Bio-Crude Production Improvement during Hydrothermal Liquefaction of Biopulp by Simultaneous Application of Alkali Catalysts and Aqueous Phase Recirculation

This study focuses on the valorization of the organic fraction of municipal solid waste (biopulp) by hydrothermal liquefaction. Thereby, homogeneous alkali catalysts (KOH, NaOH, K2CO3, and Na2CO3) and a residual aqueous phase recirculation methodology were mutually employed to enhance the bio-crude yield and energy efficiency of a sub-critical hydrothermal conversion (350 °C, 15–20 Mpa, 15 min). Interestingly, single recirculation of the concentrated aqueous phase positively increased the bio-crude yield in all cases, while the higher heating value (HHV) of the bio-crudes slightly dropped. Compared to the non-catalytic experiment, K2CO3 and Na2CO3 effectively increased the bio-crude yield by 14 and 7.3%, respectively. However, KOH and NaOH showed a negative variation in the bio-crude yield. The highest bio-crude yield (37.5 wt.%) and energy recovery (ER) (59.4%) were achieved when K2CO3 and concentrated aqueous phase recirculation were simultaneously applied to the process. The inorganics distribution results obtained by ICP reveal the tendency of the alkali elements to settle into the aqueous phase, which, if recovered, can potentially boost the circularity of the HTL process. Therefore, wise selection of the alkali catalyst along with aqueous phase recirculation assists hydrothermal liquefaction in green biofuel production and environmentally friendly valorization of biopulp.

The assisting-approach of horseradish peroxidase immobilized onto amine-functionalized superparamagnetic iron oxide nanoparticles as a biocatalyst

To enhance the removal of dye, horseradish peroxidase (HRP) was immobilized onto amine-functionalized superparamagnetic iron oxide and used as a biocatalyst for the oxidative degradation of Acid black-HC dye. The anchored enzyme was characterized by sets of techniques such as vibrating sample magnetometer, Fourier transform infrared, X-ray diffraction, thermogravimetric, scanning electron microscopy, BET and BJH methods, nitrogen adsorption-desorption measurements , Zeta potential, energy dispersive X-ray (EDX), and transmission electron microscopy. The Michaelis constant (K m ) values of free peroxidase and immobilized horseradish peroxidase were determined that equal 4.5 and 5 mM for hydrogen peroxide; 12.5 and 10 mM for guaiacol, respectively. Besides, the free peroxidase is thermally stable at 40°C however, the immobilized enzyme was up to 60°C. In the catalytic experiment, the immobilized HRP showed superior catalytic activity compared with free HRP for the oxidative decolorization and removal of Acid black-HC dye. The impacts of experimental parameters for instance catalyst dosage, pH, H 2 O 2 concentration, and temperature, were investigated. The reaction followed second-order kinetics and the thermodynamic activation parameters were determined.

Investigation on Mn3O4 Coated Ru Nanoparticles for Partial Hydrogenation of Benzene towards Cyclohexene Production Using ZnSO4, MnSO4 and FeSO4 as Reaction Additives

Mn3O4 coated Ru nanoparticles (Ru@Mn3O4) were synthesized via a precipitation-reduction-gel method. The prepared catalysts were evaluated for partial hydrogenation of benzene towards cyclohexene generation by applying ZnSO4, MnSO4 and FeSO4 as reaction additives. The fresh and spent catalysts were thoroughly characterized by XRD, X ray fluorescence (XRF), XPS, TEM and N2-physicalsorption in order to understand the promotion effect of Mn3O4 as the modifier as well as ZnSO4, MnSO4 and FeSO4 as reaction additives. It was found that 72.0% of benzene conversion and 79.2% of cyclohexene selectivity was achieved after 25 min of reaction time over Ru@Mn3O4 with a molar ratio of Mn/Ru being 0.46. This can be rationalized in terms of the formed (Zn(OH)2)3(ZnSO4)(H2O)3 on the Ru surface from the reaction between Mn3O4 and the added ZnSO4. Furthermore, Fe2+ and Fe3+ compounds could be generated and adsorbed on the surface of Ru@Mn3O4 when FeSO4 is applied as a reaction additive. The most electrons were transferred from Ru to Fe, resulting in that lowest benzene conversion of 1.5% and the highest cyclohexene selectivity of 92.2% after 25 min of catalytic experiment. On the other hand, by utilizing MnSO4 as an additive, no electrons transfer was observed between Ru and Mn, which lead to the complete hydrogenation of benzene towards cyclohexane within 5 min. In comparison, moderate amount of electrons were transferred from Ru to Zn2+ in (Zn(OH)2)3(ZnSO4)(H2O)3 when ZnSO4 is used as a reaction additive, and the highest cyclohexene yield of 57.0% was obtained within 25 min of reaction time.

