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This study discusses the influence of fluidization and gasification parameters on the hydrogen composition in syngas. For gasification conditions, when Stage 1 and Stage 2 gasifier temperature is 900 °C, the hydrogen content in syngas is 35.59 mol.% when the activated carbon is used as bed material. For using zeolite as bed material, the hydrogen content is 38.25 mol.%. The hydrogen content is higher than that under other conditions, but if the Steam/Biomass ratio is increased to 0.6, the hydrogen content resulted from zeolite as bed material is the highest 39.38 mol.%. For fluidization parameters, when Stage 2 bed material size is changed to 0.46 mm, no matter the bed material is activated carbon or zeolite, the hydrogen content in syngas is the best among three particle sizes. In terms of operating gas velocity, when gas velocity is 1.5 Umf, the hydrogen content is higher. For fluidization parameters, the two bed materials can increase hydrogen content in syngas effectively in Stage 2 fluidized bed, and their effects are similar to each other. However, considering the fluidization parameters, the hydrogen content in syngas when activated carbon is used as bed material is better than that when the zeolite is used.

In this study, a core–shell structured catalyst composed of a nickel core coated with a high thermal-stability shell layer was prepared for the decomposition of waste plastics to produce hydrogen. Ceria–zirconia mixed metal oxide was used as the coating layer to protect the active phase of the catalyst. The as-prepared catalyst was firstly tested using a methane cracking process to evaluate its stability under high temperature and coking conditions. The special redox characteristics of the Ni@CeO2–ZrO2 core–shell-structured catalyst provide lattice oxygen to oxidize carbon produced during the reaction and extend the life of the catalyst during the coking resistance test. Different pore sizes in the functional shell were prepared by adding a templating agent, and the catalyst was tested for its ability to produce hydrogen from plastic waste. The CeO2–ZrO2 shell promoted the production of active oxygen species and enhanced the dispersion of the Ni cores, which are beneficial attributes for plastic waste decomposition.

Phosphorus and operating temperature not only affect the agglomeration behavior but also the transformation and migration of heavy metals. Accordingly, this study examined the effect of temperature and phosphorus in a fluidized bed combustion process to understand the emission and distribution of heavy metals by both experimental and thermodynamic calculations. The experimental results indicated that the sodium-phosphate reactions occur before the sodium-silicate reaction in the solid phase when the ratio of P/Na was 1/2. A low-melting-point sodium phosphate component, such as NaPO

Agglomeration occurs during municipal sewage sludge (MSS) fluidized bed co-combustion which might affect heavy metal distribution in the bottom ash. A study on the mobility and speciation of heavy metals accompanied with agglomeration behavior and phosphorus addition should be noticed during the MSS co-combustion. The aim of this study was to evaluate the total content and speciation of heavy metals (Pb, Cd and Cr) during the MSS fluidized bed co-combustion by chemical sequential extraction and thermodynamics Equilibrium Calculation. Results indicated that the effect of phosphorus on the agglomeration/defluidization as the function of inhabitation and promotion. Distribution of heavy metals (Pb, Cd and Cr) show similar trends with the presence of a lower ratio of P/Na: the relative concentration of heavy metals in solid phase with the increased of phosphorus. In addition, the relative concentration of heavy metals in solid phase show the raise tendency with the increased of phosphorus under the circumstance of the higher ratio of P/Na due to the formation of the lower-melting-points compounds like NaPO3, the proportion of Pb and Cr residual form increased. While the percentage of Cd residual form reduced with the increasing of the amount of phosphorus. This phenomenon can be contributed by the H3PO4 would priority to react with Al2O3 and reduced the form of a stable compound CdO-Al2O3. Defluidization behavior is found with various P/Na ratios which resulting significantly different influences on particle agglomeration. High-melting-point compound, Na3PO4 (1613 K), is observed to inhibit Na2O-SiO2 formation at lower P/Na ratio. On the contrary, defluidization time decreases with increasing the P/Na ratio due to low-melting-point species Na-phosphates, NaPO3 (900 K) was formed in system.

