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Mulberry leaf (Mori Folium) extract (MLE) is known to have anti-obesity effects. In this study, the enhanced effects of MLE after bioconversion treatment using Pectinex (BMLE) on obesity were explored, and the underlying mechanisms were investigated using the active components, neochlorogenic acid (5-CQA) and cryptochlorogenic acid (4-CQA), whose amounts were increased by bioconversion of MLE. Both MLE and BMLE inhibited lipid accumulation in 3T3-L1 adipocytes without cytotoxicity and suppressed the expression of CCAAT/enhancer-binding protein alpha (C/EBPα). In addition, MLE and BMLE decreased high-fat diet-induced adipose tissue mass expansion. Notably, BMLE significantly increased antiadipogenic and anti-obesity effects compared to MLE in vitro and in vivo. The active ingredients increased by bioconversion, 5-CQA and 4-CQA, inhibited the protein levels of C/EBPα and the mRNA levels of stearoyl-CoA desaturase 1 (Scd1). These findings provide new insights into the therapeutic possibility of using bioconversion of MLE, by which upregulation of 5-CQA and 4-CQA potently inhibits adipogenesis.

Welding and local heat treatment with a high-power laser for GPa-grade transformation-induced plasticity (TRIP) steel were studied. When the focal length and scan speed were controlled under a fixed laser power, defect-free full penetration conditions were achieved at various heat inputs. The effects of laser heat input on the mechanical properties of the steel were evaluated. The results showed that a softened zone was lowered to 350 HV of hardness by tempered martensite under all laser conditions. As the heat input increased, the zone became wider. When an appropriate heat input of 20-60 mm/J was irradiated, the tensile strength and elongation were improved as compared with the base material. Under these conditions, the softened zone was significantly narrowed by the TRIP effect under tensile stress, and base metal fracture occurred. In addition, the laser increased the hardness in the weld metal and further activated the TRIP effect of the retained austenite. However, at a heat input of 90 J/mm, the TRIP effect was limited in the tensile test due to the wide softened zone and the increased hardness of sub-critical heat affected zone during the laser process. In this study, the effective heat input of the laser formed a full-penetration joint and locally enhanced strength and elongation simultaneously.

Gas metal arc (GMA) welding is widely used in the machinery industry. The quality of a welded joint is affected by the penetration of root pass welding in the V-groove joint. Automation using GMA welding is continuously required, and root pass welding automation is required to automate the entire welding process. In particular, the development of a prediction model that can ensure full penetration back-bead is required for the automation of root pass welding. In this study, a convolutional neural network (CNN) model was applied to predict the occurrence of back-bead in V-groove butt joint GMA root pass welding. The bead profile was measured using a laser vision sensor system and it was used as the input data for the prediction model, and the bead occurrence was used as the output data for the model. A total of 12,873 bead profiles were extracted and pre-processed through cutting, resizing, and thresholding. The CNN model consists of nine layers, and performs three convolution and two pooling operations. The accuracy of the prediction model was 99.5%, and through this study, it was demonstrated that the quality of root-pass welding can be controlled by using convolutional neural network and it can contribute to automation.

Catalytic co-conversion of Kraft lignin (KL) and linear low-density polyethylene (LLDPE) over mesostructured catalysts was examined using a micro-pyrolyzer equipped with gas chromatography-mass spectrometry/flame ionization detector (MPy-GC/MS/FID). Mesoporous catalysts of Al-SBA-15 and mesoZSM-5 were synthesized and characterized by N2 sorption, ammonia temperature programmed desorption, and X-ray diffraction. The characterization results indicated that mesoZSM-5 had the smaller average pore size (4.10 nm) than Al-SBA-15 (10.70 nm), but its total acidity (both weak and strong acid sites) was much higher than Al-SBA-15. When they were applied as catalysts in the pyrolysis of KL and LLDPE, the mesoZSM-5 exhibited higher catalytic activity for aromatic hydrocarbon production due to its higher acidity and MFI pore structure. Indeed, synergistic synthesis of aromatic hydrocarbons was achieved via the catalytic co-pyrolysis of KL and LLDPE because of the H-donating effect of LLDPE; the experimental yields (GC/MS area; abundance vs. time) of aromatic hydrocarbons in the oils obtained from catalytic co-pyrolysis of KL/LLDPE (1:1) over Al-SBA-15 (8.76 × 107) and mesoZSM-5 (27.58 × 107) were ∼1.5 fold higher than the theoretical yields.

