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Hydrodeoxygenation (HDO) is effective for upgrading bio-oil to biofuel. However, the upgrading cost increased due to the high consumption of external hydrogen. In this paper, the hydrogen generated from cheap water using zinc hydrolysis for in situ bio-oil HDO was reported. The effect of different temperatures (200 °C, 250 °C and 300 °C) on bio-oil HDO over Pd/C catalyst was investigated in a batch reactor. The results show that 250 °C yielded biofuel with the highest heating value at 30.17 MJ/kg and the highest hydrocarbons content at 24.09%. Physicochemical properties including heating value, total acid number and chemical compositions of the produced biofuels improved significantly in comparison with that of the original bio-oil. [ABSTRACT FROM AUTHOR]

A series of NiO/HZSM-5 catalysts were used to convert alkali lignin to hydrocarbon biofuels in a two-stage catalytic pyrolysis system. The results indicated that all NiO/HZSM-5 catalysts reduced the content of undesirable phenols, furans, and alcohols of the biofuel compared to non-catalytic treatment. The NiO/HZSM-5 catalyst with the lowest amount of NiO generated the highest biofuel yield in all catalytic treatments, and it also produced biofuel with the highest content of hydrocarbons. The emission of carbon oxides (CO and CO2) increased in the treatments with higher-NiO loading HZSM-5 due to the redox reaction between NiO and the oxygenated compounds in the bio-oil. Ni2SiO4 was generated in the used NiO/HZSM-5 catalysts during the high-temperature pyrolysis process. [ABSTRACT FROM AUTHOR]

Individually, sunflower oil produced from inedible sunflower seeds with hulls and sunflower meats without hulls were catalytically cracked over the ZSM-5 catalyst in a fixed-bed reactor at three reaction temperatures (450 °C, 500 °C, and 550 °C). Characterizations of hydrocarbon biofuel, distillation residual, and non-condensable gas were carried out. The reaction temperature on the hydrocarbon biofuel yield and quality from sunflower seed oil and sunflower meat oil were discussed and compared. In addition, a preliminary cost analysis of the sunflower seed dehulling was carried out. The results showed that the highest hydrocarbon biofuel yield was obtained from upgrading sunflower meat oil at 500 °C. The highest meat hydrocarbon biofuel yield was 8.5% higher than the highest seed hydrocarbon biofuel yield. The reaction temperature had a significant effect on the distribution of non-condensable gas components. Furthermore, the reaction temperature affected the yield and properties of hydrocarbon biofuel. The unit cost of producing sunflower meat oil was lower than that of producing sunflower seed oil. Comprehensively, sunflower meat could be a more economical feedstock than sunflower seed to produce hydrocarbon biofuel. [ABSTRACT FROM AUTHOR]

Catalytic fast pyrolysis (CFP): The cover image demonstrates one promising technology (CFP) for converting biomass to liquid biofuels. The yield and quality of biofuels are depended on biomass species, reactor type, operating conditions (temperature, heating rate, etc.) and the activity of appropriate catalysts. Based on current catalytic research, a novel two‐stage reactor was tested for exploration of catalytic biomass pyrolysis. Lignocellulosic biomass materials such as prairie cordgrass can be converted into hydrocarbon biofuel over bifunctional Co‐Mo/HZSM‐5 catalysts, for which the effects of different metal loading levels were investigated for their influence on the pyrolysis products (bio‐oil, bio‐char, and non‐condensable gas). The physicochemical properties (such as water content, density, viscosity, higher heating value, and chemical composition) of pyrolysis products were characterized. The results indicate that integrating two‐stage catalytic pyrolysis system and Co‐Mo/HZSM‐5 could improve the yields and quality of bio‐oil with higher hydrocarbon content. Although further research is needed, the study confirms that catalytic biomass pyrolysis using a two‐stage reactor system might be an effective pathway for converting lignocellulosic biomass to advanced biofuels. More details can be found in the Full Paper by Shouyun Cheng, Lin Wei, Xianhui Zhao et al. on page 706 in Issue 6, 2016 (DOI: 10.1002/ente.201500452). [ABSTRACT FROM AUTHOR]

