Hydrodeoxygenation Reaction Research Articles

Raney® nickel-catalyzed hydrodeoxygenation and dearomatization under transfer hydrogenation conditions—Reaction pathways of non-phenolic compounds

Abstract Catalytic reduction of oxygen-containing aromatic compounds has been studied under transfer hydrogenation (TH) conditions at 150 °C in 2-PrOH as a hydrogen donor. Raney® nickel is used as a heterogeneous catalyst. The reaction of aromatic non-phenolic carbonyl compounds is most likely to proceed through the pathway “aromatic ketone (aldehyde)→aromatic alcohol→alkylaromatics→saturated alkylcyclohexane”. One of the main reactions under the TH conditions is a hydrodeoxygenation (HDO) process. Unexpectedly, the hydrodeoxygenation of aromatic ketones to alkylaromatics (C O → CH2) occurs faster than of corresponding aromatic alcohols (HC OH → CH2) that means either additional reaction pathway of its hydrodeoxygenation missing for the corresponding aromatic alcohols or specific interaction of OH functionality with Raney® nickel surface obstructing (hindering) the further reduction. Benzaldehyde is shown to be less reactive than the aromatic ketones under the same reaction conditions. The main reason is proposed to be carbon monoxide release resulted from the decarbonylation of the aldehyde. Carbon monoxide demonstrates a poisoning effect on Raney® nickel surface that is evidenced in the catalyzed TH reaction of acetophenone. The HDO reaction of anisole under the same reaction conditions was a little slowly than of oxygen-containing non-phenolic aromatics.

Tapping Renewables: A New Dawn for Organic Electrosynthesis in Aqueous Reaction Media

AbstractThe birthplace of organic electrochemistry was an aqueous solution, with a biogenic, renewable compound being the reactant of the first organic electrosynthesis. Now, 170 years later, the relevance of electrosynthesis is rising again and, hence, the original work comes to the fore. Water is considered a green solvent, biogenic compounds increasingly replace fossil compounds as a feedstock for the chemical industry, and electrosynthesis bridges energy and chemistry sector. In this Minireview, we advocate the use of water as the solvent for electrochemical conversion of biogenic organic compounds. We show that, although the use of water may put certain constraints on organic electrosynthesis, using aqueous reaction media opens interesting perspectives. As illustrated on selected examples, synergies can be created for the conversion of oxygenates, for hydrogenation and hydrodeoxygenation reactions, product separation and in coupling electrochemical and biochemical processes.

Optimum Reaction Conditions for 1,4-Anhydroerythritol and Xylitol Hydrodeoxygenation over a ReOx–Pd/CeO2 Catalyst via Design of Experiments

In this study, we demonstrate that for the simultaneous hydrodeoxygenation (HDO) of 1,4-anhydroerythritol a comparable yield of tetrahydrofuran is obtained at half the previously reported H2 pressure. The simultaneous hydrodeoxygenation was conducted using a heterogeneous ReOx–Pd/CeO2 catalyst. An L9 Taguchi design of experiment was enacted to elucidate the temperature, pressure, and catalyst loading effects on the yield of the HDO reaction by testing pressures ranging from 40 to 80 bar H2, temperatures of 100–180 °C, and Re loadings of 2–4 wt %. Our design showed that the yield of this reaction is significantly affected by the reaction temperature only. An L9 Taguchi design was conducted for xylitol simultaneous hydrodeoxygenation with pressures ranging from 5 to 10 bar H2, temperatures of 140–180 °C, and Re loadings of 2–4 wt %. The xylitol design elucidated the direct relation of pressure, and the inverse relation of temperature and catalyst loading, to yield with the optimal reaction condition being 1...