Ex-situ catalytic pyrolysis of Quercus mongolica over HZSM-5 and in-line esterification of pyrolysis/catalytic pyrolysis vapors with liquid phase n-butyl alcohol were carried out in a fluidized bed reactor. The ex-situ catalytic pyrolysis over HZSM-5 beads was performed to produce bio-oil containing aromatic hydrocarbons. The temperature of the ex-situ catalytic upgrading reaction was varied from 450 °C to 600 °C, and the maximum aromatic hydrocarbons yield was obtained at 450 °C. The selectivity for aromatic hydrocarbons as a function of catalytic reaction temperature varied depending on aromatic ring number, as the selectivity for mono-aromatic hydrocarbons decreased and that for poly-aromatic hydrocarbons increased with temperature. In-line esterification of the pyrolysis/catalytic pyrolysis vapors with liquid n-butyl alcohol was also carried out, and the GC/MS analysis results showed that the acids, aldehydes and ketones in the bio-oil were converted to esters and acetals.

The thermal and catalytic pyrolysis of pine needles over HBeta catalysts with different SiO2/Al2O3 ratios (25 and 300) were investigated by thermogravimetric analysis (TGA) and pyrolyzer-gas chromatography/mass spectrometry. TGA showed that the main decomposition of pine needles occurred between 150 and 550 °C. The catalytic DTG curves revealed the same decomposition temperature region as the non-catalytic TG curve of pine needles. Pyrolyzergas chromatography/mass spectrometry suggested that the effective catalytic conversion of pyrolyzate intermediates and other hydrocarbons to aromatic hydrocarbons can be achieved using HBeta catalysts at 600 °C. HBeta(25) produced a larger amount of aromatic hydrocarbons than HBeta(300) because of its higher acid amounts. By increasing the reaction temperature from 500 to 700 °C, the formation of benzene, toluene, ethylbenzene, xylenes (BTEXs) and other polycyclic aromatic hydrocarbons was increased with a concomitant decrease in phenolics and other oxygenates. The formation efficiency of BTEXs was increased further by increasing the catalyst loading.

The detection of ~50 coalescing compact binaries with the Advanced LIGO and Virgo detectors has allowed us to test general relativity, constrain merger rates, and look for evidence of tidal effects, compact object spins, higher waveform modes, and black hole ringdowns. An effect that has not yet been confidently detected is binary eccentricity, which might be present in a small fraction of binaries formed dynamically. Here we discuss general limits on eccentricity that can, in-principle, be placed on all types of compact object binaries by a detector operating at the design sensitivity of Advanced LIGO. Using a post-Newtonian model for gravitational-wave phasing valid in the small eccentricity regime, we assess the relative measurement error for eccentricity for a variety of spinning and non-spinning binaries. Errors and correlations involving the mass and spin parameters are also investigated. We find that decreasing the low frequency limit of a detector's observational frequency band is one of the key design factors for increasing the odds of measuring binary eccentricity. We also introduce and analytically explore the eccentric chirp mass parameter, which replaces the chirp mass as the key measurable parameter combination in eccentric gravitational waveform models. The eccentric chirp mass parameter explains a degeneracy between the chirp mass and the eccentricity. This degeneracy leads to a bias in the standard chirp mass parameter. We also investigate the systematic parameter bias that arises when eccentric systems are recovered using circular waveform templates. We use both Fisher matrix and Bayesian-inference-based Markov Chain Monte Carlo (MCMC) methods to investigate these parameter estimation issues, and we find good agreement between the two approaches (for both statistical and systematic errors) in the appropriate signal-to-noise ratio regime. (abridged), 31 pages, 11 figures, 4 tables; published in Phys. Rev. D. V2: minor changes to match published version; some material moved to an appendix, minor equation renumbering

Calcined waste seashell powder from cockles and mussels was used as the pretreatment materials for kraft lignin (KL), and their impacts on the pyrolysis behavior of KL were examined using a laboratory-scale fixed bed reactor and thermogravimetric analysis. The highest intensity of the CaO peak was observed on the XRD patterns of the seashell obtained from the calcination of mussel shells at 800 °C (M8). Char foaming was not detected when the water treated KL/seashell were pyrolyzed at 500 °C. In contrast, severe char foaming and agglomeration were observed when KL alone and a physical mixture of M8 and KL (KL/M8-mix) were pyrolyzed at the same temperature. The pyrolysis of water-treated KL/M8 (KL/M8/water) also produced much higher quality oil than those of KL alone or the KL/M8 mixture, showing higher selectivity to light phenols and aromatics. The decomposition temperature of KL was also decreased using M8 with water due to the catalytic effect of calcium oxide.

