Highest Liquid Yield Research Articles

Catalytic pyrolysis of Mediterranean sea plant for bio-oil production

The main objective of the work was to investigate about the feasibility to produce high-quality bio-oil from Mediterranean sea plant by catalytic pyrolysis process. Therefore, experiments using Posidonia Oceanica at 500 °C in a fixed bed reactor were explored taking into consideration the biomass conversion and bio-products yields. The effect of different “home-made” Ni, Ce, HZSM-5 based catalysts in pyrolysis process was analyzed mainly in terms of conversion yield, bio-oil yield and bio-oil oxygen and organic compounds content. The highest liquid yields were obtained at 500 °C. Particularly, CeO2 (51.15 wt%), NiCe/HZSM-5 (50.66 wt%) and Ni/CeO2 (49.74 wt%) were the most effective catalysts and these have increased the bio-oil yield compared to non-catalytic ones (47.74 wt%). The highest conversions were obtained with Ni/HZSM-5 (80.81%) and CeO2 (79.07%) which were the most efficient catalysts. Oxygen level was decreased in bio-oils from 25.66 wt% in the starting biomass to 6–8 wt% with CeO2, Ni/CeO2 and NiCe/HZSM-5 catalysts. This is due to the potential of these catalysts to promote deoxygenation reactions, such as dehydration, decarboxylation and decarbonylation, that enhance the bio-oil quality. In terms of compositions zeolite and ceria based catalysts were the best. In absolute the highest content of hydrocarbons was obtained with HZSM-5 and Ni/HZSM-5, 39.56 and 34.91% respectively. Therefore, lower content of acids and oxygen in the bio-oil, higher hydrocarbons, combined with higher heating value show promise for production of high-quality bio-oil from Posidonia Oceanica via catalytic pyrolysis.

Co-processing of olive bagasse with crude rapeseed oil via pyrolysis.

The co-pyrolysis of olive bagasse with crude rapeseed oil at different blend ratios was investigated at 500ºC in a fixed bed reactor. The effect of olive bagasse to crude rapeseed oil ratio on the product distributions and properties of the pyrolysis products were comparatively investigated. The addition of crude rapeseed oil into olive bagasse in the co-pyrolysis led to formation of upgraded biofuels in terms of liquid yields and properties. While the pyrolysis of olive bagasse produced a liquid yield of 52.5 wt %, the highest liquid yield of 73.5 wt % was obtained from the co-pyrolysis of olive bagasse with crude rapeseed oil at a blend ratio of 1:4. The bio-oil derived from olive bagasse contained 5% naphtha, 10% heavy naphtha, 30% gas oil, and 55% heavy gas oil. In the case of bio-oil obtained from the co-pyrolysis of olive bagasse with crude rapeseed oil at a blend ratio of 1:4, the light naphtha, heavy naphtha, and light gas oil content increased. This is an indication of the improved characteristics of the bio-oil obtained from the co-processing. The heating value of bio-oil from the pyrolysis of olive bagasse alone was 34.6 MJ kg-1 and the heating values of bio-oils obtained from the co-pyrolysis of olive bagasse with crude rapeseed oil ranged from 37.6 to 41.6 MJ kg-1. It was demonstrated that the co-processing of waste biomass with crude plant oil is a good alternative to improve bio-oil yields and properties.

The effect of pyrolysis atmosphere on bio-oil yields and structure

ABSTRACTA food industry waste, almond shell, was pyrolyzed under three different environment static, nitrogen, and steam to produce bio-oil and its derivatives. The oil yield obtained at pyrolysis temperature of 600°C was 24.23% in a static atmosphere, whereas it increased to 27.25% and 33.05% in nitrogen and steam atmospheres, respectively. The bio-oil obtained under steam atmosphere is very efficient due to the production of high liquid and gas yields. Moreover, co-feeding steam during the pyrolysis altered the bio-oil structure by increasing the aliphatics and reducing the asphaltenes. Moreover, steam treatment also increases H/C and heating value of bio-oils. According to the obtained results, steam pyrolysis is an alternative option for future applications in refineries.

