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Corncob was pyrolyzed using ZnCl2 in a pyrolysis plant equipped with a fluidized bed reactor to co-produce furfural and acetic acid. The effects of reaction conditions, the ZnCl2 content and contacting method of ZnCl2 with corncob on the yields of furfural and acetic acid were investigated. The pyrolysis was performed within the temperature range between 310 and 410 °C, and the bio-oil yield were 30–60 wt% of the product. The furfural yield increased up to 8.2 wt%. The acetic acid yield was maximized with a value of 13.1 wt%. A lower feed rate in the presence of ZnCl2 was advantageous for the production of acetic acid. The fast pyrolysis of a smaller corncob sample mechanically mixed with 20 wt% of ZnCl2 gave rise to a distinct increase in furfural. A high selectivity for furfural and acetic acid in bio-oil would make the pyrolysis of corncob with ZnCl2 very economically attractive.

Bio-oils, which are multicomponent mixtures, were produced from two different biomass (rice straw (rice oil) and sawdust of oak tree (oak oil)) by using the slow pyrolysis process, and chemical compositional screening with GC-MS detected several hazardous compounds in both bio-oil samples. The two bio-oils vary in their chemical compositional nature and concentrations. To know the actual hazard potentialities of these bio-oils, toxicological assessments were carried out in a comparative approach by using in vitro (Jurkat T and HepG2 cell) as well as in vivo (Caenorhabditis elegans) systems. A dose-dependent increase in cytotoxicity, cell death (apoptosis), and genotoxicity were observed in cultured cell systems. Similarly, the in vivo system, C. elegans also displayed a dose-dependent decrease in survival. It was found that in comparison with rice oil, oak oil displayed higher toxicity to all models systems, and the susceptibility order of the model systems were Jurkat T > HepG2 > C. elegans. Pursuing the study further toward the underlying mechanism by exploiting the C. elegans mutants screening assay, the bio-oils seem to mediate toxicity through oxidative stress and impairment of immunity. Taken together, bio-oils compositions mainly depend on the feedstock used and the pyrolysis conditions which in turn modulate their toxic potentiality. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1409–1419, 2014.

In order to produce a clean producer gas, the air gasification of dried sewage sludge was conducted in a two-stage gasifier that consisted of a bubbling fluidized bed and a tar-cracking zone. The kind and amount of bed materials, the kind of additives in the upper-reactor, and the moisture content in the sewage sludge were selected as operating variables in order to investigate their effects on the development of the producer gas characteristics. In our experiments, the gasification of a dried sewage sludge sample containing 30 wt.% of moisture with a combination of calcined dolomite as the bed material and activated carbon in the tar-cracking zone removed the most tar and produced the highest hydrogen concentration. The total tar removal efficiency and the H2 content in the producer gas from the sample noted above reached 88.4% and 32.1 vol.%, respectively. The LHVs of all the producer gases were high with values above 7 MJ Nm−3.

In this experiment, air gasification was conducted with a fraction of mixed plastic wastes using a two-stage gasifier. Calcined dolomite as a bed material and activated carbon as a tar-cracking additive were simultaneously used for the production of a producer gas containing low tar and high hydrogen. The effects of the bed material, equivalence ratio (ER), amount of activated carbon, and temperatures in two reaction zones (the upper- and lower-reactor) on the composition of producer gas and amount of tar generated were investigated. When the amount of activated carbon increased from 0 to 900 g using calcined dolomite as the bed material, the concentrations of H 2 and CO in the producer gas increased sharply from 14.9 to 26.1 vol% and from 9.4 to 16.8 vol%, respectively. When 900 g of activated carbon was applied, the total tar amount was about 96% less than that obtained with only silica sand as the bed material. The maximum Lower Heating Value (LHV) of the producer gas was about 13.4 MJ/Nm 3 .

