scholarly journals Determination of intraparticle diffusivity and fluid-to-solid mass transfer coefficient from single concentration history curve in circulated-type fixed-bed reactor

2017 ◽  
Vol 36 (1-2) ◽  
pp. 571-585 ◽  
Author(s):  
Noriyoshi Sonetaka ◽  
Yoshimi Seida ◽  
Takuto Nakano ◽  
Eiji Furuya
Keyword(s):  
Analytical Method ◽  
Decay Curve ◽  
Batch Reactor ◽  
Fixed Bed ◽  
Adsorption Kinetic ◽  
Test Method ◽  
Fixed Bed Reactor ◽  
Experimental Conditions ◽  
Reactor Test ◽  
Mixed Batch

In this study, a simple analytical procedure for determining the adsorption kinetic parameters Ds and kF from a single concentration history (decay curve) in circulate-type fixed-bed reactor test method was investigated. A simple and reliable method to obtain the parameters Ds and kF from the decay curve of circulate-type fixed-bed reactor was developed based on an advanced analytical method for the completely mixed batch reactor test method. The experimental conditions in the circulate-type fixed-bed reactor method that meet the application criteria of the advanced analytical method for the completely mixed batch reactor test method were investigated based on the theoretical decay curves of the test methods. Experimental conditions, such as large liquid–solid ratio Zϕ, short contact time z/u, and small bed height Z, which make the decay behaviors in the circulate-type fixed-bed reactor close to those of the completely mixed batch reactor, were evaluated quantitatively on theoretical basis. Furthermore, the reliability of the adsorption kinetic parameters obtained in this study was verified by comparing the kF values with those from a reported empirical correlation equation for kF.

scholarly journals The Effect of Pyrolysis Temperature on Copyrolysis of Lignite and Pistachio Seed in a Fixed-bed Reactor

2021 ◽  
Vol 15 ◽  
pp. 49-52
Author(s):  
Özlem Onay
Keyword(s):  
Elemental Analysis ◽  
Pyrolysis Temperature ◽  
Fixed Bed ◽  
Product Distribution ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Oil Yield ◽  
Pyrolysis Oil ◽  
Nitrogen Gas ◽  
Experimental Conditions

Co-pyrolysis of lignite and pistachio seed (CPLPS) under nitrogen gas was performed in a Heinze retort. The effect of pyrolysis temperature on product distribution of CPLPS investigated under heating rate of 10°Cmin-1 and blending ratio of 50(wt)%. Biomass is higher yield to be pyrolyzed than lignite and addition of biomass promotes the pyrolysis of lignite. In the range of the experimental conditions investigated the yield of the product is proportional to pyrolysis temperature. On the other hand, considerable synergetic effects were observed during the co-pyrolysis in a fixed bed reactor leading to increase in oil yield. Maximum pyrolysis oil yield of 27.2% was obtained at pyrolysis temperature of 550°C. The obtained oils are characterized by GC, and elemental analysis.

Population dynamics in an aerobic submerged fixed bed reactor (ASFBR) process

2002 ◽  
Vol 46 (1-2) ◽  
pp. 257-260 ◽  
Author(s):  
I. Lorda-de-los-Ríos ◽  
E. Bécares-Mantecón ◽  
I. Tejero-Monzón
Keyword(s):  
Population Dynamics ◽  
Oxygen Concentration ◽  
Fixed Bed ◽  
High Load ◽  
Fixed Bed Reactor ◽  
Synthetic Wastewater ◽  
Organic Load ◽  
Experimental Conditions ◽  
Low Load ◽  
Aeration Conditions