Lignocellulosic biomass is an abundant and environment-friendly source for renewable energy production. The value and application of biochar, which is obtained from the thermochemical conversion of biomass, is increasing rapidly because of its high carbon content and porosity. The property of biochar, such as surface area, porosity, and number of functional groups, can be improved by controlling the conditions of biomass conversion, biochar activation, and functionalization methods. The production and activation of biochar as well as its potential use for soil remediation, pollutant adsorption, and biorefinery have been reviewed extensively over recent decades. This paper provides a conceptual approach for biochar production and activation together with its application as a catalyst for biorefineries and the removal of environmental contaminants.

Various MgO impregnated catalysts were used for the catalytic co-pyrolysis (CCP) of cellulose and linear low-density polyethylene (LLDPE) at 600 °C in ambient pressure. Micro reactor-gas chromatography, a semi-batch reactor, was used as a reactor and gas chromatogram/mass spectrometry/flame ionization detector were used for product detection. Three kinds of MgO impregnated catalysts, MgO/Carbon (MgO/C), MgO/Al2O3, and MgO/ZrO2, were prepared by the impregnation of MgO to different supporting material s, C, Al2O3, and ZrO2, respectively. Activities of the three MgO-impregnated catalysts were compared with 1:5 of feedstock to catalyst ratio. MgO/C produced the highest quality oil, which consisted of a large amount of aromatic hydrocarbons during the catalytic pyrolysis (CP) of cellulose. When the MgO catalysts were applied to CCP, the selectivity to aromatic hydrocarbons over MgO/C were 13.42%, which were also much higher than those over the other catalysts, including bulk MgO, demonstrating the effectiveness of the MgO/C catalyst on aromatics formation. Importantly, the experimental BTEXs (benzene, toluene, ethylbenzene, xylenes) yields of CCP over MgO/C were also much higher than the theoretical yields, highlighting the effectiveness of hydrogen-rich LLDPE on the CP of cellulose over MgO/C. Further investigation of the cellulose/LLDPE mixing ratio showed that the amount of BTEXs during the CCP of cellulose and LLDPE could be maximized by adjusting the cellulose to LLDPE mixing ratio to 25:75.

Hierarchical zeolites have superior catalytic properties over purely microporous zeolites, leading to the enhanced diffusivity of molecules and strong acidity of the catalyst. In this study, hierarchical desilicated mesoporous ZSM-5 and Beta were prepared by the desilication of commercial microporous zeolites and applied to the catalytic pyrolysis of wood polymer composites. Hierarchical desilicated mesoporous ZSM-5 and Beta showed the typical X-ray diffraction patterns of microporous ZSM-5 and Beta with higher mesoporosity compared to the parent materials. The activity of the desilicated zeolites for the catalytic pyrolysis of wood polymer composites was evaluated using a thermogravimetric analysis and tandem micro reactor-gas chromatography/mass spectrometry. Among the catalysts tested, the lowest decomposition temperatures of wood polymer composites were observed using hierarchical desilicated mesoporous Beta followed by hierarchical desilicated mesoporous ZSM-5 and ZSM-5. This trend correlated well with the mesoporosity of the catalysts. The formation efficiency of hierarchical desilicated mesoporous ZSM-5 was highest followed by microporous ZSM-5, hierarchical desilicated mesoporous Beta, and Beta, indicating that in addition to mesoporosity, the shape selectivity induced by microporosity and strong acidity are important for the aromatization of pyrolysis vapors. In addition, the aromatic formation efficiency of the catalysts differed according to the properties of wood polymer composites. Compared to wood polymer composite 2, wood polymer composite 1 produced a larger quantity of aromatics during catalytic pyrolysis over all the catalysts at 500 °C owing to its higher polyethylene content. Both wood polymer composites exhibited a similar aromatic formation efficiency during catalytic pyrolysis at 600 °C because the diffusion hindering effect of polypropylene molecules to the catalyst pores was lower at the higher temperature.

