Sudong Yin

Subcritical hydrothermal liquefaction of cattle manure to bio-oil: effects of conversion parameters on bio-oil yield and characterization of bio-oil.

In this study, cattle manure was converted to bio-oil by subcritical hydrothermal liquefaction in the presence of NaOH. The effects of conversion temperature, process gas, initial conversion pressure, residence time and mass ratio of cattle manure to water on the bio-oil yield were studied. The bio-oil was characterized in terms of elemental composition, higher heating value, ultraviolet-visible (UV/Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Results showed that the bio-oil yield depended on the conversion temperature and the process gas. Higher initial conversion pressure, longer residence time and larger mass ratio of cattle manure to water, however, had negative impacts on the bio-oil yield. The higher heating value of bio-oil was 35.53MJ/kg on average. The major non-polar components of bio-oil were toluene, ethyl benzene and xylene, which are components of crude oil, gasoline and diesel.

Alkaline hydrothermal conversion of cellulose to bio-oil: Influence of alkalinity on reaction pathway change

The effects of alkalinity on alkaline hydrothermal conversion (alkaline-HTC) of cellulose to bio-oil were investigated in this study. The results showed that the initial alkalinity greatly influenced the reaction pathways. Under initial strong alkaline conditions with final pH greater than 7, alkaline-HTC only followed the alkaline pathway. However, under initial weak alkaline conditions with final pH of less than 7, acidic as well as alkaline pathways were involved. The main mechanism behind this change of reaction pathways under weak alkaline conditions was that carboxylic acids were first formed from cellulose via the alkaline pathway and then neutralized/acidified the alkaline solutions. Once the pH of the alkaline solutions decreased to less than 7, the acidic instead of the alkaline reaction pathway occurred. This change of the reaction pathways with initial alkalinity partly explained the inconsistent results in the literature of alkaline-HTC bio-oil compositions and yields.

Hydrothermal Conversion of Cellulose to 5-Hydroxymethyl Furfural

5-hydroxymethyl furfural (HMF) is an important biomass-derived material for alkane bio-oil production. HMF is currently produced from edible glucose and fructose. Until recently, some researchers successfully applied ionic liquids to convert cellulose, a type of inedible biomass, to HMF. However, ionic liquids usually are toxic and/or require sophisticated skills to prepare. It would be more cost-effective if water can be employed as the reaction media. This paper studied hydrothermal conversion of cellulose to HMF under acidic, neutral and alkaline conditions. The results showed that, at 275–320°C and the reaction residence time of 0–30 min, the order of HMF yields followed the order of acidic, neutral and alkaline conditions. In terms of HMF purity, the order changed to neutral, acidic and alkaline conditions. Moreover, high temperatures (>300°C) and long reaction residence time had negative effects on the HMF yields in acidic and neutral solutions, mostly because of the promoted decomposition and the polymerization of HMF to levulinic acid and char, respectively. Therefore, the conditions of acidic aqueous solutions, medium range temperatures and short reaction residence time were recommended for hydrothermal conversion of cellulose to HMF. On the other hand, this study revealed that cellulose can also be converted to HMF under alkaline conditions. With the carboxylic acids produced from cellulose under alkaline conditions, the initial alkaline hydrothermal condition can gradually become acidic.

Bio-solubilization of Chinese lignite I：extra-cellular protein analysis

Abstract A white rot fungus strain, Trichoderma sp. AH, was isolated from rotten wood in Fushun and used to study the mechanism of lignite bio-solubilization. The results showed that nitric acid pretreated Fushun lignite was solubilized by T. sp. AH and that extracellular proteins from T. sp. AH were correlated with the lignite bio-solubilization results. In the presence of Fushun lignite the extracellular protein concentration from T. sp. AH was 4.5 g/L while the concentration was 3 g/L in the absence of Fushun lignite. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of the extracellular proteins detected at least four new protein bands after the T. sp. AH had solubilized the lignite. Enzyme color reactions showed that extracellular proteins from T. sp. AH mainly consisted of phenol-oxidases, but that lignin decomposition enzymes such as laccase, peroxidase and manganese peroxidases were not present.

Bio-solubilization of Chinese lignite II:protein adsorption onto the lignite surface

Abstract Lignite bio-solubilization is a promising technology for converting solid lignite into oil. This study concerns the adsorption of lignite-solubilizing enzymes onto the lignite surface. Adsorption capacity, infrared spectral analysis and driving forces analysis are studied as a way to help understand the bio-solubilization mechanism. The results show that the amount of lignite bio-solubilization is proportional to the amount of adsorbed lignite-solubilizing enzymes. An increase in lignite-solubilizing enzyme adsorption of 10% leads to a 7% increase in lignite bio-solubilization. However, limited amounts of enzymes can be adsorbed by the lignite, thus resulting in low percentages of bio-solubilization. Infrared spectral analysis shows that side chains, such as hydroxyl and carbonyl, of the lignite structure are the main, and necessary, structures where lignite-solubilizing enzymes attachto the lignite. Furthermore, driving force analysis indicates that the electrostatic force between lignite and enzymes is the main adsorption mechanism. The forces are influenced by solution pH levels, the zeta potential of the lignite and the isoelectric points of the enzymes.

