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Hydrocarbons (fuel) derived from agricultural waste biomass are potential alternatives, and these hydrocarbons are within range of jet fuel and diesel. In the current research work, date seeds are considered a feedstock for bio-oil (composed of oxygenated hydrocarbons) and is subjected to hydro-deoxygenation to produce green jet fuel and diesel. Hydro-deoxygenation is exothermic reaction and involves cracking for which a novel heterogeneous catalyst is synthesised. The heterogeneous catalyst consists of an acidic nature precursor derived from waste glass (SiO2) and active metals (tungsten, nickel and palladium) to provide the acidic sites for better-desired product yield. The synthesised catalysts are characterised in detail by the following techniques X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDXS), Brunauer–Emmett–Teller (BET), Ammonia-Temperature programmed desorption (TPD) and X-ray Photoelectron Spectroscopy (XPS) and based on characterisation it is revealed that synthesised will be suitable for hydro-deoxygenation. The most appropriate combination of metal and precursor is Pd-SiO2. Product oil's optimised degree of deoxygenation (DOD) is found to be 93.7% with the following parameters: temperature 340 °C, time 4 h and 4 wt.% of Pd on SiO2. Further on, to prove the commercial viability of the catalyst, it was subjected to five consecutive experimental runs, and it was much active till 5th run if treated before each run. Thus, it can be concluded that bio-oil source is agricultural waste, and for catalyst precursor waste glass is considered; so by considering these factors, the product oil produced has components which lie within the range of jet fuel and diesel, which can be economical as well as eco-friendly source of fuel. [ABSTRACT FROM AUTHOR]

Biomass has supplanted traditional fuels as the principal renewable energy source due to its carbon neutrality. Because of its high viscosity, thermal instability, and undesired coke production, biomass oil has limited applicability; however, hydro-treatment procedures can address these drawbacks and produce bio-oil fuels that meet industry standards. Consequently, compounds containing hydroxyl entities, especially oxygenated aromatics, are treated using the hydro-deoxygenation (HDO) process. Deoxygenation has seen the rise of effective transition metal-supported catalysts, both noble and non-noble, which have impeded the usage of traditional sulfided catalysts. Nevertheless, there are a number of reports in the literature of successful HDO processes using sulfided catalysts. As a model material for waste biomass, date pits were deoxygenated using 10 % Co–MoS2 produced via incipient wet impregnation in this study. The catalyst had a specific surface area of 15 m2/g, as proven by the nitrogen adsorption/desorption technique, the most essential analysis. Additionally, the catalyst was analyzed using XRD, SEM-EDX, HRTEM, and FTIR (for both the biomass deoxygenated products and the catalyst). The date pit pyrolysates were subjected to temperatures ranging from 100 to 500 °C in a 2-stage catalytic reactor for HDO. At 300 °C, 400 °C, and 500 °C, the condensable and non-condensable fractions could be identified. Deoxygenated aromatics were initially detected at 400 °C, with a complete conversion to benzene derivatives occurring at 500 °C, in contrast to the furanic products, which were primarily prevalent at 300 °C. At 18.12 % for the condensable fraction and 30.70 % for the non-condensable fraction, toluene had the highest relative area. Various oxygenated aromatic HDO reaction routes leading to toluene production were covered. The findings presented here opens the door to the potential widespread usage of Co–MoS2 in HDO processes with actual biomass fuels.

The purpose of this investigation was to explore the possibility of utilising post-sap residues for bio-oil production, that are produced after liquid fertiliser extraction from Kappaphucus alverizii, red macroalgae. The sap — a liquid fertiliser — was expelled by crushing the K. alverizii. The residual macroalgae were hydrothermally liquified at varying operating conditions (temperature, biomass to solvent ratio, residence time, catalyst dose), in order to understand its influence over the productdistribution and composition from thehydrothermal liquefaction (HTL) process. The maximal yield for crude bio-oil was 28.4 ± 0.6 wt.%, which was possible only when the HTL reactor was operated in presence of a ZSM-5 catalyst at 300 °C using 20 g of biomass for 30 min duration. Still, the bio-oil derived from the HTL process seems to possess higher oxygen content. Hence, the hydro-deoxygenation (HDO) process was carried out to upgrade the crude bio-oil into oxygenates less oil. The bio-char along with ZSM-5 derived from the previous HTL process was utilised as a catalyst in the HDO process. Catalysed HDO processes were able to improve the HHV of upgraded oil to 36.7 MJ/kg. Overall, this study implies that the crude bio-oil can be effectively produced from the post-sap residue, which can be further upgraded to calorific-rich fuel. [ABSTRACT FROM AUTHOR]