Fast pyrolysis of Saccharina japonica alga in a fixed-bed reactor for bio-oil production

Macro-algae are recognized as a potential feedstock for renewable energy and fuel production. Saccharina japonica is a kind of macro-algae that has been extensively cultivated in Korea. Through pyrolysis, S. japonica can be converted into bio-oil, gas, and char. In this study, we investigated the fast pyrolysis of S. japonica in a fixed-bed reactor at different temperatures from 350 to 550°C with sweeping-gas flow rates of 100, 300, and 500ml/min. As the pyrolysis temperature was increased from 350°C to 500°C, the bio-oil yields decreased while the gas yields increased. The highest liquid yield (40.91wt%) was obtained at a pyrolysis temperature of 350°C with a sweeping-gas velocity of 300ml/min. The major compositions in the bio-oil were di-anhydromannitol (34.45%), iso-sorbide (19.84%), and 2-methyl furyl ketone (8.43%). The gas products (including CO, CO2, H2, and hydrocarbon gases from C1 to C4), were analyzed by gas chromatography with an FID and a TCD. The bio-chars contained a high carbonaceous content can be used as a pollution-free solid fuel or for the production of activated carbon and other chemicals.

Pyrolysis of Xanthium strumarium in a fixed bed reactor: Effects of boron catalysts and pyrolysis parameters on product yields and character

ABSTRACTPyrolysis of Xanthium strumarium has been performed in a fixed-bed tubular reactor with boron minerals (ulexite, colemanite, and borax) and without catalyst at three different temperatures ranging from 350°C to 550°C with heating rate of 50°C/min. The amounts of bio-oil, bio-char, and gas generated, also the compositions of the resulting bio-oils were identified by GC-MS and FT-IR. The influences of pyrolysis parameters, such as temperature and catalyst on product yields were investigated. Temperature and catalyst were found to be the main factors affecting the conversion of Xanthium strumarium into solid, liquid, and gaseous products. The highest liquid yield (27.97%) including water was obtained with 10% colemanite (Ca2B6O11.5H2O) catalyst at 550°C temperature at a heating rate of 50°C/min when 0.224 > Dp > 0.150 mm particle size raw material and 100 cm3/min of sweeping gas flow rate were used.

Catalytic Fast Pyrolysis of Lignin over High‐Surface‐Area Mesoporous Aluminosilicates: Effect of Porosity and Acidity

Catalytic fast pyrolysis (CFP) of lignin with amorphous mesoporous aluminosilicates catalysts yields a high fraction of aromatics and a relatively low amount of char/coke. The relationship between the acidity and porosity of Al-MCM-41, Al-SBA-15, and Al-MSU-J with product selectivity during lignin CFP is determined. The acid sites (mild Brønsted and stronger Lewis) are able to catalyze pyrolysis intermediates towards fewer oxygenated phenols and aromatic hydrocarbons. A generalized correlation of the product selectivity and yield with the aluminum content and acidity of the mesoporous aluminosilicates is hard to establish. Zeolitic strong acid sites are not required to achieve high conversion and selectivity to aromatic hydrocarbon because nanosized MCM-41 produces a high liquid yield and selectivity. The two most essential parameters are diffusion, which is influenced by pore and grain size, and the active site, which may be mildly acidic, but is dominated by Lewis acid sites. Nanosized grains and mild acidity are essential ingredients for a good lignin CFP catalyst.