Although hydrodeoxygenation (HDO) is proven a promising process for upgrading pyrolysis bio-oil to hydrocarbon biofuel, catalyst efficiency remains a challenge. Integrating heterogeneous catalysts with supercritical liquid in a bio-oil HDO process was investigated in this study. Bifunctional Fe-Ni/HZSM-5 catalysts were firstly used to upgrade bio-oil to hydrocarbon biofuel in supercritical methanol. The loading of Fe and Ni did not change HZSM-5 crystalline structure, but BET surface area and total pore volume of Fe-Ni/HZSM-5 catalysts decreased significantly compared to HZSM-5 support. Physicochemical properties of biofuel produced by Fe and/or Ni loaded HZSM-5 catalysts such as water content, total acid number, viscosity and higher heating value improved in comparison with raw bio-oil. Bimetallic Fe-Ni/HZSM-5 catalysts were more effective for bio-oil HDO compared to monometallic Fe/HZSM-5 or Ni/HZSM-5 catalyst , and this was attributed to the synergistic effect of Fe and Ni on HZSM-5 support. Fe-Ni(2)/HZSM-5 catalyst produced biofuel with the highest hydrocarbon content at 28.60%. [ABSTRACT FROM AUTHOR]

The role of catalyst is essential in processes of upgrading biomass pyrolysis bio-oil into hydrocarbon biofuel. While the majority of heterogeneous catalytic processes are conducted in the presence of gas (nearly ideal) or liquid phase, a growing number of processes are utilizing supercritical fluids (SCFs) as reaction media. Although hydrodeoxygenation (HDO) is proven a promising process for pyrolysis bio-oil upgrading to hydrocarbon biofuel, catalyst efficiency remains a challenge. Integrating heterogeneous catalysts with SCFs in a bio-oil HDO process was investigated in this study. Bifunctional Co-Zn/HZSM-5 catalysts were firstly used to upgrade bio-oil to biofuel in supercritical methanol. The loading of Co and Zn did not change HZSM-5 crystalline structure. Physicochemical properties of biofuel produced by Co and/or Zn loaded HZSM-5 catalysts such as water content, total acid number, viscosity and higher heating value improved. Bimetallic Co-Zn/HZSM-5 catalysts showed enhanced reactions of decarboxylation and decarbonylation that resulted in higher yields of CO and CO 2 . Bimetallic Co-Zn/HZSM-5 catalysts were more effective for bio-oil HDO than monometallic Co/HZSM-5 or Zn/HZSM-5 catalyst , which was attributed to the synergistic effect of Co and Zn on HZSM-5 support. Bimetallic Co-Zn/HZSM-5 catalysts increased biofuel yields and hydrocarbons contents in biofuels in comparison with monometallic Co/HZSM-5 and Zn/HZSM-5 catalysts. 5%Co15%Zn/HZSM-5 catalyst generated the highest biofuel yield at 22.13 wt.%, and 15%Co5%Zn/HZSM-5 catalyst produced biofuel with the highest hydrocarbons content at 35.33%. Hydrogenation and esterification are two dominant reactions in bio-oil HDO over Co-Zn/HZSM-5 catalysts in supercritical methanol. The energy efficiency of biofuel product was 30.99–58.80% for Co-Zn/HZSM-5 catalysts. Co-Zn/HZSM-5 is a promising catalyst to produce biofuel with high quality in bio-oil HDO. [ABSTRACT FROM AUTHOR]

Catalytic liquefaction can effectively convert solid biomass into liquid bio-crude that could be upgraded to advanced biofuel, but the exploration of green and efficient catalysts remain a challenge. In this study, bifunctional Zn/HZSM-5 catalysts were firstly combined with supercritical ethanol to produce bio-crude in pine sawdust catalytic liquefaction. The catalysts were characterized by BET, NH 3 -TPD, XRD and TEM. The effects of Zn/HZSM-5 catalysts with different Zn loading ratios on the yield and quality of bio-crude and gas were investigated. The results showed that Zn/HZSM-5 and HZSM-5 catalysts improved the yields of bio-crude compared to no catalyst treatment. The use of HZSM-5 based catalysts reduced the contents of oxygenated compounds including acids, ketones, phenols and alcohols in bio-crude products. Hydrocarbons content of the bio-crudes produced by HZSM-5 based catalysts increased compared to bio-crude produced by no catalyst treatment. Compared to HZSM-5 catalyst, Zn/HZSM-5 catalysts exhibited better catalyst performance to improve bio-crude quality due to the additional decarbonylation, decarboxylation and dehydrogenation reactions induced by Zn loading. 15%Zn/HZSM-5 catalyst resulted in the highest yields of bio-crude at 59.09 wt.%, and 10%Zn/HZSM-5 catalyst produced bio-crude with the highest hydrocarbons content at 15.03%. The four stages of mechanism for biomass liquefaction reactions on Zn/HZSM-5 catalysts in supercritical ethanol was proposed. [ABSTRACT FROM AUTHOR]