Air gasification of dried sewage sludge was conducted in a two-stage gasifier. In the experiments, natural occurring materials, such as natural zeolite, olivine and dolomite, as well as biomass-based and coal-based activated carbons, were applied to the upper reactor of a two-stage gasifier, while sand and calcined dolomite were used as the fluidized bed material in the lower reactor. The reusability of the spent coal-based activated carbon and spent calcined dolomite was also investigated. The combination of calcined dolomite as the bed material and coal-based activated carbon in the upper reactor produced the highest H2 (28 vol.%) and CO (21 vol.%) contents. Furthermore, total amount of tar generated with the combination was 91% less than that generated with no additive in the upper reactor and sand in the lower reactor. The H2 content and tar removal efficiencies in the experiments with the spent activated carbons and spent calcined dolomites were shown to be better than those without additives in the upper reactor.

Gasification experiments with railroad wood ties treated with creosote were conducted in a two-stage gasifier to produce a high caloric producer gas with low tar content. In the experiments, sand and dolomite as the bed material were compared, and the effects of temperature in a range from 666 to 818 °C and equivalence ratio from 0.19 to 0.52 were also investigated. Additionally, the effectiveness of additives (biomass-based activated carbon, coal-based activated carbon and dolomite) and their combination on the removal of tar were examined. As a result, the combination of dolomite as the bed material and coal-based activated carbon in the tar cracking zone gave the best performance with respect to tar removal. With this combination, the total amount of tar was reduced by 91.9%, compared to that obtained by using only sand as the bed material in the gasifier. Furthermore, the tar content in the producer gas was below 0.1 g/N m 3 . Coal-based activated carbon also improved the production of hydrogen up to about 29 vol.%. The LHVs of most producer gases in these experiments were above 7 MJ/N m 3 .

A waste fraction of high impact polystyrene (HIPS) containing brominated flame retardants and antimony trioxide (Sb 2 O 3 ) as a synergist was pyrolyzed in a bench-scale system equipped with a fluidized bed and char separation system. Experiments were carried out to observe the effects of the reaction temperature and three additives (CaO, Ca(OH) 2 , oyster shells) on the removal of bromine. An analysis of the pyrolysis oils obtained showed the oils were mainly composed of toluene, ethyl-benzene, styrene, cumene, α-methylstyrene, 1,3-diphenylpropane, 1,3-diphenylbutane and (1-bromoethyl)-benzene. When the Ca-based additives were used, the concentration of styrene was markedly increased; whereas, those of ethlybenzene and cumene were reduced. The total bromine content of pyrolysis oil produced without any additive at 459 °C was about 5 wt.%. When Ca(OH) 2 and oyster shells were applied, the total bromine contents of the pyrolysis oils were decreased to 1.3 and 2.7 wt.%, respectively. The antimony content in the pyrolysis oil was relatively small due to the efficient operation of the char separation system.

In this study, the thermal degradation of a waste fraction of acrylonitrile–butadiene–styrene containing brominated flame retardants was performed to reduce halogen content in the pyrolysis oil. Thermal degradation was completed using Ca-based additives (calcium oxide, calcium hydroxide and oyster shells) in a bench-scale pyrolysis plant equipped with a fluidized bed reactor and char separation system. Pyrolysis was carried out in a temperature range of 430–510 °C. In the absence of any additive, the oil yield amounted to about 77 wt.%. With the additives, the oil yield was markedly reduced to within a range of 45–64 wt.%. The principle compounds in the oils were toluene, ethylbenzene, styrene, cumene, α-methylstyrene, phenol and heteroatom-containing compounds. When Ca(OH)2 was applied, total bromine and chlorine contents in the oil decreased to 0.05 and 0.04 wt.%, respectively. In addition, Ca(OH)2 reduced the antimony content in the oil to below 0.001 ppm. Most of the halogens and antimony in the feed material were present in the char obtained after pyrolysis.

