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The oxidative fast pyrolysis of plastics was studied in a conical spouted bed reactor with a fountain confiner and draft tube. An inexpensive fluid catalytic cracking (FCC) spent catalyst was proposed for in situ catalytic cracking in order to narrow the product distribution obtained in thermal pyrolysis. Suitable equivalence ratio (ER) values required to attain autothermal operation were assessed in this study, i.e., 0.0, 0.1, and 0.2. The experiments were carried out in continuous regime at 550 degrees C and using a space-time of 15 gcatalyst min gHDPE -1. The influence of an oxygen presence in the pyrolysis reactor was analyzed in detail, with special focus on product yields and their compositions. Operation under oxidative pyrolysis conditions remarkably improved the FCC catalyst performance, as it enhanced the production of gaseous products, especially light olefins, whose yields increased from 18% under conventional pyrolysis (ER = 0) to 30% under oxidative conditions (ER = 0.1 and 0.2). Thus, conventional catalytic pyrolysis led mainly to the gasoline fraction, whereas light olefins were the prevailing products in oxidative pyrolysis. Moreover, the oxygen presence in the pyrolysis reactor contributed to reducing the heavy oil fraction yield by 46%. The proposed strategy is of great relevance for the development of this process, given that, on one hand, oxygen cofeeding allows solving the heat supply to the reactor, and on the other hand, product distribution and reactor throughput are improved. This work was carried out with financial support from Spain's ministries of Science, Innovation and Universities RTI2018-101678-BI00 (MCIU/AEI/FEDER, UE) and RTI2018-098283-JI00 (MCIU/AEI/FEDER, UE) and Science and Innovation PID2019-107357RB-I00 (MCI/AEI/FEDER, UE) and TED2021-132056B-I00 (MCI/AEI/FEDER, UE), the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 823745, and the Basque Government IT1645-22.

Pyrolysis of Date Palm Petiole (DPP) and Date Palm Seed (DPS) biomass was conducted by fast pyrolysis and on-line analysis of the outlet stream by gas chromatography connected to mass spectrometry (Py-GCMS) at different temperatures (450, 500 and 600 °C) in order to study the effect of this variable on the product distribution. The concentration of the components in the volatile stream (bio-oil and non-condensable gases) was greatly influenced by temperature and, to a minor extent, by the content of the biomass components (cellulose, hemicellulose and lignin). The most abundant compound families quantified are acids, anhydrosugars, ketones, furans and phenols. The most abundant compound identified was levoglucosan, which is mainly derived from the degradation of cellulose, with its relative content being as high as 18.3% for DPS pyrolysis at 450 °C and considerably lower for DPP pyrolysis (12.2%). The relative content of acetic acid was as higher as 10.2% at 450 °C for DPP pyrolysis. The knowledge of product composition is crucial for the development of large scale fast pyrolysis units for the valorization of these Tunisian agricultural wastes.

The present study evaluates elastic and inelastic contact forces in predicting the fluidization characteristics of irregularly shaped Titania nanoparticle agglomerates in a bench-scale conical fluidized bed. At first, experiments were performed to identify the mutual effects of gas velocity and agglomerate size on the instantaneous pressure, bed pressure drop and bed expansion ratio. Rigid complex-agglomerates (∼100−200 μm) were mainly formed in the partially fluidized regime, while soft simple-agglomerates (∼20−70 μm) were primarily formed in the spouting regime. The simulations were performed through the CFD-DEM approach. The error analysis of results in the partially fluidized regime revealed that the combination of Hertz-Mindlin and Johnson-Kendall-Roberts (HM + JKR) model led to a better prediction of the bed pressure drop and bed expansion ratio than the spring-dashpot (LSD) model. In the transition flow regime, the Hysteretic model led to better results of the instantaneous pressure values than those proposed for other flow regimes. In the spouting flow regime, the HM and Thornton models led to over-estimation of bed pressure drop when compared to the LSD model. The comparative results of this study provide promising new insights into the collision mechanism of polydisperse agglomerates in different flow regimes for industrial aspects.

