Organic Liquid Yield Research Articles

Production of pyrolytic lignin for the phenolic resin synthesis via fast pyrolysis

Recycling of waste wood into resol type phenol-formaldehyde (PF) resins via fast pyrolysis was demonstrated. Waste wood collected from the building demolition site in Finland was pyrolyzed with 20 kg/h circulating fluidized bed pyrolysis pilot unit. Pilot was operated with high organic liquid yield (60 wt% on average) and the produced fast pyrolysis bio-oil was fractionated by water addition into aqueous phase and water insoluble phase. The obtained fractions were characterized, and the water-insoluble viscous lignin fraction was used in the synthesis of PF-resins. Commercial phenol was successfully replaced by pyrolytic lignin fraction at 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% producing resins of low in free formaldehyde content, but resins with high replacement ratio exhibited higher viscosities. The use of H2O/n-butanol mixture as solvent at a ratio 70:30 wt/wt% proved capable to prolong the storage time of the resin and helped to maintain the viscosity at acceptable values for at least 2 weeks before their use in the targeted application. Finally, the gluing performance of the resins was evaluated by measuring the tensile shear strength of lap joints formed by gluing 5 mm thick beech wood veneers. All the produced resins fulfilled a dry strength limit of ≥ 10 N/mm2. Wet strength limit ≥ 7 N/mm2 was fulfilled by the resins with the replacement ratio up 40 wt%, but resins with replacement ratio of 50 wt% had somewhat reduced wet strength. These results confirm a promising protentional application of pyrolysis derived lignin fraction in phenolic wood adhesives, at least in dry conditions.

Novel Hot Vapor Filter Design for Biomass Pyrolysis.

Fast pyrolysis is a mature technology for the conversion of solid biomass into a liquid intermediate, fast pyrolysis bio-oil (FPBO). FPBO has so far been used mainly as heating fuel, but the target is to use it for the production of sustainable fuels and chemicals in the future. In the pyrolysis process, inorganic materials (ash) from the biomass are mostly sequestered in char particles, which can be separated with cyclones. Small particles (<10 μm) escape the cyclones and condense with vapors. In bio-oils, these solid materials are unfavorable because they can cause erosion, corrosion, and blockages at injection nozzles in power generation systems and deactivate the catalyst in bio-oil upgrading. Hot vapor filtration using either moving bed or barrier filters has been tested on a small scale for the removal of fine particles from the pyrolysis vapors. The challenges with these filter types have been the increased pressure drop across the filter with time, inefficient solid removal, and loss in organics. A new hot vapor filter combining both a barrier filter and a moving bed filter was constructed and tested to overcome these problems. In this filter system, the filter elements are inserted in a vessel, where hot sand flows through to continuously remove the cake over filter candles. The filter was successfully tested with stem chips, contaminated wood, and forest residue for 6-8 h without any pressure increase. The organic liquid yield decreased in the best case only by 3 wt % using the lowest filtration temperature and shortest residence time. The oil properties were slightly affected by cracking of the sugar fraction, which decreased the oxygen content, microcarbon residue, and carbonyl content but increased the acidity. Only minor improvements in metal removal were seen due to the high detection limits of metal analysis.

Valorization of Eucalyptus, Giant Reed Arundo, Fiber Sorghum, and Sugarcane Bagasse via Fast Pyrolysis and Subsequent Bio-Oil Gasification.

Fast pyrolysis of giant reed Arundo (Arundo donax), fiber sorghum (Sorghum bicolor L.Moench), eucalyptus (Eucalyptus spp.), and sugarcane bagasse (Saccharum officinarum) was studied in bench-scale bubbling fluidized bed reactor. Product yields were determined, and detailed physicochemical characterization for produced fast pyrolysis bio-oils (FPBOs) was carried out. The highest organic liquid yield (dry basis) was observed with sugarcane bagasse (59–62 wt %), followed by eucalyptus (49–53 wt %), giant reed Arundo (39 wt %), and fiber sorghum (34–42 wt %). After the pyrolysis experiments, produced FPBOs were gasified in an oxygen-blown autothermal catalytic reforming system for the produced synthesis gas. The gasifier consists of a partial oxidation zone where the FPBO is gasified, and the raw syngas is then reformed over a fixed bed steam-reforming catalyst in the reforming zone. The gas production (∼1.7 Nm3/kg FPBO) and composition (H2 ∼ 50 vol %, CO 20–25 vol %, and CO2 25–30 vol %) were similar for all FPBOs tested. These results show that the combination of fast pyrolysis with subsequent gasification provides a technically feasible and feedstock flexible solution for the production of synthesis gas.