Study of bifunctionality of Pt/SBA-15 catalysts for HDO of Dibenzofuran reaction: Addition of Mo or use of an acidic support

Mesoporous silica SBA-15 and ZrSBA-15 (Si/Zr = 10) were prepared and used as supports of platinum and molybdenum based catalysts to be tested in the hydrodeoxygenation (HDO) reaction of dibenzofuran (DBF) as a model compound present in biomass derived bio-oil, at 3 MPa and 275 °C. It is evaluated the bifunctionality of Pt based catalysts by adding Mo to the catalyst formulation or by increasing the acidity of the material support employed. The catalysts showed significant differences in HDO activity as well as selectivity towards O-free products. The incorporation of Mo positively affected the DBF conversion and selectivity, obtaining better results than monometallic catalysts. In contrast, the presence of Zr in the support sharply decreased the conversion of the monometallic Pt sample and also of the bimetallic PtMo one, although in a lesser extent. Considering characterization results, the activity was explained in terms of acidity, reducibility, surface metal exposure and interaction between the phases present. PtMo/SBA-15 sample presented better catalytic results due to an intermediate acidity, better reducibility and greater Pt + Mo surface exposure. Moreover, the presence of Mo decreases the amount of carbon on the surface, improving the catalyst stability. The interaction of Pt-Mo seems to play an important role.

Synergistic Effect of Zn in a Bimetallic PdZn Catalyst: Elucidating the Role of Undercoordinated Sites in the Hydrodeoxygenation Reactions of Biorenewable Platforms

The promotional role of Zn in hydrodeoxygenation (HDO) reactions of 5-hydroxymethyl furfural (HMF) to produce 2,5-dimethyl furan (DMF) over the Pd catalyst was studied using plane-wave density functional theory (DFT) calculations. HMF is first hydrogenated to form bis(hydroxymethyl) furan (BHMF), which undergoes HDO to form DMF. In order to provide a mechanistic explanation to the experimental observation, DFT calculations focusing on the energetics of the HDO reaction steps for BHMF conversion to DMF were performed on three different surfaces: Pd(111), Pd(211), and PdZn(211). Zn was assumed to preferentially substitute the defect sites of the bimetallic catalyst in reduced metallic state. Calculated values of activation energies for C–O dissociations steps were significantly reduced on the PdZn(211) surface, compared to the Pd(111) and Pd(211) surfaces. Therefore, theoretical results provided a clue to the reactivity of the Zn-decorated step sites for the HDO reaction.

1,2-Propanediol as a Surrogate Molecule of Glycerol for Mechanistic Studies of Selective Hydrodeoxygenation Reactions over Mo2C and Cu/Mo2C Surfaces

The upgrading of glycerol, a byproduct from biodiesel production, is important for developing more sustainable biomass conversion technologies. Nonetheless, the low vapor pressure and structural co...

Development of Bifunctional Hydrodeoxygenation Catalyst Rh‐HY for the Generation of Biomass‐Derived High‐Energy‐Density Fuels

Liquid‐phase hydrodeoxygenation (HDO) of phenol, anisole, and guaiacol over rhodium‐doped, high‐silica content zeolite catalysts (Si/Al = 15), HY, is investigated in a high‐pressure‐fixed bed reactor. These catalysts are characterized by inductively coupled plasma optical emission spectrometry, scanning electron microscopy with energy‐dispersive spectroscopy, thermogravimetric analysis, X‐ray diffraction, N2 physisorption, ammonia temperature‐programmed desorption, temperature‐programmed oxidation, temperature‐programmed reduction, 27Al magic angle spinning nuclear magnetic resonance, and X‐ray photoelectron spectroscopy. The effects of reaction temperature (150–250 °C) and weight hourly space velocity (WSHV = 1.0–2.8 h−1) on activity, stability, and product distribution are investigated. The main products obtained from HDO reactions are methylcyclopentane, cyclohexane, methylcyclohexane, and bicyclohexyl. Cyclohexanone is the most abundant oxygenated product along with deactivation. For all tested catalysts, increasing the reaction temperature up to 250 °C improves the HDO reactions without significant activity or selectivity loss. Higher rhodium loading extends the catalyst life and increases the activity and cyclohexane selectivity for the guaiacol feed. The experiments indicate that anisole, phenol, and guaiacol undergo aromatic hydrogenation on rhodium particles first, followed by deoxygenation on the acid sites over zeolite combined with additional hydrogenation.