Draft tubes have emerged as promising internal devices to overcome the scale up limitations of the spouted bed. Although only a few parameters define draft tubes, the design of these devices is complex and remains a challenging task, as knowledge concerning the gas–solid flow pattern in the spouted bed is required for a proper implementation. Therefore, this study aims to propose a new criterion for the design of draft tubes (nonporous and open-sided) based on the average spout diameter measured by a borescopic technique in conical spouted beds without draft tube. Based on the radial and axial particle velocity profiles, hydrodynamic analysis, and cycle time distributions, the new configurations are compared with those without tube and with conventional draft tubes. The new open-sided tube provides maximum particle velocities of 480.90 ± 14.60 mm/s in the spout and 90.10 ± 4.40 mm/s in the annulus. These values are lower and higher than the particle velocities obtained without draft tube in the spout and annulus regions, respectively, which means it modifies particle residence time in these regions. The new open-sided tube provides a more efficient gas–solid contact than any conventional one, with spouting behaviour being very similar to the configuration without tube (differences in the minimum spouting velocity being in the 2–6% range), which is a key aspect for scale up purposes.

Various drag models were implemented in a superquadric CFD-DEM code and validated for the simulation of spherical and ellipsoidal particles in spouted beds. The most suitable drag models were identified by comparing the predicted local particle velocity with those measured by particle tracking velocimetry (PTV). The model by Beetstra et al. is the one that best reproduces the experimental results for the spouting of spherical particles, whereas the one by Sanjeevi et al. is the most suitable for ellipsoidal irregular ones. Their capability for the prediction of key operating parameters was demonstrated in both conical and prismatic spouted beds, as they correctly predict the minimum spouting velocity (ums) and fountain height in different configurations (without draft tube and different draft tubes) for particles of different size and shape. The CFD-DEM model predicts the preferential orientation of ellipsoidal particles at each location in the bed and the influence of internal devices on this parameter, which is of the utmost importance in the design of reliable coating apparatuses in the pharmaceutical industry.

The combination of delocalized units for the fast pyrolysis of biomass to produce bio-oil followed by centralized units for the gasification of bio-oil appears as an economically attractive option for the full-scale production of syngas because transportation of bio-oil is less costly than that of biomass. First goal of this study lies in the validation of a bio-oil feeding device made up of a line-thermostated at 60–80 °C and a non-atomizing injector cooled by water. This injector allows feeding the crude bio-oil in continuous mode into the conical spouted bed reactor without being clogged by the pyrolytic lignin in the bio-oil. The effect of gasification temperature on gas properties, tar composition, and carbon conversion efficiency were assessed in the 800–900 °C range. The results show that temperature promotes tar reduction (from 40.7 to 12.5 g/Nm3), carbon conversion efficiency (from 91.2 to 96.3 %) and gas yield (from 1.37 to 1.85 Nm3/kg on a dry basis) as temperature is increased from 800 to 900 °C. A novel aspect of this study is the detailed characterization of the tar evolution with temperature, which, to our knowledge, is an aspect that has not been approached in the literature related to raw bio-oil gasification. This work was carried out with the financial support from Spaińs ministries of Science and Innovation (PID2019-107357RB-I00 (MCIU/AEI/FEDER, UE), TED2021-132056B-I00 (MCI/AEI/FEDER, UE) and PLE21210-008062 (European Union Next GenerationEU/PRTR)) and the Basque Government (IT1645-22). Moreover, this project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745.

The use of spouted beds for batch drying has already been approached in the literature, in which the design of internal devices and aspects related to energy efficiency have been investigated, but there is hardly any information on continuous drying. This paper analyses the performance of a fountain confined conical spouted bed in continuous drying of fine and ultrafine sands, whose configuration has been optimized in previous studies. Capacity curves have been established and the influence of operating parameters has been analyzed. Drying capacity is higher with fine sand, which is explained by the difference in physical properties of the sands. Furthermore, the best use of the energy available is attained with high sand flow rates, which allows reaching energy efficiencies above 95% and 91% for fine and ultrafine sand. This analysis allows predicting the performance of spouted beds in the continuous drying of powder materials in large scale conditions.