TiO2 particles were prepared by chemical vapor condensation and used to synthesize MnOx/TiO2 mesoporous materials by impregnation. The Mn-doped TiO2 particles were smaller (8.5 nm vs. 10.5 nm) and had greater surface areas (203.7 m2 g−1 vs. 134.4 m2 g−1) than undoped particles. They were also smaller and had a greater surface area than similarly doped commercial P25, indicating highly dispersed Mn species on the surfaces of the crystalline TiO2. The resulting materials’ photocatalytic activities towards methylene blue decomposition were compared: the synthesized TiO2 particles with MnO2 showed higher photocatalytic activity than the similarly doped commercial P25.

Air gasification was conducted with fractions of construction woody wastes in a two-stage gasifier, consisting of a fluidized bed zone and a tar cracking zone. The aim of this work is to investigate the influence of reaction conditions and additives on the composition of producer gas and tar content in producer gas. A producer gas obtained with activated carbon of 540 g at an ER of 0.26 was mainly composed of H2 (25 vol.%), CO (22 vol.%) and CH4 (5 vol.%). Regarding tar removal efficiency, activated carbon was better than olivine. The tar removal rate with virgin activated carbon reached up to 80%. The reuse of spent activated carbon caused an efficiency loss in tar removal to some extent. Overall, it seems that the strong need for intensive downstream tar removal measurements can be removed with the use of a two-stage gasifier and the application of activated carbon.

Air gasification was conducted with a fraction of mixed plastic wastes in a newly developed two-stage gasifier. In this work, the influence of the reaction parameters, such as equivalence ratio, upper-reactor temperature and feed size, on the producer gas composition and tar removal were investigated. In addition, the effects of activated carbon and dolomite were also examined. At an equivalence ratio of 0.21, a very clean producer gas was obtained with a LHV of 13.44 MJ/Nm 3 . Activated carbon had a better tar removal efficiency than dolomite. The amount of additive had significant effects on the tar removal efficiency and hydrogen production. When 640 g of activated carbon was applied, the total tar production was about 2.5 times less and H 2 production two times higher than without activated carbon.

Experiments were carried out with a woody waste fraction using a two-stage gasifier consisting of a fluidized bed zone and a tar cracking zone that was filled with activated carbon. In the experiments, the effects of experimental conditions such as the temperature and the equivalence ratio were investigated. In addition, the results of the experiments with virgin activated carbon, without activated carbon, and with spent activated carbon were compared. The producer gases that were obtained in the experiments were analyzed using GCs (FID and TCD) and a GC–MS system. The producer gas obtained with the application of activated carbon at an ER of 0.2 had high H2 content (16 vol.%, N2-free), and its lower heating value was above 10 MJ/Nm 3 . In addition, the total amount of the tar captured by the scrubbers and the electrostatic precipitator was reduced sixfold when activated carbon was applied.

Fractions of waste polypropylene and polyethylene were pyrolyzed in a pyrolysis plant under different conditions. In this study, the influence of the reaction temperature (650–750 °C), the feed rate, and the kind of fluidizing medium on the product spectrum were investigated. Pyrolysis of the PP fraction produced oils up to 43 wt. % of the product. With respect to the PE fraction, the maximum oil yield was above 60 wt. % of the product. The target compound was BTX aromatics, whose amount in the oils reached 53 wt.% for the PP fraction and 32 wt. % for the PE fraction. It was shown that the PE fraction yielded a higher liquid product compared to the PP fraction, and that the concentration of aromatics in the oil increased at higher reaction temperatures for both the PP and PE fractions. A higher feed rate and the use of a gas product as the fluidizing medium were favored for the production of oils for both the PP and PE fractions. The oils that were obtained in the experiments almost had no metal and chlorine contents. The maximum heating value of the gas obtained in the experiments was about 50 MJ/kg.

Mixed plastic wastes are very difficult to mechanically recycle into new products because of their nonhomogeneity. Therefore, pyrolysis and gasification seem to be very effective in the extraction of energy from mixed plastic wastes in the form of oil and gas. In this study, a fraction of mixed plastic wastes was pyrolyzed in a bench-scale plant equipped with a fluidized-bed reactor and a char removal system. This study has two aims. The first is to find out the optimum reaction temperature for a high yield of benzene, toluene, and xylene (BTX) aromatics. The second is to find out the best additive for chlorine removal. To find out the optimum reaction temperature for the maximum BTX content, experiments at a temperature range of 660−780 °C were carried out. The pyrolysis oils that were obtained from the experiments were composed of aliphatics and mono- and polyaromatic compounds. The reaction temperature had a positive effect on the BTX aromatics yield. The maximum BTX aromatics yield was obtained at 719...