Hydrothermal liquefaction of Chlorella vulgaris and Nannochloropsis gaditana in a continuous stirred tank reactor and hydrotreating of biocrude by nickel catalysts

Continuous hydrothermal liquefaction and further upgrading of the algal biocrude are of great importance for algae biofuel process scale-up and improvement of fuel properties. In this study, two strains of microalgae were used for processing in a continuous stirred tank reactor at 350 °C and 24 MPa for 15 min residence time. An average of 36.2 wt% and 31.5 wt% biocrude yields were achieved for Chlorella vulgaris and Nannochloropsis gaditana, respectively. The obtained biocrude was further upgraded by hydrotreating using commercial NiMo/Al2O3 and NiW/Al2O3 catalysts at two temperatures (250 °C and 400 °C) in a batch autoclave reactor for 4 h. Products distribution, analysis by elemental content, gas chromatography (GC), gel permeation chromatography (GPC), thermogravimetric analysis (TGA) and nuclear magnetic resonance spectroscopy (1H NMR) on upgrading products indicate that upgrading by both catalysts lead to improved physicochemical fuel properties, during 250 °C upgrading step, decarbonylation, decarboxylation and repolymerization are the dominant reactions while hydrodeoxygenation and cracking reaction are more promoted at 400 °C. The gasoline, kerosene and diesel oil components in the algal biocrude were increased from 18 wt% to >30 wt% after catalytic upgrading.

Hydrodeoxygenation of furfural-acetone condensation adduct over alumina-zirconia and silica-zirconia supported nickel catalysts

Hydrodeoxygenation (HDO) reaction of furfural-acetone condensation adduct (FAA) using Ni-supported catalyst were investigated. The used of alumina-zirconia and silica-zirconia served as the support of Ni catalyst. The physicochemical properties of the catalysts were evaluated by X-Ray Diffraction (XRD) and N2-physisorption. The catalyst testing using 10% Ni/Al2O3-ZrO2 and 10% Ni/SiO2-ZrO2 for HDO reaction of FFA for 4 h in the presence of water using batch reactor at 200°C showed the network reaction containing partial and total hydrogenation, ring opening and hydrocracking into furanyl-alkane derivatives and hydrocarbon derivatives, such as, 4-(furan-2-yl)butan-2-one (4); 4-(4,5-dihydrofuran-2-yl)butan-2-one (5); 4-(tetrahydrofuran-2-yl)butan-2-one (6); (E)-1,5-di(furan-2-yl)pent-1-en-3-one (7); 1,5-di(furan-2-yl)pentan-3-one (8); 1-(furan-2-yl)-5-(tetrahydrofuran-2-yl)pentan-3-one (9); non-1-en-3-one (10); and decane (11), with the total yield in 55-81%. By increasing the Ni loading into 20%, the increasing conversion of HDO product is observed. The used of Al2O3-ZrO2 and SiO2-ZrO2 as support catalysts direct product selectivity. The Ni/SiO2-ZrO2 promote the formation of 1,5-di(furan-2-yl)pentan-3-one (8), whereas Ni/Al2O3-ZrO2 gave non-1-en-3-one (10) as major compound.

Integrated Conversion of Cellulose to High-Density Aviation Fuel

Summary The catalytic conversion of renewable lignocellulose to transportation fuels is crucial to establish energy security and mitigate CO2 emissions. Here, we describe an effective and integrated strategy for the production of high-density aviation fuel with cellulose, an abundant and inedible raw biomass. First, cellulose was selectively converted to 2,5-hexanedione in a separation yield of 71.4%. Subsequently, a mixture of C12 and C18 branched polycycloalkanes was directly obtained in a carbon yield of 74.6% by the aldol condensation-hydrogenation and hydrodeoxygenation reaction of 2,5-hexanedione and hydrogen over a dual-bed catalyst system. The polycycloalkane mixture obtained by this process has high density (0.88 g mL−1) and low freezing point (225 K). In real application, they can be used as advanced aviation fuel or additives to improve the volumetric heat values of conventional aviation fuels.