In this paper, catalytic hydro-deoxygenation (HDO) of bio-oil’s model molecules (acetic acid, 4-ethylguaiacol, and furfural) using Ni$_{2}$P/HZSM-5 catalyst was carried out to better identify the products and make the modeling work of HDO process more reliable. Results showed that low temperatures favored the formation of acetaldehyde and acetone during acetic acid HDO, but disfavored the formation of aromatic hydrocarbons. Acetone was produced via the self-ketonization reaction of acetic acid. In most cases of 4-ethylguaiacol HDO, phenol, cresol, and 2, 4-dimethylphenol were the primary products. For furfural HDO, the major furan and CO products proved that the direct decarbonylation of furfural was the main reaction. Accordingly, the main pathways of acetic acid, 4-ethylguaiacol, and furfural HDO were proposed, which could provide significant guidance for the upgrading of crude bio-oil.

• Glyceride-based oil was converted into normal alkanes necessary for producing HRJ. • Pd/C and NiMo/γ-Al 2 O 3 were tested with various experimental conditions. • Fresh and used catalysts were characterized through TGA, FTIR, XRD and SEM. Initially converting the glyceride-based oils derived from biomass into straight-chain alkanes are necessary for producing hydro-processed renewable jet (HRJ). In this study, palm oil was turned into C 15 –C 18 alkanes over two different catalysts, Pd/C and NiMo/γ-Al 2 O 3 , with various reaction conditions such as temperature, pressure, weight hourly space velocity (WHSV) and H 2 -to-oil ratio. The fresh and used catalysts after hydro-processing reaction were then characterized through the techniques including TGA, FTIR, XRD and SEM. The liquid products were analysed through GC-MS/FID and the concentrations of C 15 –C 18 were determined. The gas products, such as CO 2 , CO, C 3 H 8 , CH 4 and H 2 , were analysed through GC-TCD for indirectly "visualizing" the reaction, including the performances of hydro-deoxygenation (HDO) as well as decarbonylation/decarboxylation, hydrogenolysis, the occurrence of methanation and the consumption of hydrogen. The suggested experimental conditions over these two catalysts were elaborated based on the concentration of n-alkanes and gas products. [ABSTRACT FROM AUTHOR]

Abstract Renewable aviation fuel produced from hydro-processing has been a commercially available technique currently. Studies conducted recently were toward finding an appropriate catalysts to produce the jet fuel range products with high normal alkanes and low aromatics. This study focused on hydro-processing of waste cooking oil (WCO) into straight alkanes, which can serve as the blendstock for aviation fuel after further cracking and isomerizing, over two different catalysts, pre-sulfurized NiMo/γ-Al 2 O 3 and Pd/C, under various experimental conditions such as reaction temperature, pressure, liquid hourly space velocity (LHSV) and H 2 -to-oil ratio. The resulting liquid and gas products from the two catalysts were analyzed through GC-MS/FID and GC-TCD for judging the performances of hydro-deoxygenation (HDO) as well as decarboxylation (DCO2)/decarbonylation (DCO). The fresh and spent catalysts were examined through XRD, FTIR, TGA and SEM to characterize the catalysts before and after hydro-processing. The performance of Pd/C, based on the concentrations of produced C 15 ∼C 18 normal alkanes, was higher than NiMo/γ-Al 2 O 3 with low reaction temperature, low hydrogen pressure, low LHSV, low H 2 -to-oil ratio and short time-on-stream. Highlights • Fresh and spent NiMo/γ-Al 2 O 3 and Pd/C were examined by XRD, FTIR, TGA and SEM. • HDO/decarbonylation/decarboxylation were studied with various reaction conditions. • Pd/C was found to be better than NiMo/γ-Al 2 O 3 for producing C 15 -C 18 alkanes. [ABSTRACT FROM AUTHOR]

Abstract For the purpose of promoting hydro-processed renewable diesel as the local replacements of traditional diesel and transestification biodiesel, the experimental investigation and techno-economic analysis were carried out in this study. The experiment was conducted with varying reaction temperature, pressure, weight hourly space velocity (WHSV) and H 2 -to-oil ratio over the NiMo/γ-Al 2 O 3 catalyst and the conversion, selectivity and yield were determined. The experimental conditions and results were input into process simulation model for determining the mass and energy flows at the scale of 600 tonnes per day. Furthermore, the techno-economic analysis was conducted based on the mass and energy balances obtained from process simulation, and the locally quoted capital and operating costs, yielding to the minimum renewable diesel price (MRDP) of $1.72/L. The effects of hydrogen, plant capacity, catalyst as well as the operating conditions on MRDP were demonstrated and discussed. Highlights • The operating conditions for renewable diesel production were studied. • The TEA was performed based on the simulated large-scale mass and energy balances. • The minimum renewable diesel selling price was obtained as $1.72/liter. [ABSTRACT FROM AUTHOR]