Non-edible sunflower oils that were extracted from sunflower residual wastes were catalytically cracked over a ZSM-5 catalyst in a fixed-bed reactor at three different reaction temperatures: 450°C, 500°C and 550°C. The catalyst was characterized using XRD, FT-IR, BET and SEM. Characterizations of the upgraded sunflower oils, hydrocarbon fuels, distillation residues and non-condensable gases were carried out. The effect of the reaction temperature on the yield and quality of liquid products was discussed. The results showed that the reaction temperature affected the hydrocarbon fuel yield but had a minor influence on its properties. The highest conversion efficiency from sunflower oils to hydrocarbon fuels was 30.1%, which was obtained at 550°C. The reaction temperature affected the component content of the non-condensable gases. The non-condensable gases generated at 550°C contained the highest content of light hydrocarbons (C 1 C 5 ), CO, CO 2 and H 2 . Compared to raw sunflower oils, the properties of hydrocarbon fuels including the dynamic viscosity, pH, moisture content, density, oxygen content and heating value were improved. [ABSTRACT FROM AUTHOR]

In this study, the pine sawdust thermal conversions over HZSM-5 catalyst were carried out under different reaction temperatures in a two-stage catalytic pyrolysis reactor. Higher temperatures in the catalytic reactor tended to decrease the yield of bio-oil and change the component of bio-oil. The results from the gas chromatography–mass spectrometry (GC–MS) analysis showed that the pyrolysis reaction at 500 °C and catalytic reaction at 500 °C treatment obtained the highest hydrocarbon content (58.63%) and the highest C 8 –C 12 content (48.03%) in the oil phase of the bio-oil. The X-ray diffraction (XRD) and selected-area-electron-diffraction (SEAD) characterization showed that the distortion of the ZSM-5 zeolite lattice occurred before and after use. The Brunauer–Emmett–Teller (BET) characterization indicated that the formation of coke increased as the catalytic temperature rose. The physical characterization of bio-oils, such as water content, density, viscosity, pH, and higher heating value (HHV) further demonstrated that HZSM-5 catalyst was beneficial in achieving low viscosity and higher HHV bio-oils. All the results suggest that the two-stage catalytic pyrolysis reactor with HZSM-5 catalyst has a great potential for achieving advanced biofuel. [ABSTRACT FROM AUTHOR]

In this study, modified clean fractionation process was optimized for prairie cordgrass, with usage of alternative organic constituent - ethyl acetate. Other constituents of the solvent mixture included ethanol and water. Clean fractionation solvent was used in different proportions of the constituents. Process efficiency was determined by lignin recovery, solvent composition, as well as time and temperature applied to each sequential process. Glucose yield during enzymatic hydrolysis and overall pretreatment were calculated. Optimal conditions (125°C, 37 min, with the solvent composition of ester:ethanol:water = 32.5:22.5:45) yielded a 20% lignin recovery, 38% glucose yield during enzymatic hydrolysis and 26% xylose recovery in aqueous fraction. [ABSTRACT FROM AUTHOR]