Aqueous Dehydration, Hydrogenation, and Hydrodeoxygenation Reactions of Bio-Based Mucic Acid over Ni, NiMo, Pt, Rh, and Ru on Neutral or Acidic Catalyst Supports

Hydrotreatment of mucic acid (also known as galactaric acid, an glucaric acid enantiomer), one of the most promising bio-based platform chemicals, was systematically investigated in aqueous media over alumina, silica, or carbon-supported transition (nickel and nickel-molybdenum) or noble (platinum, ruthenium and rhodium) metals. Mucic acid was only converted into mucic-1,4-lactone under non-catalytic reaction conditions in N2 atmosphere, while the 5 MPa gaseous H2 addition triggers hydrogenation in the bulk phase, resulting in formation of galacturonic and galactonic acid. However, dehydroxylation, hydrogenation, decarbonylation, decarboxylation, and cyclization occurred during catalytic hydrotreatment, forming various partially and completely deoxygenated products with a chain length of 3–6 C atoms. Characterization results of tested catalysts were correlated with their activity and selectivity. Insufficient pore diameter of microporous supports completely hindered the mass transfer of reactants to the active sites, resulting in negligible conversion of mucic acid. A comprehensive reaction pathway network was proposed and several industrially interesting compounds were formed, including levulinic acid, furoic acid, and adipic acid. However, selectivity towards adipic acid, a bio-based nylon 6,6 precursor, was low (up to 5 mol%) in aqueous media and elevated temperatures.

Influence of carburization time on the activity of Mo2C/CNF catalysts for the HDO of guaiacol

Carbon nanofiber (CNF) supported β-Mo2C-based catalysts were synthetized by carbothermal hydrogen reduction at 750 °C for different times (1, 2, 4, 6 and 18 h) in order to study both the carbide phase formation and the CNF stability during this key stage. Catalysts were characterized by N2 physisorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, inductively coupled plasma optical emission spectrometry and scanning transmission electron microscopy. Subsequently, catalysts were evaluated in the hydrodeoxygenation (HDO) of guaiacol using a batch autoclave reactor at mild conditions of temperature and pressure (300 °C and 20 bar of H2). Liquid products were analysed after 2 h of reaction by gas chromatography. In all cases, β-Mo2C phase was formed during the carburization, and crystal sizes increased (from 6 to 18 nm as measured by XRD) as the carburization time did. However, a deep gasification of the support was observed in catalysts carburized above 6 h, resulting in a dramatic loss of specific surface area. In the guaiacol HDO reaction, higher conversions (72–80 %) and HDO ratios (53–63 %) were obtained using catalysts carburized for 2 h and onwards. Considering the carbide content in the catalyst, 1 and 2 h carburized catalysts exhibited the highest values of formation of HDO products: phenol, cyclohexane + benzene and anisole. Besides this, a clear relationship between the Mo2C surface area (SMo2C) and the product formation rate could be inferred for the catalysts carburized at 1, 2 and 4 h, in which the textural properties were not affected by the carburization time. On the other hand, longer carburization times had a worse performance despite the largest values of SMo2C, being this fact related to the dramatic loss of the catalyst textural properties.

