Conversion of biomass model compound under hydrothermal conditions using batch reactor

Fuel ◽  
2009 ◽  
Vol 88 (9) ◽  
pp. 1656-1664 ◽  
Author(s):  
Wahyudiono ◽  
Mitsuru Sasaki ◽  
Motonobu Goto
Keyword(s):  
Model Compound ◽  
Batch Reactor ◽  
Hydrothermal Conditions

scholarly journals Effects of Pretreatment with Ionic Liquids on Cellulose Hydrolysis under Hydrothermal Conditions

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3572 ◽  
Author(s):  
Toshitaka Funazukuri ◽  
Shingo Ozawa
Keyword(s):  
Ionic Liquids ◽  
Filter Paper ◽  
Biomass Conversion ◽  
Batch Reactor ◽  
Cellulose Hydrolysis ◽  
Reaction Rates ◽  
Crystalline Cellulose ◽  
Hydrothermal Conditions ◽  
Imidazolium Chloride ◽  
Product Yields

Hydrothermal hydrolysis in hot pressurized liquid water (HPLW) is attractive for biomass conversion into valuable products because it achieves high reaction rates without catalysts and additives. The hydrothermal hydrolysis of high crystalline cellulose requires higher reaction temperature than polysaccharides having low crystallinity. It can be expected to increase the reaction rate or decrease temperature by decreasing the crystallinity. In the present study ashless filter paper as a fibrous pure cellulose sample was pretreated with ionic liquids (ILs) such as imidazolium chloride ILs containing alkyl side chains ranging from two to six carbons, and with an aqueous solution of bis(ethylenediamine ammonium) copper (BEDC). Herein, the pretreatment with ILs was to regenerate filter paper: dissolving in ILs at 373 K for 120 min or in an aqueous BEDC solution at room temperature, precipitating by adding water, washing the solid, and then drying. Subsequently, the pretreated filter paper samples were hydrolyzed at 533 K and 5.0 MPa in HPLW in a small semi-batch reactor, and the effects of the pretreatment with ILs or BEDC on reaction rates and product yields were examined. While the crystallinity indexes with all ILs and BEDC after the pretreatments decreased to 44 to 47 from the original sample of 87, the reaction rates and product yields were significantly affected by the IL species. At 533 K and 5.0 MPa, the dissolution rate with [AMIM][Cl] was nine times as fast as that for untreated sample.

Decomposition of a Lignin Model Compound under Hydrothermal Conditions

2007 ◽  
Vol 30 (8) ◽  
pp. 1113-1122 ◽  
Author(s):  
Wahyudiono ◽  
T. Kanetake ◽  
M. Sasaki ◽  
M. Goto
Keyword(s):  
Model Compound ◽  
Hydrothermal Conditions ◽  
Lignin Model Compound ◽  
Lignin Model

In situ X-ray absorption spectroscopy measurement of vapour-brine fractionation of antimony at hydrothermal conditions

2008 ◽  
Vol 72 (2) ◽  
pp. 667-681 ◽  
Author(s):  
G. S. Pokrovski ◽  
J. Roux ◽  
J.-L. Hazemann ◽  
A. YU. Borisova ◽  
A. A. Gonchar ◽  
...  
Keyword(s):  
Salt Water ◽  
Batch Reactor ◽  
Total Concentration ◽  
Hydrothermal Systems ◽  
Hydrothermal Conditions ◽  
Geological Evidence ◽  
X Ray ◽  
Liquid Phases ◽  
X Ray Absorption

AbstractDespite the growing geological evidence that fluid boiling and vapour-liquid separation affect the distribution of metals in magmatic-hydrothermal systems significantly, there are few experimental data on the chemical status and partitioning of metals in the vapour and liquid phases. Here we report on an in situ measurement, using X-ray absorption fine structure (XAFS) spectroscopy, of antimony speciation and partitioning in the system Sb2O3-H2O-NaCl-HCl at 400°C and pressures 270—300 bar corresponding to the vapour-liquid equilibrium. Experiments were performed using a spectroscopic cell which allows simultaneous determination of the total concentration and atomic environment of the absorbing element (Sb) in each phase. Results show that quantitative vapour-brine separation of a supercritical aqueous salt fluid can be achieved by a controlled decompression and monitoring the X-ray absorbance of the fluid phase. Antimony concentrations in equilibrium with Sb2O3 (cubic, senarmontite) in the coexisting vapour and liquid phases and corresponding SbIII vapour-liquid partitioning coefficients are in agreement with recent data obtained using batch-reactor solubility techniques. The XAFS spectra analysis shows that hydroxy-chloride complexes, probably Sb(OH)2Cl0, are dominant both in the vapour and liquid phase in a salt-water system at acidic conditions. This first in situ XAFS study of element fractionation between coexisting volatile and dense phases opens new possibilities for systematic investigations of vapour-brine and fluid-melt immiscibility phenomena, avoiding many experimental artifacts common in less direct techniques.