Effect of low-temperature hydrothermal treatment of HZSM-5 extrudates on the production of deeply-deoxygenated bio-oil via ex-situ catalytic fast pyrolysis of biomass

Catalytic fast pyrolysis (CFP) of biomass has high potential for producing deoxygenated bio-oil in one single process. HZSM-5 is a widely used catalyst for this purpose and various parameters have already been extensively investigated on this catalytic material. Limited studies were performed on the effect of low-temperature hydrothermal treatment of the catalyst with none being applied in ex-situ CFP in a lab-scale pyrolysis unit. The current paper therefore reports the investigation of HZSM-5 characteristics and activities when hydrothermally treated by steam at 550 °C for 5 h. The treatment modified the catalyst in a positive way that can increase 30% of the non-aqueous catalytic bio-oil yield. A maximum organic liquid yield of 11.4 wt% was achieved with 6.7 wt% being heavy fraction and 4.7 wt% being light fraction. These heavy and light bio-oils had very low oxygen contents of 4.3 and 1.6 wt%, respectively. This is equivalent to 93% oxygen removal compared to its corresponding non-catalytic bio-oil. Based on the elemental, FTIR, and GC/MS analyses, the hydrothermal treatment slightly increased the bio-oil oxygen content. Characterization of the catalysts reveal irreversible catalyst deactivation by dealumination. The severity of the deactivation increased continuously with higher amount of biomass being fed to the process. However, the catalyst deoxygenation ability was still acceptable for producing partially-deoxygenated bio-oil even after applying the biomass-to-catalyst ratio of 20.5.

Improving Fast Pyrolysis Bio-Oil Yield and Quality by Alkali Removal from Feedstock.

Alkali removal from forest residues, eucalyptus residues, and wheat straw was studied by water and dilute nitric acid leaching. Leaching parameters were optimized for each feedstock in laboratory-scale experiments. After the optimization of leaching on the laboratory scale, nitric acid-leached and untreated feedstocks were pyrolyzed in a bench-scale bubbling fluidized bed unit. In the case of eucalyptus residues and wheat straw, nitric acid leaching was found to increase the organic liquid yield compared to untreated feedstock. In addition, the sugar content of the fast pyrolysis bio-oils was increased, and the alkali content reduced. On the other hand, the pyrolysis experiments with acid-leached forest residues were unsuccessful due to the bed agglomeration. These problems are expected to be a result of the lack of catalytically active elements in biomass which enhance especially the cracking reactions of lignin. Finally, the results were demonstrated in the pilot-scale unit where nitric acid-leached oat straw was pyrolyzed with high organic liquid yield.

Effects of CoMo/γ-Al2O3 Catalysts on Product Hydrocarbon and Phenol Distribution during Hydrodeoxygenation of Oxidized Bio-Oil in a Batch Reactor

Hydrodeoxygenation is an essential process for producing liquid transportation fuels. In this study, the effects of CoMo/γ-Al2O3 catalysts form and loading ratio on the hydrodeoxygenation upgrading of bio-oil were investigated in a batch reactor. Raw bio-oil was first oxidized with hydrogen peroxides and oxone to obtain the oxidized bio-oil with reduced levels of aldehydes and ketones, increasing the organic liquid yield during hydrodeoxygenation by suppressing the coke formation. CoMo/γ-Al2O3 was selected as the catalyst because of its low cost and commercial availability. The effect of the reduction and sulfidation of CoMo/γ-Al2O3 catalyst on the hydrodeoxygenation of the oxidized bio-oil was compared. The effect of the catalyst loading ratio on bio-oil hydrodeoxygenation using sulfided CoMo/γ-Al2O3 catalysts was also investigated. The research results showed that the sulfided CoMo/γ-Al2O3 catalyst facilitated the formation of hydrocarbons, while the reduced CoMo/γ-Al2O3 catalyst produced more phenols in the organic liquids. Moreover, a high sulfided catalyst loading ratio promoted the formation of hydrocarbons.