The effect of metal loading over Ni/γ-Al2O3 and Mo/γ-Al2O3 catalysts on reaction routes of hydrodeoxygenation of rubber seed oil for green diesel production

Abstract Hydrodeoxygenation (HDO) of vegetable oil is one of the promising key processes designed for a possible convenient method for automotive clean fuel production. The HDO of rubber seed oil into diesel range hydrocarbon over non-sulphided monometallic (Ni/γ-Al2O3 and Mo/γ-Al2O3) catalysts were investigated. The catalysts were synthesized via conventional wet impregnation method using 3 wt.%, 12 wt.% and 15 wt.% Ni and Mo loading over γ-Al2O3 support, to examine the influence of metal loading on catalytic activity, coke deposition, and reaction routes. The synthesized catalysts were subjected to characterization techniques including XRD, FESEM coupled with EDX, BET, TEM, TGA, ICP-OES and H2TPR. All the catalysts were tested for HDO reaction at 623.15 K, 3.5 MPa, H2/oil of 1000 N (cm3/cm3) with WHSV = 1 h−1 in a continuous flow fixed bed tubular reactor. The hydrocarbon products were analyzed using gas chromatography, and intermediates were identified using GC–MS. The Ni supported catalysts showed comparatively higher surface area, small particle size, homogeneous dispersion of particles, higher crystallinity and lower reduction temperature, low coke deposition. Proposed reaction mechanism suggests the decarboxylation (DCO2) reaction occurred mainly over Ni supported catalysts. Whereas, higher Ni loading reduced the extent of decarboxylation (DCO2) reaction. Additionally, Mo supported catalysts allowed the deoxygenation reaction to occur and higher Mo loading enhanced the extent of hydrodeoxygenation (HDO). The triglycerides conversion for all the catalysts was 99.9%. The catalysts with higher metal loading showed overall higher catalytic activity for hydrodeoxygenation of RSO. 15 wt.% Ni loading produced higher hydrocarbon yield (55.1 wt.%) whereas, 15 wt.% Mo loading produced up to 61.7 wt.%. Mo comparatively produced high amount of C16 (15.7 wt.%), and C18 (30.7 wt.%) hydrocarbons. Whereas, Ni produced mainly C15 (20.9 wt.%) and C17 (20.3 wt.%) hydrocarbons. Significant findings were observed on hydrocarbon yield, intermediates, and amount of coke formation. Mo supported catalysts shows significant HDO activity with less concentration of oxygenated component in the mixture. Besides Mo supported catalysts exhibit the high amount of coke deposition compared to Ni supported catalysts.

The role of defect sites and oxophilicity of the support on the phenol hydrodeoxygenation reaction

This work studies the effect of support defect sites on the performance of Pd/CexZr1-xO2 (x = 0.00; 0.25; 0.50; 0.75; 0.90) catalysts for the hydrodeoxygenation of phenol in the gas phase at 573 K. The activity and selectivity for hydrodeoxygenation of phenol depends significantly on the support used. Increasing the Zr content from x = 0.0 to 0.5, the reaction rate for hydrodeoxygenation and the selectivity to benzene remains very low. However, upon increasing the Zr content above x = 0.5 a sudden jump in reaction rate and selectivity to benzene is observed. Interestingly, this activity and selectivity boost has no direct correlation with the density of acid sites or the concentration of defects on the support. Rather, the selectivity to deoxygenated products is found to depend on the oxophilicity of the support. Increasing the Zr content enhances the strength of the interaction between the O of the carbonyl group and the oxophilic site. It is proposed that the oxophilicity of these catalysts is related to the structure of the CexZr1-xO2 solid solution formed. In addition, it is observed that the degree of deactivation during the reaction also depends on the Ce/Zr molar ratio of the support. Pd/ZrO2, Pd/Ce0.10Zr0.90O2 and Pd/Ce0.25Zr0.75O2 catalysts readily deactivate during reaction, whereas the phenol conversion only slightly decreases for Pd/CeO2, Pd/Ce0.75Zr0.25O2 and Pd/Ce0.50Zr0.50O2 catalysts. The results reveal that the density of Zr species on the surface is responsible for catalyst deactivation. The stronger adsorption between the oxygen from the phenol with Zr cations resulted in an accumulation of O-containing byproducts and catalyst deactivation.