The development of promising magnetic nanocatalysts is one of the key research topics in the field of catalysis. This is because of their versatile surface physicochemical, magnetic, and size-dependent catalytic properties. Herein, an optimization strategy for the synthesis of high-value fuel grade chemicals from hydro-deoxygenation of biomass-derived furfural and vanillin using a nanostructured magnetic Fe(NiFe)O4-SiO2 catalyst, synthesized by a facile one-pot procedure, was presented. Accordingly, effects of calcination temperature from 400, 500, 600 to 700 °C on the structure-activity properties of the magnetic Fe(NiFe)O4-SiO2 catalyst was systematically studied. The magnetic Fe(NiFe)O4-SiO2 catalyst calcined at 500 °C exhibited the best catalytic performance, giving full conversions of vanillin and furfural, with good selectivity of 63 and 59% to cyclohexane and n-pentane (fuel grade chemicals), respectively. The prowess of this catalyst was attributed to its abundant acid properties in addendum to high BET surface area.

Syngas produced through gasification of carbonaceous materials has provided a gateway to a host of processes for the production of various chemicals including transportation fuels. The basis of the production of gasoline and diesel-like fuels is the Fischer Tropsch Synthesis (FTS) process. It has been argued that only transition metal catalysts (usually Co or Fe) are active toward the CO hydrogenation and subsequent chain growth in the presence of hydrogen. In this paper, we demonstrate that carbon nanotube (CNT) surfaces are also capable of hydro-deoxygenating carbon monoxide and producing long chain hydrocarbons similar to those obtained through the FTS but with orders of magnitude higher activity than the present state-of-the-art FTS catalysts. Using advanced experimental tools such as XPS and microscopy techniques to characterize CNTs, C-O functional groups have been identified as the active sites for the enhanced catalytic activity. Furthermore, quantum Density Functional Theory (DFT) calculations confirm that C-O groups (on CNT surfaces) are catalytically active sites for the reduction of CO with H 2 , and capable of sustaining chain growth. These findings create a new paradigm for CNT-based hydrogenation catalysts and provide a new route for obtaining clean, earth abundant, alternative fuels through the use of efficient and renewable catalyst. [ABSTRACT FROM AUTHOR]

The article discusses research investigating a mild hydrotreating process for biomass pyrolysis oils to produce a refinery feedstock suitable for use. According to the authors, fast pyrolysis produces a liquid product that is highly corrosive and immiscible with hydrocarbons despite its high percentage mass yield, which makes it unsuitable for use in a conventional petroleum refinery or as a finished fuel. The authors also note that catalytic hydroprocessing, which is an alternative that can remove oxygen to make a gasoline- or diesel-like product, is not cost effective. Topics include the results of an economic analysis that suggests mild hydroprocessing is economically viable and produces a product suitable for use in refinery processes.

Ambient pressure hydro-deoxygenation (HDO) of the phenolic-rich pyrolysis liquid fraction is a complex task due to the presence multiple phenolic compounds and light oxygenates. The phenolic-rich fraction differs from the overall pyrolysis liquid, known to be prone to re-polymerization and coking in the reactor or of the catalyst. In the present research, hydro-deoxygenation of oxygen-containing compounds in the phenolic fraction over Mo-based catalysts was carried out for the first time. It was found that Mo-based catalysts can successfully upgrade the phenolics into aromatics, the conversion rate was nearly 100%. The small amount of light oxygenates in the phenolic-rich fraction had no obvious effect on the hydro-deoxygenation reaction, the phenolic conversion was more than 95%. After assessing the performance for a representative phenolic model compound, the reaction was also successfully carried out on the phenolic fraction of the real pyrolysis liquid. It can be concluded that the catalysts can also be used for the HDO of the real pyrolysis liquid fraction at atmospheric pressure. • A phenolic-rich fraction was solvent-extracted from a pyrolysis liquid (bio-oil). • The phenolics were upgraded into aromatics over Mo-based catalysts by HDO. • The hydro-deoxygenation reaction was carried out at ambient pressure. • The upgrading exhibits good selectivity. • The light oxygenates had little effect on the HDO of phenolics. [ABSTRACT FROM AUTHOR]