The production of sewage sludge in South Korea is continually increasing. Until now, much of the sewage sludge in the country has been disposed of by dumping it into the ocean, which the London Convention wants stopped. Therefore, new sewage sludge treatment methods should be sought. Sewage sludge can be energetically utilized through gasification, which produces combustible gases such as H2, CO, and CH4. During the gasification of a biomass, however, a large amount of tar is also formed. In this paper we report the results of the experiments that were conducted on the air gasification of dried sewage sludge in a newly developed two-stage gasifier. In such experiments, activated carbon was applied to reduce the tar components of the producer gas. The total amount of tar that was reduced was 6-fold when activated carbon was used in the upper reactor of the gasifier. The effects of the reaction conditions, such as the reaction temperature and the equivalence ratio, on the gas composition were also investiga...

The kinetic parameters for the pyrolysis of Oriental white oak were evaluated by thermogravimetric analysis (TGA). The white oak was pyrolyzed in a fluidized bed reactor with a two-staged char separation system under a variety of operating conditions. The influence of the pyrolysis conditions on the chemical and physical characteristics of the bio-oil was also examined. TGA showed that the Oriental white oak decomposed at temperatures ranging from 250 to 400 °C. The apparent activation energy ranged from 160 to 777 kJ mol− 1. The optimal pyrolysis temperature for the production of bio-oil in the fluidized bed unit was between 400 and 450 °C. A much smaller and larger feed size adversely affected the production of bio-oil. A higher fluidizing gas flow and higher biomass feeding rate were more effective in the production of bio-oil but the above flow rates did not affect the bio-oil yields significantly. Recycling a part of the product gas as a fluidizing medium resulted the highest bio-oil yield of 60 wt.%. In addition, high-quality bio-oil with a low solid content was produced using a hot filter as well as a cyclone. With exception of the pyrolysis temperature, the other pyrolysis conditions did not significantly affect the chemical and physical characteristics of the resulting bio-oil.

Radiata pine sawdust was pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The influence of the reaction conditions on the production of bio-oil was investigated through the establishment of mass balance, and the examination of the products' chemical and physical characteristics. The optimal reaction temperature for the production of bio-oil was between 673 and 723 K, and the yield was above 50 wt.% of the product. An optimal feed size also existed. In a particle with a size that was less than 0.3 mm, the bio-oil yield decreased due to overheating, which led to gas formation. A higher flow rate and feeding rate were found to be more effective for the production of bio-oil, but did not significantly affect it. The main compounds of bio-oil were phenolics, including cresol, guaiacol, eugenol, benzendiol and their derivatives, ketones, and aldehydes. In addition, high-quality bio-oils, which contained less than 0.005 wt.% of solid, no ash and low concentrations of alkali and alkaline earth metals, were produced due to the char removal system.

Rice straw and bamboo sawdust were pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The effects of the reaction conditions on the production of bio-oil, and the efficiency of a char removal system, were investigated. In each experiment, the mass balance was established and the products’ chemical and physical characteristics were examined. To elucidate how the reaction temperature affects the production of bio-oil, experiments were conducted at a temperature range of 415–540 °C in the case of the rice straw and 350–510 °C in the case of the bamboo sawdust. In addition, the influence of the feed size, the feed rate, and the kind of fluidizing medium on the production of bio-oil with each feed was investigated. The optimal reaction temperature for the production of bio-oil was between 440 and 500 °C in the case of the rice straw and 405–450 °C in the case of the bamboo sawdust. With respect to the bamboo sawdust, the maximum bio-oil yield was above 70 wt.% of the product. In the study of the influence of the feed rate and the feed size on the production of bio-oil, a higher feed rate and a smaller feed size were found to be more effective in the production of bio-oil. Finally, the use of product gas as a fluidizing medium enhanced the production of bio-oil. The main compounds of bio-oil were phenolics, furfural, acetic acid, levoglucosan, guaiacol, and alkyl guaiacol. In addition, high-quality bio-oils, which contained low concentrations of alkali and alkaline earth metals, were produced due to the excellent performance of the char separation system.