In this study, an aerobic submerged fixed bed reactor's (ASFBR) population dynamics has been studied in order to know its behavior in different conditions of organic load and oxygen concentration. The reactor was fed with synthetic wastewater. Tested variables and applied values were: 1) Variations in organic load (OL): 16–65 g COD/m2/d. 2) Variations in influent's COD concentration: 40–400 g COD/m3. 3) Variations in specific air flow (SAF): 15–127 m3air/kgCOD. Biofilm samples were taken at the top of the reactor. This study showed important variations in the composition and abundance of the microfauna depending on the experimental conditions. Variations in influent concentration had no significant effect on the abundance of the studied groups. However, differences depending on organic load and aeration conditions were observed. Organic load influenced every group studied but with different results. Sessile cilliates, metazoa and flagellates were abundant in low load, while crawling ones were in high load. Aeration intensity influenced most of the groups except Peranema and Vorticella spp. Despite obtaining good yields, not many protozoa, typical of biofilms under conventional processes, were found. Thus, a great variety of microorganisms, such as many classes of sessile and crawling cilliates, were not found. Important nitrifying activity was obtained at 20 cm depth in a bed. From this point, the heterotrophic and nitrifying populations exist but are inactive.

scholarly journals Gas-phase elemental mercury removal by nano-ceramic material

2020 ◽  
Vol 10 ◽  
pp. 184798041989975
Author(s):  
Tao Zhu ◽  
Weidong Jing ◽  
Xing Zhang ◽  
Wenjing Bian ◽  
Yiwei Han ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gas Flow ◽  
Removal Rate ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Mercury Adsorption ◽  
Experimental Conditions ◽  
Physical And Chemical

The nano-ceramic which is mesoporous silica material was applied to test the removal efficiency of gas-phase Hg0 using a fixed-bed reactor. The physical and chemical properties of nano-ceramic were investigated by various techniques such as BET surface area (BET), X-ray diffraction, fourier transform infrared spectrometer (FTIR), and scanning electron microscope (SEM); then, the sample was tested for mercury adsorption under different conditions. The mercury adsorption tests shown that different Hg0 concentration, adsorption temperature, gas flow rate, and different gas components have significant effects on the mercury removal performance of nano-ceramic, and the adsorption removal rate of nano-ceramic can be 75.58% under the optimal experimental conditions. After fitting the experimental data to the adsorption model, it was found that the theoretical maximum mercury adsorption amount q max of nano-ceramic is 1.61 mg g−1 and there were physical and chemical adsorption at the same time. The adsorption kinetics fitting results shown that the adsorption process of nano-ceramic exhibits multi-segment characteristics of “transmembrane–diffusion–adsorption.”

scholarly journals Anaerobically fermented spent mushroom substrates improve nitrogen removal and lead (II) adsorption

2021 ◽  
Vol 83 (7) ◽  
pp. 1691-1702
Author(s):  
Yunlong Yang ◽  
Ling Li ◽  
Shuqian Sun ◽  
Ershu Lin ◽  
Jibo Xiao
Keyword(s):  
Nitrogen Removal ◽  
Room Temperature ◽  
Sequencing Batch Reactor ◽  
High Throughput Sequencing ◽  
Batch Reactor ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Carboxyl Group ◽  
Thomas Model ◽  
Piggery Wastewater

Abstract In this study, spent mushroom substrates (SMSs) were fermented anaerobically at room temperature to gain liquid SMSs (LSMSs) that were used to remove nitrogen from the piggery wastewater with a low C/N ratio in a sequencing batch reactor (SBR) and solid SMSs (SSMSs) that were utilized to adsorb Pb2+ from Pb2+-containing wastewater in a fixed-bed reactor (FBR). After LSMSs supplement, the removal efficiency of both total nitrogen (TN) and NH+4-N increased from around 50% to 60–80%. High-throughput sequencing results presented an obvious change in microbial diversity, and some functional microorganisms like Zoogloea and Hydrogenophaga predominated to promote nitrogen removal. Pb2+ did not emerge from the effluent until 240 min with the corresponding concentration being less than 3 mg/L when using 30-day SSMSs as adsorbents, and it was demonstrated to be appropriate to use the Thomas model to predict Pb2+ sorption on SSMSs. Although various functional groups played a role in binding ions, the carboxyl group was proved to contribute most to Pb2+ adsorption. These results certified that the anaerobically fermented SMSs are decidedly suitable for wastewater treatment.