In this present study, hydro-deoxygenation (HDO) process was performed to upgrade the liquefied bio-oil of Nostoc punctriforme biomass. The engine performance and emission properties of the enriched bio-oil and blends (with diesel) were evaluated. The HTL resulted in highest bio-oil yield of 47.5 wt% at a temperature of 300 °C at 60 min with calorific value of 32.5 MJ/kg. At 60 min and temperature of 300 °C with 1 wt% of heterogeneous catalyst the upgraded HDO-bio-oil yield reached 38.4 wt% with deoxygenation percentage of 70%. The properties of upgraded bio-oil are HHV of 44.74 MJ/kg, Kinematic viscosity of 6.23 mm2/s and density 923 kg/m3 respectively. The response surface methodology (RSM) was used for modeling and optimizing the upgraded bio-oil yield. The optimized RSM conditions for upgraded bio-oil yield (44.5 wt%) are temperature of 280 °C, catalyst load of 0.6 wt%, and time of 120 min. The physiochemical properties of upgraded bio-oil are in agreement with ASTM standards. Equal proportion of bio-oil to diesel (D50: B50) reduced the brake thermal efficiency to 6.66% with reduced NO x emission and slight increase in CO emission. This study highlights that microalga fuels are better renewable energy resource with reduced greenhouse gas emission. [Display omitted] • Hydrothermal liquefaction of N. punctiforme produced 47.5 wt% of bio-oil. • Hydro-deoxygenation resulted in 38.4 wt% of upgraded bio-oil with HHV 44.74 MJ/kg. • Upgraded fuel physiochemical properties are within ASTM standards. • Engine performance and emissions tests of bio-oil were comparable to diesel fuel. [ABSTRACT FROM AUTHOR]

• Bio oil was obtained from the cattail biomass grown in wastewater. • Liquefaction experiments produced 32.4 wt% of bio-oil with HHV of 29.88 MJ/kg. • The deoxygenation efficiency of carbon-supported catalyst was used in HDO process. • HDO process the upgraded bio-oil yield was 24.1 wt% with HHV of 37.63 MJ/kg. • Cattail biomass is promising for the bio-oil production and wastewater treatment. This study targets the value addition of cattails biomass cultivated from wastewater through hydrothermal liquefaction (HTL) and Hydro-deoxygenation (HDO) process in presence of carbon supported catalyst. Cattails biomass for bio-oil production was cultivated from wastewater through advanced phyto-rid technology (AP-RT). Liquefaction experiments produced 32.4 wt% of bio-oil with HHV of 29.88 MJ/kg for 15 g of biomass at a temperature of 300 ℃ at a reaction time of 60 min. Activated carbon (rice husk) supported niobium catalyst was produced via wet impregnation method. The deoxygenation efficiency of carbon-supported catalyst (0–5 wt%) was studied in HDO process. From the HDO process the upgraded bio-oil yield was 24.1 wt% with deoxygenation degree of 75% for catalyst load (3 wt%) with HHV of 37.63 MJ/kg. Approximately 1.17 g of deoxygenated bio-oil was obtained from 15 g of biomass. Gas Chromatographic and Mass Spectroscopic (GC–MS) analysis showed hydrocarbons content of 28% in HTL and 38% in HDO bio-oil with reduced oxygenates. The carbon supported catalysts in reusability studies showed deoxygenation percentage of 56% and carbon recovery of 81% at the end of 4th cycle. [ABSTRACT FROM AUTHOR]

The production of alternative fuels is more than essential to the energy and transportation sectors. Biomass based oil generation through a pyrolysis process is one of the attempts to develop a sustainable way for energy production. One of the main concerns of pyrolysis oil is the undesired properties such as high oxygen level, acidic, viscosity and low heating value. The corrosiveness of pyrolysis oil is a threat to the existing transportation infrastructure and modern engines. For the past decade, research studies have been conducted to develop catalysts that can increase the pyrolysis oil quality through hydro-deoxygenation. From monofunctional, bifunctional with noble metals and non-noble metals to bimetallic catalysts (two metals and a support), hydro-deoxygenation has rapidly evolved in term of catalysts. This review paper studied and analyzed the progress of metals supported catalysts for hydro-deoxygenation of pyrolysis oil and its model compounds. Ru, Pt and Pd supported catalysts performed best among the noble metals supported catalysts. However, noble metals supported catalysts are expensive. Non noble metal such as Ni's performance was comparable to Pt supported catalysts. Recently developed bimetallic catalysts were aimed to improve performance of hydrodeoxygenation at low cost. Nickel and Cobalt were widely used non-noble metals for bimetallic catalysts. • The evolution of catalysts for HDO of pyrolysis oil is reported. • Mono-functional, bifunctional, bimetallic and multi-metallic catalysts are discussed. • Non-noble metals based catalysts are preferred over noble metals based catalysts. • Ni based catalysts had the highest selectivity for hydrocarbons compounds. • Bimetallic supported catalysts are developed for reducing the overall cost. [ABSTRACT FROM AUTHOR]