Catalytic Hydrothermal Conversion of Glucose to Light Petroleum Alkanes

The production of carbon-neutral liquid fuels from renewable biomass has attracted worldwide interest in an age of depletion of fossil fuel reserves and pollutions caused by utilization of fossil petroleum. Currently, commercial bio-oil production technologies include bio-ethanol, bio-diesel and pyrolysis bio-oil. But, these bio-oils mainly consist of alcohols and aromatic chemicals rather than alkanes of the main components of gasoline and diesel. Direct utilization of these bio-oils can corrode car engines as well as emitting large unburned hydrocarbons particles through automotive combustion system. Therefore, in this study, catalytic hydrothermal conversion (CHTC) of glucose to alkanes in a single batch reactor was investigated with respect to effects of conversion parameters such as initial pressure of process gas H2 , pH level of aqueous solution and catalysts on alkane yields and compositions. Results showed that the highest alkane yield of 21.6% (based on the mol of the input glucose) was obtained at 265 °C, with 300 psi of H2 process gas, 0.5 g catalyst of 1w%. Pt/Al2 O3 and a residence time of 15 h. The alkane yield was significantly influenced by the initial pressure of H2 , which increased with increasing H2 pressure. On the other hand, the alkane yields first increased and then decreased with pH levels. Also, more alkanes were produced by Pt/Al2 O3 than Pd/Al2 O3 . Regarding alkane compositions, high initial pressure of H2 favored the production of relatively heavy C3–4 alkanes. With 300 psi of initial H2 , C3 H8 and C4 H10 accounted for 75% of the total produced alkanes. All of the experimental data in this study lead to one conclusion that petroleum alkanes can be directly produced from glucose.Copyright

Hydrothermal Gasification of Waste Biomass Under Alkaline Conditions

Hydrothermal gasification is a promising technology for the treatment of wet organic biomass, and as such, has been subject to significant research effort. It is well known that two groups of catalysts exhibit high activity for hydrothermal gasification—broadly classified as platinum group metals and alkali salts. In the present work, this effect is further investigated through a study of the synergistic effects of sodium carbonate and Pt/Al2 O3 on gas yield from cellulose at 315°C. Results indicate that dilute alkali appears far more efficient in promoting gasification reactions in the presence of Pt/Al2 O3 . Potential mechanisms and a comparison with the alkaline degradation pathways of glucose are discussed.© 2009 ASME

Hydrothermal Conversion of Cattle Manure to Biooil: Effects of Conversion Parameters on Biooil

Due to intensive feedlots operations, the role of cattle manure has changed from a cheap fertilizer to an agricultural waste. Hydrothermal conversion (HTC) is a potential technology of converting cattle manure waste to biooil. In this paper, HTC of cattle manure was studied with regards to the effects of conversion temperature, pressure, residence time, process gas and mass ratios of cattle manure to water on yields and properties of biooil. Results showed that within the temperature range of 260 ∼ 360 °C, biooil yield first increased and then decreased. The maximum biooil yield was obtained at 310 °C. The biooil yield was not further improved by higher initial operating pressure. In contrast, it decreased biooil yields from 38.49% under 0 psig to 6.51% under 150 psig. Longer residence times also reduced biooil yield. Compared with 38.49% of biooil produced with 15-minute residence time, only 12.95% of biooil remained after 40-minute residence time. Process gases also had important impacts on biooil yield. When N2 was replaced with CO, the maximum biooil yield increased to 48.76%. But, when air was used as process gas, the biooil yield decreased to 27.97%. Also, biooil yield decreased with larger mass ratios of cattle manure to water. When the ratio was 2, biooil yield was only 1.46% much less than 48.76% with ratio of 0.25. Therefore, biooil yield from HTC of cattle manure largely depended on the conversion temperatures and process gases. Higher conversion pressures, longer residence time and larger mass ratios of cattle manure to water had negative impacts on biooil yield. The mean high heating value of biooil from HTC of cattle manure was 37.0 MJ/kg.Copyright

Hydrothermal Conversion of Cattle Manure to Biooil: Biooil Definitions

A number of researchers have reported that biooil was produced through hydrothermal conversion of different types of biomass. However, it is difficult to evaluate and compare these biooils in terms of yields and chemical properties. They applied different organic solvents to extract biooil from products after hydrothermal conversion of biomass. The purpose of this study is to assess the impact of extraction solvents on the quantity and chemical structure of biooil. Cattle manure was used as one type of biomass feedstock for biooil production. And dichloromethane (CH2 Cl2 ), chloroform (CHCl3 ) and diethyl ether (C4 H10 O) were used for biooil extraction. Results showed that extraction solvents influenced biooil yields. The highest biooil yield of 48.78 wt% of volatile content of cattle manure was obtained when using CH2 Cl2 solvent. The main components of biooil extracted by CH2 Cl2 and CHCl3 were ketones and carboxylic acids, while those extracted by C4 H10 O were aromatic chemicals. In terms of elemental compositions and high heating values of biooil, no statistically apparent differences were caused by different solvents. The mean elemental compositions (by weight) of biooils were carbon of 73.79%, hydrogen of 8.18%, nitrogen of 4.38% and oxygen of 13.65%. And the mean high heating value of biooil was 36.74 MJ/kg.Copyright