scholarly journals Recycling techniques of polyolefins from plastic wastes

2013 ◽  
Vol 10 (1) ◽  
pp. 114-122 ◽  
Keyword(s):  
Liquid Fraction ◽  
Fixed Bed ◽  
Raw Material ◽  
Fixed Bed Reactor ◽  
Major Type ◽  
Mechanical Recycling ◽  
Experimental Conditions ◽  
Waste Products ◽  
Plastic Wastes ◽  
Recycling Techniques

Disposing of plastic wastes to landfill is becoming undesirable due to legislation pressures, rising costs and the poor biodegradability of commonly used polymers. In addition, incineration meets with strong societal opposition. Therefore, recycling either mechanical or chemical, seems to be the only route of plastic wastes management towards sustainability. Polyolefins, mainly polyethylene (LDPE or HDPE) and polypropylene (PP) are a major type of thermoplastic used throughout the world in a wide variety of applications. In Western Europe alone approximately 22 million tones of these polymers are consumed each year, representing an amount of 56% of the total thermoplastics. In the present investigation the recycling of LDPE, HDPE and PP was examined using two different methods: the dissolution/reprecipitation and pyrolysis. The first belongs to the mechanical recycling techniques while the second to the chemical/feedstock recycling. During the first technique the polymer can be separated and recycled using a solvent/non-solvent system. For this purpose different solvents/non-solvents were examined at different weight percent amounts and temperatures using either model polymers as raw material or commercial waste products (packaging film, bags, pipes and food retail products). At all different experimental conditions and for all samples examined the polymer recovery was always greater than 90%. The quality of the recycled polymer was examined using FTIR and DSC. Furthermore, pyrolysis of LDPE, HDPE and PP was investigated with or without the use of an acid FCC catalyst. Experiments were carried out in a laboratory fixed bed reactor. The gaseous product was analyzed using GC, while the liquid with GC-MS. A small gaseous and a large liquid fraction were obtained from all polymers. Analysis of the derived gases and oils showed that pyrolysis products were hydrocarbons consisting of a series of alkanes and alkenes, with a great potential to be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels.

An Experimental Study of Steam Gasification of Biomass over Precalcined Copper Slag Catalysts

2013 ◽  
Vol 634-638 ◽  
pp. 479-489 ◽  
Author(s):  
Shuang Hui Deng ◽  
Jian Hang Hu ◽  
Hua Wang ◽  
Juan Qin Li ◽  
Wei Hu
Keyword(s):  
Fixed Bed ◽  
Copper Slag ◽  
Biomass Gasification ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Hydrogen Yield ◽  
Mass Ratio ◽  
Experimental Conditions ◽  
Gasification Efficiency ◽  
Gasification Temperature

Biomass gasification was separated from catalytic pyrolysis in a two-stage fixed bed reactor with precalcined copper slag catalysts placed in a secondary reactor. The effects of gasification temperature (720-950°C), steam to biomass (S/B) mass ratio (0-2g/g), precalcined copper slag to biomass (C/B) mass ratio (0-2g/g) and copper slag precalcined at different temperatures (800-1000°C) on characteristics of biomass gasification were investigated. The experimental results show that the increase of gasification temperature, S/B mass ratio, C/B mass ratio and precalcination temperature are all favorable for raising gasification efficiency and enhancing the H2 production. With copper slag precalcined at 1000°C for 5 hours as catalyst under the experimental conditions examined, the H2 content, the hydrogen yield, the gas yield and the gasification efficiency reach the maximum of 59.16%, 0.72 Nm3/kg, 1.22 Nm3/kg and 77.56%,respectively.

scholarly journals Kinetic and Fixed Bed Studies for Copper Removal from Solutions by Walnut Tree Sawdust (Juglans regia Linnaeus)

2017 ◽  
Vol 19 (2) ◽  
pp. 327-335
Keyword(s):  
Flow Rate ◽  
Kinetic Models ◽  
Kinetic Data ◽  
Batch Reactor ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Copper Removal ◽  
Bed Height ◽  
Experimental Parameters ◽  
Pseudo Second Order