Drying is a highly energy-intensive process and dryers are considered one of the most energy-consuming industrial equipment. Nevertheless, the energy contribution of the draft tube in the spouted bed has hardly been studied. This equipment is widely recognized as a versatile and efficient gas-solid contact method for several chemical and physical operations. Thus, the objective of this study is to perform an energy analysis of a draft tube conical spouted bed for particulate materials. Drying of alumina, soybean, and barley has been performed with three different configurations: without tube and with nonporous and open-sided tubes. Energy Efficiency, Drying Efficiency, and Specific Energy Consumption have been the parameters considered for energy analysis. The nonporous tube provided the best energy performance for diffusive materials, such as barley and soybean particles, with reductions in the energy consumption in the range from 31.60% to 42.40% in relation to configuration without tube. The configurations with open-sided tube and without tube provided similar energy performance for all materials. Therefore, this study contributes to support that draft tubes are promising devices for improving energy issues in the spouted bed, mainly in the processing of low moisture materials.

Explicit dimensionless models are proposed for estimating the minimum spouting velocity, operating pressure drop and peak pressure drop in open-sided draft tubes spouted bed using the genetic programming (GP). The models are developed based on 664 experimental data for minimum spouting velocity, 660 for peak pressure drop and 652 for operating pressure drop. The parameters of significant influence are considered as GP input variables, and reliable semi-empirical correlations have been obtained. The models predict the hydrodynamic parameters analyzed with average absolute relative errors of 12.90%, 15.99% and 10.92% for the minimum spouting velocity, peak pressure drop and operating pressure drop, respectively. A comparison of literature correlations with the present ones shows that the latter lead to considerably lower errors from the experimental data. The prediction capability of the new models was evaluated in a range of operating and geometric conditions and a close agreement with the experimental data was observed.

The hydrodynamic behavior of cohesive TiO2 nanoparticle agglomerates was studied in a conical fluidized bed. The effects of size, particle polydispersity, and airflow velocity were analyzed in the transition regime from heterogeneous to homogeneous and turbulent fluidization. The simple-agglomerates size was ~25–75 μm with fractal dimensions of ~1.95–2.50. Adhesive CFD-DEM simulations were performed to study the interaction between the simple-agglomerates by combining Mindlin-Dersiewicz and Johnson-Kendall-Roberts (JKR) contact models. The effects of restitution and friction coefficients, probability density function, and coordination number of agglomerates were studied on the particle velocity profiles in the spout and annular zones. The error analysis results showed that bed dynamics is more sensitive to a change in the friction coefficient than in the restitution coefficient. A good agreement between the results was found for friction and restitution coefficients close to one, which is evidence of nearly elastic collisions between TiO2 agglomerates.

Spouted bed stability and operation is greatly affected by particle features. Accordingly, the hydrodynamic behaviour of conical spouted beds has been studied for fine particles differing in size and density in a wide range of inlet air flow rates. This knowledge is essential for a successful scaling up and industrial implementation of the spouted bed. Therefore, the effect air velocity and solid properties (density and size) have on local solid velocity has been ascertained in a fountain confined conical spouted bed using a borescope technique (Particle Tracking Velocimetry, P T V ) applied to several bed configurations. The results show a close relationship between the inlet air velocity and the local solid velocity, with the gas-solid contact being especially vigorous in the configurations without draft tube and with the open-sided draft tube. The solid circulation flow rate is lowest when a nonporous draft tube is used due to the low solid vertical velocities in the annulus, even at high air flow rates. Nevertheless, vertical velocities in the annular zone increase when particle size and density are increased, although these velocities are lower in the spout and fountain regions due to the higher momentum exchange required for their acceleration.

Open-sided draft tubes provide an optimal gas distribution through a cross flow pattern between the spout and the annulus in conical spouted beds. The design, optimization, control, and scale-up of the spouted beds require precise information on operating and peak pressure drops. In this study, a multi-layer perceptron (MLP) neural network was employed for accurate prediction of these hydrodynamic characteristics. A relatively huge number of experiments were accomplished and the most influential dimensionless groups were extracted using the Buckingham-pi theorem. Then, the dimensionless groups were used for developing the MLP model for simultaneous estimation of operating and peak pressure drops. The iterative constructive technique confirmed that 4-14-2 is the best structure for the MLP model in terms of absolute average relative deviation (AARD%), mean square error (MSE), and regression coefficient (R2). The developed MLP approach has an excellent capacity to predict the transformed operating (MSE = 0.00039, AARD% = 1.30, and R2 = 0.76099) and peak (MSE = 0.22933, AARD% = 11.88, and R2 = 0.89867) pressure drops.