Hydroprocessing of carinata oil over an Al 2 O 3 supported Mo-Zn catalyst in a batch reactor at 350 °C with an initial H 2 pressure of 300 psi was carried out to produce hydrocarbon biofuel. A series of Mo-Zn/Al 2 O 3 catalysts with different Zn/Mo molar ratios (0, 1, 2, 3, ∞) were prepared and characterized using XRD, FT-IR, BET and TEM. The effects on the physicochemical properties and yield of products from using no catalyst and Al 2 O 3 based catalysts were discussed. The introduction of Mo and/or Zn did not change the crystalline structure of Al 2 O 3 . The combining of Mo and Zn on Al 2 O 3 improved catalytic performance and was helpful to improve some of the physicochemical properties of hydrocarbon biofuel including hydrocarbon content, moisture content, density, total acid number and higher heating value (HHV). The catalyst which exhibited the best catalytic performance had a Zn/Mo molar ratio of 2:1. At the 2:1 ratio of Zn/Mo, the hydrocarbon biofuel produced displayed the highest hydrocarbon content (81.05%) and the lowest moisture content, and the highest sum content of CO and CO 2 in the gas produced. The introduction of Mo and Zn on Al 2 O 3 was helpful for the hydroprocessing of carinata oil for hydrocarbon biofuel production. [ABSTRACT FROM AUTHOR]

Upgrading pyrolysis oil by hydrodeoxygenation (HDO) is a promising route for the production of advanced biofuels. The proper reaction conditions and catalysts are important for the success of this process. Previously our research group investigated the ratio of Zn and Pd on the synergistic effect for HDO bio-oil upgrading. This present research focuses on determining the optimal reaction conditions for HDO conversion of pyrolysis oil produced from pine sawdust. Temperatures of 150, 200 and 250 °C and hydrogen pressures of 1.38, 2.76 and 4.14 MPa were evaluated. Syngas, liquids and coke were the primary products evaluated. Syngas was characterized using a Gas chromatography (GC). The liquids were characterized using a Gas chromatography–mass spectrometry (GC–MS). Increasing reaction temperature resulted in increased coke yields. Treatment at 250 °C and 1.38 MPa resulted in the highest hydrocarbon content (6.06%). The treatment at 200 °C and 1.38 MPa produced the largest amounts of hydrocarbons in C 6 –C 12 range (5.07%). The physicochemical characterizations further support the GCMS results. Syngas analysis revealed that higher hydrogen pressure leads to increased hydrogen consumption and results in more oxy-compounds conversion to hydrocarbons. The syngas analysis also supports the liquid analysis result. [ABSTRACT FROM AUTHOR]

Catalytic cracking of camelina oil over Zn/ZSM-5 catalyst in a fixed-bed tubular reactor was investigated. An optimization study on the catalytic cracking conditions based on nine well-planned orthogonal experiments was carried out. Three main operation conditions including reaction temperature, liquid hourly space velocity and oil extraction press frequency were studied to examine their effects on the yield and quality of hydrocarbon biofuel produced. Characterization of the catalyst, hydrocarbon biofuel and non-condensable gas was conducted. There was no significant difference between the bulk structures of fresh Zn/ZSM-5 and used Zn/ZSM-5. Small ZnO particles dispersed well on the parent ZSM-5. Hydrocarbon biofuel contained 65.18% hydrocarbons and its properties including dynamic viscosity, density and higher heating value were improved after upgrading, compared to camelina oil. It was found that the oil extraction press frequency was the most important factor and liquid hourly space velocity was the least important factor for the hydrocarbon biofuel production. In addition, the optimum conditions for camelina oil upgrading were a combination of reaction temperature of 550 °C, a liquid hourly space velocity of 1.0 h −1 and an oil extraction press frequency of 15 Hz. [ABSTRACT FROM AUTHOR]

Cracking of camelina oil over non-catalyst and ZSM-5 catalyst doped with different Zn concentrations (0, 10, 20 and 30 wt.%) in a fixed-bed reactor was investigated. The fresh and used catalysts were characterized using XRD, FT-IR, BET and TEM. Characterizations of the produced hydrocarbon biofuel, distillation residual and non-condensable gas were carried out. The effect of non-catalyst and catalyst on the physicochemical properties and yield of products was discussed. The results showed that the introduction of Zn did not change the zeolite crystalline structure and ZnO might deposit on the external surface and/or inside the pores of the support ZSM-5. After upgrading, hydrocarbon biofuel had a lower viscosity, lower density, higher heating value (HHV) and higher water content than raw camelina oil. The optimum Zn concentration to ZSM-5 was 20 wt.%, at which the highest hydrocarbon biofuel yield and comprehensively the best quality were obtained. Compared to non-catalytic cracking of camelina oil, the loading of Zn to ZSM-5 could improve some physicochemical properties of the hydrocarbon biofuel. In addition, the loading of Zn to ZSM-5 could facilitate the chemical reactions such as decarbonylation and dehydrogenation. [ABSTRACT FROM AUTHOR]