Demonstration of catalytic properties of de-inking sludge char as a carbon based sacrificial catalyst

De-inking sludge (DIS) is generated as a waste stream from secondary fibre paper mills during the de-inking stage of the paper pulping process; in order to ensure end of waste to landfill an alternative valorisation route is required for this waste. At the same time, an inexpensive sacrificial catalyst is essential to achieve the techno-economic feasibility of biomass gasification and pyrolysis. The present work explores the potential of DIS char as a catalyst using a 2 kg/h Thermo-Catalytic Reforming (TCR®) system, which involves intermediate pyrolysis combined with a unique integrated catalytic reforming step. Wood was used for the TCR catalytic experiments with a DIS char to biomass ratio (wt.%) of 0.3:1 and 0.65:1. Results have shown that hydrogen relative volumes and syngas yields, are positively correlated with the increase in DIS char to wood ratio. Average hydrogen relative volumes of 28.30 vol.% and syngas yields of 47.64 wt.% were achieved. Organic liquid yields were significantly reduced in favour of higher syngas yields, implying the suitability of DIS char as a tar reduction catalyst in gasification or pyrolysis. The influence of TCR DIS char is less profound on the chemical distribution in the organic phase of bio-oil; a reduction on PAHs from 38.82 % to 26.70 % though was determined with the use of DIS char, according to the relative abundance peak areas from the GC–MS chromatograms. The oxygen content of bio-oil was significantly reduced due to cracking of higher molecular weight organics.

Synthesis of Metal Organic Framework Material MIL-101

MIL-101 is a typical metal-organic framework. Mil-101, like the other metal-organic frameworks (MOFs) is a material with high porosity, large surface area, adjustable micro-pore size, and easy functional structure. Contrary to the most MOFs, Mil-101 has a high hydrothermal stability. All of the characteristics collectively make MIL-101 a good candidate for a catalyst support. In this paper, the synthesis methods of MIL-101 materials have been reviewed. It is pointed out that the hydrothermal synthesis method has many problems such as complicated process, many organic waste liquid and low yield. The room temperature fast synthesis method has the potential to provide industrialized production of MIL-101 with its unique advantages.

Standard liquid fuel for industrial boilers from used wood

The purpose of the research was to validate if the fast pyrolysis bio-oil (FPBO) from used wood would meet both the specifications set by the standard EN 16900–2017 for use of FPBO in industrial boilers and REACH requirements. Commercial used wood Class C was used for fast pyrolysis. The dominant material groups in the feedstock were (virgin) wood (58%) and chemically treated wood (41%). The contents of heavy metals and plastics were low.The pyrolysis experiments were carried out in a bench scale bubbling fluidized bed reactor (1 kg/h). Organic liquid yields were lower (42 − 47%) than with sawdust (64%) but at the same level with those from stored forest residues (46%). The lower organic liquid yield was partly caused by the ash in the feedstock. The liquid product had a high water mass fraction, which resulted in a spontaneous phase separation. The phases were mixed together, and a part of water was evaporated at 40 °C to obtain a single phase product with a water mass fraction of 21%. The liquid product was a homogenous fluid, which in most cases met the demands of the EN standard and the specifications for REACH.Thermodynamic equilibrium calculation suggests that fluidized bed combustion of the pyrolysis char may increase the risk of corrosion and ash melting problems. The recycled wood case is self-sufficient in terms of heat and energy input to the process and will produce excess electricity and district heating for export.

