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In this paper, a series of Cu-Fe-Ti and Co-Fe-Ti oxide catalysts were prepared by sol gel method. Cu-Fe-Ti and Co-Fe-Ti oxide catalysts showed the moderate catalytic activity for selective catalytic reduction (SCR) of NO with NH 3 at low temperature. The catalysts with the molar ratio as 4:1:10 (M:Fe:Ti) were selected as the representatives for comparison of reaction properties and H 2 O resistance, which were denoted as Cu-Fe/TiO 2 and Co-Fe/TiO 2 respectively. The characterization results manifested Co-Fe/TiO 2 owned more adsorption capacity of the reactants and Cu-Fe/TiO 2 had better redox ability. The in situ DRIFTS experiments indicated that adsorbed NH 3 species and nitrate species both exhibited reaction activity for Co-Fe/TiO 2 , while nitric oxide was only be reduced by adsorbed NH 3 species through Eley-Rideal mechanism for Cu-Fe/TiO 2 at 150 °C. Co-Fe/TiO 2 exhibited the better resistance to H 2 O and its temperature window shifted towards the higher temperature in presence of 10 vol% H 2 O, while the SCR activity of Cu-Fe/TiO 2 was inhibited significantly in the whole temperature range investigated. The suppression of adsorption and activation for NH 3 and NO x might be the reasons for the reversible inactivation, which was confirmed by the inhibitation of catalytic activities for separation NH 3 and NO oxidation under the wet condition. We speculated that different thermal stability of adsorbed species and redox capacity of catalysts leaded to the different SCR behavior in absence and presence of H 2 O. [ABSTRACT FROM AUTHOR]

In this contribution, HZSM-5 zeolites were modified by ethylene diamine tetraacetic acid (EDTA) to selectively eliminate the strong external acid sites, and the modified catalysts were then used to conduct the microwave assisted catalytic fast pyrolysis (MACFP) of mushroom waste (MW). Experiment results showed that the modification of HZSM-5 with EDTA had no significant effect on topological structure, and the surface area and total acid sites decreased while the pore volume increased within the modification time regions. Among the modified catalysts, an EDTA treatment for 2 h (labeled as 2H-Z5) performed prominent promise for removing oxygenated chemicals and promoting the aromatic species as well as inhibiting the formation of coke. Simultaneously, the effects of various regeneration steps for deactivated 2H-Z5 catalysts on products distribution were studied, and the highest relative content of hydrocarbons (19.9%) and the lowest coke yield (3.48%) could be obtained under the third regeneration cycle condition. [ABSTRACT FROM AUTHOR]

In this paper, HZSM-5 catalyst was modified by pre-coked to cover the strong external acid sites by methanol to olefins reaction, and the modified catalysts were then applied to conduct the catalyst fast pyrolysis of mushroom waste for upgraded bio-fuel production. Experiment results showed that the strong external acid sites and specific surface area decreased with pre-coked percentage increasing from 0% to 5.4%. Carbon yields of hydrocarbons increased at first and then decreased with a maximum value of 53.47%. While the obtained oxygenates presented an opposite variation tendency, and the minimum values could be reached when pre-coked percentage was 2.7%. Among the achieved hydrocarbons, toluene and p -xylene were found to be the main products, and the selectivity of p -xylene increased at first and then decreased with a maximum value of 34.22% when the pre-coked percentage was 1.3%, and the selectivity of toluene showed the opposite tendency with a minimum value of 25.47%. [ABSTRACT FROM AUTHOR]

A novel technology of two-step fast microwave-assisted pyrolysis (fMAP) of corn stover for bio-oil production was investigated in the presence of microwave absorbent (SiC) and HZSM-5 catalyst. Effects of fMAP temperature and catalyst-to-biomass ratio on bio-oil yield and chemical components were examined. The results showed that this technology, employing microwave, microwave absorbent and HZSM-5 catalyst, was effective and promising for biomass fast pyrolysis. The fMAP temperature of 500°C was considered the optimum condition for maximum yield and best quality of bio-oil. Besides, the bio-oil yield decreased linearly and the chemical components in bio-oil were improved sequentially with the increase of catalyst-to-biomass ratio from 1:100 to 1:20. The elemental compositions of bio-char were also determined. Additionally, compared to one-step fMAP process, two-step fMAP could promote the bio-oil quality with a smaller catalyst-to-biomass ratio. [ABSTRACT FROM AUTHOR]

