Non-catalytic Liquefaction Research Articles

Mono-and bi-metal catalytic hydrothermal liquefaction of food waste: Screening the process parameter on product yield and characterizations

Biofuels and chemicals derived from wet food waste (FW) can serve as a strategy to significantly reduce emissions and mitigate environmental pollution while preventing the loss of valuable resources. Hydrothermal liquefaction (HTL) is one of the most promising thermochemical techniques for converting wet waste into crude oil-like products (biocrude). In this study, catalytic HTL of FW was carried out using cobalt (Co), magnesium (Mg), and cobalt-magnesium (Co–Mg) supported on ZSM-5 to produce high-quality biocrude. The impact of key operating parameters, such as reaction solvent, temperature, reaction holding time, and catalyst amount, was investigated. In comparison to non-catalytic liquefaction, catalytic liquefaction significantly improved the biocrude yield. The maximum biocrude yield (60.89 wt%) was achieved with bimetallic Co–Mg/ZSM-5 catalysts at 280 °C with 10 wt% of catalyst at a reaction time of 15 min. Various analytical methods, including GC-MS, FT-IR, CHNS, TGA, and NMR, were employed to identify the composition and quality of the biocrudes. Catalytic liquefaction with Co–Mg/ZSM-5 in an ethanol solvent resulted in a higher percentage of ester compounds (74.15%, area percentage). The biocrude obtained through the catalytic process had lower oxygen and nitrogen content, which led to a higher heating value (HHV). Biocrude quantification revealed the presence of 12.16 wt% of linoleic ester compounds. The concentration of total nitrogen (TN) in the catalytic aqueous phase was as high as 2.44 g/L, significantly greater than the 0.32 g/L found in the non-catalytic aqueous phase. Furthermore, the optimum Co–Mg/ZSM-5 catalyst demonstrated excellent reusability and stability in FW liquefaction.

Hydrogen-donating behavior and hydrogen-shuttling mechanism of liquefaction solvents under Fe- and Ni-based catalysts

The H-donating solvent plays a crucial role in both oil yield and products distribution during direct coal liquefaction. Meanwhile, liquefaction catalyst significantly influences the H-donating behavior of the solvent and the pathways of hydrogen transfer. In view of insufficient understanding on the impact of catalysts on H-donating behavior of solvent and hydrogen transfer pathways in direct liquefaction, in this study, non-H-donating solvents including naphthalene, 1-methylnaphthalene and pyrene (Py) and H-donating solvents including tetralin (THN) and 9,10-dihydroanthracene (DHA) were chosen as the solvents. The Shenhua nano-sized Fe-based and the prepared Ni/Al2O3 catalysts were used to investigate their effect on H-donating behavior of the solvent and H-shuttling mechanism. Results show that liquefaction solvent obviously affects coal conversion and products distribution no matter Fe-based or Ni-based catalyst was used. When non-H-donating solvent is used as liquefaction solvent, coal conversion is lower than that with THN or DHA as solvent. The addition of Py to THN as solvent improves the utilization of effective hydrogen in non-catalytic liquefaction, which is ascribed to hydrogen transfer effect of Py; however, hydrogen transfer mainly occurs through direct combination of gaseous H2 with radicals generated from coal pyrolysis in presence of Fe-based catalyst, with minimal shuttle action of solvent hydrogen. On the contrary, the Ni-based catalyst aids in enhancing the hydrogen shuttle effect of the solvent, and the hydrogen transfer path primarily involves H2 to solvent and then to coal, which is ascribed to good hydrogenation ability of Ni-based catalyst. Under the action of Fe-based catalyst, DHA as liquefaction solvent exhibits lower H-donating capability compared to THN, and approximately 65% of total hydrogen consumption is effectively utilized for coal liquefaction, along with about 35% of total hydrogen consumption for the hydrogenation, ring opening, and side-chain scission reactions of DHA. However, about 96% of total hydrogen consumption is effectively utilized for coal liquefaction when THN used as solvent, indicating that THN as liquefication solvent is more conducive to the transfer of gaseous hydrogen to free radical fragments from coal pyrolysis compared to DHA.