The production of sewage sludge in Korea amounts to 2 million ton/y. It is disposed mainly by ocean dumping. At the London Convention, however, there was a strong demand for this practice to be stopped. Therefore, new treatment methods for sewage sludge should be found. One of the strong candidates for these new methods is the pyrolysis technique, which obtains oil from the organic part of sewage sludge. The pyrolysis oil, however, usually shows bad characteristics, mainly due to its low heating value and high contaminant content. In this study, digested and dried sewage sludge containing polymer flocculants was pyrolyzed in a temperature range of 446–720 °C in a pyrolysis plant equipped with a fluidized bed reactor. The mass balance was established in each experiment, and the produced gas and oil were analyzed with the aid of GCs and a GC-MS system. In the experiments, above 50 wt % pyrolysis oil was obtained with a maximum caloric value of 33 MJ/kg. In addition, the authors tried to reduce contaminants ...

Poly(methyl methacrylate) (PMMA) is a versatile transparent thermoplastic that is used in a wide range of fields and applications, such as in the lenses of exterior lights of automobiles, in electronics, in food containers and in artificial marble. When PMMA is subject to thermal degradation conditions, it degrades mainly into its monomer, methyl methacrylate (MMA). In this study, a virgin PMMA copolymer composed of 97.5% methyl methacrylate, 2.5% methyl acrylate (MA) and PMMA waste plastics were investigated. Kinetic measurements of the thermal degradation of the virgin copolymer were carried out with a TGA. The Chatterjee–Conrad (CC) and Freeman–Caroll (FC) models were applied to determine the pyrolysis kinetic parameters. Both models simulated the experimental DTG curves fairly well. In addition, pyrolysis of the virgin copolymer and the PMMA wastes was carried out using a fluidized bed reactor to recover the monomer. The reaction temperatures ranged from 450 to 500 °C. In each case, the rate of oil recovery was over 97%, and the content of the MMA in the oils was up to 98 wt%. The MMA recovered from the experiments can be used as feedstock for the polymerization of PMMA.

Sawdust of radiata pine was pyrolyzed in a bench scale plant equipped mainly with a fluidized bed, a char separation system, and a series of quenching columns. In the experiments, the influence of reaction temperature and feed size on the yield of bio-oil was investigated. In addition, the efficiency of the char separation system, which was composed of a cyclone, as well as a hot filter, was examined by considering the content of alkali and alkali earth metals in the bio-oil. Chemical and physical analyses were also conducted with each pyrolysis product fraction. The maximum yield of bio-oil, 67 wt% of product, was obtained at 474 °C. A smaller particle size was found to be better for the production of bio-oil due to good heat transfer into the inner part of the feed. Bio-oils obtained with the char removal system contained about 0.01 wt% of ash. In particular, a sample of bio-oil had characteristics of being almost alkali and alkali earth metal free, and had less than 1 ppm of calcium, magnesium, and potassium. The char that was produced had a higher heating value of 26 MJ/kg. Therefore, it can be used as an energy-supplying source.

Rice straw is one of the main renewable energy sources in Korea, and bio-oil from rice straw is produced using a bench-scale plant that is equipped mainly with a fluidized bed and a char removal system. We investigated how the reaction temperature affected the production of bio-oil and the efficiency of a char removal system. To elucidate how the temperature was dependent on the production of bio-oil, experiments were conducted between 400 °C and 600 °C at a feed rate of ∼1 kg/h. The mass balance was established in each experiment, and the produced gas and oil were analyzed with the aid of gas chromatography and a gas chromatography−mass spectroscopy (GC−MS) system. The effect of pretreating rice straw was also investigated by comparing the yield of bio-oil and the content of alkali metals in the bio-oil from the experiments on unwashed rice straw with the corresponding values of washed rice straw. The char removal system is composed of a cyclone and a hot filter. After every experiment, we examined the p...