[Display omitted] • Constructing pseudo-boehmite on kaolin has well retention for Pb, Cd, Cr and Zn. • Revealing adsorption properties of heavy metals coexisting at high temperature. • Electron transfer in adsorption is from HOMO of heavy metals to LUMO of adsorbents. • Experiments and simulations showed that the adsorption capacity is Cr>Zn>Pb>Cd. Heavy metals produced by coal combustion tend to bring environmental pollution. The modified additives were prepared by kaolin to capture heavy metals from coal combustion and analyzed by XRD, XRF, FT-IR, SEM and BET. The experimental results showed that the retention rates of heavy metals were ranked as Cr > Zn > Pb > Cd. The best retention of heavy metals was achieved at 1000 °C, while the retention capacity gradually decreased from 1000 to 1300 °C. The trapping effect of heavy metals in dynamic experiment is better than static experiment at 1300 °C. The general ranking of the adsorption capacity of the additives for the four heavy metals was pseudo boehmite-metakaolin (PBK) > aluminum sulfate impregnated metakaolin (AlSK) > metakaolin (MKA) > original kaolin (OKA). The PBK was the best adsorbent with the greatest retention rates of 77.35 %, 74.68 %, 83.35 % and 80.41 % for Pb, Cd, Cr and Zn, respectively. In addition, PBK showed the most significant improvement in the trapping of four heavy metals, with an average improvement of 37.79 % compared to no additives. The geometry models of heavy metal compounds and adsorbents were optimized. The heavy metal oxides were more stable than the chlorides and were more easily adsorbed. There is competitive adsorption between oxides and chlorides of heavy metals. The Al-O-Si-H and Al-O-Si are the best adsorption surfaces for OKA and MKA, respectively. However, CdO and CdCl 2 are hardly adsorbed on the Si-O surface of OKA. The frontline orbitals of four heavy metal oxides/chlorides, θ-Al 2 O 3 and α-Al 2 O 3 have been simulated. Computer simulations show that the mechanism of heavy metal oxide/chloride adsorption on additives is a stronger electron transfer induced interaction between the highest occupied molecular orbital of the adsorbate and the lower unoccupied molecular orbital of the adsorbent, which facilitates the formation of stable chemical bonds. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis lignin (EHL) is produced in large quantities during the fermentation of lignocellulosic biomass to produce ethanol, resulting in environmental pollution and resource waste. HZSM-5/MCM-41 core–shell zeolites (H/M) loaded with transition metal Mn, Fe, Co, Ni, Cu, and Zn at different loading levels (2, 4, 6, 8, and 10 wt%) were prepared as catalysts. Py-GC/MS was employed to investigate their effects on the selectivity for and relative abundance of monocyclic aromatic hydrocarbons (MAHs) in the catalytic pyrolysis products of EHL. On this basis, bimetal-loaded H/M catalysts were constructed, namely Fe-Zn@H/M, Fe-Co@H/M, Fe-Ni@H/M, Co-Zn@H/M, Co-Ni@H/M, and Zn-Ni@H/M. Co-Ni@H/M increased the selectivity for and relative abundance of MAHs by 11.68% and 28.01%, respectively, compared with the H/M catalyst. Moreover, Co-Ni@H/M induced a further increase in the selectivity for and abundance of MAHs compared with the corresponding monometal-loaded catalysts. The characterization results indicated that bimetallic Co and Ni loading were uniformly dispersed on the catalyst surface and did not change the structure of the parent catalyst but affected the pore characteristics and acidic site distribution of the catalyst. Further analysis of the pyrolysis products suggested that bimetallic Co and Ni loading enhanced the dealkylation capacity of the catalyst for furans, aldehydes and phenol derivatives. Oligomerization, cyclization and aromatization of short alkyl chains were promoted in the MAHs by Co-Ni@H/M. Meanwhile, bimetallic Co and Ni loading inhibited the polymerization of phenols and other oxygen-containing compounds by promoting dehydration, decarboxylation and decarbonylation, which indirectly reduced the formation of coke. [Display omitted] • Enzymatic hydrolysis lignin was used to prepare MAHs via catalytic fast pyrolysis. • Six bimetal-loaded catalysts by transition metal modification were constructed. • The highest selectivity of MAHs was obtained under Co-Ni@H/M. • The synergistic effects of Co and Ni during catalytic pyrolysis was investigated. [ABSTRACT FROM AUTHOR]

An eight-phased AA/O process has advantages of saving energy power, cost, and enhancing nitrogen and phosphorus removal; it does not need equipment for sludge and mixed liquor recycle and also it required small land for construction. A computer program was built based on activated sludge model No. 2d (ASM2d) for simulating the performance of multi-tank AA/O activated sludge process in Wuxi campus, southeast university. The difficulty of simulation is the system operation with unsteadily state condition. The results indicated that the growth rate constant of ammonia oxidizing bacteria was 1.4day -1 and yield coefficient was 0.14. According to simulation, heterotrophic organism XH, phosphate accumulating organism XPAO, and ammonia oxidizing bacteria XAOB decreased in the anaerobic tanks because of the lysis reaction. Then the XH, XPAO, and XA increased in the aerobic tanks due to aerobic growth. The heterotrophic microorganism; phosphorus accumulating organism; and autotrophic bacteria concentrations increased in quantities by about 56, 36, and 74% in tank one due to changes in the environmental state condition from anaerobic to aerobic and decreased in quantities by about 20, 44, and 0.14% in the tank three due to changes in the environmental state condition from aerobic to anoxic. The ratio of total nitrifying species to total active biomass varied between 1 and 12% in multi-tank AA/O process. The multi-tank AA/O system achieved 89 ± 1.3%, 87.7 ± 1.1%, 73.6 ± 2.1%, and 83.7 ± 0.9% of chemical oxygen demand, NH4 + -N, TN, and total phosphorus (TP) removal efficiencies, respectively, during a six-month operation with the effluent meeting Chinese sewage discharge standard GB18918-Grade A. [ABSTRACT FROM AUTHOR]