Fast pyrolysis converts >60 wt% of lignocellulosic materials into bio-oil. The two-step bio-oil hydrotreatment concept has had a major impact in the development of bio-oil hydro-treatment. In the first step, known as stabilization, the carbonyl and carboxyl functional groups are transformed into alcohols between 373 and 573 K, in the presence of noble metals (Pt, Ru and Pd) supported on carbon and metal oxides. In the second step, between 623 and 673 K, cracking and hydro-deoxygenation occur using Ru, Ni or sulfided CoMo catalysts. Transition metal phosphides and carbides are also active. The first section is devoted to summarizing the current understanding of bio-oil composition. The second section is an overview of bio-oil hydrotreatment processing parameters. Many of the bio-oil hydrotreatment studies in the literature are based on model compound results, which are reviewed in the third section. Section four is devoted to review studies with bio-oil fractions and the nature of polymerization and cross linked reactions responsible for catalyst deactivation. The progress in the development of new catalysts is discussed in section five. The review ends with a discussion on future prospects and challenges to hydrotreat pyrolysis bio-oils. • The two steps hydrotreatment concept had a major impact in the development of the field • Most common catalysts used in stabilization step: Pt, Ru and Pd • Most common catalysts for de-oxygenation: Ru, Ni and sulfided CoMo • Separation of bio-oil into fractions and separate processing is necessary • HDO of oligomeric fractions is challenging [ABSTRACT FROM AUTHOR]

In monitoring the photo-catalytic reaction of salicylic acid over RIT, two catalytic degradation reactions are observed: one is the de-carboxylation; and the other is the hydro-deoxygenation. The photo-induced e–h pair from the crystalline titania domain in RIT plays the key role in the de-carboxylation degradation. The Ru0/ Ru4+ ratio of Ru 2 O in RIT is the pivitol factor in the direct cleavage of C aro O bond via hydro-deoxygenation. [Display omitted] • Two degradation steps are observed in the photo-catalysis of SA over RIT; i.e. de-carboxylation and hydro-deoxygenation. • The e–h pair induced from TiO 2 plays the key role in initializing the de-carboxylation. • The Ru0/Ru4+ ratio of Ru 2 O is the pivitol factor in the direct cleavage of C aro O bond via hydro-deoxygenation. • The best selectivity for C aro O bond cleavage (71.9%) is shown in the RIT-1, Ru/Ti = 3.53%, route. Ruthenium oxide incorporated titania (RIT) photocatalyst, with verified ruthenium oxide ratio, have been prepared for photo-degradation. In monitoring the photo-catalytic reaction of salicylic acid over RIT, two degradation steps are observed. The first one is the de-carboxylation. The other step is the hydro-deoxygenation. The final product collected from the degradation is benzene. On the basis of experimental results, the photo-induced e–h pair from the crystalline domain of titania in RIT plays the key role in inducing the de-carboxylation degradation. As for the hydro-deoxygenation reaction, the Ru0/ Ru4+ ratio of incorporated ruthenium oxide in RIT is the pivitol factor in the direct cleavage of C aro O bond of phenol. The best selectivity for C aro O bond cleavage (71.9%) is shown in the RIT-1, Ru/Ti = 3.53%, route. If the ratio of Ru/Ti reaches to 10.81% (RIT-3), the selectivity decreases to 4.8%. [ABSTRACT FROM AUTHOR]

The development of promising magnetic nanocatalysts is one of the key research topics in the field of catalysis. This is because of their versatile surface physicochemical, magnetic, and size-dependent catalytic properties. Herein, an optimization strategy for the synthesis of high-value fuel grade chemicals from hydro-deoxygenation of biomass-derived furfural and vanillin using a nanostructured magnetic Fe(NiFe)O4-SiO2 catalyst, synthesized by a facile one-pot procedure, was presented. Accordingly, effects of calcination temperature from 400, 500, 600 to 700 °C on the structure-activity properties of the magnetic Fe(NiFe)O4-SiO2 catalyst was systematically studied. The magnetic Fe(NiFe)O4-SiO2 catalyst calcined at 500 °C exhibited the best catalytic performance, giving full conversions of vanillin and furfural, with good selectivity of 63 and 59% to cyclohexane and n-pentane (fuel grade chemicals), respectively. The prowess of this catalyst was attributed to its abundant acid properties in addendum to high BET surface area. [ABSTRACT FROM AUTHOR]