Production of Bio-Crude Oil from Microalgae Chlorella sp. Using Hydrothermal Liquefaction Process

Currently, microalgae have attracted as potential feedstock for biofuel production. Hydrothermal liquefaction was proposed as technology to convert microalgae into bio-crude oil. Microalgae used in this study was Indonesia-cultivatedChlorellasp.,This work investigated the effect of temperature (200°C, 225°C, 250°C), biomass weight-water ratio (1:20, 2:20, 3:20), and residence time (10, 20, 30 minutes) on bio-crude oil yield of non-catalytic hydrothermal liquefaction. The highest bio-crude oil yield was 2.25%, obtained at temperature of 250°C biomass weight-water ratio of 1:20, and residence time of 10 minutes. The highest component of bio-crude oil was alcohols. The low bio-crude oil yield was caused by the longer residence time of cooling step (driving gas conversion), low amount of carbon-hydrogen content and high amount of oxygen-ash content in biomass. Furthermore, the highest component of bio-crude oil was alcohols, stimulated by low carbon content coupled with high oxygen content inChlorellasp.

Unsupported Ni metal catalyst in hydrothermal liquefaction of oak wood: Effect of catalyst surface modification

Hydrothermal liquefaction of oak wood was carried out in tubular micro reactors at different temperatures (280–330 °C), reaction times (10–30 min), and catalyst loads (10–50 wt%) using metallic Ni catalysts. For the first time, to enhance the catalytic activity of Ni particles, a coating technique producing a nanostructured surface was used, maintaining anyway the micrometric dimension of the catalyst, necessary for an easier recovery. The optimum conditions for non-catalytic liquefaction tests were determined to be 330 °C and 10 min with the bio-crude yield of 32.88%. The addition of metallic Ni catalysts (Commercial Ni powder and nanostructured surface-modified Ni particle) increased the oil yield and inhibited the char formation through hydrogenation action. Nano modified Ni catalyst resulted in a better catalytic activity in terms of bio-crude yield (36.63%), thanks to the higher surface area due to the presence of flower-like superficial nanostructures. Also, bio-crude quality resulted improved with the use of the two catalysts, with a decrease of C/H ratio and a corresponding increase of the high heating value (HHV). The magnetic recovery of the catalysts and their reusability was also investigated with good results.

Effect of catalysts on liquefaction of alkali lignin for production of aromatic phenolic monomer

Hydrothermal liquefaction (HTL) has emerged as a promising technology for producing fuels/chemicals. Lignin liquefaction was carried out with different temperature 250, 270, 290 and 310 °C in the presence of 50% ethanol-50% water (v/v) and a reaction time 30 min. The catalyst reaction with 10 wt% each catalyst of Pd/C, Fe/C, Co/C and Ni/C at 270 °C for 30 min reaction time was carried out. For non-catalytic reaction maximum bio-oil (68.2 wt%) was obtained at 270 °C while catalytic reaction with Co/C catalyst gave highest bio-oil (73.2 wt%). The obtained bio-oil has been analyzed with the help of GC-MS, FT-IR, NMR, GPC and CHNS. On the basis of GC-MS analysis, the main monomeric phenolic compounds produced were phenol, 2-methoxy-phenol, 4-ethyl-phenol, 2-methoxy-4-ethyl-phenol and 2,6-dimethoxy-phenol, due to their high concentrations it was feasible to select these five monomeric phenols as target compounds. It was seen that compared to the non-catalytic liquefaction reaction, the catalytic (Pd/C, Co/C, Ni/C and Fe/C) liquefaction reaction promotes the hydrogenation and hydrogeoxygenation of bio-oils. The possible reaction pathways have been explored in this studied.

Catalytic hydrothermal liquefaction of rice straw for production of monomers phenol over metal supported mesoporous catalyst

The catalytic (SBA-15, Ni/SBA-15, Al/SBA-15 and Ni-Al/SBA-15) hydrothermal liquefaction (HTL) of rice straw biomass was examined at different temperature with different amount of catalyst in the presence of different solvents. In comparison with water solvent liquefaction, the bio-oil yield significantly increased under alcoholic solvent (ethanol and methanol). The highest bio-oil yield was observed for water (44.3 wt%) with Ni-Al/SBA-15, while for ethanol (56.2 wt%), and for methanol (48.1 wt%) with, Ni/SBA-15 catalyst. The loading of Ni and Al on SBA-15, the acid strength of the catalyst enhanced. Bio-oils yield were analyzed with the help of GC–MS, FT-IR, NMR, GPC and CHNS. From the GC–MS analysis, the main monomeric phenolic compounds were produced, phenol, 4-ethyl-phenol, 2-methoxy-phenol, 2-methoxy-4-ethyl-phenol and Vanillin. It was observed by CHNS and GPC analysis of the bio-oil, compared to the non-catalytic liquefaction reaction, the catalytic liquefaction reaction promotes the hydrogenation/hydrodeoxygenation and produced lower molecular weight bio-oils.