Quinolone antibiotics (QNs) can be potential hazard to environment and human. Combination of experimental and theoretical studies was used to analyze the adsorption properties of norfloxacin, ciprofloxacin and ofloxacin on modified thermally activated kaolin (KL). Main factors (calcination temperature, dose, pH, cations and regeneration) affecting the adsorption were discussed. Adsorption processes fit the pseudo-second order kinetic and Langmuir model well. The adsorption removal of norfloxacin, ciprofloxacin and ofloxacin can reach 88.53%, 89.43% and 91.46%, respectively. Cations inhibited adsorption, and AlS-KLB can maintain 80% efficiency in five cycles under optimal conditions. Simulations showed that the materials had good adsorption capacity for QNs, and the "①" of KL had the best capacity. Simulations explain the adsorption mechanism: F, H, O atoms of QNs are covalently bonded to O atoms from KL, Al 2 O 3 and Al (OH) 3 , C atoms from amorphous carbon and H atoms from C-H and Al (OH) 3. The Al atoms of Al 2 O 3 and Al, Si atoms of KL are ionically bonded to F, H, O atoms of QNs. This study shed new light on the removal of QNs by providing low-cost and efficient modified KL and elucidating the adsorption mechanism in conjunction with DFT simulations. [Display omitted] • We prepared modified thermally-activated kaolin for removal of NOR, CIP and OFL. • AlS-KLB achieved 88.53%, 89.43% and 91.46% removal of NOR, CIP and OFL respectively. • Models for adsorption systems were constructed and optimised based on DFT theory. • All three QNs are covalently and ionically bonded to thermally activated KL. • Adsorption energy, chemical bond numbers and charge transfer caused differences. [ABSTRACT FROM AUTHOR]

Direct carbon fuel cell (DCFC) is a device, which converts chemical energy of carbon into electrical energy through electrochemical oxidisation directly and its performance enormously depends on the characteristics of the fuel used. In this study, oak sawdust is used to prepare the activated carbon for the DCFC, with K2CO3 as the activating agent. Nickel catalyst is applied to improve the electrical conductivity, while HNO3 treatment is used for the purpose of surface modification and ash removal. The performance of the prepared activated carbon in DCFC is evaluated in a self-built DCFC anode apparatus. The results show that the BET surface area of activated carbon reaches 1240 m2/g under the following conditions: activation temperature, 1173 K; activation time, 2 h; and impregnation ratio, 1. Electrical conductivity is well improved through the nickel catalyst while the amount of surface oxygen functional groups is increased and ash content is decreased through the HNO3 treatment. When used as the fuel in the DCFC anode, the self-made activated carbon exhibits predominant performance among all tested carbon fuels, including graphite, activated carbon fibre, etc. © 2011 Canadian Society for Chemical Engineering [ABSTRACT FROM AUTHOR]

There has been an increasing interest in alternative fuels made from biomass which is abundant and renewable. Bio-oil and bio-diesel seem to be such promising liquid fuels. Bio-oil produced by fast pyrolysis of biomass is highly viscous, acidic, and has high water content. To overcome these problems as a fuel, a method of emulsifying bio-oil with bio-diesel was performed in the previous paper, and a stable mixture of bio-oil and bio-diesel was successfully prepared. In this paper, several properties of the mixture are discussed by using TG, FTIR and H NMR. The results show us that, compared with crude bio-oil, some properties of bio-oil/bio-diesel mixture such as water content, acid number, viscosity are much improved. The thermal decomposition of the mixture under air/nitrogen is shown using a thermogravimetric analyzer (TGA). Further information about the functional groups is exhibited through Fourier Transform infrared spectrometer (FTIR) and nuclear magnetic spectroscopy (NMR). [ABSTRACT FROM AUTHOR]

n experimental study of the SNCR process with urea as reducing agent and sodium salts as additive has been carried out, and detailed analysis of the reaction mechanism has been given here. In the temperature range of 800-975 °C, NO concentration decreases at first and then increases while the concentration of NO increases at first and then decreases with the increasing of temperature, and the turning point is 900 °C. With increasing of normalized stoichiometric ratio of reduction nitrogen to NO (NSR), NO removal efficiency increases, while the concentration of NO also increases, which decreases overall NO removal efficiency. With sodium salts as additive, the concentration of NO decreases with increasing of sodium salts addition at all temperatures, while the concentration of NO decreases at first and then increases at low-temperature side of the temperature window and increases at high-temperature side with additional increasing, whose changing extent is smaller than NO. Since sodium salts as additive can remove NO effectively and have no large influence on the removal of NO, the effect of sodium salts as additive is the combined effect of the production of active radicals and the removal of HNCO produced by the decomposition of urea through neutralization reactions, which is more important. To achieve the same effect under each condition, the needed addition of NaOH and CHCOONa is less than that of NaCO counting as Na atom. For the decomposition of CHCOONa can produce CHCOO, its addition can promote the reduction of NO more obviously at the lower temperature than NaCO or NaOH. Overall NO removal efficiency at 900 ‡C with NSR=1.5 had been improved from about 30% to 70.45% through the addition of sodium salts. Sodium salts as additive caused the flue gas to become alkaline gas, but it was not serious for sodium salts existing as NaNCO. [ABSTRACT FROM AUTHOR]