A novel borescopic technique together with the monitoring of pressure fluctuation signals (power spectral distribution, PSD) has been used to track fine particles and characterize solid flow dynamics in fountain confined conical spouted beds. Radial and axial particle velocity profiles have been obtained for different configurations, and spout-annulus and fountain core-periphery interfaces have been delineated. The downward particle velocities in the annulus peak at intermediate positions in this zone, whereas the upward velocities in the dilute zones (spout and fountain core) peak at the axis or close to this position. Among the different configurations analysed in this work, the system without draft tube shows the greatest vertical particle velocities in almost all the different radial and axial positions. The evolution of the spout size along the bed depends on the configuration used, but all of them differ from those commonly reported in the literature. Thus, the spout expands from the bed bottom to the surface, without any neck at an intermediate bed level. Furthermore, the cross-sectional spout shape has been delineated in the systems with open-sided draft tube, and significant spout expansion is observed due to air percolation from the spout into the annulus through the opened faces. Finally, the average spout diameters of the systems without draft tube and with open-sided draft tubes have been compared with those predicted by literature correlations. Those proposed by San Jose et al. and Volpicelli et al. provide the best fit for the configurations without draft tube and with open-sided draft tube, with their relative errors being 9.83% and 8.88%, respectively.

This review collects a wide range of initiatives and results that expose the potential of the refineries to be converted into waste refineries. Thus, they will use their current units for the valorization of consumer society wastes (waste plastics and end-of-life tires in particular) that are manufactured with petroleum derivatives. The capacity, technological development, and versatility of fluid catalytic cracking (FCC) and hydroprocessing units make them appropriate for achieving this goal. Polyolefinic plastics (polyethylene and polypropylene), the waxes obtained in their fast pyrolysis, and the tire pyrolysis oils can be cofed together with the current streams of the industrial units. Conventional refineries have the opportunity of operating as waste refineries cofeeding these alternative feeds and tailoring the properties of the fuels and raw materials produced to be adapted to commercial requirements within the oil economy frame. This strategy will contribute in a centralized and rational way to the recycling of the consumer society wastes on a large scale. Furthermore, the use of already existing and, especially, depreciated units for the production of fuels and raw materials (such as light olefins and aromatics) promotes the economy of the recycling process.

Catalytic pyrolysis of date palm seeds (DPS) has been carried out in a pyroprobe connected online with a GC/MS. The effect of a HZSM-5 zeolite on the product distribution has been studied at 450 and 500 °C by using different catalyst/biomass mass ratios (1, 2, 5) and that of a dolomite catalyst at 450 °C using a catalyst/biomass mass ratio of one. Product distributions have been monitored and their trends explained based on the properties of the catalysts used. The HZSM-5 promotes the formation of incondensable gases and aromatic hydrocarbons due to its high acidity and shape selectivity. The concentrations of incondensable gases and hydrocarbons increase markedly with the catalyst/biomass mass ratio, with their peak area percentages ranging from 23.6 to 54.1% and from 7.1 to 24.5%, respectively. At the same time, a significative reduction in the amount of acids, ketones, phenols, furans, and anhydrosugars has been determined. The dolomite catalyst enhances ketonization reactions, which leads to a significant increase in the content of ketones, accounting for a value of around 27%.

A new general explicit correlation is proposed to predict the heat transfer coefficient of fluids condensing in conventional and mini channels. The expression has been developed by correlating the Numix number with Remix, Prmix, phase density ratio, Pres, WeGT, and FrL using genetic programming for the two-phase flow. The model has been validated with a big dataset consisting of 6521 data samples, covering a wide range of fluids used in refrigeration and heat pump industries, cross-sectional geometries (different diameters), mass fluxes, and saturation temperatures. The new generalized correlation fits the wide range of data points used with an average relative error of 17.82 %. The same database has been used to compare predictions of eight correlations available in the literature, but they failed to give a reasonable estimation of the present experimental results.