Controlled operation of a membrane SBR for inhibitory wastewater treatment

2009 ◽  
Vol 60 (3) ◽  
pp. 655-661 ◽  
Author(s):  
A. Vargas ◽  
J. L. Sandoval ◽  
G. Buitrón
Keyword(s):  
Membrane Fouling ◽  
Model Compound ◽  
Feeding Strategy ◽  
Batch Reactor ◽  
Sole Source ◽  
Synthetic Wastewater ◽  
Feedback Signal ◽  
Transmembrane Pressure ◽  
Practical Implementation ◽  
High Concentrations

This work presents the design and practical implementation of a control strategy for the operation of a sequencing batch reactor with a submerged membrane. The bioreactor is used for treating wastewater that is inhibitory for sufficiently high concentrations. The strategy combines the use of a robust feeding strategy to ensure biodegradation near an optimal unknown concentration value, using only the dissolved oxygen concentration as feedback signal, and a strategy to minimize membrane fouling based on flux and transmembrane pressure measurements during filtration. The strategy was tested on a 10 L laboratory bioreactor treating synthetic wastewater containing 4-chlorophenol as inhibitory model compound and sole source of carbon. Experimental results show the applicability of the proposed strategy.

scholarly journals Ru-Catalyzed Oxidative Cleavage of Guaiacyl Glycerol--Guaiacyl Ether-a Representative -O-4 Lignin Model Compound

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 832 ◽  
Author(s):  
Melián-Rodríguez ◽  
Saravanamurugan ◽  
Meier ◽  
Kegnæs ◽  
Riisager
Keyword(s):  
Model Compound ◽  
Supported Catalysts ◽  
Batch Reactor ◽  
Aerobic Oxidation ◽  
Catalytic Performance ◽  
Ruthenium Catalysts ◽  
Consecutive Reaction ◽  
Lignin Model Compound ◽  
Lignin Model ◽  
A Minor

The introduction of efficient and selective catalytic methods for aerobic oxidation of lignin and lignin model compounds to aromatics can extend the role of lignin applications in biorefineries. The current study focussed on the catalytic oxidative transformation of guaiacyl glycerol--guaiacyl ether (GGGE)–a -O-4 lignin model compound to produce basic aromatic compounds (guaiacol, vanillin and vanillic acid) using metal-supported catalysts. Ru/Al2O3, prepared with ruthenium(IV) oxide hydrate, showed the highest yields of the desired products (60%) in acetonitrile in a batch reactor at 160 C and 5-bar of 20% oxygen in argon. Alternative catalysts containing other transition metals (Ag, Fe, Mn, Co and Cu) supported on alumina, and ruthenium catalysts based on alternative supports (silica, spinel, HY zeolite and zirconia) gave significantly lower activities compared to Ru/Al2O3 at identical reaction conditions. Moreover, the Ru/Al2O3 catalyst was successfully reused in five consecutive reaction runs with only a minor decrease in catalytic performance.

scholarly journals Investigation of the effect of operational parameters and SnO2-coupling on the photocatalytic activity of TiO2

2013 ◽  
Vol 15 (4) ◽  
pp. 551-559
Keyword(s):  
Hydrogen Peroxide ◽  
Photocatalytic Activity ◽  
Light Intensity ◽  
Model Compound ◽  
Batch Reactor ◽  
Coupled System ◽  
Operational Parameters ◽  
First Order ◽  
First Order Kinetics ◽  
Pseudo First Order

<p>The effect of different operational parameters in UV/TiO2 process, such as initial dye concentration (20-50 mg l-1), light intensity (8-45 W m-2), pH (2.83-10.22), hydrogen peroxide concentration (100-500 mg l-1), temperature (21-45 ˚C) and photocatalyst concentration (150-900 mg l-1) were investigated on the decolorization of Acid Yellow 23 as a model compound from monoazo textile dyes. The apparent first-order rate constants (kap) were evaluated which confirms pseudo first-order kinetics. kap increased with the enhancement of pH, light intensity and temperature. A desired concentration found for hydrogen peroxide (400 mg l-1) and photocatalyst concentration (750 mg l-1). The SnO2 photocatalyst was not as effective as TiO2 but had the same desired concentration (750 mg l-1). Then TiO2+SnO2 suspensions (375+375 mg l-1) as photocatalysts were employed for decolorization at different solution thicknesses. The results showed that the coupled particles were not much different from single TiO2 system at the solution thickness of 4.5 cm in a batch reactor. But the coupled system was more effective when the solution thickness was reduced to 2.5 cm. Over 90% of decolorization occurs at the solution thickness of 1.1 cm after 30 min of irradiation while 90% decolorization takes place at the solution thickness of 4.5 cm after 100 min of irradiation.</p>

scholarly journals Ageing of low-firing prehistoric ceramics in hydrothermal conditions