• The CHP of lignocellulosic biomass was carried out over a hierarchical catalyst. • The products of CFP and CHP of rice husk are compared. • CHP of rice husk (RH) over hierarchical catalyst led to a high hydrocarbons content. • The optimum conditions for the CHP of RH were 400 °C and 35 bar. In this study, we compare the products of catalytic fast pyrolysis (CFP) and catalytic hydropyrolysis (CHP) of rice husk over an HZSM-5-based hierarchical catalyst. The results suggest that the addition of hydrogen inhibits polycondensation reactions, leading to a reduction of 2.3 wt% in coke yield at 400 °C and 35 bar. The presence of hydrogen increases the relative content of hydrocarbons in both liquid and gas products, with a more significant increase in CH 4 and C 2 –C 3 yield in the gas, suggesting that hydrodeoxygenation, decarbonylation, and decarboxylation reactions are promoted. Alkali-treatment of the HZSM-5 improves the catalytic activity and coking resistance of the catalyst. The addition of an extra external MCM-41 layer to the alkali-treated HZSM-5 further improves the catalytic activity, resulting in a relative hydrocarbon content of 48.9%, which is higher than that obtained with the alkali-treated HZSM-5 and pristine HZSM-5. We also report the effect of pressure on the products. As the pressure increases from 1 to 35 bar, the relative content of hydrocarbons increases from 39.9 to 48.9%, while the coke yield decreases from 3.4 to 1.9 wt%, and CH 4 and C 2 –C 3 yields decrease from 10.3 wt% and 5.1 wt% to 14.2 wt% and 6.7 wt%, respectively. As the temperature increases from 300 to 400 °C, the relative content of hydrocarbons increases from 38.2% to 48.9%. Both CH 4 and C 2 –C 3 yields reach the highest values of 14.2 wt% and 6.7 wt% at 400 °C and 35 bar. [ABSTRACT FROM AUTHOR]

The excessive consumption of fossil fuels leads to a large amount of carbon dioxide (CO 2) being released into the atmosphere, destroying the natural balance of the carbon cycle system, causing the greenhouse effect, and aggravating global climate change. Electrocatalytic CO 2 reduction (E-CO 2 R) to produce value-added chemicals and synthetic fuels can not only solve the excessive emission of CO 2 but also realize the regeneration of carbon fuel. Given the unclear relationship between morphology and performance of copper-based catalysts for E-CO 2 R. The morphology of CuS nanomaterials prepared under different sulfur sources is different, which affects the performance of E-CO 2 R. In this study, a series of CuS nano-catalysts with multiple morphologies were prepared by using different sulfur precursors and surfactants based on morphology and structure regulation strategies, and E-CO 2 R performance tests were conducted to determine the structure-activity relationship between morphology and formate selectivity. Flower spherical morphology exhibited better Faraday efficiency for formate, followed by nanoparticles and finally nanospheres. After the surfactant was added, the morphology of CuS changed differently, such as adjusting the particle size of nano-flowers, alleviating the agglomeration of nano-particles, and forming hollow nano-spheres or composite morphology. These changes increased the electrochemical surface area and improved the performance of the electrocatalytic preparation of formate from CO 2 R. Density functional theory (DFT) was used to explain the reaction mechanism of E-CO 2 R to formate on different Cu surfaces, and the linear relationship between the work function corrected by sulfur content on each surface and the binding energy of *CO 2 was quantified. Bader charge analysis demonstrated that the stability of *OCHO was related to the algebraic sum of S and intermediate charges on each surface, and the formation energy of CO product intermediate *COOH was linear with that of HCOOH product intermediate *OCHO. [Display omitted] • Morphology-controlled CuS catalyst for selective electrochemical CO 2 reduction of formate. • The Faraday efficiency of formate formation reached 79.7 % at －1 V vs RHE. • DFT reveals the mechanism of S doping on Cu surface for electroreduction of CO 2 conversion. [ABSTRACT FROM AUTHOR]