This study examined the catalytic co-pyrolysis of yellow poplar wood and polyethylene terephthalate over basic calcium oxide and acid zeolites, such as HY (SiO2/Al2O3: 30), Hβ (25), HZSM-5 (23), to maximize the yields of aromatics using thermogravimetric analysis and tandem μ-reactor-gas chromatography/mass spectrometry. The maximum decomposition temperature of polyethylene terephthalate on the catalytic thermogravimetric analysis over HZSM-5 (452 °C) was reduced by co-feeding with yellow poplar wood to 444 °C because of its catalytic property and the effective interaction between the catalytic co-pyrolysis intermediates of yellow poplar wood and polyethylene terephthalate. Non-catalytic co-pyrolysis produced smaller amounts of large molecular polyethylene terephthalate pyrolyzates because of the more effective secondary cracking and deoxygenation. Calcium oxide was effective in the deacidification and acid zeolites were efficient in aromatics production during the catalytic co-pyrolysis of yellow poplar wood and polyethylene terephthalate. Among the acid zeolites, HZSM-5 showed the highest efficiency on benzene, toluene, ethylbenzene, and xylenes (BTEXs) production, followed by Hβ and HY because of its strong acidity and proper pore size. The experimental MS intensities of BTEXs obtained from the catalytic co-pyrolysis of yellow poplar wood and polyethylene terephthalate over HZSM-5 (1083 × 106) were larger than their theoretical value (998 × 106). Compared to the single stage catalytic co-pyrolysis of yellow poplar wood and polyethylene terephthalate over ex-situ HZSM-5, the two-stage catalytic co-pyrolysis over in-situ calcium oxide and ex-situ HZSM-5 produced the much larger amounts of BTEXs during seven times sequential experiments.

The issues over increases in energy demand and environmental pollution attributed to excessive use of fossil fuel have been the driving forces of the exploration for eco-friendly resource. Lignocellulosic biomass consisting of carbohydrates and lignin can be a renewable feedstock for replacing fossil fuels in the future because it is a plentiful and carbon neutral material. Especially, lignin, cross-linked phenolic polymers, is a topic of interest owing to its abundant production from pulp/paper industries as well as lignocellulose based biorefinery. The large potential of platform chemicals and biofuels from lignin has opened up an extensive range of opportunities to develop thermal and catalytic conversion technology. Over a few decades, several lignin conversion processes including catalytic pyrolysis, catalytic depolymerization, and catalytic oxidation have been developed to improve target products yields and to suppress side reactions. More recently, lignin-first approaches which maintain carbohydrates intact by selective extraction of lignin as valuable phenolics from whole biomass has been suggested. This review introduces recent ten years progress on thermal and catalytic conversion technology in terms of process type, catalyst development, and target products. This review is expected to offer an influential information for future research into the thermal and catalytic conversion of lignin as well as lignocellulosic feedstock.

A base catalyst is expected to suppress coke formation of the catalyst, leading to less catalyst deactivation and more efficient production of bio-oil. To examine the feasibility of a solid-base catalyst as a lignin pyrolysis catalyst, MgO loaded on supports with different textural, acid, and base properties (i.e. carbon, Al2O3, and ZrO2) was applied. In addition, because the co-processing of biomass with plastic significantly improves the quality of bio-oil in the catalytic pyrolysis process, co-pyrolysis of lignin with linear low-density polyethylene was performed, and the effects of the MgO catalysts were analyzed. Thermogravimetric analysis and a tandem micro-reactor–gas chromatography/mass spectrometry system were used to evaluate the performance of the MgO catalysts in terms of thermal decomposition behavior and yield of monoaromatic hydrocarbons. Overall, MgO supported on carbon (MgO/C) showed the highest yield of aromatic hydrocarbons during the pyrolysis of lignin, due to its well-balanced acid/base sites and high surface area. Also, MgO/C exhibited the strongest positive synergy toward the production of aromatic hydrocarbons during co-pyrolysis, which suggests that a metal oxide with base properties supported on high-surface-area carbon could be an efficient catalyst for producing bio-oil with high energy density fuel additives from the lignin.