In the present work, a core-shell structured Co/SiO2@HZSM-5 catalyst was prepared for hydrogen production from syngas of plastic waste gasification. The cobalt catalyst was coated with HZSM-5 shell through a hydrothermal process, and the Co/SiO2@HZSM-5, with different loadings of HZSM-5 (e.g., 10–30 wt %) exhibited excellent activity and durability for dehydrogenation reactions. The amount of HZSM-5 was found to be an important factor for hydrogen production. Temperature-programmed reduction with H2 and temperature-programmed desorption of ammonia was applied to determine the active site and the acidity of prepared catalyst, respectively. The prepared Co/SiO2@HZSM-5 was tested through reforming of plastic gasification syngas and shown superior hydrogen production ability (∼90%) and stability (over 15 h). The effects of reduction-oxidation behavior on the catalytic performance were also discussed.

Herein, we investigated the influence of gasification and fluidization parameters on the H2 content of syngas and the retention of heavy metals (Cu and Pb) in a bed material during a two-stage fluidized bed gasification process. The results indicated that a temperature of 900 °C in both stages resulted in the highest H2 content (32.4 mol%) in syngas. When different equivalence ratios (ERs) were investigated, it was found that the highest H2 content in syngas (25.4 mol%) was achieved at an ER of 0.3. A particle size of 0.46 mm in the fluidized bed led to an increase in the H2 content of syngas. Moreover, increasing the operating gas velocity led to an increase in the H2 content of syngas. The heavy metal concentration in the bed material was the highest at 500 °C. When the influences of different particle sizes and operating gas velocities were compared, it was observed that a particle size of 0.46 mm and gas velocity of 1.5 U/Umf resulted in increased heavy metal concentrations in the bed material, which indicates that the reduction in the particle size and the increase in the operating gas velocity enhanced gasification and improved the retention of heavy metals.

Agglomeration that occurs during municipal sewage sludge (MSS) fluidized bed co-combustion might affect heavy metal distribution and the transformation of bottom ash. A study on the mobility and speciation of heavy metals that accompanies agglomeration behavior and phosphorus addition should be examined during MSS co-combustion. Meanwhile, the aim of this study was to evaluate the total content and speciation of heavy metals during the MSS fluidized bed co-combustion by the chemical sequential extraction procedure (SEP). The risk assessment code (RAC) and individual contamination factor (ICF) are calculated to evaluate the mobility of heavy metals and their environmental risks in agglomerates. Moreover, identification of agglomerates is established by both characterization (scanning electron microscopy/energy-dispersive spectroscopy, X-ray photoelectron spectroscopy) and thermodynamic simulation (HSC chemistry software). The experimental results indicated that P and Na would form the lower melting-point compounds such as NaPO3 and Na2O in the bottom ash, which promoted agglomeration during MSS fluidized bed co-combustion. According to the simulation, Na and P have a stronger affinity than Si and Cr, and this reaction is not only influenced by particle agglomeration, but also by heavy metal distribution during modified MSS co-combustion. Nevertheless, the results of ICFs and RACs obtained from the SEP indicated that for heavy metals trapped in agglomerates, a weaker binding such as physical covering by eutectics might be considered as the dominant reaction compared with chemical binding to form a metal complex.

The thermochemical treatment of waste plastics to produce H2-rich syngas is a promising technique for both waste management and the regeneration of valuable energy resources. In this paper, we report the synthesis of Ni@CeO2 core–shell catalyst with different shell thicknesses. The H2 production ability of the Ni@CeO2 core–shell catalysts was tested and compared to that of the supported Ni/CeO2 catalyst, and it was determined that the H2 yield of the Ni@CeO2 core–shell catalysts was significantly higher than that of the supported Ni/CeO2 catalyst. Owing to the hollow space between the core and shell providing a reacting space for heterogeneous catalysis, the amount of H2 obtained employing the Ni@CeO2-0.5 catalyst, which was obtained using 0.5 mmol cerium nitrate, was the highest of all analyzed Ni@CeO2 catalysts in this study. The optimal H2 production rate of 730.6 mmol/(h g was obtained at 700 °C when the equivalence ratio (ER) was 0.1.