Catalytic cracking of carinata oil over fresh and regenerated Zn/Na-ZSM-5 catalyst in a fixed-bed reactor at 450 °C was carried out to produce hydrocarbon biofuel. The effect of the fresh and regenerated Zn/Na-ZSM-5 on the hydrocarbon biofuel’s quality and yield was discussed. Characterization of the catalyst, hydrocarbon biofuel and gas were carried out. The hydrocarbon biofuel yield obtained over regenerated Zn/Na-ZSM-5 increased but the coke yield and distillation residual yield decreased, compared to fresh Zn/Na-ZSM-5. The regeneration of Zn/Na-ZSM-5 had a minor influence on the density of the hydrocarbon biofuel, but the higher heating value (HHV) decreased, and the viscosity and acid value increased over regenerated Zn/Na-ZSM-5. The regeneration of Zn/Na-ZSM-5 reduced the decarboxylation, decarbonylation and dehydrogenation of carinata oil, which caused the lower content of CO 2 , CO, H 2 and light hydrocarbons (C 1 –C 5 ). A preliminary test of the distillation residual mixture upgrading over fresh Zn/Na-ZSM-5 was performed, suggesting that the distillation residual mixture could be recycled for further upgrading. The produced gas including H 2 , CO and light hydrocarbons might be reused as syngas for ether power generation or production of value chemicals. [ABSTRACT FROM AUTHOR]

Highlights: [•] The first study of integrated microwave torrefaction and pyrolysis of corn stover. [•] Microwave torrefied pyrolysis favored phenols and hydrocarbons production. [•] Organic acids were significantly reduced in bio-oils. [•] Up to 26.7 area% hydrocarbons in the bio-oil were produced. [ABSTRACT FROM AUTHOR]

Abstract: Microwave pyrolysis of Douglas fir sawdust pellet was investigated to determine the effects of reaction temperature and time on the yields of bio-oil, syngas, and charcoal using a central composite design (CCD) and response surface analysis. The research results indicated that thermo-chemical conversion reactions can take place rapidly in large-sized biomass pellet by using microwave pyrolysis. The yields of bio-oil and syngas were increased with the reaction temperature and time. The highest yield of bio-oils was 57.8% (dry biomass basis) obtained at 471°C and 15min. GC/MS analysis indicated that the bio-oils were mainly composed of phenols, guaiacols, furans, ketones/aldehydes, and organic acids. The yield of specific chemicals such as furans and phenolic compounds were highly related to the reaction temperature. The syngas contained high value chemicals, such as carbon monoxide, methane, and short chain hydrocarbons. A third-order reaction mechanism fits well the microwave pyrolysis of Douglas fir pellet with activation energy of 33.5kJ/mol and a frequency factor of 3.03s−1. [Copyright &y& Elsevier]

Abstract: Microwave pyrolysis of distillers dried grain with solubles (DDGS) was investigated to determine the effects of pyrolytic conditions on the yields of bio-oil, syngas, and biochar. Pyrolysis process variables included reaction temperature, time, and power input. Microwave pyrolysis of DDGS was analyzed using response surface methodology to find out the effect of process variables on the biofuel (bio-oil and syngas) conversion yield and establish prediction models. Bio-oil recovery was in the range of 26.5–50.3wt.% of the biomass. Biochar yields were 23.5–62.2% depending on the pyrolysis conditions. The energy content of DDGS bio-oils was 28MJ/kg obtained at the 650°C and 8min, which was about 66.7% of the heating value of gasoline. GC/MS analysis indicated that the biooil contained a series of important and useful chemical compounds: aliphatic and aromatic hydrocarbons. At least 13% of DDGS bio-oil was the same hydrocarbon compounds found in regular unleaded gasoline. [Copyright &y& Elsevier]