Mesostructured aluminosilicates of Al-MSU-F (commercial), Al-SBA-15 (home-made), and mesoMFI (a mesoporous aluminosilicate with MFI structure, home-made), with a silica-to-alumina ratio of 40, were used as catalyst for the in-situ catalytic pyrolysis (CP) of empty fruit bunches (EFB) at 600 °C. The highest selectivity to aromatic hydrocarbons in bio-oil was obtained over mesoMFI due to its higher acidity than Al-SBA-15 and Al-MSU-F. In addition, ex-situ CP of EFB using mesoMFI was compared with in-situ CP; the ex-situ configuration produced higher aromatic hydrocarbons than the in-situ configuration. Meanwhile, in-situ and ex-situ catalytic co-pyrolysis (CCP) of EFB (with a H/Ceff ratio less than 0.3) and polypropylene (PP) (with a high H/Ceff ratio about 2) were carried out using the mesoMFI at 600 °C to investigate the supplementary effect of PP on the deoxygenation of EFB-derived pyrolyzates for producing aromatic hydrocarbons. Ex-situ CCP of EFB/PP (with the mass ratios of 75/25, 50/50, and 25/75) resulted in a lower formation of aromatic hydrocarbons than the in-situ CCP. In addition, the thermal decomposition behavior of EFB, PP, and EFB/PP in non-catalytic and catalytic (mesoMFI) pyrolysis/co-pyrolysis was investigated using thermogravimetric analysis (TGA); use of catalyst reduced the temperature of PP thermal degradation, but did not change the maximum reactivity temperature of EFB degradation.

The concerns over the increasing energy demand and cost as well as environmental problems derived from fossil fuel use are the main driving forces of research into renewable energy. Lignocellulosic biomass comprised of cellulose, hemicellulose, and lignin is an abundant, carbon neutral, and alternative resource for replacing fossil fuels in the future. Solvent liquefaction of lignocellulosic biomass is a promising route to obtain biofuels, bio-based materials, and chemicals using a range of solvents as reaction media under moderate reaction conditions. Recently, several researchers have considered novel approaches for enhancing the process efficiency and economics. This review article reports the state-of-the-art knowledge of lignocellulose liquefaction in the recent three years with the main focus on the feedstock, liquefaction technology, target products, and degradation mechanism of each biomass component. This review is expected to provide an important reference for research into the solvent liquefaction of lignocellulose in the near future.

TiC-reinforced metal matrix composites were fabricated by laser cladding and FeCrCoNiAlTiC high entropy alloy powder. The heat of the laser formed a TiC phase, which was consistent with the thermodynamic calculation, and produced a coating layer without interfacial defects. TiC reinforcing particles exhibited various morphologies, such as spherical, blocky, and dendritic particles, depending on the heat input and coating depth. A dendritic morphology is observed in the lower part of the coating layer near the AISI 304 substrate, where heat is rapidly transferred. Low heat input leads to an inhomogeneous microstructure and coating depth due to the poor fluidity of molten pool. On the other hand, high heat input dissolved reinforcing particles by dilution with the substrate. The coating layer under the effective heat input of 50 J/mm2 had relatively homogeneous blocky particles of several micrometers in size. The micro-hardness value of the coating layer is over 900 HV, and the nano-hardness of the reinforcing particles and the matrix were 17 GPa and 10 GPa, respectively.

High density polyethylene (HDPE) was applied as a co-feeding feedstock on the catalytic pyrolysis (CP) of yellow poplar (YP) over mesoporous catalysts, Al-MCM-48 s(SiO2/Al2O3: 23, 80) and Al-MSU-F(SiO2/Al2O3: 82). Compared to the non-catalytic thermogravimetic (TG) analysis of HDPE, catalytic TG analysis of HDPE had much lower decomposition temperatures, 407 °C over Al-MCM-48(23), 432 °C over Al-MCM-48(80) and 446 °C over Al-MSU-F(82). On the other hand, the decomposition temperatures of HDPE increased up to 460 °C over Al-MCM-48(23), 482 °C over Al-MCM-48(80), and 492 °C over Al-MSU-F(82) by applying the mixture of HDPE and YP as a feedstock on the catalytic TG analysis. The experimental yields of aromatic hydrocarbons obtained from the catalytic co-pyrolysis (CCP) of YP and HDPE over mesoporous catalysts were much higher than their theoretical yields. Among mesoporous catalysts, Al-MCM-48(23) produced the larger amount of aromatic hydrocarbons (2.89%) on the CCP of HDPE and YP than those (2.34–2.48%) over Al-MCM-48(80) and Al-MSU-F(82) and also provided the highest synergistic effect on the formation of aromatic hydrocarbons. The higher synergistic effect over Al-MCM-48(20) was achieved by applying the higher YP/HDPE ratio in the feedstock (3/1), higher catalyst/sample ratio (4/1), and higher reaction temperature (600 °C).