A novel internal device called fountain confiner has been developed, which stabilizes the system and allows operating with fine particles, even without any type of draft tube. Given the stability this device confers upon the system, lower minimum spouting velocities than in conventional systems are required, and therefore the correlations in the literature overestimate this hydrodynamic parameter. Accordingly, runs have been carried out using this novel device in order to study the hydrodynamics and the influence geometric and operating factors have on the minimum spouting velocity in fountain confined conical spouted beds, with and without draft tubes. The beds are made up of fine sand and sawdust particles. Based on an experimental design, it was ascertained that, although certain factors are influential in given configurations, those of greater influence in all the configurations are the solid properties, static bed height and gas inlet diameter. Therefore, new correlations have been proposed for predicting the minimum spouting velocity in each configuration.

Pressure fluctuation analysis has been used to identify different flow regimes in spouted beds. Although this is a promising cost-effective tool for process control and design purposes, it has hardly been used in spouted beds operating with fine and irregular particles. Therefore, the aim of this paper is to apply pressure fluctuation analysis to spouted beds operating with fine and irregular particles, either without tube or equipped with draft tube. The minimum spouting velocities estimated by the spectral analysis in systems without tubes differ from those obtained based on the characteristic curves in the range from 10.60% (sand) to 3.50% (glass beads). Thus, the main novelty of this study lies in the application of pressure fluctuation and spectral analyses in spouted beds operating with fine and irregular particles by considering the influence of the internal devices. Therefore, the methodology proposed based on both hydrodynamic and spectral analyses is a feasible and promising alternative for delimiting the minimum spouting velocity and stable operating conditions in industrial processes, especially when the aim is process control and scaling up.

This study examined elutriation, attrition, and segregation in a conical spouted bed with a fountain confiner and incorporating an open sided draft tube. Fine silica sand with a wide particle size distribution was employed as a model material, operating in both the batch and continuous modes. The use of a fountain confiner is crucial when operating with fine particles, because otherwise the bed rapidly exhibits significant entrainment. The extent of attrition was quantified using a tracing technique based on differently-coloured sand fractions as well as monitoring size distributions by sieving. Particle breakage was found to be the primary attrition mechanism, and the fountain confiner was determined to limit the elutriation of fine particles resulting from breakage. Consequently, only a small fraction of the finest particles were entrained from the bed. The incorporation of a confiner increased operational stability while reducing segregation, especially in the upper half of the bed where the majority of segregation typically occurs. Thus, the bed was perfectly mixed apart from very minimal segregation close to the wall and at the bottom of the contactor. These results provide a basis for the design and operation of larger scale equipment for the continuous drying of materials.

Spouted beds are extensively used in different industries. The minimum spouting velocity is a critical hydrodynamic parameter needed for the design and scale-up of these systems. This study deals w...

The effect the solid inlet design has on the continuous drying of sand in a conical spouted bed has been studied. Five designs have been tried, four feeding the solid from the top and the fifth one...

The catalytic cracking of 2-methoxy-4-methylphenol (MMP) and of a mixture of this compound (20 wt%) with n-hexadecane (C16) has been conducted in a CREC Riser Simulator Reactor at 400-550 °C using ...

The flow and mixing behavior of two miscible liquids has been studied in an innovative static mixer by using CFD, with Reynolds numbers ranging from 20 to 160. The performance of the new mixer is compared with those of Kenics, SMX, and Komax static mixers. The pressure drop ratio (Z-factor), coefficient of variation (CoV), and extensional efficiency (α) features have been used to evaluate power consumption, distributive mixing, and dispersive mixing performances, respectively, in all mixers. The model is firstly validated based on experimental data measured for the pressure drop ratio and the coefficient of variation. CFD results are consistent with measured data and those obtained by available correlations in the literature. The new mixer shows a superior mixing performance compared to the other mixers.