Sieving and Acid Washing as a Pretreatment to Fast Pyrolysis of a High Ash Hog Fuel

Mineral matter can negatively influence liquid yield and product properties from the fast pyrolysis of woody biomass residuals. Biomass pretreatment approaches to reduce the ash content represent a potential pathway to expand the feedstock flexibility of fast pyrolysis. In this work, ash reduction in biomass pyrolysis oil via sieving the fines portion of a hog fuel as well as washing the fractionated hog fuel with nitric acid was investigated prior to the conversion in CanmetENERGY-Ottawa’s 5–10 kg/h fast pyrolysis system. It was found that sieving the material was much less influential on the liquid yield and product properties relative to nitric acid washing. Product analysis showed up to 40% increase in organic liquid yield and up to 30% decrease in biochar yield on a dry, ash-free basis by nitric acid washing the fractionated hog fuel. Pyrolysis reaction water was minimized when nitric acid washing the feedstock, which has important implications for the phase separation of the pyrolysis liquids. Throu...

Catalytic pyrolysis of demineralized lignocellulosic biomass

The effect of ash removal pre-treatment of lignocellulosic biomass prior to catalytic pyrolysis for producing biofuels was investigated. Non-catalytic and catalytic pyrolysis of demineralized and raw biomass was performed in Py-GC/MS and bench-scale experiments to study the performance of in-bed and ex-bed upgrading. Pre-treated biomass shows a significant increase in the organic liquid yield in experiments performed at 600 °C: from 31 to 42 wt% compared to raw biomass, as well as a significant reduction of char yield. The performance of in-bed catalytic pyrolysis of pre-treated biomass over HZSM-5 is limited compared to the corresponding raw material. However, ex-bed catalytic pyrolysis of pre-treated biomass at 600 °C results in an overall increased yield of BTX compounds. Pyrolysis vapors from pre-treated biomass present a suitable composition for catalytic upgrading after secondary vapor-phase reactions. Additionally, demineralization reduces the total acid number of derived liquids in catalytic and non-catalytic pyrolysis.

Fuels from Reliable Bio-based Refinery Intermediates: BioMates

The overall aim of the project “BioMates” is to develop a conversion process for agricultural residues (cereal straw) or energy crops (miscanthus) into a liquid intermediate with reliable properties for the co-processing in existing petroleum refineries. The process is divisible into two individual steps—ablative fast pyrolysis and mild hydrotreatment. Both biomass feedstocks were pyrolysed in a laboratory plant and optimal parameters leading to highest organic liquid yield were determined to be 540 °C at the hot surface, 50 bar hydraulic pressure and 80 rpm of rotational speed of the ablation plate. Different setups for condensation and catalytic vapour upgrade were tested and best results regarding highest organic yield with lowest water content could be achieved with a two-stage condensation operating at about 68 °C condensation temperature in the first stage. Here, a total yield of 41 wt% in (oxygenated) organic compounds could be achieved in the first stage condensate compared to only 36 wt% in the tarry phase of single stage condensation. Catalysts for direct upgrading of vapours were tested but found to be inappropriate in the current setup. For mild hydrotreatment conventional sulphidized catalyst and newly developed non-sulphidized catalysts were tested. The new catalysts showed high initial reactivity but fast deactivation. Currently, the commercial catalyst with NiMo-system on Al2O3-support performed best, especially at 8 MPa hydrogen supply pressure and 360 °C operating temperature. Here, water content below 1 wt%, a density of organic product below 0.9 kg dm−3 and a lower heating value above 39 MJ kg−1 was achieved. Electrochemical compression and purification can supply hydrogen at necessary pressure and flow rate with acceptable energy demand and by that can replace mechanical compression on the supply side and pressure swing adsorption system in the recycle loop. The project aims were fully achieved in TRL3-4 and will be demonstrated in TRL5 until the end of the project.

Moisture content as a design and operational parameter for fast pyrolysis

Fast pyrolysis trials of wheat straw were performed in a pilot plant featuring a screw reactor and two stage condensation system. Trials differed in the moisture content of the used biomass (1.2%, 9.2%, and 23.6%) and the sweeping gas flowrate. Higher moisture feedstock seems to lead to higher bio-oil production but the largest organic liquid yield occurred at intermediate feedstock moistures. Increasing the sweeping gas flow rate at the system leads to a higher liquid yield richer in organics. Based on these results it is concluded that the highest organic liquid yield is not observed for dry feedstock because the missing water vapour leads to longer hot vapour residence time, favouring secondary gas phase cracking reactions.Information and yields obtained at the pilot were scaled up to industrial scale (500 kg h−1 of feedstock) and used to construct an Aspen Plus® model that can be used to estimate heat availability in different parts of the system as well as simulate a dryer that would employ available internal process heat. This model was used to investigate the impact of using moister feedstock in the process. Enough heat is available for drying moist feedstock by using flue gas of the heat carrier loop in a different manner as in the current design.