This paper describes the effect of equivalence ratio and steam/biomass ratio on the gas production of a two-stage fluidized bed gasifier. The calcium oxide was employed as bed material in the second stage to evaluate the influence of gasification efficiency. The result shows the H2 molar percentage increased by approximately 2–3 mol% at the end of the second stage fluidized bed reactor without adding CaO. The second stage fluidized bed gasifier plays an important role of cracking and reforming of tar which generated from the first stage one. On the other hand, when the calcium oxide was used as the bed material in the second stage, it enhanced the generation of H2 under most parameters. Highest H2 molar percentage in syngas was observed as 37 mol% at ER and S/B ratio is 0.3 and 2, respectively. Generally, more H2 generation through second stage gasifier was found than that in first stage by 6.1–12.8%.

In this study, a two-stage fluidized bed gasifier was used to investigate the effect of the equivalence ratio (ER) and steam/biomass ratio (S/B) on the synthetic gas distribution while activated carbon (AC) was added as the bed material in secondary gasifier (Stage II). The experimental results showed that when the empty bed (without the bed material) was used for the Stage II reaction, the hydrogen (H2) content in the synthetic gas emitted from the Stage II reactor was 2–3 mol% higher than that from the first-stage gasifier (Stage I). It was supposed that using the Stage II reactor prolongs the reaction time and thereby increases the H2 production. Besides, when the AC was added in the Stage II gasifier, the H2 concentration, the total gas yield, and gas heating value reached their maximum (30 mol%) when ER and S/B were 0.3 and 1.5, respectively.

A novel and simple synthetic approach toward core–shell Fe@Al2O3 nanocomposites were developed in this study. The as-synthesized catalyst was applied to convert the methane into carbon nanotubes. Moreover, due to the properties of the core–shell structure, the amount of surfactant can be adjusted to control the pore size of the shell and further control the diameter of the carbon nanotubes. In this study, the conversion of CH4 was up to 97% and the carbon production was 135 mgC/gcat.*h, which is much higher than traditional supported catalysts under similar reaction conditions. In addition, the carbon product quality (IG/ID) was up to 1.96. The enhanced CH4 catalytic activity for the core–shell Fe@Al2O3 catalyst originated from the combined acidic sites on the surface of the Al2O3 shell and the high carbon diffusion rate of the Fe core, which led to the high efficiency of CH4 conversion and longer lifetime of the catalyst.

This study investigated the effects of temperature and the use of additives on the distribution of gaseous products (H 2 , CO, CO 2 , and CH 4 ) and organic pollutants (BTEX and PAHs) during the fluidized bed gasification of woody waste in bed agglomeration/defluidization processes. The results indicated that the hydrogen content increased with an increase in temperature. However, the concentrations of CO, CO 2 , and CH 4 decreased. Moreover, the concentrations of BTEX were significantly influenced by temperature, but the concentrations of PAHs were stable at approximately 100,000 μg/Nm 3 . On the other hand, the addition of CaO and Al 2 O 3 enhanced the production of hydrogen. Then, the emission concentrations of both organics increased with time and decreased with the occurrence of agglomeration. The PAH emission increased dramatically when only SiO 2 was present, but PAHs were adsorbed when CaO and Al 2 O 3 were added during the defluidization process.

A core-shell type catalyst was applied to convert polyethylene (PE) plastic wastes into hydrogen using a two-stage pyrolysis-catalysis reactor. The effects of catalyst: plastic ratio, reaction temperature, and the suppression of coke formation on catalytic performance were investigated. Ni-Ce bimetallic catalyst was synthesized via modified polyol method, and the silica coating with different Ni:Si molar ratio was prepared with the extension of Stober method. Different thickness of silica shell was synthesized and tested for hydrogen production from PE waste. The encapsulation of Ni-Ce core by silica shell could effectively inhibit the sintering of nanoparticles under high temperature conditions. The highest amount of hydrogen production was found when the catalyst: plastic weight ratio was 1.0, and the catalytic reaction temperature was 800 °C. The core-shell catalyst also exhibited great ability of coking resistance, showing great catalytic performance within 5 times of reuse.