Catalytic pyrolysis (CP) of waste plastic film over mesoporous catalyst, Al-MSU-F, was investigated using polystyrene (PS) and polyethylene terephthalate (PET) as the model plastic resins. Thermogravimetric analysis of PS and PET indicated that their decomposition temperatures were shifted to the much lower temperature owing to the high diffusion ability of reactant into mesopore of Al-MSU-F. Py-GC/MS analysis for the CP of PS and PET revealed that the large amount of aromatics can be obtained by the use of Al-MSU-F and it was further increased by using the higher catalyst/polymer ratio. CP products of PET over Al-MSU-F showed the high selectivity to mono aromatic hydrocarbons. Meanwhile, those of PS revealed the high selectivity to poly aromatics.

The catalytic copyrolysis of torrefied cork oak (TOak) and high density polyethylene (HDPE) over mesoporous HY catalysts was performed using a tandem μ-reactor-gas chromatograph/mass spectrometry/flame ionization detector. Two types of mesoporous HY catalysts with different acidity, MesoHY-1 and MesoHY-2, were prepared by pseudomorphic synthesis with various surfactant ratios. For comparison, a commercial microporous HY was also used as a catalyst. The properties of the catalysts were measured by N2-sorption, X-ray diffraction, and NH3-temperature programmed desorption. Compared to the catalytic pyrolysis of cork oak (Oak), that of TOak produced a larger amount of mono aromatic hydrocarbons (MAHs) over all HY catalysts. The catalytic copyrolysis of TOak and HDPE over micropore HY and MesoHY-1 produced a larger amount of MAHs than that over MesoHY-2 due to the higher acidities. Although both micropore HY and MesoHY-1 have similar acidity, MesoHY-1 showed stronger synergy for the formation of MAHs on catalytic copyrolysis than micropore HY owing to its larger pore, which allows the easier diffusion of HDPE reaction intermediates into the pore of the catalysts.

The catalytic co-pyrolysis of biomass carbohydrates and LLDPE over mesoporous catalysts, mesoporous ZSM-5 (MZSM-5) and Al-SBA-15, was investigated using a tandem micro reactor-GC/MS system. The properties of the synthesized MZSM-5 and Al-SBA-15 were characterized by N2-sorption, X-ray diffraction, and NH3-temperature programmed desorption. Compared to Al-SBA-15, MZSM-5 showed better performance in the production of aromatic hydrocarbons during the catalytic pyrolysis of carbohydrates (avicel (cellulose) and xylan) due to the stronger acidity of MZSM-5. The catalytic co-pyrolysis of carbohydrates and LLDPE showed synergistic aromatic formation due to the supply of more effective hydrocarbon pool species and an efficient Diels-Alder reaction between the pyrolyzates of the carbohydrates and LLDPE. When avicel was torrefied, the aromatic yields were increased further in catalytic pyrolysis/co-pyrolysis.

Egg-shell-type pellet catalysts were prepared by selectively placing nickel and/or ruthenium on the outer region (shell) of alumina pellets so that the active components can be utilized effectively in steam methane reforming (SMR) reaction with high gas-hourly space velocity conditions. To ensure the reproducibility of catalyst preparation, we evaluated two types of commercial alumina pellets. And, we finally selected one commercial alumina pellet, which had uniform pores distribution. The thickness of the ruthenium-shell can be controlled by optimizing the evaporation temperature and rotating speed while preparing an ‘egg-shell-type’ 1 wt. % Ru/alumina catalyst. When applied to a SMR reaction, as the space velocity of the reactant increased in SMR reaction, ‘egg-shell-type’ 1 wt. % Ru/alumina catalyst showed a higher methane conversion than a ‘homo-type’ 1 wt. % Ru/alumina pellet catalyst, in which the active metal was uniformly dispersed in the whole region of pellet. Since ruthenium is a costly noble metal, we prepared a Ni/Ru bimetal catalyst [‘egg-shell-type’ 5 wt. % Ni/0.7 wt. % Ru bimetal catalyst] substituting nickel for some portion of the ruthenium in order to increase the economic feasibility. The bimetal Ni/Ru catalyst showed even better CH4 conversion than the egg-shell-type catalyst containing ruthenium only. We also confirmed that the egg-shell-type catalyst effectively utilized its active components in the SMR reaction.