Modification of natural clinoptilolite and ZSM-5 with different oxides and studying of the obtained products in lignin pyrolysis

In this work, different metal oxides (MO) supported on two types of zeolites: 1) natural clinoptilolite (NZ) and 2) synthetic zeolite, ZSM-5 were prepared and tested as catalysts in the fast pyrolysis of hardwood lignin. NZ was modified with the CaO and MgO by a simple two steps procedure consisting of an ion exchange reaction and a subsequent calcination at 773 K. The synthetic ZSM-5 was modified with several MO species (Ni, Cu, Ca, Mg) by a wet impregnation and calcination at 873 K. ?he prepared catalysts were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDS) and measurement of specific surface area (BET method). Acid sites were characterized and quantified by pyridine (py) absorption using Fourier transform infrared spectroscopy (FTIR). The catalysts exhibit catalytic activity depanding on modification, reaction temperature and of the MO contents. The highest yield of useful phenol in bio-oil was obtained with NiO/ZSM-5 (34.8 wt.%) which exhibits the highest specific surface area and the highest concetration of Br?nsted and Lewis acid sites. The studied catalysts did not increase significantly the content of polycyclic aromatic hydrocarbons (PAHs) and heavy compounds compared to non-catalytic experiment.

Research on Computer Simulation in Titanium Dioxide Photocatalytic Experiment

experiment is the basis of research on titanium dioxide (TiO2) photocatalysis. However, the proceeding of experiment need consume large amount of time, finance and vigor. Computer simulation realizes the mutual effect with outside by system of computer simulating authentic material, which can reduce unnecessary consumption. Computer simulation application provides new tool for TiO2 catalytic experiment and improve the efficiency. This paper summarized the basic structure of TiO2 as well as the mechanism and process of photocatalysis, introduced the main method and relative software of theoretical simulation mathematics, and summarized the advantage of computer simulation in micro field based on the limitation of experiment.

Use of Hydroxyl Radical Yield to Investigate a Urea and Cobalt Modified TiO2 Photocatalyst Degrading Rhodamine B under UV and Visible Light

Material modification of TiO2 photo-catalyst (NMTi) by doping urea and cobalt via sol-gel method was used to achieve high efficiency degradation of rhodamine B (RhB) under visible light (Vis). Although good removal (up to 42% of TOC removed) of RhB by Degussa P25 under ultra violet irradiation, P25 did not effectively degrade RhB (up to 14% TOC removed) under Vis. In the batch photo-catalytic experiment with Vis irradiation, the removal efficiencies of absorbance and TOC by NMTi were 28 and 30%. We used terephthalic acid as fluorescence probe to catch hydroxyl radical (OH) and calculated their quantum yields. The OH yields of NMTi with Vis irradiating was 8.91×10-6 while P25 of 2.65×10-6 (P25 of 1.44×10-5 and NMTi of 1.00×10-5 under UV). The OH yields of NMTi were higher than that of P25 under Vis, but otherwise under UV irradiation. Therefore, our new composited NMTi was more effective than P25 under Vis for both absorbance and TOC removal of RhB. It seemed possessed the application potential under Vis irradiation.

The Removal of Deinking Wastewater Using Neutralization, Activated Carbon, and Hydrogen Peroxide Oxidation

Treatment of deinking wastewater with neutralization, activated carbon, and hydrogen peroxide oxidation is investigated. Discusses the various factors of the neutralization experiment and catalytic experiment on the influence of the experimental results. The results show that for the 20mL deinking wastewater, first neutralize it to pH=4 with dilute sulfuric acid, then the mass fraction of 0.8mLH2O2 (mass fraction of 30%) and 0.8g active carbon powder in oxidative 19min under conditions of pH=3 with an optimum addition of 0.8mg H2O2 (30%) as well as 0.8g active carbon powder, the CODcr can be reduced from 31000mg/L to 2300 mg/L, and the color unit can be reduced from 15000 to 0 after treatment ,its CODcr and color unit decrease significantly and the removal rates reach 90% and 100% respectively.

Antibody-catalyzed formation of a 14-membered ring lactone

Monoclonal antibody (MAb) F123, raised against a macrocyclic phosphonate transition-state analogue, catalyzed an intramolecular transesterification of the corresponding hydroxy ester to give a 14-membered ring lactone. The MAb reaction displayed enzyme-like Michaelis–Menten kinetics with a Km of 255 µM and a kcat of 0.01 min–1 based on p-nitrophenol release and calculated on an active-site basis. Substrate specificity and competitive inhibition by a transition state analogue (Ki = 3 µM) demonstrated that the catalytic activity was associated with binding in the antibody-combining site. The lactone product was isolated from a large-scale catalytic experiment through ether extraction and identified by gas chromatography – mass spectroscopy.Key words: macrocyclization, lactones, catalytic antibodies.