Fast Pyrolysis of Dried Sugar Cane Vinasse at 400 and 500 °C: Product Distribution and Yield

Fast pyrolysis of sugar cane vinasse, a byproduct from the integrated sugar–ethanol process, has not been investigated so far. In this work, fast pyrolysis of dried sugar cane vinasse was carried out at 400 and 500 °C in a drop-tube type N2-purged reactor, and the yields and compositions of the oil, char, and gas were determined. The results show that the water-free bio-oil yield was low and independent of the pyrolysis temperature. This is probably due to the high potassium content of the vinasse. For other biomass fuels, it is well established that alkali metals catalyze secondary reactions in the vapor-phase of the pyrolysis product, thereby reducing the organic liquid yield and increasing the gas and water yields. The char yield decreased, and the gas yield increased with temperature. 45% to 55% of the carbon in the vinasse was retained in the chars. Thus, approximately half of the carbon in the vinasse could be sequestered if the chars are returned to the soil. Moreover, since over 85% of the potassium in the vinasse was also retained in the chars, pyrolysis may be an interesting option for the production of biochar with a high potassium content for fertilizer. The recovery of most of the potassium with the chars indicates that the liquid and gaseous pyrolysis products could be burned in a boiler with lower ash-related problems than the original vinasse.

Hydrodeoxygenation of pinyon-juniper catalytic pyrolysis oil using red mud-supported nickel catalysts

Red mud (RM) is an alkaline waste generated in the Bayer process of alumina production. In the present study red mud supported nickel catalysts (Ni/RM) were prepared at different concentrations of nickel (10, 20, 30, 40, 50, and 65 wt.%) and used to hydrodeoxygenate (HDO) pinyon-juniper (PJ) catalytic pyrolysis oil. Increasing the nickel content improved the activity of Ni/RM catalysts for HDO reactions. Maximum organic liquid yield (68.6%) was obtained when 40%Ni/RM was used. The upgraded oil had oxygen content of 1.35 wt.% and higher heating value of 45.77 MJ/kg compared to 24.88 wt.% and 28.41 MJ/kg, respectively, for the crude oil. For comparison, commercial Ni/SiO2-Al2O3 was also evaluated in HDO experiments. The HDO oil properties obtained using 40%Ni/RM at reaction temperature of 400 °C was similar to that of commercial Ni/SiO2-Al2O3 at reaction temperature of 450 °C. However, the organic liquid yield was much higher for 40%Ni/RM (68.6%) compared to the commercial Ni/SiO2-Al2O3 (41.8%). The commercial Ni/SiO2-Al2O3 produced more gas (27.6%) than the 40%Ni/RM (16.4%) and the coke yields for the commercial catalyst and Ni/RM catalyst were 7.3% and 4.2% respectively. Overall, application of Ni/RM improved HDO reactions and reduced cracking and coke formation compared to commercial Ni/SiO2-Al2O3.

Experimental comparison of two bench scale units for fast and intermediate pyrolysis

Comparison of different literature results for fast pyrolysis of biomass is difficult due to the variety in feedstock, process conditions, analyses, and detail of the provided data. The presented experiments represent a concerted effort to directly compare two bench scale units (10kgh−1) for fast and intermediate pyrolysis on the basis of the same set of biomass feedstock and the same pyrolysis reactor temperature. Hybrid poplar, wheat straw, a blend (hybrid poplar/wheat straw/forest thinnings) and beech wood have been used as feedstocks. Organic liquid yields for intermediate pyrolysis are 17–21 % and that of fast pyrolysis 26–51 %. The advantage of higher organic liquid yields from fast pyrolysis decreases with the ash content of biomass due to catalytically active minerals. It is concluded that the importance of the primary pyrolysis temperature level and the hot vapour residence time is significantly reduced with increasing ash content of the biomass. Carbon balances show that ash is not only increasing the total char yield as inorganic material, but also leads to a higher fraction of carbon material being retained in the char. Analyses of the liquid fractions reveal that pyrolytic degradation appears generally more evolved for the case of intermediate pyrolysis. Moreover, it was observed that there is a correlation between the ratio of CO to CO2 in the permanent gas after pyrolysis and the yield of organic liquids (dry basis). This correlation differs between the two processes and is suitable to predict the organic liquid yield based on permanent gas measurements. Three of the four feedstocks were supplied as part of a Round Robin Test organized by International Agency Bioenergy Task 34 ‘Direct thermal liquefaction’ and the obtained results can be directly compared even beyond the scope of this work.