Catalytic Flash Pyrolysis of Biomass Using Different Types of Zeolite and Online Vapor Fractionation

Bio-oil produced from conventional flash pyrolysis has poor quality and requires expensive upgrading before it can be used as a transportation fuel. In this work, a high quality bio-oil has been produced using a novel approach where flash pyrolysis, catalysis and fractionation of pyrolysis vapors using two stage condensation are combined in a single process unit. A bench scale unit of 1 kg/h feedstock capacity is used for catalytic pyrolysis in an entrained down-flow reactor system equipped with two-staged condensation of the pyrolysis vapor. Zeolite-based catalysts are investigated to study the effect of varying acidities of faujasite Y zeolites, zeolite structures (ZSM5), different catalyst to biomass ratios and different catalytic pyrolysis temperatures. Low catalyst/biomass ratios did not show any significant improvements in the bio-oil quality, while high catalyst/biomass ratios showed an effective deoxygenation of the bio-oil. The application of zeolites decreased the organic liquid yield due to the increased production of non-condensables, primarily hydrocarbons. The catalytically produced bio-oil was less viscous and zeolites were effective at cracking heavy molecular weight compounds in the bio-oil. Acidic zeolites, H-Y and H-ZSM5, increased the desirable chemical compounds in the bio-oil such as phenols, furans and hydrocarbon, and reduced the undesired compounds such as acids. On the other hand reducing the acidity of zeolites reduced some of the undesired compounds in the bio-oil such as ketones and aldehydes. The performance of H-Y was superior to that of the rest of zeolites studied: bio-oil of high chemical and calorific value was produced with a high organic liquid yield and low oxygen content. H-ZSM5 was a close competitor to H-Y in performance but with a lower yield of bio-oil. Online fractionation of catalytic pyrolysis vapors was employed by controlling the condenser temperature and proved to be a successful process parameter to tailor the desired bio-oil properties. A high calorific value bio-oil having up to 90% organics was produced using two staged condensation of catalytic pyrolysis vapor. Zeolite-based acidic catalysts can be used for selective deoxygenation, and the catalytic bio-oil quality can be further improved with staged vapor condensation.

Pyrolysis of giant mullein (Verbascum thapsus L.) in a fixed-bed reactor: Effects of pyrolysis parameters on product yields and character

ABSTRACTSlow pyrolysis of giant mullein (Verbascum thapsus L.) stalks have been carried out in a fixed-bed tubular reactor with (Al2O3, ZnO) and without catalyst at four different temperatures between 400 to 550°C with a constant heating rate of 50°C/min and with a constant sweeping gas (N2) flow rate of 100 cm3/min. The amounts of bio-char, bio-oil, and gas produced were calculated and the compositions of the obtained bio-oils were determined by gas chromatography-mass spectrometry. The effects of pyrolysis parameters, such as temperature and catalyst, on the product yields were investigated. The results show that both temperature and catalyst have significant effects on the conversion of Verbascum thapsus L. into solid, liquid, and gaseous products. The highest liquid yield of 40.43% by weight including the aqeous phase was obtained with 10% zinc oxide catalyst at 500°C temperature. Sixty-seven different products were identified by gas chromatography-mass spectrometry in the bio-oils obtained at 500°C temperature.

Effect of microwave pretreatment on pyrolysis of crude glycerol–olive kernel alternative fuels

Pyrolysis is considered to be a sustainable energy technology and is practiced widely in waste management. In this study, three issues were explored: (a) the implication of crude glycerol addition to lignocellulosic biomass in pyrolysis, (b) the effect of microwave pretreatment on the pyrolysis product yields and (c) study of pyrolysis parameters and assessment of products quality. Characterization of the above glycerol–biomass mixtures along with pyrolysis products was performed by ICP–OES, SEM, EDX and GC techniques. It was resulted that higher liquid yield (max 59.53% v/v) obtained by pyrolysis of pretreated mixtures at 500°C, compared to pyrolysis yields of non-pretreated mixtures, due to the prevalence of recombination reactions in pyrolysis of the microwave-pretreated mixtures. The gas produced from the microwave pretreated feedstock-based pyrolysis showed an enriched syngas (H2+CO) concentration (84.9% v/v), compared to the non-microwave pretreated samples (79.1% v/v), at 720°C. No significant effect, either on the char yields or on the char structural characteristics were observed. Consequently, microwave pretreatment before pyrolysis, can serve as a potential pretreatment for enhanced production of fuels via post-pyrolysis.

