content, and the stable component content reached 90.16%. This may be attributed to the higher hydrogenation activity from Raney Ni combined with acid MoOx species and the thermal stability of the catalyst. Moreover, the obtained upgraded bio-oil mixture could be used as a solvent for raw bio-oil’s esterification. Therefore, it has the potential to reduce methanol solvent usage and energy consumption for solvent separation during the two-step treatment of raw bio-oil in this context. Compared with the OHE (one-step esterification-hydrogenation) process, THE showed a better performance for raw bio-oil upgrading with higher alcohols and stable compounds, which is more favorable for the saturation and stability of bio-oil’s complex components step by step.

Mild hydrogenation of bio-oil and its derived phenolic monomers over Pt–Ni bimetal-based catalysts

Mild prehydrogenation of phenolics in bio-oil is known to effectively alleviate the severe coking that occurs on the surface of the cracking catalysts. This study investigated the hydrogenation of phenolic monomers (i.e., phenol, catechol, and guaiacol) over Pt–Ni/SiO2 at different Ni/Pt ratios. The results show that the hydrogenation of aromatic rings preferentially occurred over the Pt–Ni/SiO2 catalyst, with a slight hydrogenolysis of the Caryl–OR bond. The prepared Pt–Ni/SiO2 catalysts not only offered a good dispersion of the Pt and Ni species on SiO2, but also promoted spontaneous dissociation of H2 and facile diffusion of the resulting H atoms on Pt–Ni/SiO2, thereby contributing to its remarkable catalytic performance. The optimized 3Pt6Ni/SiO2 catalyst not only achieved a high phenolic conversion of 66%−99% and a high liquid product yield of 80%, but also significantly inhibited the side reaction of the products leading to gas formation. Furthermore, a stable phenolic conversion of ~80% within 24 h indicates the superior stability of 3Pt6Ni/SiO2. Subsequently, catalytic cracking of the hydrotreated bio-oil was investigated. The results indicate that mild hydrogenation benefits the formation and aromatization of light olefin intermediates, leading to increased formation of monocyclic aromatic hydrocarbons. The oil phase yield of the bio-oil fraction was 38.6%, comprising entirely hydrocarbons, of which 82.2% were monocyclic aromatic hydrocarbons. Hence, this study provides a promising approach for converting the phenolics in bio-oil into highly hydrogenated products, which are ready for the subsequent catalytic cracking.

Low-Energy Mild Electrocatalytic Hydrogenation of Bio-oil Using Ruthenium Anchored in Ordered Mesoporous Carbon

Hereby, we develop a novel Fe(III)/Fe(II) ion pair based low-energy electrocatalytic hydrogenation of bio-oil using well-dispersed ruthenium nanoparticles anchored in ordered mesoporous carbon as e...

Hydrogenation of bio-oil via gas-liquid two-phase discharge reaction system

Abstract In view of current technical problems of catalyst coking inactivation, poor equipment safety and large amount of hydrogen consumption, which are caused by high hydrogen pressure and operating temperature in bio-oil hydrogenation, an innovative gas-liquid two-phase discharge reaction system was constructed and applied to actualize the hydrogenation of bio-oil under catalyst-free, normal temperature and pressure conditions. Single-factor experiments were performed to explore the effects of working voltage, gas-flow rate and reaction time on the deoxygenation rate and high heating value of refined bio-oil. Furthermore, with the results of multi-factor orthogonal experiments, the operating parameters optimization model for the deoxidation rate of bio-oil was developed. The reasonable reaction pathways for the hydrogenation of various oxygenated compounds under gas-liquid two-phase discharge reaction conditions were well inferred. Under optimized operating parameters, the deoxidation rate of 65.26% with the high heating value of 35.15 MJ/kg of bio-oil were achieved. GC–MS analysis results demonstrated that aldehydes, ketones were completely diminished, and alcohols, esters, phenols and acids were decreased. A remarkable increase of hydrocarbons was revealed, which indicated the quality of bio-oil was significantly improved. As a result, this gas-liquid two-phase discharge reaction system can perform hydrogenation of bio-oil efficiently.

Co-cracking of bio-oil distillate bottoms with vacuum gas oil for enhanced production of light compounds