Catalytic co-pyrolysis of polypropylene and Laminaria japonica was carried out using Py-GC/MS and a fixed-bed reactor over different catalysts: HZSM-5, mesoporous MFI, Pt/mesoporous MFI, and mesoporous Al-SBA-16. The contents of oxygenates, acids, and wax species were reduced substantially by catalytic upgrading, whereas the contents of aromatics and light hydrocarbons in the gasoline and diesel range were significantly increased, enhancing the economic value of the bio-oil. Among the catalysts used in this study, Pt/mesoporous MFI showed the highest catalytic upgrading capability, which was attributed to large pore size, strong Bronsted acid sites, and the catalytic effect of added Pt.

Silicoaluminophosphate molecular sieve, SAPO-11, was applied for the first time to the catalytic pyrolysis of xylan and dealkaline lignin. The isothermal fast catalytic pyrolysis of xylan and dealkaline lignin over different amounts of SAPO-11 and their product analysis were performed concurrently using a pyrolyzer GC/MS. Large amounts of oxygenated pyrolyzates produced from the non-catalytic pyrolysis of xylan at 500 °C were converted to furans, light hydrocarbons, and aromatic hydrocarbons using SAPO-11. When the catalyst to sample ratio was increased from 1:1 to 5:1 and 10:1, the selectivity toward aromatic hydrocarbons was increased dramatically. Phenolic compounds, such as guaiacols and vanillin, were the main products of the non-catalytic pyrolysis of dealkaline lignin. These phenolic compounds were upgraded efficiently into aromatics by the catalytic pyrolysis of dealkaline lignin over SAPO-11. By increasing the catalyst to sample ratio from 1:1 to 10:1, much larger amounts of aromatic hydrocarbons were obtained due to the increased catalyst acid sites. A phenolic pool mechanism was suggested as the major reaction pathway for the catalytic pyrolysis of dealkaline lignin over SAPO-11.

This study focused on the simultaneous removal of NO and SO

The in-situ catalytic fast pyrolysis of pinecone over HY catalysts, HY(30; SiO2/Al2O3), HY(60), and 1% Ni/HY(30), was studied by TGA and Py-GC/MS. Thermal and catalytic TGA indicated that the main decomposition temperature region of pinecone, from 200 to 400 °C, was not changed using HY catalysts. On the other hand, the DTG peak heights were differentiated by the additional use of HY catalysts. Py-GC/MS analysis showed that the efficient conversion of phenols and other oxygenates formed from the pyrolysis of pinecone to aromatic hydrocarbons could be achieved using HY catalysts. Of the HY catalysts assessed, HY(30), showed higher efficiency in the production of aromatic hydrocarbons than HY(60) because of its higher acidity. The aromatic hydrocarbon production was increased further by increasing the pyrolysis temperature from 500 to 600 °C and increasing the amount of catalyst due to the enhanced cracking ability and overall acidity. The use of 1% Ni/HY(30) also increased the amount of monoaromatic hydrocarbons compared to the use of HY(30) due to the additional role of Ni in enhancing the deoxygenation and aromatization of reaction intermediates.

The effects of the torrefaction of cellulose on catalytic co-pyrolysis with polypropylene (PP) over HZSM-5 and HBeta catalysts were examined in a pyrolyzer-GC/MS/TCD/FID system. Torrefied cellulose produced larger quantities of aromatic hydrocarbons during catalytic pyrolysis over both BETA and HZSM-5 catalysts than raw cellulose due to the change in crystallinity and structure of cellulose. Among the catalysts tested, HZSM-5(30) showed the highest performance for the production of aromatic hydrocarbons from the catalytic pyrolysis of torrefied cellulose. The synergy effect for the production of aromatic hydrocarbons was also observed on the catalytic co-pyrolysis of torrefied cellulose and PP over HZSM-5, even when a low catalyst to sample ratio was applied. The maximum BTEXs yield (33.4 wt.%) was achieved from the catalytic co-pyrolysis of torrefied cellulose and PP at a catalyst to sample ratio of 3/1 and a torrefied cellulose to PP ratio of 1/3.

The two-stage catalytic pyrolysis of lignin over in-situ natural zeolite (NZ) and ex-situ HZSM-5 was examined using a tandem fixed bed reactor. The physicochemical properties of the catalysts, HZSM-5 and NZ, were characterized by N2 adsorption-desorption and temperature programed desorption of ammonia. The overall performance for the catalytic pyrolysis of lignin was evaluated by the comparing lignin conversion, aromatic formation, and amount of coke deposited from the two-stage catalytic pyrolysis with those from a single-stage catalytic pyrolysis with ex-situ HZSM-5. Compared to the single-stage catalytic pyrolysis, the two-stage catalytic pyrolysis produced a larger amount of aromatics with a smaller amount of coke due to the pre-catalytic effect of NZ. These positive effects caused by the use of the two-stage catalyst were maximized by increasing the amounts of in-situ natural zeolite and the temperature of the ex-situ HZSM-5 catalyst bed to 600 °C.