With the new municipal solid waste classification policy implemented in China, attention on achieving the waste-to-energy disposal of "dry waste" has been growing. Pyrolysis conversion of organic waste into value-added chemicals is a promising method to treat solid waste. However, after removing the non-combustible components of "dry waste", the obtained high-organic solid waste (HSW) contains various heavy metals, which requires urgent attention during thermochemical conversion. To mitigate heavy metals risk, kaolin was employed as additive during HSW pyrolysis, and intercalation–exfoliation and thermal activation modifications were performed on the kaolin to further immobilize and stabilize heavy metals in the derived chars. The characterization results illustrated that the interlayer spacing, pore volume and diameter of kaolin were expanded after intercalation–exfoliation modification, providing more opportunities for the adsorption of metals. The thermal activation method favored the transformation of kaolin into metakaolin via dehydroxylation to enhance its nonhexacoordinated Al proportion and chemisorption. During 450–650 °C, kaolin exhibited an effective solid enrichment performance for targeting heavy metals, and the intercalation–exfoliation and thermal activation modification further enhanced the adsorption capacity of the kaolin for Cd, Cr, Pb and Cr, Cu, Pb, Zn, respectively. Compared with Cu and Zn, additives demonstrated better stabilization effects for Cd, Pb, and Cr, transforming more bioavailable fractions to the residual speciation. Overall, a higher pyrolytic temperature (650 °C) and the addition of effective additives could simultaneously increase the residual fraction and decrease the bioavailable fraction of heavy metals in HSW-derived chars, reducing the potential ecological risk. [Display omitted] • Fixation of heavy metals during high-organic solid waste pyrolysis was studied. • Intercalation-exfoliation expanded kaolin interlayer spacing, pore volume/diameter. • Moderate thermal activation temperature increased specific surface area of kaolin. • Additive addition and higher pyrolysis temperature stabilized Cd, Cr and Pb better. • Pyrolysis at 650 °C with FA-kaolin was optimal to reduce ecological risks of chars. [ABSTRACT FROM AUTHOR]

Experimental and theoretical studies are combined to analyze the adsorption properties of modified kaolin for heavy metal (Pb, Cd, Zn and Cr) from coal combustion. The results indicate that the retention effect of kaolin for Pb, Cd, Zn and Cr has been significantly enhanced after intercalation-exfoliation combined with acid/alkali modification, which is mainly attributed to more active sites for adsorption, richer porosity and more effective in retarding coking of coal ash. The higher oxygen concentration is positive to the enrichment of heavy metals at 900–1200 ℃, while the coking of coal ash and the thermal conversion of additives become the main factors affecting the absorption at 1200–1300 ℃. The acid/alkali modification effectively promotes the inductive effect of electron transfer between modified kaolin and heavy metals to form stable chemical adsorption. The electron transfer induction of modified kaolin for Pb, Cd is higher than Zn, Cr at 900–1000 ℃, while the adsorption activity of mullite and cristobalite for Zn, Cr is stronger than Pb, Cd at 1200–1300 ℃. In addition, Pb, Cd and Zn are more readily adsorbed as oxides by additives at 900–1300 °C. The results shed new light on strengthening the adsorption activity of kaolin to Pb, Cd, Zn and Cr in high temperature. [Display omitted] • The thermal conversion of additive has a significant effect on the adsorption activity. • The higher oxygen concentration is positive to the enrichment of heavy metals. • Modified kaolin has selectivity for the adsorption of Pb, Cd, Zn and Cr at 900 ℃–1300 ℃. • The acid/alkali modified KAc-kaolin effectively promotes the nucleophilic sensitivity. • Pb, Cd and Zn are more readily adsorbed as oxides by additives at 900 °C–1300 °C. [ABSTRACT FROM AUTHOR]

[Display omitted] • A microwave-heated fluidized bed system was first built. • Further improving the efficiency of the CFP of biomass and bio-oil quality. • The pyrolysis characteristics of different catalysts and biomass ratios was studied. • Hierarchical micro-mesoporous catalyst has strong regeneration ability. To improve the efficiency of the catalyst fast pyrolysis (CFP) of rice husk and the quality of bio-oil, we integrate both microwave heating and fluidized bed reactor methods and build a microwave-heated fluidized bed system. In this study, the liquid yield from the CFP of rice husk in a microwave-heated fluidized bed (55.3 wt.%) is significantly higher than that obtained from a fixed bed (47.6 wt.%). Meanwhile, the relative content of hydrocarbons from microwave assisted catalytic fast pyrolysis (MACFP) of rice husk (RH) over a hierarchical micro-mesoporous composite molecular sieve (HM-2.0 T) is 67.6 % higher than that (51.6 %) of the organic base modified HZSM-5 (HT-2.0) and HZSM-5 (40.2 %) in the microwave-heated fluidized bed system. Furthermore, we focused on the ratio of biomass to catalyst in CFP processing and discover that the increased amount of catalyst promoted the decarbonylation and decarboxylation reactions, producing more hydrocarbon compounds, however, the excessive amount of catalyst does not contribution to higher monocyclic aromatic hydrocarbon selectivity. Besides, the hierarchical micro-mesoporous composite catalyst had strong regeneration ability and reusability. The selectivity of monocyclic aromatics remained high when the regeneration times increase from 1 to 4, which provided possibilities for applications of hierarchical micro-mesoporous composite catalyst in industrial production in the future. [ABSTRACT FROM AUTHOR]