This study focuses on the promotion of biomass gasification for hydrogen production in a fluidized bed reactor with the bed additives zeolite, CaO, and Ca- and Mg-based silica sands. The results show that zeolite has higher capacity for enhancing hydrogen promotion abilities than CaO with the amount was 200 g in tests. Regarding the Ca- and Mg-based silica sands, Ca/SiO2 decreases the CO2 selectivity and Mg/SiO2 enhances the H2 selectivity owing to CO2 adsorption via the formation of CaO and the promotion of the water gas shift reaction, respectively. The optimal concentration of Mg-based bed materials corresponds to a Mg concentration of 0.5 wt.%. The additives play important roles in increasing the reaction rate, enhancing the biomass gasification, and promoting carbon transformation.

This study modifies a defluidization time prediction model under the influence of agglomeration inhibition provided by the addition of Al into a fluidized bed system. Operational parameters, such as the Al/Na ratio, temperature, gas velocity, and the particle size of bed materials, were considered by the prediction model developed by Lin et al., and thermodynamic consideration of the Al–Na–Si reaction system revealed the agglomeration mechanism. An exponential decay of fN was found with the increase of the Al/Na ratio, and the data analysis gave a regression formula of fN = 0.0601 + 0.4983 ∗ exp [− 4.4183 ∗ (Al/Na ratio)], with an R2 of 0.9972. The simulation data generally match well with the experimental results, particularly at lower operation temperatures and Geldart B group's particles, with acceptable average errors of − 8.4% and − 4.9%, respectively. However, relatively poor matches were found in the cases with different gas velocities, a higher operation temperature (900 °C), and a larger particle size (Geldart D group) of bed materials.

The aim of this study was to develop a fundamental understanding of the association between lead (Pb) species and leachability behavior in the simulated municipal solid waste incinerator (MSWI) fly ash during the thermal treatment process. Two main factors that influence this process, temperature and the carbon content in the simulated ash, were also studied. In the sequential extraction results, the main distribution pattern of Pb in treated simulated ash was carbonate fraction with different temperatures when the carbon content was 3.5%. The chief fraction of the raw simulated ash (carbon content=0%) was carbonate and that of raw simulated ash when carbon content was increased was Fe-Mn oxide Electron spectroscopy for chemical analysis (ESCA) results showed that Pb (element) in treated simulated ash could increase the toxicity characteristic leaching procedure (TCLP) concentration of Pb when temperatures reached 700°C. With a temperature of 900°C, PbSiO3 was present in the treated simulated ash ...

This study presents the effect of particle agglomeration on syngas emission during the biomass air gasification process. Various operating conditions such as operating temperature, equivalence ratio (ER), and amount of bed materials are employed. The concentrations of H 2 and CO increase along with the operating time as agglomeration begins, while CO 2 decreases at the same time. However, there is no significant change in the emission concentration of CH 4 during the defluidization process. The lower heating value increases while the system reaches the agglomeration/defluidization under various operating parameters. When the system reaches the agglomeration/defluidization process, the LHV value sharply increases. The results are obtained when the system reaches agglomeration/defluidization. The temperature increases while bed agglomeration occurs. A higher temperature increases the production of H 2 and CO, contributing to the LHV calculation.

Biomass gasification plays an important role in finding a solution to the energy crisis, and the fluidized bed (FB) is recognized as an important technique for using biomass. However, this process significantly tends toward bed material agglomeration. Accordingly, the aim of this study is to emphasize the effects of operating conditions and different Na concentrations on agglomeration behavior during FB air gasification. Defluidization time decreases as Na concentration increases from 0.8 to 3%. Defluidization time decreases as temperature and the amount of bed materials increase. In addition, no significant change in the trend for this process occurs as the equivalence ratio increases. Adding CaO and Al2O3 can significantly prolong this process, and the inhibition level follows the sequence: Al2O3 > CaO. The same observations are noted during both incineration and air gasification in the FB at various operating conditions.