Hydrothermal liquefaction of macroalgae: Influence of zeolites based catalyst on products

Hydrothermal liquefaction (HTL) of Ulva prolifera macroalgae (UP) was carried out in the presence of three zeolites based catalysts (ZSM-5, Y-Zeolite and Mordenite) with the different weight percentage (10–20 wt%) at 260–300 °C for 15–45 min. A comparison between non-catalytic and catalytic behavior of ZSM-5, Y-Zeolite, and Mordenite in the conversion of Ulva prolifera showed that is affected by properties of zeolites. Maximum bio-oil yield for non-catalytic liquefaction was 16.6 wt% at 280 °C for 15 min. The bio-oil yield increased to 29.3 wt% with ZSM-5 catalyst (15.0 wt%) at 280 °C. The chemical components and functional groups present in the bio-oils are identified by GC-MS, FT-IR, 1H-NMR, and elemental analysis techniques. Higher heating value (HHV) of bio-oil (32.2–34.8 MJ/kg) obtained when catalyst was used compared to the non-catalytic reaction (21.2 MJ/kg). The higher de-oxygenation occurred in the case of ZSM-5 catalytic liquefaction reaction compared to the other catalyst such as Y-zeolite and mordenite. The maximum percentage of the aromatic proton was observed in bio-oil of ZSM-5 (29.7%) catalyzed reaction and minimum (1.4%) was observed in the non-catalyst reaction bio-oil. The use of zeolites catalyst during the liquefaction, the oxygen content in the bio-oil reduced to 17.7%. Aqueous phase analysis exposed that presence of valuables nutrients.

Hydrothermal liquefaction of Ulva prolifera macroalgae and the influence of base catalysts on products

Hydrothermal liquefaction of Ulva prolifera macroalgae (UM), an aquatic biomass, was carried out in an autoclave reactor at different temperature (270, 290 and 310 °C) and reaction holding time (10, 20 and 30 min.). The catalytic reactions of UM were carried out in the presence of three basic catalysts (KOH, NaOH and Na2CO3) with the different catalyst amount. Maximum bio-oil yield for non-catalytic liquefaction was (12.0 wt%) at 290 with 10 min reaction time. In the catalytic reaction the maximum bio-oil yield (26.7 wt%) was observed with KOH (0.1 g) catalyst. The chemical components and functional groups present in the bio-oils are identified by GC–MS, FT-IR, 1H-NMR, TGA and elemental analysis techniques. Majorly nitrogen containing compounds were found with catalytic reaction in bio-oils. The higher heating value (33.6 MJ kg−1) as well as the higher carbon content (64.2%) was observed in the case of catalytic liquefaction bio-oil.

Alkali catalyzed liquefaction of corncob in supercritical ethanol–water

Corncob liquefaction in supercritical ethanol–water was performed with and without the addition of an alkali catalyst by direct addition or biomass impregnation in a 250-cm3 batch reactor. The effects of temperature, solvent and alkali addition on the biomass conversion level and oil yield were investigated to find the optimum condition. For non-catalytic liquefaction using a 1:1 (v/v) ethanol: water ratio, a maximum oil yield and conversion level of 49.0% and 93.4%, respectively, were obtained at 340 °C. For alkali catalytic liquefaction, the oil yield with KOH addition (57.5%) was higher than that from KOH-impregnated corncob liquefaction (43.3%). The oil from liquefaction with KOH addition had higher heating value (26.7–35.3 MJ kg−1) than the corncob (19.1 MJ kg−1). The dominant components of the obtained oil were found by GC/MS analysis to be aldehyde, ester, phenol derivatives and aromatic compounds.