Mixed plastics collected from the DSD (Duales System Deutschland), different in their content of polyesters and polystyrene, were pyrolyzed in a laboratory scale fluidized bed reactor to yield aromatic oils and heat-providing gas. Four experiments were carried out in a fluidized bed reactor at different temperatures between 685 and 738°C and feed rates between 400 and 900 g h −1 . The most important oil products were benzene, toluene, xylenes and styrene with a total yield of 30–40% by weight. The results are compared to those of a technical scale reactor with a longer residence time. It was shown that the concentration of chloro-organic compounds in the oil decreases at longer residence times.

A fraction of plastic wastes from DSD (Duales System Deutschland) which is depleted in polyvinylchloride (PVC) was pyrolyzed at 638, 690 and 735°C in a technical-scale fluidized bed reactor. At 638°C over 50 wt.% of the pyrolysis product was an oil with a boiling point less than 295°C; this can be used as feedstock in a steam cracker. The experiment at 690°C yielded about 40 wt.% of an oil, about the half of which consists of benzene, toluene and xylene (BTX-aromatics). At the highest reaction temperature of 735°C, the main product was a highly aromatized oil; the BTX-aromatics content is about 20 wt.% of the pyrolysis product.

Bio-oils, which are multicomponent mixtures, were produced from two different biomass (rice straw (rice oil) and sawdust of oak tree (oak oil)) by using the slow pyrolysis process, and chemical compositional screening with GC-MS detected several hazardous compounds in both bio-oil samples. The two bio-oils vary in their chemical compositional nature and concentrations. To know the actual hazard potentialities of these bio-oils, toxicological assessments were carried out in a comparative approach by using in vitro (Jurkat T and HepG2 cell) as well as in vivo (Caenorhabditis elegans) systems. A dose-dependent increase in cytotoxicity, cell death (apoptosis), and genotoxicity were observed in cultured cell systems. Similarly, the in vivo system, C. elegans also displayed a dose-dependent decrease in survival. It was found that in comparison with rice oil, oak oil displayed higher toxicity to all models systems, and the susceptibility order of the model systems were Jurkat THepG2C. elegans. Pursuing the study further toward the underlying mechanism by exploiting the C. elegans mutants screening assay, the bio-oils seem to mediate toxicity through oxidative stress and impairment of immunity. Taken together, bio-oils compositions mainly depend on the feedstock used and the pyrolysis conditions which in turn modulate their toxic potentiality.

Fractions of waste square timber and waste ordinary plywood were pyrolyzed in a pyrolysis plant equipped with a fluidized bed reactor and a dual char separation system. The maximum bio-oil yield of about 65 wt.% was obtained at reaction temperatures of 450–500 °C for both feed materials. For quantitative analysis of bio-oil, the relative response factor (RRF) of each component was calculated using an effective carbon number (ECN) that was multiplied by the peak area of each component detected by a GC-FID. The predominant compounds in the bio-oils were methyl acetate, acids, hydroxyacetone, furfural, non-aromatic ketones, levoglucosan and phenolic compounds. The WOP-derived bio-oil showed it to have relatively high nitrogen content. Increasing the reaction temperature was shown to have little effect on nitrogen removal. The ash and solid contents of both bio-oils were below 0.1 wt.% due to the excellent performance of the char separation system.