2012 ◽  
Vol 6 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Petra Zemenová ◽  
Alexandra Klouzková ◽  
Martina Kohoutková
Keyword(s):  
Bronze Age ◽  
Model Compound ◽  
Raw Materials ◽  
Archaeological Site ◽  
Hydrothermal Conditions ◽  
The Czech Republic ◽  
Archaeological Ceramics ◽  
Object A ◽  
Prehistoric Ceramics ◽  
The Bronze Age

Remains of a prehistoric ceramic object, a moon-shaped idol from the Bronze Age found in archaeological site Zdiby near Prague in the Czech Republic, were studied especially in terms of the firing temperature. Archaeological ceramics was usually fired at temperatures below 1000?C. It contained unstable non-crystalline products, residua after calcination of clay components of a ceramic material. These products as metakaolinite can undergo a reverse rehydration to a structure close to kaolinite. The aim of this work was to prove whether the identified kaolinite in archaeological ceramics is a product of rehydration. The model compound containing high amount of kaolinite was prepared in order to follow its changes during calcination and hydrothermal treatment. Archaeological ceramics and the model compound were treated by hydrothermal ageing and studied by XRF, XRD and IR analyses. It was proved that the presence of kaolinite in the border-parts of the archaeological object was not a product of rehydration, but that it originated from the raw materials.

Anaerobic/aerobic treatment of colorants present in textile effluents

2004 ◽  
Vol 50 (2) ◽  
pp. 149-155 ◽  
Author(s):  
R. Ma. Melgoza ◽  
A. Cruz ◽  
G. Buitrón
Keyword(s):  
Sequencing Batch Reactor ◽  
Model Compound ◽  
Batch Reactor ◽  
Textile Wastewater ◽  
Synthetic Wastewater ◽  
Aerobic Treatment ◽  
Produce Water ◽  
Real Wastewater ◽  
Initial Color ◽  
Reactive Azo Dyes

The operation of an anaerobic/aerobic process used to degrade the colorants present in textile wastewater is presented. The objective is to produce water that can be reused. Two particular cases were studied: the degradation of a synthetic wastewater containing the colorant disperse blue 79 (DB79) as a model compound and a real textile effluent containing reactive azo dyes. The biodegradation was achieved using a single tank operated as sequencing batch reactor. It was observed that the DB79 was biotransformed to amines in the anaerobic stage decolorizing the wastewater. The amines formed were subsequently mineralized in the aerobic phase. An increase of toxicity was observed in the anaerobic stage due to the amines formation, but the wastewater was detoxified after the aerobic treatment. Removal efficiencies of DB79 around 92% were observed after the treatment. Around 96% of the initial color of the real wastewater was effectively removed. It was observed that the biomass pre-acclimatized to the degradation of DB79 was more effective for the color removal than a freshly inoculum used.

Degradation of acid orange 7 by a controlled anaerobic–aerobic sequencing batch reactor

2006 ◽  
Vol 54 (2) ◽  
pp. 187-192 ◽  
Author(s):  
G. Buitrón ◽  
K.M. Martínez ◽  
A. Vargas
Keyword(s):  
Organic Carbon ◽  
Azo Dye ◽  
Inflection Point ◽  
Sequencing Batch Reactor ◽  
Model Compound ◽  
Batch Reactor ◽  
Control Variable ◽  
Synthetic Wastewater ◽  
Acid Orange 7 ◽  
Acid Orange

The degradation of a mono azo dye in an automated and controlled anaerobic–aerobic sequencing batch reactor (SBR) is described in this work. The experiments were conducted with a synthetic wastewater containing acid orange 7 as the model compound to degrade and glucose as the co-substrate in a molar relationship 1:40 (substrate/co-substrate). It was possible to control the anaerobic and aerobic stages, using the redox potential (ORP) as the only control variable. The strategy detects an inflection point in the ORP signal, indicating the end of the reaction. The efficiency of removal of total organic carbon was between 85% and 90%. Azo dye was removed with 85% efficiency during the anaerobic stage.

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