Pyrolysis of energy cane bagasse and invasive Chinese tallow tree (Triadica sebifera L.) biomass in an inductively heated reactor

The growing demand for energy and the increasing opposition to fossil fuels has given rise to the need for alternative fuels. The pyrolysis process is one viable option that converts lignocellulosic biomass into liquid fuel. This study focuses, for the first time, on the use of an induction heating mechanism to pyrolyze biomass from energy cane (Saccharum complex) bagasse and invasive Chinese tallow trees (Triadica sebifera L.). Energy cane and tallow wood were pyrolyzed at 500, 550, 600, 650, and 700°C at atmospheric pressure in a laboratory scale batch process with an initial loading of 15g and 30g for energy cane bagasse and CTT respectively. The results indicate that the highest liquid yield was obtained at 500°C for both biomasses. The yields of char declined and the gas yields increased as the reaction temperature increased, as the biomass was more thoroughly decomposed at the higher reaction temperatures. GC–MS results show that the liquid product was rich in oxygenated compounds such as phenols, ketones and alcohols for biomasses at all temperatures. Bio-oil obtained from pyrolysis of Chinese tallow tree showed small concentration of fatty alcohols. Concentration of smaller compounds in the liquid product increased as the reaction temperature increased. Highest energy content and liquid yields (34MJ/kg and 35.4%) amongst the tested temperatures was obtained at 500°C for both energy cane and tallow wood pyrolysis. Higher heating values were obtained for bio-oil from energy cane compared to tallow tree biomass.

Characteristics of products from the pyrolysis of oil palm fiber and its pellets in nitrogen and carbon dioxide atmospheres

The present study focuses on the pyrolysis characteristics of OPF (oil palm fiber) and OPFP (oil palm fiber pellet) in N2 and CO2 to evaluate the impacts of biomass pattern and carrier gas on the three-phase products. Three different reaction temperatures of 400, 450, and 500 °C along with 30 min pyrolysis are considered. The results indicate that OPFP pyrolysis gives a higher liquid yield when compared to OPF pyrolysis, and the liquid yield using CO2 as a carrier gas is higher than that using N2. The influences of carrier gas and biomass pattern on the components in bio-oils are not profound. The deoxygenation and dehydrogenation mechanisms on solid biomass are obviously exhibited, and the latter is more pronounced than the former. The higher heating values of OPF and OPFP from pyrolysis are intensified up to 39 and 24%, respectively. The CO2 and CO concentration distributions suggest that the most drastic pyrolysis reaction develops at 7–9 min. On account of more energy required for breaking methoxyl groups, CH4 formation is later than CO and CO2 formations. In summary, OPFP pyrolyzed in a CO2 environment is a feasible operation for producing bio-oils, thereby saving facility space and achieving CO2 utilization.

Hierarchical macro–mesoporous Al2O3-supported NiK catalyst for steam catalytic cracking of vacuum residue

A hierarchical macro–mesoporous Al2O3-supported NiK catalyst was prepared using macroporous alumina, and this catalyst was used for steam catalytic cracking of vacuum residue. Ni was well dispersed on the hierarchical macro–mesoporous alumina, which had a high surface area and a highly ordered porous structure. The hierarchical porous catalyst exhibited better catalytic performance (higher liquid yield and higher conversion) than the mesoporous alumina supported NiK catalyst. This good catalytic performance was due to the porosity, which improved access of the vacuum residue to the Ni active sites. Furthermore, the hierarchical porous NiK catalyst showed good stability and was regenerable.