In the process of municipal solid waste (MSW) pyrolysis, kaolinite possesses an outstanding trapping effect on semi-volatile metal vapors (Pb, Cd) through physical and chemical adsorption. In this paper, the microscopic mechanism of PbCl 2 and CdCl 2 adsorption on the surface of Al rings and Si rings of kaolinite was investigated by combining Monte Carlo method with density functional theory (DFT). The calculations indicate that the continuously enriched pore structure in the process of dehydroxylation indirectly influences the adsorption of PbCl 2 /CdCl 2 by kaolinite. Under the non-bond interaction and electron transfer induction, PbCl 2 molecules are more conveniently adsorbed on the Al-(001) surface than CdCl 2 , while the adsorption sites of CdCl 2 molecules are more widely distributed on the Si-(001) surface. Moreover, the transform in the Al-coordination and the exposed active oxygen atoms significantly affect the adsorption activity of kaolinite (the capability to gain and lose electrons). Considering the energy barrier and electrophilic nucleophilic sensitivity, it is more feasible for PbCl 2 /CdCl 2 to be adsorbed near IV/V-coordinated Al and active O under Van der Waals action. Subsequently, IV/V-coordinated Al will act as an electron acceptor, and the active oxygen atoms after dehydrogenation will serve as an electron donor. Under the induction of the energy difference of frontier orbitals, the electrons transfer will encourage the formation of more stable adsorption states. The results shed new light on strengthening the adsorption activity of kaolinite to PbCl 2 /CdCl 2 in the process of MSW pyrolysis. Image 1 • The pore structure possesses an indirect effect on the adsorption of PbCl 2 /CdCl 2. • PbCl 2 and CdCl 2 are dominant in the adsorption of Al-(001) and Si-(001) surfaces respectively. • PbCl 2 and CdCl 2 are more feasibly adsorbed near IV/V–Al and active O under van der Waals force. • The electrostatic force promotes the adsorption of PbCl 2 near the residual hydroxyl groups. • Active oxygen atoms and IV/V–Al have nucleophilicity and electrophilicity, respectively. [ABSTRACT FROM AUTHOR]

This paper reports the results obtained for microwave-assisted catalytic fast pyrolysis (MACFP) of rice husk. The MACFP process employed a hierarchical catalyst prepared via a combination of organic alkali treatment (TPAOH) and the generation of an external layer of MCM-41-type mesoporous channels. We propose this catalyst which is used for the first time for pyrolysis of lignocellulosic biomass, as a tool to reduce coke agglomeration and increase hydrocarbon yields. Our results indicate that during catalyst preparation the mass fraction of cetyltrimethylammonium bromide (CTAB) has a direct effect on the content of MCM-41 formed on top of the HZSM-5 core. For MACFP, we hypothesize that the small molecules generated from thermal decomposition of rice husk react further to form aromatic and aliphatic hydrocarbons by decarbonylation, decarboxylation, oligomerization and aromatization. The highest hydrocarbon yield (60.5%) was obtained for a catalyst modified by a 2.0 mol/L TPAOH solution, with 10 wt% of CTAB (template for producing MCM-41), as well as with digestion and crystallization at 110 °C for 24 h. In addition, the highest liquid yield (47.6 wt%) was obtained at 550 °C. The relative content of hydrocarbons goes through a maximum of 60.5% with CTAB mass fraction which was higher than values obtained with MCM-41 (3.2%) and HZSM-5 (36.0%). Characterization and catalytic testing results suggest that the digestion temperature plays a more important role in the catalyst synthesis than the crystallization temperature. High digestion temperature (120 °C) decreases the overall hydrocarbon selectivity from 60.5% (110 °C) to 39.2%. The relative content of oxygenates reached the lowest value of 35.9% at the digestion and crystallization temperature of 110 °C. The synergistic effect of the MCM-41 shell and the HZSM-5 core promotes the catalytic activity, leading to outstanding deoxygenation capabilities and excellent selectivity to BTEX (52.7%). Unlabelled Image • We carried out pyrolysis of lignocellulosic biomass with a hierarchical catalyst. • The hierarchical catalyst was composed of HZSM-5 core and MCM-41 shell. • The hydrocarbons content is higher than the value obtained with other catalysts. • MACFP of RH led to 60.5% relative content of hydrocarbons. [ABSTRACT FROM AUTHOR]