[EN] A study was carried out on the valorization of different waste plastics (HDPE, PP, PS and PE), their mixtures and biomass/HDPE mixtures by means of pyrolysis and in line oxidative steam reforming. A thermodynamic equilibrium simulation was used for determining steam reforming data, whereas previous experimental results were considered for setting the pyrolysis volatile stream composition. The adequacy of this simulation tool was validated using experimental results obtained in the pyrolysis and in line steam reforming of different plastics. The effect the most relevant process conditions, i.e., temperature, steam/plastic ratio and equivalence ratio, have on H-2 production and reaction enthalpy was evaluated. Moreover, the most suitable conditions for the oxidative steam reforming of plastics of different nature and their mixtures were determined. The results obtained are evidence of the potential interest of this novel valorization route, as H-2 productions of up to 25 wt% were obtained operating under autothermal conditions. This work was carried out with the financial support from Spain's ministries of Science, Innovation and Universities (RTI2018-098283-JI00 (MCIU/AEI/FEDER, UE)) and Science and Innovation (PID2019-107357RB-I00 (MCI/AEI/FEDER, UE)), the European Union's Horizon 2020 research and innovation programme under the Marie SklodowskaCurie grant agreement No. 823745, and the Basque Government (IT1218-19 and KK-2020/00107).

Bed symmetry has been analysed in fountain confined conical spouted beds operating with fine particles. Thus, vertical particle velocities and the spout shape have been determined in a wide range of spouting air velocities and bed configurations. Bed symmetry is widely accepted in the spouted beds without draft tubes or with nonporous ones, but this is not the case when open-sided draft tubes are used. Thus, radial particle velocity profiles differ depending on the cross-sectional angular plane considered in the open-sided draft tubes. The spout expands preferentially along the tube opened surface, and is wider as spouting air velocity and aperture ratio are increased. The literature correlations proposed for the average spout diameter have been analysed and no one is valid for estimating this parameter in the whole range of spouting air velocities and configurations analysed in these systems operating with fine particles. This work has received funding from Spain's Ministry of Science and Innovation (PID2019-107357RB-I00 (AEI/FEDER, UE)), the Basque Gov- ernment (IT1218–19 and KK-2020/00107) and the European Commis- sion (HORIZON H2020-MSCA RISE-2018. Contract No.: 823745). M. Tellabide thanks Spain's Ministry of Education, Culture and Sport for his Ph.D. grant (FPU14/05814). I. Estiati thanks the University of the Basque Country for her postgraduate grant (ESPDOC18/14).

[EN] The steam pyrolysis of pinewood sawdust has been conducted in a bench scale plant provided with a conical spouted bed reactor (CSBR). This process is of uttermost relevance for the in-line valorisation of pyrolysis volatiles, specifically for their catalytic steam reforming for hydrogen production. The influence of temperature on the product yields has been analyzed in the 500-800 degrees C range. A detailed analysis of the volatile stream (condensable and non-condensable components) has been carried out by chromatographic techniques, and the char samples have been characterized by ultimate and proximate analyses, N-2 adsorption-desorption, and Scanning Electron Microscopy. A high bio-oil yield was obtained at 500 degrees C (75.4 wt%), which is evidence of the suitable features of the conical spouted bed reactor for this process. As temperature was increased, higher gas and lower liquid and char yields were obtained. Steam was fully inert at low pyrolysis temperatures (500-600 degrees C), and only had a little influence at 700 degrees C due to the low gas residence time in the conical spouted bed reactor. At 800 degrees C, the reaction mechanism was controlled by gasification reactions. The composition of the liquid fraction was considerably influenced by pyrolysis temperature, with a less oxygenated stream as temperature was increased. Thus, phenolic compounds accounted for the major fraction at low pyrolysis temperatures, whereas hydrocarbons prevailed at 800 degrees C. The char obtained in the whole temperature range can be further used as active carbon or energy source. This work was carried out with the financial support from Spain's ministries of Science, Innovation and Universities (RTI2018-101678-B-I0 0 (MCIU/AEI/FEDER, UE) and RTI2018-098283-J-I0 0 (MCIU/AEI/FEDER, UE) ) and Science and Innovation (PID2019-107357RB-I0 0 (AEI/FEDER, UE) ) and the Basque Government (IT1218-19 and KK-2020/00107) . Moreover, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745.