Liquefaction of Lignocellulose in Fractionated Light Bio-Oil: Proof of Concept and Techno-Economic Assessment

The direct thermal liquefaction of lignocellulose can provide a biocrude that could be used as a precursor for biofuels. However, earlier attempts to use the whole reactor effluent as a liquefaction medium, by recycling it to the liquefaction reactor, were hampered by the buildup of heavy products. This paper reports on the integration of the liquefaction reaction and the fractionation of the reactor effluent to recover and recycle the light oil fraction of it to be used as a liquefaction solvent. The fractionation is based on solvent extraction and temperature-swing regeneration. Here, we demonstrate steady-state liquefaction of pine wood with high and constant liquid yields (90 C %) and constant liquid qualities over several recycles. The liquefaction was done at a temperature of 320 °C and at a pressure of 7–10 MPa. Process simulation confirms a significant savings in energy demand by incorporating the extraction in the process, compared to an alternative liquefaction/distillation scheme. A techno-economic assessment further estimates that a biocrude could be produced at an energy-equivalent crude oil price of 54 $/barrel at a wood cost of 85 $/dry ton.

Fast Pyrolysis of Spent Coffee Waste and Oak Wood Chips in a Micro-tubular Reactor

Fast pyrolysis of spent coffee waste, a major non-cellulosic material, and oak wood chips, a cellulosic material, was carried out in a micro tubular reactor over a temperature range of 550 to 750°C with sweep gas flow rates of 20 and 500 mL/min. When the temperature was raised from 550 to 750°C, the gas yields were significantly enhanced, but the liquid yields were reduced. The highest liquid yield, 63.4 wt%, was obtained after pyrolysis of spent coffee waste at 550°C at a sweep gas rate of 500 mL/min. The highest gas yield, 65.74 wt%, was obtained after pyrolysis of the oak wood chips at 750°C at a sweep gas flow rate of 20 mL/min. The gas products primarily included considerable amounts of CO, CO2, and hydrocarbon-rich gases but no hydrogen. Furthermore, regardless of the biomass source, the hydrocarbon-rich gases were qualitatively similar and largely consisted of methane, ethane, ethylene, propane, and propylene. The gas chromatography-mass spectrometry analysis of the pyrolyzed bio-oils demonstrated that the major compounds were phenol derivatives, aldehydes, ketones, acids, and alcohols.

Production and Evaluation of Liquid Hydrocarbon Fuel from Thermal Pyrolysis of Virgin Polyethylene Plastics

Pyrolysis of virgin polyethylene plastics was studied in order to produce hydrocarbon liquid fuel. The pyrolysis process carried out for low and high-density polyethylene plastics in open system batch reactor in temperature range of 370 to 450°C.
 Thermo-gravimetric analysis of the virgin plastics showed that the degradation ranges were between 326 and 495 °C. The results showed that the optimum temperature range of pyrolysis of polyethylene plastics that gives highest liquid yield (with specific gravity between 0.7844 and 0.7865) was 390 to 410 °C with reaction time of about 35 minutes. Fourier Transform Infrared spectroscopy gave a quite evidence that the produced hydrocarbon liquid fuel consisted mainly alkanes and the x-ray diffraction showed no sulfur in the produced hydrocarbon liquids.

Impact of solvent type and condition on biomass liquefaction to produce heavy oils in high yield with low oxygen contents

Bio-oils produced by processes such as slow or fast pyrolysis typically contain high water and oxygen contents, which make them incompatible with conventional fuels. It is therefore necessary to upgrade the bio-oils to reduce their oxygen and water contents. The bio-oil upgrading process can consume up to 84wt% of the initial bio-oil it is therefore important to develop other alternative approaches to generate high quality bio-oil. Thermolytic liquid solvent extraction (LSE) has been considered as a potential viable process due to the high liquid yield, better product quality and water free nature of the final products.In this study, a novel LSE process of biomass liquefaction has been studied under various conditions of solvent type, temperature, and biomass species. Compared to currently available commercial pyrolysis approaches, this process using tetralin as a solvent is shown to be capable of generating high quality bio-oil with low oxygen contents (ca. 5.9%) at extremely high overall conversions of up to 87 and 92 (%) dry and ash free basis (DAF) from Scotch pine and miscanthus, respectively. Overall, the study has demonstrated the advantages of LSE for bio-oil generation from biomass, in terms of producing high conversions to liquid products that are compatible with existing petroleum heavy feedstocks.