Catalytic Upgrading of Pyrolytic Oil via In-situ Hydrodeoxygenation

Lignocellulosic biomass derived from non-food crops cultivated on lands that are increasingly marginal for more favoured major crops is a potential source of sustainable renewable energy. This study explores the transformation of crude organic phase pyrolytic oil derived from Napier grass biomass into high-grade biofuel precursors via hydrodeoxygenation reaction over platinum and palladium catalysts with in-situ hydrogen generation from methanol. The reaction was conducted in a high-pressure stainless steel batch reactor at 350 °C, 20 wt% methanol ratio, 2 wt% catalyst loading and 60 min reaction time. The result of physicochemical analysis showed that the higher heating value of the organic liquid products collected over the catalysts increased by 35–40% relative to the raw sample. Gas chromatography-mass spectrometry results revealed significant reductions in the oxygenated compounds such as methoxyaromatics, methoxyphenols, acids, aldehydes. The degree of deoxygenation and overall extent of upgrading observed was 50–54% and 56–60%, respectively. The gas products collected were mainly carbon monoxide, carbon dioxide, hydrogen and methane. Hydrodeoxygenation, hydrogenolysis, hydrogenation, dehydration, demethylation, hydrocracking, decarbonylation and decarboxylation were the main upgrading reactions, and a multiple reaction network was proposed.

Guaiacol hydrodeoxygenation as a model for lignin upgrading. Role of the support surface features on Ni-based alumina-silica catalysts

The hydrodeoxygenation (HDO) of guaiacol is a model reaction for the upgrading of the lignin component of bio-oils, in the framework of the production of fuels from the most abundant and renewable biomass source. While Ni-based catalysts are now widely recognized as suitable catalysts for this reaction, the role of the catalyst support is far less investigated. In this work, Ni-based catalysts for the HDO reaction of guaiacol were prepared using a series of alumina-silica supports characterized by a different amount of silica (0–40%). A wide range of metal contents (0–45%) was also investigated. The reaction was performed in H2 at 50 bar and 300 °C, determining conversion, product distribution and HDO degree. Besides a notable role played by the Ni amount, the catalyst performance is markedly affected by the morphological and surface features of the support. The measured isoelectric point of the bare supports appeared to be predictive of the final performance of the relative Ni-based catalyst: the more acidic the isoelectric point, the better the overall performance of the catalyst. A regeneration treatment in mild conditions was developed to fully restore the starting surface features of the catalysts.

Kinetics study and reactor simulation of full-range low-temperature coal tar during hydrodeoxygenation process

ABSTRACTA good adaptability kinetic model for hydrodeoxygenation (HDO) of full-range low-temperature coal tar (LCT) is established and applied to an isothermal trickle-bed reactor. The accurate kinetic parameters are obtained by gPROMS. The effects of reaction conditions on catalyst activity and HDO reaction in different positions of the reactor are discussed. Interestingly, the result shows that liquid hourly space velocity has no effect on internal diffusion during HDO of crude oil or diesel oil, but affects the internal diffusion during HDO of LCT, because LCT contains more resins and asphaltenes. The research results can provide a theoretical basis for reactor design and macro-control of hydrogenation process.

Thermo-chemical conversion of scrap tire waste to produce gasoline fuel

Catalytic hydropyrolysis (CHP) of scrap tire was investigated for production of gasoline fuel. Effects of CHP process variables such as catalysts type ((activated carbon, AC), Ir/C, Rh/C, Pt/C, Ru/C, and Pd/C), temperature (200–450 °C), time (30–120 min), catalyst loading (0–40 wt%), and hydrogen pressure (0.1–12 MPa) on the CHP products distribution and properties of the hydropyrolysis oil (HPO) were examined. Ru/C was identified as the most suitable catalyst in terms of the HPO quality and the catalytic effect predominantly came from the noble metal. Temperature was the most influential factor affecting the yield and quality of the HPO and followed by the order of catalyst loading > H2 pressure > time. Higher temperature, time, and catalyst loading would decrease the yield of HPO and increase the yield of gaseous product whereas contrary results were observed with increasing the H2 pressure. With added noble metals, the hydrodenitrogenation, hydroSization, and hydrodeoxygenation reactions of the HPO were promoted and greatly lowered N, O, and S contents of the HPO with increasing the temperature, time, catalyst loading, and H2 pressure. The lowest N, O, and S contents of 0.02, 0.41 and 0.41 wt% of HPO were achieved at 430 °C, 60 min, 10 wt% Ru/C, and 12 MPa H2. The higher-heating value of the HPOs varied between 44 and 46 MJ/kg depending on the reaction conditions. More than half of the energy of the ST was converted into the HPO. The HPO mainly consisted of saturated and unsaturated hydrocarbons one to five benzene derivatives. The distillate fraction between 35 and 250 °C of the HPO is more than 80 wt%. Thus, we view that CHP is an alternative way to produce high quality hydro-carbon fuel from scrap tire.