Seamless co-processing of pyrolysis bio-oil within existing petroleum refineries is the most synergistic and economic way to improve biorefinery output. Coprocessing bio-oil with vacuum gas oil (VGO) is one logical pathway. Bio-oil has a viscosity and molecular weight range similar to that of VGO, and the hydrogen-rich nature of VGO can chemically complement the bio-oil hydrogen deficiency. Distillation of biomass pyrolysis oils produces solid residues with a significant fraction of fixed carbon and heavy volatiles. Maximization of yields of light compounds like olefins and gasoline-range aromatics are crucial for both attainment of desired product output levels as well as to follow methods that mimic petroleum-based methods and chemistries. Herein we discuss a systematic study on the additive coprocessing of specific bio-oil distillation bottoms with VGO. Tail-gas reactive pyrolysis (TGRP) bio-oils from spirulina, switchgrass, and guayule biomasses were distilled, and their bottoms were subject to analytical experiments in mixtures with VGO over different zeolite catalysts (no catalyst, HZSM-5, Y-zeolite). Switchgrass-based bottoms exhibit greater hydrogen deficiency and higher oxygen content compared with that of spirulina or guayule. Switchgrass-based bottoms, with or without VGO, produced more aromatics and less olefins and alkanes, compared with spirulina or guayule bottoms. When compared across different mixing ratios, thermal cracking of a 10:1 guayule/VGO mixture resulted in higher aromatics yields than even the VGO by itself. Addition of more VGO up to a 1:1 ratio of VGO/switchgrass bottoms nearly tripled the production of BTEX compounds. For hydrogen-rich bottoms spirulina and guayule, LPG-range olefins yields increased nearly 50% for 1:1 VGO/bottoms blends, compared with theoretical yields.

Hydrogenation of bio-oil into higher alcohols over Ru/Fe3O4-SiO2 catalysts

Liquid-phase hydrogenation of a solution of furfural, phenol and acetic acid has been studied in the 50–235°C range over magnetic Ru/Fe3O4-SiO2 catalyst targeting the renewable production of second generation biofuels with minimum hydrogen consumption. Phenol was fully hydrogenated to cyclohexanol in the entire temperature range. Below 150°C, furfural was mainly hydrogenated to tetrahydrofurfuryl alcohol while hydrogenolysis to cyclopentanol was the main reaction pathway above 200°C. The hydrogenation rate was doubled in an acidic solution (pH=3) as compared to that at a pH6. The spent catalyst was regenerated and reused in subsequent catalytic runs.

Upgrading of liquid fuel from fast pyrolysis of biomass over modified Ni/CNT catalysts

A series of non-sulfided nickel-based catalysts with HNO3-pretreated CNTs as support ((x1+x2) wt.% NiMo/CNTs, xi represents the Ni or Mo loading amount) were synthesized, and evaluated for the hydrogenation of bio-oil model compounds (acetic acid, furfural and hydroxyacetone) and raw bio-oil. Acetic acid was chosen for the initial screening of catalysts. Results showed that reduced (10+10) wt.% NiMo/CNT catalyst exhibited the highest activity. Hydrogenation of other model compounds and raw bio-oil was then carried out over reduced (10+10) wt.% NiMo/CNT catalyst. A synergistic effect was observed in the hydrogenation process of a model compound mixture, which led to the aldol condensation between furfural and hydroxyacetone to give a C8 compound, which could give most valuable hydrocarbon after deep hydrogenation. After the upgrading process, both the pH and the hydrogen content of bio-oil increased, and the oxygen content decreased, which were all desirable for the further application of upgraded bio-oil.

Upgrading of bio-oil into advanced biofuels and chemicals. Part III. Changes in aromatic structure and coke forming propensity during the catalytic hydrotreatment of a fast pyrolysis bio-oil with Pd/C catalyst

This study has investigated the hydrotreatment of bio-oil (derived from the fast pyrolysis of mallee woody biomass) in a batch reactor under 10MPa pressure with Pd/C catalyst at temperatures between 150°C and 300°C. Our results indicate that the chemical fractions, coking tendency as well as the aromatic structures are highly influenced by the hydrotreating conditions such as temperature and time. The repolymerisation surpasses the hydrogenation of bio-oil at the low hydrotreating temperatures (e.g. 150–200°C) and short hydrotreating durations (e.g. <3h). On the contrary, high hydrotreating temperatures (e.g. 250–300°C) and long reaction durations (e.g. 6–12h) can effectively convert the heavier fractions into lighter fractions, and thus further reduce the coking tendency of the hydrotreated products. However, these harsh operational conditions cannot decrease the number of large aromatic ring systems. Most importantly, it is found that the combination of esterification and hydrotreatment can produce more stable bio-oil with lower coking tendency and less large aromatic ring systems than the direct hydrotreatment of bio-oil.

Catalytic Fast Pyrolysis: A Review

Catalytic pyrolysis is a promising thermochemical conversion route for lignocellulosic biomass that produces chemicals and fuels compatible with current, petrochemical infrastructure. Catalytic modifications to pyrolysis bio-oils are geared towards the elimination and substitution of oxygen and oxygen-containing functionalities in addition to increasing the hydrogen to carbon ratio of the final products. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalysts and the production of aromatics from bio-oil using cracking zeolites. Research is currently focused on developing multi-functional catalysts used in situ that benefit from the advantages of both hydrodeoxygenation and zeolite cracking. Development of robust, highly selective catalysts will help achieve the goal of producing drop-in fuels and petrochemical commodities from wood and other lignocellulosic biomass streams. The current paper will examine these developments by means of a review of existing literature.