• Chemical liquid deposition optimized pore-opening size and outer acidity of HZSM-5. • HZSM-5 modified by TiO 2 performed higher weak acidity for catalyzing. • Serial two-step reactor owned microwave-assisted fixed bed and reforming furnace. • The pyrolysis and catalytic upgrading processes can be independently controlled. • High selectivity of monocycle aromatics was obtained by small catalyst loading. The ex-situ catalytic upgrading of vapors from the microwave-assisted pyrolysis of bamboo sawdust for aromatics-rich bio-oil production was investigated. It was found that the sequential two-stage reactor, with microwave-assisted fixed bed and independent vertical reforming furnace, could separately optimize both the pyrolysis and catalytic upgrading processes. Besides, for purpose of decreasing coke generation and enhancing aromatics yield during the catalytic fast pyrolysis (CFP) of bamboo, chemical liquid deposition (CLD) was used to modify HZSM-5, which played a significant role in reducing external acid sites and narrowing the pore-opening size of catalyst. Experimental results illustrated that the yield of pyrolyzed oil initially increased, and then decreased, with increasing pyrolysis temperature, achieving its maximum at 550 ℃. In addition, the effect of different CLD modifying conditions (modifier type, deposited amount, and deposition time) on aromatics proportion of the obtained bio-oil was further explored. The consequences presented the TiO 2 -modified HZSM-5 (deposited amount, 4%; deposition time, 4 h) provided the maximal yield of BTX (benzene, toluene and xylene, 23.58%) compared to the original HZSM-5 (BTX: 16.96%), and the coke generation clearly declined. Simultaneously, the catalytic temperature and catalyst to biomass mass ratio (C/B) in ex-situ upgrading process were also investigated, and it was found that the concentration of BTX was maximized at catalytic temperature of 500 ℃, and C/B = 1. [ABSTRACT FROM AUTHOR]

Magnetic Co0.5Zn0.5Fe2O4 nanoparticles were prepared by the nitrate-alcohol-solution combustion and calcination technique. The morphology and composition of Co0.5Zn0.5Fe2O4 nanoparticles were characterized by the scanning electron microscopy (SEM), the transmission electron microscopy (TEM), the X-ray diffraction (XRD), the energy-dispersive spectroscopy (EDS), the vibrating sample magnetometer (VSM), the Fourier transform infrared spectrometer (FTIR), and the Brunauer-Emmett-Teller measurement (BET). The concentration of the ferric nitrate and the calcination temperature were the two key factors to the property of Co0.5Zn0.5Fe2O4 nanoparticles. To achieve greater adsorption capacity and durability of materials, magnetic Co0.5Zn0.5Fe2O4 nanoparticles calcined at 400 °C with ferric nitrate concentration of 0.84 M were employed to remove reactive red 2BF (RR-2BF). The pseudo-second-order kinetic model could be applied to describe the adsorption process of RR-2BF onto Co0.5Zn0.5Fe2O4 nanoparticles in the initial RR-2BF concentrations of 100–400 mg L−1, and the adsorption process could be fitted well by Langmuir model. The above adsorption experiments results suggested that the adsorption of RR-2BF onto Co0.5Zn0.5Fe2O4 nanoparticles was the monolayer adsorption mechanism. The effect of the dye solution pH on the adsorption process had been explored. At the same time, the removal efficiency for RR-2BF onto Co0.5Zn0.5Fe2O4 nanoparticles could maintain more than 72% after 10 cycles. [ABSTRACT FROM AUTHOR]

• We performed microwave assisted catalytic fast pyrolysis of rice husk over alkali-treated HZSM-5 at concentrations greater than 1.0 mol/L. • Organic treatment with TPAOH is more moderate than the treatment with NaOH and creates mesoporous structures in the HZSM-5 while retaining the acidic sites in the micropores. • The novel catalyst increases the yield of hydrocarbons from pyrolysis and reduces the coke yield. • The organic alkaline treatment led to a moderate modification compared to inorganic alkali treatment. • The catalytic activity of HZSM-5 modified with TPAOH is higher than that of the catalyst modified with NaOH. We performed microwave-assisted catalytic fast pyrolysis (MACFP) of rice husk (RH) over an alkali-treated HZSM-5 zeolite, for production of hydrocarbons. The treatment consisted in the modification of the HZSM-5 by the organic base tetrapropylammonium hydroxide (TPAOH) solution at several concentrations. We characterized the resulting catalysts by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), N 2 adsorption-desorption, and temperature-programmed sorption of ammonia (NH 3 -TPD). The results suggest that the TPAOH treatment generated mesoporous structures in the HZSM-5, while preserving its microporous structure and crystallinity. We obtained the highest yield (45.9%) of hydrocarbons from MACFP of rice husk (RH) at 550 °C. As the TPAOH concentration increases, the relative content of BTEX hydrocarbons (benzene, toluene, ethylbenzene, and xylene) reaches a maximum value of 22.9% at 2.0 mol/L. A comparison of results obtained over the organic base TPAOH (HZSM-5 modified by 2.0 mol/L TPAOH solution) with those obtained over an inorganic base (HZSM-5 modified by 2.0 mol/L NaOH solution) shows a 4.3% increase in the relative content of monocyclic aromatic hydrocarbons for the TPAOH. In addition, the TPAOH-treated catalyst shows excellent selectivity of BTEX (58.5%), which is higher than the selectivity obtained with the parent HZSM-5 (51.2%) and NaOH-treated HZSM-5 (53.9%). The TPAOH-modified HZSM-5 catalyst effectively reduced coke formation by 4.6% compared to MACFP over the parent HZSM-5, most likely because TPAOH decreases the concentration of strong acidic sites on the outer surface of the catalyst, creating a mesoporous structure while retaining the weak acidic sites on the HZSM-5 inner surface. The new catalyst generated in this work contains a moderate amount of mesopores structures, which allows for effective upgrading of pyrolysis vapors while simultaneously reducing coke formation, thereby addressing a significant problem in the development of the catalytic fast pyrolysis process. [ABSTRACT FROM AUTHOR]