Biomass gasification is a promising and sustainable process to produce renewable and CO2-neutral syngas (H2 and CO). However, the contamination of syngas with tar is one of the major challenges to limit the deployment of biomass gasification on a commercial scale. Here, we propose a hybrid plasma-catalytic system for steam reforming of tar compounds over honeycombbased catalysts in a gliding arc discharge (GAD) reactor. The reaction performances were evaluated using the blank substrate and coated catalytic materials (gamma-Al2O3 and Ni/gamma-Al2O3). Compared with the plasma alone process, introducing the honeycomb materials in GAD prolonged the residence time of reactant molecules for collision with plasma reactive species to promote their conversions. The presence of Ni/gamma-Al2O3 gave the best performance with the high conversion of toluene (86.3%) and naphthalene (75.5%) and yield of H2 (35.0%) and CO (49.1%), while greatly inhibiting the formation of byproducts. The corresponding highest overall energy efficiency of 50.9 g/kWh was achieved, which was 35.4% higher than that in the plasma alone process. Characterization of the used catalyst and long-term running indicated that the honeycomb material coated with Ni/gamma-Al2O3 had strong carbon resistance and excellent stability. The superior catalytic performance of Ni/gamma-Al2O3 can be mainly ascribed to the large specific surface area and the in situ reduction of nickel oxide species in the reaction process, which promoted the interaction between plasma reactive species and catalysts and generated the plasma-catalysis synergy., National Natural Science Foundation of China [51907087]; Natural Science Foundation of Jiangsu Province [BK20190675]; Postdoctoral Science Foundation of China [2020M671289]; Natural Science Foundation for Colleges in Jiangsu Province [19KJB470005]; European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement [823745]; Royal Society Newton Advanced Fellowship [NAF/R1180230]; British Council [623389161]; Scientific and Technological Research Council of Turkey (TUBITAK Project) [219M123], The support of this work by the National Natural Science Foundation of China (no. 51907087), the Natural Science Foundation of Jiangsu Province (no. BK20190675), the Postdoctoral Science Foundation of China (no. 2020M671289), and the Natural Science Foundation for Colleges in Jiangsu Province (no. 19KJB470005) is gratefully acknowledged. The authors acknowledge the funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement (no. 823745). X.T. thanks the support of the Royal Society Newton Advanced Fellowship (NAF/R1180230) and the British Council (No. 623389161). J.Y. acknowledges funding from the Scientific and Technological Research Council of Turkey (TUBITAK Project Contract No. 219M123).

The 3A zeolites are excellent adsorbents for industrial-scale gas dehydration because of the low energy required for regeneration and ease of operation. A computational study of the dehydration of an industrial feed stream containing ethane and water was performed using an in-house code that included an appropriate equilibrium adsorption isotherm. The validated computational model was used to examine the impact of particle size on the process dynamics and the corresponding pressure drop. The water concentration along the adsorption column was also investigated. To increase the process capacity, the packed adsorption bed was divided into two distinct layers, which were operated with different particle sizes. The length of each layer was determined by a parametric study. The best breakthrough time, i.e., 107,800 s, at the allowed pressure drop was obtained when the lengths of the first and second layers were 4.5 and 1 m, respectively. The results showed that the new two-layer adsorption bed could save around 33.8% in total energy requirement in comparison to that of a single bed.

[EN]n recent decades, the production of H-2 from biomass, waste plastics, and their mixtures has attracted increasing attention in the literature in order to overcome the environmental problems associated with global warming and CO2 emissions caused by conventional H-2 production processes. In this regard, the strategy based on pyrolysis and in-line catalytic reforming allows for obtaining high H-2 production from a wide variety of feedstocks. In addition, it provides several advantages compared to other thermochemical routes such as steam gasification, making it suitable for its further industrial implementation. This review analyzes the fundamental aspects involving the process of pyrolysis-reforming of biomass and waste plastics. However, the optimum design of transition metal based reforming catalysts is the bottleneck in the development of the process and final H-2 production. Accordingly, this review focuses especially on the influence the catalytic materials (support, promoters, and active phase), synthesis methods, and pyrolysis-reforming conditions have on the process performance. The results reported in the literature for the steam reforming of the volatiles derived from biomass, plastic wastes, and biomass/plastics mixtures on different metal based catalysts have been compared and analyzed in terms of H-2 production. This work was carried out with the financial support from Spain's Ministries of Science, Innovation and Universities (Grant RTI2018-101678-B-I00 (MCIU/AEI/FEDER, UE) and Grant RTI2018-098283-J-I00 (MCIU/AEI/FEDER, UE)) and Science and Innovation (Grant PID2019-107357RB-I00 (AEI/FEDER, UE)) and the Basque Government (Grants IT1218-19 and KK-2020/00107). Moreover, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745.