Catalytic Hydrothermal Liquefaction of Soy Protein Concentrate

We report herein on the hydrothermal catalytic liquefaction of soy protein concentrate. Catalyst screening experiments have shown that metal catalysts (e.g., 5 wt % Pt, Pd, or Ru) supported on porous solids (e.g., carbon, Al2O3) produce crude bio-oils with less heteroatom content than does noncatalytic liquefaction of this material under otherwise identical conditions. The catalysts had little influence on the biocrude yield. Of the different catalytic materials tested, Ru/C had the greatest influence on the biocrude composition. The heating value of the biocrude produced from liquefaction at 350 °C for 120 min with a 20 wt % loading of Ru/C was 16% higher than the heating value from the noncatalytic run (37 MJ/kg vs 43 MJ/kg). Moreover, the heteroatom content of this biocrude from catalytic liquefaction was less than half that of its noncatalytic counterpart (16.6 wt % vs 7.8 wt %). The catalyst reduced sulfur levels in the biocrude to below detection limits and the nitrogen level to 45% of that in the n...

Non-catalytic liquefaction of microalgae in sub-and supercritical acetone

Abstract In the present study, a microalga ( Chlorella pyrenoidosa ) was treated in sub/supercritical acetone in the absence of catalyst by using a high pressure bath reactor. Influence of process variables such as temperature (varied from 170 to 350 °C), acetone/microalga ratio (varied from 2/2.5 to 16/2.5), and time (varied from 5 to 120 min) on the yields of product factions and properties of biocrude has been studied. Temperature was the most influential factor affecting the products yield and properties of the biocrude, and the highest biocrude yield of 60.1 wt.% was achieved at 290 °C. Addition of acetone not only promoted the conversion of microalga but also favored the biocrude yield due to the incorporation of acetone into the biocrude. Furthermore, liquefaction of microalga in acetone made the conversion milder that than of in water. The biocrude was less viscous than that of oil produced from hydrothermal liquefaction under otherwise identical reaction conditions. The biocrudes, which contained significant carbon and hydrogen than that of the original algal biomass, had higher heating values ranging from 28.7 to 37.1 MJ/kg. The most abundant compounds for the biocrude are unsaturated fatty acids (9,12,15-octadecatrienoic acid) and hydrocarbons (2-hexadecene, 3,7,11,15-tetramethyl-). CO 2 was the dominant component in the gaseous products under all experimental conditions. Deoxygenation and denitrogenation are necessary if one to expect to produce transportation fuels from this kind of biocrude.

Gasification and liquefaction of solid fuels by hydrothermal conversion methods

Spruce needles, reed, peat and oil shale samples, representing available natural resource of solid organic feedstock, were submitted to the hydrothermal conversion. Non-catalytic liquefaction (NL – 380°C, 4h, feed-to-water ratio 1:3) and Ni-catalyzed gasification (CG – 400°C, 0.5h, feed-to-catalyst-to-water ratio 1:2:10, initial pressure with argon to 20bar) were the conditions of the conversion used. Both processes were performed using supercritical water in 30 and 500cm3 autoclaves, and resulted in redistribution of the organic matter (OM) of the solid fuel feedstocks between gaseous, liquid, and solid conversion products. NL of Kukersite oil shale resulted in almost total conversion of oil shale kerogeneous OM to the benzene soluble oil (63%) and gas (31%). Biomass samples and peat known as specially rich in oxygen content (33–49%), the latter being mostly transferred to carbon dioxide and water, whereas the oils obtained from biomass and peat were characterized by oxygen contents 16–18%. Content of hydrocarbons was higher in the shale oil and peat oil compared to bio-oils. In CG, all organic carbon in the initial solid matter of the biomass samples, and up to 75% of that in peat, was transferred to gas with CH4 concentrations in the range of 36–40vol.%. The main gaseous compound produced from oil shale was H2 and its concentration as high as 61vol.% was measured. It was demonstrated that using NL and CG hydrothermal conversion methods, solid fuels can be upgraded to gaseous and liquid products with a higher energy density than the original feedstock.