Palm kernel shells were pyrolyzed in a pyrolysis plant equipped with a fluidized-bed reactor and a char-separation system. The influence of reaction temperature, feed size and feed rate on the product spectrum was also investigated. In addition, the effect of reaction temperature on the yields of phenol and phenolic compounds in the bio-oil was examined. The maximum bio-oil yield was 48.7 wt.% of the product at 490 degrees C. The maximum yield of phenol plus phenolic compounds amounted to about 70 area percentage at 475 degrees C. The yield of pyrolytic lignin after its isolation from the bio-oil was approximately 46 wt.% based on the water and ash free oil. The pyrolytic lignin was mainly composed of phenol, phenolic compounds and oligomers of coniferyl, sinapyl and p-coumaryl alcohols. From the result of a GPC analysis, the number average molecular weight and the weight average molecular weight were 325 and 463 g/mol, respectively.

Systems biology is a multi-disciplinary approach to the study of the interactions of various cellular mechanisms and cellular components. Owing to the development of new technologies that simultaneously measure the expression of genetic information, systems biological studies involving gene interactions are increasingly prominent. In this regard, reconstructing gene regulatory networks (GRNs) forms the basis for the dynamical analysis of gene interactions and related effects on cellular control pathways. Various approaches of inferring GRNs from gene expression profiles and biological information, including machine learning approaches, have been reviewed, with a brief introduction of DNA microarray experiments as typical tools for measuring levels of messenger ribonucleic acid (mRNA) expression. In particular, the inference methods are classified according to the required input information, and the main idea of each method is elucidated by comparing its advantages and disadvantages with respect to the other methods. In addition, recent developments in this field are introduced and discussions on the challenges and opportunities for future research are provided.

The catalytic degradation of polypropylene was carried out over ferrierite catalyst using a thermogravimetric analyzer as well as a fixed bed batch reactor. The activation of reaction was lowered by adding ferrierite catalyst, which was similar with that from ZSM-5. Ferrierite produced less gaseous products than HZSM-5, where the yields of i-butene and olefin over ferrierite were higher than that over HZSM-5. In the case of liquid product, main product over ferrierite is C 5 hydrocarbon, while products were distributed over mainly C 7 -C 9 over HZSM-5. Ferrierite showed excellent catalytic stability for polypropylene degradation.

Catalytic upgrading of bio-oil was carried out over Ga modified ZSM-5 for the pyrolysis of sawdust in a bubbling fluidized bed reactor. Effect of gas velocity (U o /U mf ) on the yield of pyrolysis products was investigated. The maximum yield of oil products was found to be about 60% at the U o /U mf of 4.0. The yield of gas was increased as catalyst added. HZSM-5 shows the larger gas yield than Ga/HZSM- 5. When bio-oil was upgraded with HZSM-5 or Ga/HZSM-5, the amount of aromatics in product increased. Product yields over Ga/HZSM-5 shows higher amount of aromatic components such as benzene, toluene, xylene (BTX) than HZSM-5.

The catalytic activities of Al-MCM-41-P, synthesized through the post-synthetic grafting method, and Al-MCM-41-D, synthesized through the direct sol-gel method, in the pyrolysis of high-density polyethylene (HDPE) were compared in the present work. Thermogravimetric analyses under static conditions were also carried out to estimate the activation energies of the catalytic decomposition reactions of HDPE. Higher catalytic activities and lower activation energies of the catalytic decomposition reactions of HDPE were observed when Al-MCM-41-P was applied compared to when Al-MCM-41-D was applied, which may be due to the fact that Al-MCM-41-P has more acid sites compared to Al-MCM-41-D.

0 20 40 60 80 100 Sand 2500g/No additive (Previous results ref. [14]) CD 1500g/No additive (Run1) CD 1500g+DSS ash 200g/No additive (Run2) CD 1500g+DSS ash 500g/No additive (Run3) CD 2000g/No additive (Run4) CD 1500g/CD 600g (Run5) CD 1500g/AC 600g (Run6) CD 1500g/AC 600g/15 wt.% moisture content (Run7) CD 1500g/AC 600g/22 wt.% moisture content (Run8) CD 1500g/AC 600g/30 wt.% moisture content/Sample 2 after ADP (Run9) CD 1500g/AC 600g/30 wt.% moisture content/Sample 3 before ADP (Run10) Total tar amount (g/kg DSS) Tar removal efficiency (%)