Al- and Ca-based materials can serve as metal sorbents or agglomeration inhibitors in fluidized beds. Although particle agglomeration could affect the adsorption efficiency of metal sorbents, Al- and Ca-based materials have been found to inhibit the particle agglomeration phenomenon during the incineration process. Accordingly, this study emphasizes the effect of particle agglomeration on heavy metal adsorption by Al- and Ca-based sorbents in a fluidized bed. The results show that Al- and Ca-based sorbents inhibit the tendency of particle agglomeration caused by Na. Thus, high concentrations of heavy metals exist mainly in fine particles compared to those present in the large particles when Na is added to the system. However, the addition of Na apparently increased the adsorption efficiency and followed the sequence of Cr > Cd > Pb with an increase in the operating temperature. A comparison of sorbents and Na additive for the relative enrichment factor showed that Na plays an important role in capturing Cr with Al- and Ca-based sorbents. Also, both sorbent adsorption and Na agglomeration are the dominant mechanisms for capturing Cd. The results of adding Na and an Al-based sorbent presented positive effects for Pb adsorption; however, a negative effect was observed with the addition of Na and a Ca-based sorbent at low temperatures.

Taiwan is currently confronted by problems on dense population and limited space. In this regard, incineration as a widely used waste treatment technology functions as an alternative to landfill treatment. This study emphasizes the comparison of emission characteristics of pollutants such as NOx, SOx, particulates, and global warming gas (CO2) between incinerators and thermal power plants in Taiwan. From the data and construction information presented here, four types of incinerators as defined by different air pollution control devices (APCDs) are discussed. Taiwan's MSW incineration is considered an available and successful technology for renewable energy exploitation as compared to that of other countries. Thus, a comparison of the pollutant control and emission characteristics of MSW incineration showed that its pollutants are much lower than those from thermal power plants. The pollutants emission level (PEL) of different pollutants shows that the particulates, NOx, and SOx in thermal power plants are about 31, 16, and 267 times more than those in incinerators. Estimation CO2 emission level (CEL) values indicate that the CO2 generated from thermal power plants is lower than those emitted from MSW incineration processes. The reasons for this are the different carbon content, heat energy transfer rate, and heating value between MSW and thermal power stocks.

Agglomeration occurring during fluidized bed incineration not only causes the fluidization characteristics to change and the system to unexpectedly shut down, but it also leads to the generation of secondary pollutants such as heavy metals. Accordingly, the aim of this study is to estimate the mechanisms of particle agglomeration in fluidized bed incineration. Experiments are carried out, including a pilot-scale fluidized bed test and a laboratory furnace test. Thermodynamic equilibrium simulations are also considered. In addition, the speciation of agglomerates is determined from the analysis of the laboratory furnace using X-ray diffraction (XRD), electron spectroscopy for chemical analysis (ESCA), and field emission scanning electron microscopy/energy dispersive spectrometry (FESEM–EDS). The experimental results reveal that higher concentrations of metals are emitted when defluidization occurs. When we compare the results from two different agglomeration inhibitors, the Al-based additive is shown to achieve higher levels of inhibition versus a Ca-based additive. In addition, the results from our simulation illustrate that the heavy metals Pb, Cr, and Cd have different affinities with Na, Si, Al, and Ca, which causes different emission behaviors during the agglomeration inhibition processes. Good agreement is observed among the experimental data, the agglomerate characterization, and the thermodynamic equilibrium simulations. The primary mechanisms of both particle agglomeration and the emission of heavy metals are also established.

The agglomeration that occurs in a fluidized bed incineration system results in the unexpected shutdown of the system and causes secondary pollutants such as heavy metals to be generated. Addition of Al- and Ca-based additives is an efficient method to control the particle agglomeration. However, emission behavior of heavy metals in incineration processes could be influenced by the addition of agglomeration inhibitors due to both chemical reaction with metals and the fluidization behavior being changed. Accordingly, the aim of this study is to show the emission characteristics of heavy metals (Pb, Cr, and Cd) under various waste compositions (Cl and S) and the addition of agglomeration inhibitors (Al and Ca) during the defluidization process. A thermodynamic equilibrium simulation was used to predict heavy metal formation and to compare the experimental results. The results showed that the emission concentration of heavy metals increased as a result of the reduction of combustion efficiency caused by Al a...