Hydrothermal catalytic production of fuels and chemicals from aquatic biomass

AbstractOne of the promising avenues for biomass processing is the use of water as a reaction medium for wet or aquatic biomass. This review focuses on the hydrothermal catalytic production of fuels and chemicals from aquatic biomass. Two different regimes for conversion of aquatic biomass in hydrothermal conditions are discussed in detail. The first is hydrothermal liquefaction, and the second is hydrothermal gasification. The goals of these processes are to produce liquid‐fuel‐range hydrocarbons and methane or hydrogen, respectively. The catalytic upgrading of biocrude resulting from noncatalytic liquefaction and the stability and degradation of catalysts in high temperature water are also discussed. The review concludes with a brief discussion of the outlook for and opportunities within the field of hydrothermal catalytic valorization of biomass. Copyright © 2012 Society of Chemical Industry

Kinetic behavior of liquefaction of Japanese beech in subcritical phenol

Non-catalytic liquefaction of Japanese beech (Fagus crenata) wood in subcritical phenol was investigated using a batch-type reaction vessel. After samples were treated at 160°C/0.9MPa–350°C/4.2MPa for 3–30min, they were fractionated into a phenol-soluble portion and phenol-insoluble residues. These residues were then analyzed for their chemical composition. Based on the obtained data, the kinetics for liquefaction was modeled using first-order reaction rate law. Subsequently, the liquefaction rate constants of the major cell wall components including cellulose, hemicellulose, and lignin were determined. The different kinetic mechanisms were found to exist for lignin and cellulose at two different temperature ranges, lower 160–290°C and higher 310–350°C, whereas for hemicellulose, it was only liquefied in the lower temperature range. Thus, the liquefaction behaviors of these major cell wall components highlighted hemicellulose to be the most susceptible to liquefaction, followed by lignin and cellulose.

Non-catalytic liquefaction of bitumen with hydrothermal/solvothermal process

Bitumen was mainly obtained as a residue of the petroleum refining process. In fact, bitumen is of great importance to the chemical industry because of the wide variety of special properties, which has favored the development of a wide field of applications. The development of process has been proposed to recover chemical resources from bitumen that can accomplish the destruction of the bitumen into harmless to produce useful compounds. In this work, an upgrading process for bitumen and its model compounds were investigated in supercritical water and solvothermal process by using batch reactor. It was well known that water at the hydrothermal condition is considered a promising and an environmentally acceptable solvent for a wide variety of chemical reactions such as organic syntheses and decomposition of hazardous wastes into harmless compounds. The experiments were conducted at temperature of 673 K and at various reaction pressures. Instead of water, benzyl alcohol (BZA) was used as a solvent in solvothermal process at temperatures of 523–573 K. The chemical species in the liquid products were analyzed by gas chromatography mass spectrometry. The effect of pressure and reaction time on the decomposition process was presented. Ultimate analysis of solid residue was also conducted using a CHN analyzer. Moreover, this method could become an efficient method for upgrading bitumen into harmless and high yield of valuable chemical intermediates on the basis of the experimental results.

Bio-Oil from Hydro-Liquefaction of Bagasse in Supercritical Ethanol

The liquefaction of sugar cane bagasse in supercritical ethanol, with or without various proportions of water as a proton donor, was conducted in a batch reactor to evaluate the optimal conditions for bio-oil production. The following variables were studied: temperature, initial H2 pressure, and catalyst type (FeS, Fe2S3/AC, and FeSO4). For noncatalytic liquefaction using ∼100% (v/v) ethanol, a high oil yield of 59.6% (daf) and biomass conversion of 89.8% were obtained at 330 °C under initial H2 pressure of 4.93 MPa. For catalytic liquefaction in the presence of FeSO4 under the same conditions, the oil yield increased to 73.8% (daf) and the biomass conversion reached 99.9%. The bio-oil obtained had a 1.81-fold higher heating value (26.8 MJ/kg) than the original starting sugar cane bagasse (14.8 MJ/kg). From gas chromatography/mass spectrometry (GC/MS) analysis, the dominant components of the liquefaction oil were found to be phenolic compounds, aldehydes, and esters, such as phenol, phenol derivatives, and furan derivatives.

