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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 (C1-C5), CO, CO2 and H2. 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., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Hydrodeoxygenation (HDO) is an effective route to upgrade bio-oil to hydrocarbon bio-oil, but the development of efficient catalysts for bio-oil HDO still remains a challenge. In this study, non-sulfided Fe-Co/SiO 2 catalysts were used to upgrade bio-oil using HDO. A series of Fe-Co/SiO 2 catalysts with different Fe/Co mole ratios were prepared, characterized and evaluated. The Fe and/or Co loading did not change SiO 2 crystalline structure. The Fe and/or Co metals increased the amount and strength of Fe-Co/SiO 2 catalyst acidity. Physicochemical properties of upgraded bio-oils produced using Fe-Co/SiO 2 catalysts such as water content, total acid number, viscosity and higher heating values improved in comparison to raw bio-oil. Bimetallic Fe-Co/SiO 2 catalysts resulted in better HDO performance than monometallic Fe/SiO 2 or Co/SiO 2 catalysts. This was due to the synergistic effect of Fe and Co occurring on the SiO 2 support. Fe-Co/SiO 2 catalyst having medium amount of acidity was more effective for bio-oil upgrading. The highest hydrocarbons content produced using Fe-Co(1)/SiO 2 catalyst was 22.44%. The mechanism of bio-oil HDO on Fe-Co/SiO 2 catalysts is proposed. [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]

Hydrodeoxygenation (HDO) is an effective method for bio-oil upgrading. However, the high hydrogen consumption resulted in high bio-oil upgrading cost. In this study, an novel method of hydrogen generation from water for bio-oil HDO was reported. Zinc metal with zero valency was used to generate hydrogen through zinc hydrolysis reaction in the bio-oil HDO process. The effects of different temperatures (20 °C, 250 °C, 300 °C, 350 °C, 400 °C) on in situ bio-oil HDO was investigated. The results showed that high temperatures resulted in high hydrogen yield that led to promoted HDO activity over zinc metal-based materials. Although 20 °C bio-oil HDO process generated the highest oil phase yield at 14.07%, 400 °C bio-oil upgrading process produced upgraded bio-oil with highest hydrocarbons content at 68.95%. Physicochemical properties of raw bio-oil improved significantly after bio-oil HDO upgrading at higher temperatures (250 °C, 300 °C, 350 °C and 400 °C). The pH of upgraded bio-oils (5.70–6.49) increased significantly compared to raw bio-oil (3.24). The higher heating value of upgraded bio-oils (28.67–33.43 MJ/kg) increased significantly compared to raw bio-oil (15.54 MJ/kg), and valuable hydrocarbons content improved significantly from 16.94% in raw bio-oil to 37.86%–68.95% in upgraded bio-oils. [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]

Upgraded bio-oil can partly replace fossil fuels to reduce the environmental issues caused by the massive consumption of fossil fuels. Hydrodeoxygenation is a promising route for upgraded bio-oil production from pyrolysis bio-oil. Non-sulfide catalysts are effective in bio-oil hydrodeoxygenation due to low cost and high activity. Ni-Zn/Al 2 O 3 catalysts were first used to selectively produce hydrocarbon upgraded bio-oil through bio-oil hydrodeoxygenation. Upgrading pine sawdust bio-oil to upgraded hydrocarbon bio-oil was performed using a series of Ni and/or Zn loaded Al 2 O 3 catalysts. The crystalline structure of Al 2 O 3 was maintained after Ni and/or Zn loading, but BET surface area and total pore volume of Ni-Zn/Al 2 O 3 catalysts decreased significantly compared to Al 2 O 3 support. Bimetallic Ni-Zn/Al 2 O 3 catalysts were more effective than monometallic Ni/Al 2 O 3 or Zn/Al 2 O 3 catalyst . Bimetallic 15%Ni-5%Zn/Al 2 O 3 catalyst generated the highest upgraded bio-oil yield at 44.64 wt% and produced the upgraded bio-oil with the highest hydrocarbon content at 50.12%. Physicochemical properties of upgraded bio-oils including heating value, water content and pH were significantly improved in comparison with raw bio-oil. The improved catalytic performance of bimetallic Ni-Zn/Al 2 O 3 catalyst was associated with the synergistic effect of Ni and Zn on Al 2 O 3 support. [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]

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 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]