The polyol process is an effective method to generate well-dispersed nanoscale active sites on a support. To study the activity of catalysts prepared by polyol process, Cu 1.25 Co 3.75 /Al 2 O 3 , Cu 2.5 Co 2.5 /Al 2 O 3 , and Cu 3.75 Co 1.25 /Al 2 O 3 were studied in a pilot-scale incinerator system to remove benzene, toluene, ethylbenzene, xylene, and polycyclic aromatic hydrocarbons, and the effect of lead in a flue gas was also discussed. The pilot-scale experiment results indicated that Cu 1.25 Co 3.75 /Al 2 O 3 exhibited a good performance on organic compounds removal, without being poisoned by lead. The bimetal containing Cu/Co = 1/3 exhibits a better activity and stabilization on oxidation than the others. When the Cu/Co ratio was above one, the X-ray powder diffractometer, and Fourier transform infrared spectroscopy analyses results revealed that several components (Cu 0 , CuO, and CuCo 2 O 4 ) of the spent catalysts disappeared. This may be due to the active sites that were covered with an amount of CH 3 -groups.

Some studies have demonstrated that earth alkali metals promote agglomeration; however, others have shown that they inhibit the generation of agglomeration. The earth alkali metals (Mg and Ca) may cause both inhibition and promotion of agglomeration/defluidization. Therefore, this study focuses on the effect of Mg, Ca and the operating temperature on the agglomeration/defluidization of sodium during incineration in a fluidized bed reactor. The results indicate that the added Mg and Ca inhibit agglomeration and increase the defluidization time. At low Na/Mg and Na/Ca mole ratios, Mg and Ca inhibit defluidization significantly. However, the inhibition reduces as the concentration of Na increases. When the mole ratio (Na/Mg and Na/Ca) exceeds two, the inhibition of Mg and Ca is not apparent. Under these conditions, the operation temperature is the main factor with regard to agglomeration/defluidization. When Mg and Ca are added to reduce the agglomeration/defluidization, both the concentration of Na and operating temperature must be considered.

Agglomeration not only affects fluidization behaviors but also generates secondary pollutants. However, adding Al-related minerals such as clay and kaolin is an efficient way to control the agglomeration. Complex compositions of minerals may influence Al inhibition on agglomeration. Accordingly, this study is carried out to estimate the effect of Al inhibition on defluidization observed in a fluidized bed incinerator by using different Al/Na ratios. Emission of pollutants (organics and heavy metals) during the defluidization process is also considered. Several characterization studies (i.e. XRD, ESCA, and SEM/EDS) are applied to identify the eutectics from the agglomerates after defluidization. The results show that Al extends the defluidization time significantly with Al increasing. At various operating conditions, such as operating temperature, gas velocity, and particle size of bed materials, Al inhibits agglomeration by ten times delay with comparison to previous work. Moreover, concentration of organics emitted increases with operating time at the initial combustion step. After defluidization, the concentration of organics decreases apparently owing to combustion heat accumulated at the surface of the sand bed. The emission concentrations of three volatile heavy metals were similar before defluidization, but they sharply increased after the system formed defluidization. The amount of heavy metals emitted followed the order Pb > Cd > Cr at various operating conditions. Results of experiments in emissions of organics and heavy metals performed different behavior during defluidization processes.

The failure of municipal solid waste incineration (MSWI) fly ash to meet regulatory standards set through the toxicity characteristic leaching procedure (TCLP) of lead (hereafter, Pb) has resulted in its classification as a hazardous material that is unsuitable for use. In this study, a fluidized bed is proposed as a thermal treatment unit to treat MSWI fly ash. The aim of the present work is to treat fly ash by using a fluidized bed with operating conditions, including temperature, pretreatment, and an additive in the fluidized bed. We also considered the partition of the heavy-metal Pb and the emission of organics (PAHs) in the process. Results indicated that the Pb existed mainly in the solid phase, that is, the fly ash and bed materials, under different conditions. The partitioning of Pb to the fly ash was increased from 42.88 to 68.20%, with the operating temperature increased from 700 to 900 °C. When a water-washing pretreatment was applied, the Pb partitioning to the fly ash was less than that when...