The thermal and ex-situ catalytic pyrolysis of different citrus peels, Citrus paradisi peel, Citrus sinensis peel, Citrus unshiu peel, and Citrus limon peel, were studied by thermogravimetric, evolved gas analysis–mass spectrometry and tandem micro-reactor–gas chromatograph/mass spectrometry analyses. Kinetic analysis revealed more complicated reaction steps and a wider range of activation energies of citrus peels than those of wood powder due to the presence of pectin in the citrus peels. Large amounts of methanol formation from each citrus peel were also recorded by evolved gas analysis–mass spectrometry and fast pyrolysis–gas chromatograph/mass spectrometry analyses at the main decomposition temperature of pectin, between 150 and 250 °C. Mesoporous MFI was found to be a more effective catalyst for the production of mono aromatic compounds (benzene, toluene, ethylbenzene, and xylene; 3.06–4.17 C%) and light olefins (ethene, propene, butene, and butadiene; 8.13–9.13 C%) than Al-MCM-41 (mono aromatic compounds 0.67–0.93 C% and light olefins 3.61–4.58 C%) because of its higher catalytic activity in deoxygenation and aromatization due to the stronger acidity of mesoporous MFI. The yield of mono aromatic compounds over mesoporous MFI was highest from C. paradisi peel (4.17 C%), followed in order by C. sinensis peel (3.83 C%), C. unshiu peel (3.61 C%), and C. limon peel (3.06 C%), due mainly to the different contents and properties of pectin in each citrus peel. The higher activities of mesoporous MFI than Al-MCM-41 were also maintained during the 7 times sequential catalytic pyrolysis of C. paradisi peel, demonstrating the stability of mesoporous MFI catalyst.

As a replacement for activated carbon, biochar was synthesized and used for the adsorptive removal of formaldehyde and nitrogen oxide. Biochar was produced from the fast pyrolysis of the red marine macro alga, Pyropia tenera. The P. tenera char was then activated with steam, ammonia and KOH to alter its characteristics. The adsorption of formaldehyde, which is one of the main indoor air pollutants, onto the seaweed char was performed using 1-ppm formaldehyde and the char was activated using a range of methods. The char activated with both the KOH and ammonia treatments showed the highest adsorptive removal efficiency, followed by KOH-treated char, ammonia-treated char, steam-treated char, and non-activated char. The removal of 1000-ppm NO over untreated char, KOH-treated char, and activated carbon was also tested. While the untreated char exhibited little activity, the KOH-treated char removed 80% of the NO at 50°C, which was an even higher NO removal efficiency than that achieved by activated carbon.

The pyrolysis of softwoods (Pinus (P.) densiflora, P. koraiensis), hardwoods (Quercus acutissima and Liriodendron tulipifera) and nut shell of P. koraiensis was investigated using a thermogravimetric analyzer and fixed bed reactor. Thermogravimetric analysis showed that the maximum decomposition temperature of each biomass was influenced by the ash content and lignocellulosic composition of biomass. The activation energy values also varied according to the content of hemicellulose and lignin of each biomass. Large amounts of acids, such as acetic acid, were recovered from the hardwood pyrolysis reaction due to their high hemicellulose content. The nut shell of P. koraiensis and softwoods with a higher lignin content produced higher yields of phenolic compounds than the hardwoods.

Refuse-derived fuel (RDF) produced using municipal solid waste was pyrolyzed to produce RDF char. For the first time, the RDF char was used to remove aqueous copper, a representative heavy metal water pollutant. Activation of the RDF char using steam and KOH treatments was performed to change the specific surface area, pore volume, and the metal cation quantity of the char. N2 sorption, Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), and Fourier transform infrared spectroscopy were used to characterize the char. The optimum pH for copper removal was shown to be 5.5, and the steam-treated char displayed the best copper removal capability. Ion exchange between copper ions and alkali/alkaline metal cations was the most important mechanism of copper removal by RDF char, followed by adsorption on functional groups existing on the char surface. The copper adsorption behavior was represented well by a pseudo-second-order kinetics model and the Langmuir isotherm. The maximum copper removal capacity was determined to be 38.17 mg/g, which is larger than those of other low-cost char adsorbents reported previously.