Original Pt-Sn/Al2O3 catalyst for selective hydrodeoxygenation of vegetable oils

The preparation of biodiesel from fatty materials HDO provides a very constructive idea to solve the global clean energy problem. The application of catalytic technology to convert oils into green liquid hydrocarbon fuel has great potential for industrial application. The main problem with the development of green diesel technology is the limited number of available non-food sources of fatty acid triglycerides. Also the researchers have made remarkable achievements in the field of catalyst, the stability of the catalyst is insufficient and the selectivity of large molecules of direct alkanes is low. These defects hinder the large-scale resource development of biodiesel. In current paper the potential of hydrodeoxygenation (HDO) of fatty materials and model esters was explored by enhancing the synergy of platinum and tin by using heterometallic (PPh4)3 [Pt (SnCl3)5 complex. Heterometallic (PPh4)3 [Pt (SnCl3)5] complex provides in its structure platinum and tin atoms linked by a metal–metal bond that causes the originality of catalytic performance. The performance of bimetallic Pt-Sn/Al2O3 catalyst, which is characterized by the Sn/Pt molar ratio of 5/1, has been studied at hydrogen pressure 50 atm and temperature 400–480 °C. HDO reaction of a number of fatty materials has been shown to proceed with the highest ever yield of direct hydrocarbons derived from alkoxy and acyl groups of the initial ester. Also it was investigated a performance in HDO reaction of mixture containing rapeseed oil oleic acid and water that simulate cooked oil that may be a prospective soure for green hydrocarbons in megalopolises. A structural studies of the catalyst showed that its high selectivity in HDO reaction of fatty materials provided by two important factors: impregnated particles size and formation of intermettallic species of PtSn3±σ. Finally, catalysts sustained activity and stability were tested during five turns of 24 h each.

Catalytic Upgrading of Residual Biomass Derived Bio-oil over Molybdenum Carbide

The present paper reports a study of molybdenum carbide as heterogeneous catalyst in the hydrodeoxygenation (HDO) reaction of bio-oils from acacia wood or empty fruit bunches of palm oil (EFB) obtained by hydrothermal liquefaction process. Mass molybdenum carbide was prepared using commercial MoO3 as precursor through the carburization methodology. The solid was characterized by X-ray diffraction, thermogravimetric analysis and scanning electron microscopy. For comparison purposes, the HDO reaction was also performed using a NiMo-based commercial catalyst, which was exposed to sulfidation previous to catalytic test. The reactions were performed in a batch-type reactor under reducing atmosphere (H2) at 350 °C and autogenous pressure. The hexagonal β-Mo2C phase obtained during the carburization process was highly active in the deoxygenation reaction, which resulted in enhanced HDO of bio-oils whose heating value is much higher than the heating value of untreated acacia (from 27.6 to 41.1 MJ/kg) and EFB bio-oils (from 29.1 to 36.9 MJ/kg). The higher heating value of the upgraded bio-oil with Mo2C and the ease recovery of the catalyst for recycling are promising advantages for the material to be used in relevant processes as an alternative to sulfided catalysts. On the other hand, the upgraded bio-oils have physicochemical characteristics suitable for their coupling in traditional fossil fuel production processes.