The performance of Fe/olivine catalysts was tested in the continuous steam gasification of sawdust in a bench scale plant provided with a fountain confined conical spouted bed reactor at 850 degrees C. Olivine was used as catalyst support and loaded with 5 wt%Fe. The activity and stability of the catalyst was monitored by nitrogen adsorption-desorption, X-ray fluorescence spectroscopy, temperature programmed reduction, X-ray diffraction and X-ray photoelectron spectroscopy techniques, which were conducted before and after the runs. The fountain confined conical spouted bed performs well in the biomass steam gasification with primary catalysts. In fact, this reactor allows enhancing the gas-solid contact, and therefore the catalytic activity by avoiding the elutriation of fine catalyst particles. The uncatalysed efficiency of the gasification process, assessed based on the gas production and composition, H-2 production, tar concentration and composition, and carbon conversion efficiency, was consideraby improved on the Fe/olivine catalyst, with tar reduction being especially remarkable (to 10.4 g Nm(-3)). After 140 min on stream, catalyst deactivation was particularly evident, as tar concentration increased to 19.9 g Nm(-3) (90% of that without catalyst). However, Fe/olivine catalyst was still active for WGS and CH4 steam reforming reactions, with gas and H-2 productions being 1.35 Nm(3) kg(-1) and 5.44 wt%, respectively. Metal iron oxidation to Fe3O4 caused catalyst deactivation, as the reaction environment shifted from oxidizing to reducing conditions due to operational limitations. This work was carried out with financial support from the Spain's Ministries of Science, Innovation and Universities (GN1 RTI2018-098283-J-I00 GN10 (MCIU/AEI/FEDER, UE) and Science and Innovation (PID2019-107357RB-I00 (MCI/AEI/FEDER, UE), the Basque Government (IT1218-19 and KK-2020/00107), and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 823745. The authors also thank the technical and human support provided by SGIker from UPV/EHU and European funding (ERDF and ESF)

The drying of fine sand particles (below 1 mm) has been studied in a conical spouted bed fitted with a draft tube in order to ascertain the performance of a new internal device to confine the fountain. Accordingly, batch runs have been carried out using three types of draft tubes, with confiner and without it under ambient conditions. Their performances have been compared in order to ascertain the optimum configuration. The results evidence that the systems with the confiner perform much better than those without it. Thus, the drying time decreases considerably and the pressure drop and air flow rate decrease slightly when the confiner is used. The drying performance of the open-sided draft tube is superior to any other configuration, i.e., the drying time required with this tube is the shortest. Nonporous draft tubes are the worst option due to their poor gas-solid contact. Porous draft tubes have an intermediate performance.

Degradation behavior and kinetics of microalgae chlorella vulgaris, wood, scrap tire and binary and ternary mixtures were investigated by using thermogravimetry analysis method. Experiments were carried out at different heating rates of 10 − 20 and 40 ° C / min from ambient temperature to 600 °C. The results showed that decomposition of microalgae, wood and tire take place in three stages and the second stage is the main thermal decomposition step. Besides, heating rate enhancements shift the maximum peak temperature of microalgae, wood and scrap tire from 300 °C, 350 °C and 380 °C to 340 °C, 390 °C and 420 °C, respectively. In the case of the ternary mixture, the maximum peak temperature of the mixture was approximately equal to the maximum peak temperature of the tire. The interaction between materials was studied and the results showed that the interaction is inhibitive rather than synergistic. The results of kinetic investigation showed that the tire and the wood have the highest (273.64 kJ/mol) and the lowest (120.96 kJ/mol) activation energy, respectively. The presence of wood and microalgae increased the total weight loss of binary mixture of microalgae-tire and wood-tire, while tire presence did not improve the degradation of microalgae-wood mixture.