Catalysis of [formula omitted] solid acid for the liquefaction of coal

In order to study the catalysis of SO 4 2 - / ZrO 2 solid acid for the liquefaction of coal, a series of SO 4 2 - / ZrO 2 solid acids were synthesized by the method of precipitation–impregnation. The catalytic behaviours of the SO 4 2 - / ZrO 2 solid acids for the hydro-liquefaction of Shenhua coal and model compounds, such as diphenylmethane, bibenzyl and phenyl ethyl ether, were investigated. In addition, non-catalytic liquefaction and the catalytic liquefaction under N 2 were further compared with the catalytic liquefaction under H 2 in order to understand the catalytic mechanism of SO 4 2 - / ZrO 2 solid acid. The results indicate that hydro-liquefaction conversions of coal and model compounds are related to the strength, amount and nature of acid sites on the surface of SO 4 2 - / ZrO 2 , and the strong acid site responds to their catalytic activities. The SO 4 2 - / ZrO 2 solid acid catalyzes mainly the hydro-cracking, ring-opening and hydrogenation reactions of coal to produce oil and gas during the coal liquefaction. The hydro-cracking reactions in the liquefaction of model compounds and coal catalyzed by SO 4 2 - / ZrO 2 involved via carbenium ion intermediate instead of traditional radicals intermediate.

Noncatalytic liquefaction of tar with low-temperature hydrothermal treatment

Water at hydrothermal and supercritical conditions is considered a promising solvent for the degradation of hazardous waste into harmless compounds. Tar liquefaction experiments were conducted using a batch-type reactor at temperatures between 623 K and 673 K and at pressures between 25 and 40 MPa. A reaction mechanism for tar liquefaction is proposed. Moreover, on the basis of the experimental results, this method could become an efficient method for tar liquefaction, producing high yields of valuable chemical intermediates.

Effect of amines added on Banko coal liquefaction

The effect of the addition of various amines on catalytic and non-catalytic liquefaction of Indonesian Banko coal was studied. For non-catalytic liquefaction a significant increase in coal conversion to THF solubles was observed by the addition of the amines, and the increment in conversion is in the order, secondary aliphatic amine, tertiary aliphatic amine > primary aliphatic amine > aromatic amine. This order is that of the strength of their basicity. For catalytic liquefaction using pyrite the conversion was also increased by the addition of amines, and stronger basic tertiary aliphatic amines gave higher conversion than less basic primary aliphatic amines. The role of amines was considered to induce the higher loading of pyrite on coal surface by the preadsorption of the amine on the surface.

A Comparison of FeS, FeS + S and solid superacid catalytic properties for coal hydro-liquefaction

Catalyst plays an important role in direct coal liquefaction. This paper focuses on the catalytic behavior of a novel SO 4 2 - / ZrO 2 superacid catalyst in coal hydro-liquefaction. A series of hydro-liquefaction experiments were conducted under mild conditions – 400 °C, 30 min and H 2 initial pressure 4 MPa in a batch autoclave with a volume of 100 ml. The catalytic property of SO 4 2 - / ZrO 2 was compared with FeS and FeS + S by Shenhua coal. The liquefaction products catalyzed by different catalysts were analyzed by FTIR spectrum, 1H NMR spectrum and element analysis. In addition, the SO 4 2 - / ZrO 2 solid superacid was characterized. The results indicated that the SO 4 2 - / ZrO 2 solid superacid shows outstanding catalytic property for direct liquefaction of coal and gives the highest coal conversion and gas + oil yield compared to other two catalysts. The THF conversion and the extraction yield of CS 2/NMP mixed solvent of liquefied coal catalyzed with SO 4 2 - / ZrO 2 are 76.3%, daf and 81.2%, daf respectively, and the yield of gas + oil is 62.5%, daf under the condition used in this study. The pyrolysis of coal macromolecular clusters can be promoted by catalysts such as FeS, FeS + S and SO 4 2 - / ZrO 2 . There may be only the pyrolysis of volatile matter and the relaxation of the structure of coal macromolecular clusters in non-catalytic liquefaction at 400 °C. Added sulfur in FeS can improve the catalytic activity of hydrogenation. SO 4 2 - / ZrO 2 is a notable catalyst in the study of coal direct liquefaction because it shows excellent catalytic activities for the pyrolysis and the hydrogenation. In addition, it has been found that the C–O bond is the most stable group in coal liquefaction reaction except for the covalent bond between carbon and carbon.