Recent progress in the thermocatalytic processing of biomass into advanced fuels

Recent progress in the thermocatalytic processing of biomass into advanced fuels

Effect of pyrolysis temperature and catalyst on production of bio-oil and bio-char from avocado seeds

The slow pyrolysis of avocado seeds (Persea americana) was performed in a fixed-bed tubular reactor with (KOH, Al2O3) and without a catalyst, at three temperatures ranging from 400 to 600 °C, with heating rates of 50 °C/min. The amounts of bio-char, bio-oil and gas produced, as well as the compositions of the resulting bio-oils, were determined by GC–MS and FT-IR. The influences of pyrolysis parameters, such as temperature and catalysts, on product yields were subsequently investigated. Both temperature and catalysts were determined to be the main factors affecting the conversion (liquid+gas products) of avocado seeds into solid, liquid and gaseous products. The highest liquid yield (37.5 %) including water was obtained using 10 % KOH catalyst at 600 °C at a heating rate of 50 °C/min when employing 0.224 > Dp > 0.150 mm particle size raw material and a 100 cm3/min sweeping gas flow rate.

The Effect of Boron Minerals on Pyrolysis of Common Reed (Phragmites australis) for Producing Bio-oils

Pyrolysis of common reed (Phragmites australis) stalks were performed in a fixed-bed tubular reactor with (tincal, colemanite, and ulexite) and without catalyst at three different temperatures (400, 500, and 600°C) with a constant heating rate of 30°C/min and sweeping gas (N2) flow rate of 100 cm3/min. The amounts of solid (bio-char), liquid (bio-oil + water), and gaseous products were calculated and the compositions of the bio-oils were characterized by gas chromatography/ mass spectrometry. The effects of pyrolysis parameters, such as temperature and catalyst, on the product yields were investigated. The results show that both temperature and catalyst have significant effects on the conversion of Phragmites australis into solid, liquid, and gaseous products. The highest liquid yield of 34.67% by weight, including aqeous phase, was obtained with 10% ulexite at 500°C. Further, 101 different compounds were identified by gas chromatography-mass spectrometry in the bio-oils obtained at 500°C.

Influence of tin content on the texture properties and catalytic performance of bi-metallic Pt–Re and tri-metallic Pt–Re–Sn catalyst for n-octane reforming

The effect of a relatively inactive metal on the texture properties and catalytic performance of bi-metallic platinum–rhenium (Pt–Re)–S/Al2O3–Cl catalyst was investigated. The concentration of introduced tin (Sn) varied between 0.06 and 0.32 % (weight basis). The parent and modified catalysts were characterized using the following techniques; BET, X-ray diffraction, SEM–EDX, and atomic absorption spectroscopy/inductively coupled plasma spectroscopy. The bi-metallic and tri-metallic catalysts were also screened for their activity and selectivity in the reforming of n-octane under the following conditions: T = 480 °C, p = 10 bar, WHSV = 3.3 h−1 and H2:HC = 4.5. Results showed that, on n-octane conversion, selectivity have changed favorably i.e., low selectivity to aromatics but high selectivity to iso-paraffins and olefins. In addition, less cracking products were detected and high liquid yields (LYs) were obtained. However, there is a strong and closely linear correlation between aromatics and octane number. The results of this work showed that catalyst with Sn >0.14 and <0.32 performed the best catalyst i.e., no major effect on research octane number, LY and selectivity with the addition of more Sn.