Co-combustion of coal and wheat straw (WS) was conducted in a lab-scale BFB combustor. Fuel composition (coal, 70%coal+30%WS), temperature (750, 800, 850, 900, 950 °C), secondary air ratio (0, 10%, 20%, 30%) were varied to on the release of gaseous pollutant was studied. CO, NO x and SO 2 concentration in flue gas (FG) were measured on-line by a flue gas analyzer. Fly ash (FA), bottom slag (BS) and bed material (BM) were collected, digested and analyzed by ICP-OES to determine the distribution of heavy metals (e.g. Pb, Zn, Cr and Cd). Results indicated that co-combustion could improve the combustion of coal alone by reducing CO, NO x and SO 2 emission and carbon content in fly ash effectively. In co-combustion the increasing secondary air could reduce CO emission and SO 2 by enhancing disturbance and promoting sulfation respectively while the minimum NO emission was reached at the ratio of 20%. Co-combustion restrained the release of Zn, Cd and Pb compared with coal combustion alone. In co-combustion, high temperature increased their portion in the flue gas. For Zn, Pb and Cd, their content in the bottom solids increased while the portion of Cr decreased. Secondary air decreased their content in fly ash and transferred into flue gas significantly and in bottom solids content of Zn and Pb decreased while Cd increased. • Co-combustion decreased SO 2 , NO and CO emission and carbon content in fly ash. • Releases of Pb, Zn and Cd are restrained in co-combustion. • High temperatures promote the transfer of Zn, Pb and Cd in bottom solids. • Melting in the slag affected the release of Cd and Zn. • Secondary air promote the release of heavy metals. [ABSTRACT FROM AUTHOR]

The preparation of furfural, a valuable platform compound, through pyrolysis is an approach with practical prospects. Since cellulose represents the most abundant component in biomass feedstocks, enhancing its selectivity towards furfural during pyrolysis is crucial. In this study, S0 4 2-/Zr0 2 -based catalysts by loading them with various metals such as Fe, Co, Ni, Cu, and Zn was used to optimize furfural yield from cellulose. Among these catalysts, those loaded with iron (Fe) achieved the highest selectivity for furfural, with the best performance at a loading of 6 % by weight. This is because an appropriate amount of loaded metal Fe can manipulate the acidity sites on the catalyst surface, reducing the ratio of weak acid to strong acid and favoring selective production of furfural. Additionally, moderate metal loading can enhance both specific surface area and total pore volume of the catalyst, further improving catalytic performance. The research using a catalyst with the loading of 6 %wt Fe showed that the furfural content in cellulose pyrolysis products reached its maximum when the pyrolysis temperature was 600°C. Further increase in temperature led to the decomposition and conversion of furfural into other products, reducing the furfural selectivity. The addition of catalyst effectively improved the furfural selectivity in cellulose pyrolysis products, and as the ratio of catalyst to cellulose gradually increased, the furfural selectivity reached its maximum value of 31.53 % at a pyrolysis temperature of 600℃ and a catalyst to cellulose ratio of 4:1. These findings provide an insight into the use of biomass for furfural preparation and improving the efficiency of its preparation. • Metal-loaded solid acid catalysts can significantly enhance the yield of furan products. • The mechanism of cellulose pyrolysis catalyzed by Fe-loaded SO 4 2-/ZrO 2 catalyst has been clarified. • The catalytic potential of 6 %Fe-Zr in cellulose conversion to furfural is significant. [ABSTRACT FROM AUTHOR]

To investigate the catalytic pyrolysis performance of complex metal oxide catalysts for biomass, γ-Al2O3 was prepared through the precipitation method, and then ZrO2 and γ-Al2O3 were blended in the proportion of 2:8 using the co-precipitation method. Next, CeO2 was loaded on the surface of the catalyst for further modification. The three catalysts, A, ZA and CZA, were obtained. The specific surface and acidity of the catalysts were characterized by nitrogen adsorption–desorption and NH3-Temperature Programmed Desorption (NH3-TPD) respectively. The catalytic pyrolysis performance of catalysts for bamboo residues was investigated by Pyrolysis gas chromatography mass spectrometry (Py-GC/MS). Chromatograms were analyzed for identification of the pyrolysis products and the relative amounts of each component were calculated. Experimental results indicated that catalyst A had a good catalytic activity for the fast pyrolysis of bamboo residues. The addition of ZrO2 and CeO2 could continuously enhance the acidity of the catalyst and further promote the pyrolysis of macromolecular compounds and deoxidation of oxygen-containing compounds. Finally, catalyst CZA, obtained by compound modification, could not only dramatically reduce the relative content of phenol, acid and aldehyde and other oxygen-containing compounds, but also achieved the maximum hydrocarbon yield of 23.38%. The catalytic performance of catalyst CZA improved significantly compared with catalyst A. [ABSTRACT FROM AUTHOR]