Taiwan is a small, densely populated island with unique experiences in the construction and operation of incinerators. In such a small area, Taiwan has built 22 incinerators over a short span of time, combusting large amount of municipal solid waste as much as 23,250 tons per day. This study focuses on the history of construction and development of incinerators in Taiwan as well as the characteristics of pollutants, such as heavy metals (Pb, Cd, and Hg), acid gases (NO x , SO x , CO, and HCl), and dioxins emitted from the incinerators. Furthermore, the study also covers the generation and composition of municipal solid waste (MSW), and the production of energy in Taiwan. According to Taiwan’s data on pollutant emissions, the emission level of pollutants is under control and meets the stringent regulations of Taiwan Environmental Protection Administration (TEPA). Researches have shown that using air pollution control devices (APCDs) in the operation of incinerators provides effective measures for air pollutant control in Taiwan. The main advantage of using incinerators is the generation of electricity (waste-to-energy) during the incineration of municipal solid waste, producing energy that can be consumed by the general public and the industry. Taiwan’s extensive experience in incinerator construction and operation may serve as an example for developing countries in devising waste treatment technology, energy recovery, and the control of contagious viral diseases.

This paper aims to investigate the emission characteristics during the thermal treatment of co-contaminated soils containing lube oil and heavy metals (Cd, Cr, Cu, and Pb). Experiments were conducted using a laboratory-scale bubbling fluidized bed combustor under various fluidization parameters including temperature (500–800°C), air velocity (11.5–17.9 cm/s), and sand bed particle size (545–920 μm). The emission products from the system, including flue gas, fly ash, and bottom ash, were sampled, and the concentrations of heavy metals and organic pollutants (such as benzene, toluene, ethylbenzene, xylene, and polycyclic aromatic hydrocarbons) along with the metal leachability were determined. The average emissions were lowest at 800°C, air velocities were in the range of 13.7–17.9 cm/s, and sand bed particle diameters were 770–920 μm. Removal of more than 99% and 48–85% of lube oil and heavy metals, respectively, was observed. Portions of the heavy metals were vaporized and attached to the fly as...

This study was conducted to investigate the effects of various gasification temperatures in a fluidized bed gasifier on biomass-derived products and to evaluate the efficiency of syngas upgraded by a secondary catalytic reactor. The results indicated that biomass vaporization was clearly affected by gasification temperature, resulting in the obtained products having different composition ratios. Additionally, the hydrogen promotion ratios were found to be strongly dependent on the condensable products, indicating that the products were upgraded via the use of a catalyst in the secondary reactor. If biomass vaporized at suitable gasification temperatures can produce a large amount of condensable products, the products could be effectively upgraded for hydrogen production by the secondary catalytic reactor under very mild conditions (250°C). Overall, the process not only upgraded hydrogen production, but also degraded contaminants; therefore, its implementation should reduce the cost of operation and pollution control in the biomass-to-energy industry.

This study investigates the effects of toluene adsorption on the filtration efficiency of nanoparticles by a fluidized-bed adsorption reactor. Simulated flue gas is modified by different types of nanoparticle (SiO 2 and Al 2 O 3 ) with various particle sizes (10 and 80 nm) are also carried out in experiment. Therefore, the experimental results show that the removal efficiencies of the nanoparticles and toluene are in the range of 97% to 87% and 99.8% to 99.4%, respectively. Particularly, BET results show that the particles of 10 nm SiO 2 increase obstruction of the adsorbent volume with increasing toluene content. This finding shows that filtration efficiency increases with the addition of toluene.

With the concern of future energy use, hydrogen is taken as an important role in energy alternatives. In addition, biomass air gasification by using fluidized bed is an efficient and advanced method for hydrogen production. Despite of energy product generation, some pollutants such as PAHs easily formed in gasification process because of tar decomposition. Accordingly, this study provides a fundamental work of emission behavior of PAHs generated under different operating conditions such as temperature, air factor, and addition of catalysts. The experimental result shows the emission concentration of PAHs decreases with the operating temperature increases, but PAHs increases with increasing of air factor. Besides, addition of CaO resulting a reduce influence on PAHs emission, but Al 2 O 3 added in fluidized bed cause bimodal particle size segregate and reduce fluidized bed quality that leads PAHs formation during biomass air gasification.