Influence of the Feedstock on Catalytic Fast Pyrolysis with a Solid Acid Catalyst

AbstractAt RTI, we are developing a catalytic fast pyrolysis process with a new solid acid catalyst, the performance of which has been evaluated in a pilot‐scale reactor using loblolly pine. More robust technology development requires a deeper understanding of the influence of the feedstock properties of process performance defined by the organic liquid yield and composition. Seven types of woody and herbaceous biomass were tested in a 2.54 cm diameter fluidized‐bed reactor. This study shows that the product distribution and biocrude composition vary widely with different feedstocks. The yield of organic biocrude is in the range of 14.0–20.8 wt % for the tested feedstocks. The yields of incondensable gases and carbonaceous solids vary significantly from feedstock to feedstock, which may be because of the variation of the ash content in the feedstock. A feedstock with a higher ash content generates more gases; specifically more CO2 but not necessarily more CO. The chemical composition, which includes lignin, hemicellulose, and cellulose, also affects the biocrude composition and the yield of gases. We also demonstrated a positive correlation between the cellulose content and CO yield and a negative correlation between the hemicellulose content and CO yield.

Pyrolysis of Nordic biomass types in a cyclone pilot plant — Mass balances and yields

Fast pyrolysis of biomass results in a renewable product usually denoted pyrolysis oil or bio-oil, which has been suggested to be used as a direct substitute for fuel oil or as a feedstock for production of transportation fuels and/or chemicals. In the present work, fast pyrolysis of stem wood (originated from pine and spruce), willow, reed canary grass, brown forest residue and bark has been performed in a pilot scale cyclone reactor. The experiments were based on a biomass feeding rate of 20kg/h at three different reactor temperatures. At the reference condition, pyrolysis of stem wood, willow, reed canary grass, and forest residue resulted in organic liquid yields in the range of 41 to 45% w/w, while pyrolysis of bark resulted in lower organic liquid yields. Two fractions of pyrolysis oil were obtained, denoted as the condensed and the aerosol fraction. Most of the water soluble molecules were collected in the condensed fraction, whereas the yield of water insoluble, heavy lignin molecules was higher in the aerosol fraction. Based on the results of the present work, willow, reed canary grass and forest residue are considered as promising raw materials for production of pyrolysis oil in a cyclone reactor.

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.

High quality diesel-range alkanes production via a single-step hydrotreatment of vegetable oil over Ni/zeolite catalyst

A single-step hydrotreatment of vegetable oil to produce high quality diesel-ranged alkanes over Ni/zeolite catalyst is devised. The Ni/zeolite catalysts prepared by incipient wetness impregnation method using SAPO-11, ZSM-5, ZSM-22, ZSM-23 and Beta zeolites as supports are evaluated in this single-step hydrotreatment process. The effects of the support and the metal loading amount are studied from the catalytic performance and characterization results obtained by techniques such as XRD, Physisorption, NH3-TPD and Pyridine-IR. Over the 8wt%Ni/SAPO-11 catalyst, 100% conversion of soybean oil is obtained at 370°C, 4MPa and 1h−1, with an organic liquid yield of 74.8% which is nearly 90% of the maximum theoretical liquid yield. In the organic products, the alkane selectivity is 100%, and more than 85% isomerization selectivity is achieved. In order to learn the detailed scheme of the single-step hydrotreatment process, the intermediates have been analyzed from which reaction pathways are proposed and discussed.