This study investigates the adsorption kinetics and removal conditions of copper by walnut tree sawdust from synthetic solutions in the batch and fixed bed reactors. The selected experimental parameters for the batch reactor were concentration, solution pH, adsorbent amount and temperature. The optimum batch reactor conditions were applied to the fixed bed reactor. The experimental parameters of the fixed bed reactor were flow rate, bed height, and concentration. The optimum removal conditions for copper removal in the batch reactor were determined as pH (5), temperature (25oC), concentration (25 mg/L), and adsorbent dosage (10 g/L). The kinetic data obtained from the batch reactor were analyzed by the pseudo-first-order and the pseudo-second-order kinetic models and the kinetic data were successfully correlated with the pseudo-second-order model. Activation energy of the process was calculated to be 15.79 kJ/mol. The optimum parameters for the fixed bed reactor were designated as 0.5 mL/min flow rate, 100 mg/L concentration and 15 cm bed height. The kinetic data obtained from the fixed bed reactor were analyzed with the Yoon-Nelson and Thomas kinetic models. The fixed bed kinetics could be described with the Thomas model. Maximum adsorption capacity was calculated as 6.24 mg/g in the fixed bed reactor.

Influence of Catalyst and Temperature on Gasification Performance

2011 ◽  
Vol 281 ◽  
pp. 90-95
Author(s):  
Yu Feng ◽  
Bo Xiao ◽  
Klaus Goerner ◽  
Ravi Naidu
Keyword(s):  
Fixed Bed ◽  
Catalytic Performance ◽  
Steam Gasification ◽  
Fixed Bed Reactor ◽  
Temperature Level ◽  
Experimental Conditions ◽  
Temperature Range ◽  
Higher Temperature ◽  
Reactor Temperature

In the present study the catalytic steam gasification of biomass to produce hydrogen-rich gas with calcined dolomite and Nano-NiO/γ-Al2O3 as catalyst in an externally heated fixed bed reactor was investigated. The influence of the catalyst and reactor temperature on gasification performance was studied at the temperature range of 700°C-900°C. Over the ranges of experimental conditions examined, Nano-NiO/γ-Al2O3 and calcined dolomite both revealed better catalytic performance, at the presence of steam, tar was completely decomposed as temperature increases from 800°C to 900°C. Higher temperature resulted in more H2 and CO2 production, and dry gas yield. The highest H2 content of 58.27V% and the highest H2 yield of 2.23 Nm3/ kg biomass were observed at the highest temperature level of 900°C.

scholarly journals Treatment of methyl orange by the catalytic wet peroxide oxidation process in batch and continuous fixed bed reactors using Fe-impregnated 13X as catalyst

2018 ◽  
Vol 78 (4) ◽  
pp. 936-946 ◽  
Author(s):  
Jian Liu ◽  
Gang Peng ◽  
Xia Jing ◽  
Zhengji Yi
Keyword(s):  
Methyl Orange ◽  
Flow Rate ◽  
Batch Reactor ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Feed Flow Rate ◽  
Peroxide Oxidation ◽  
Wet Peroxide Oxidation ◽  
Fixed Bed Reactors ◽  
Catalytic Wet Peroxide Oxidation

Abstract Fe-impregnated 13X (Fe-13X) catalysts were prepared for catalytic wet peroxide oxidation (CWPO) of methyl orange (MO) solution in batch and continuous fixed bed reactors. A systematical study was carried out to investigate the influence of the main operating parameters on the batch reactor performance. The kinetic curves were analyzed by using a pseudo-first-order kinetic equation over the 30–70 °C temperature range. In addition, the effects of catalysts filling amount and feed flow rate on the catalytic performance of Fe-13X catalysts in a fixed bed reactor were studied. The experimental results showed that the Fe-13X catalysts achieved the highest activity (100% MO conversion and 74.5% chemical oxygen demand (COD) elimination ratio, respectively) at 25 min with trace mount of Fe leaching concentration (<2.1 mg/L) at the optimized reaction conditions (namely 1.0 g/L catalyst concentration, pH 2.0, 17.6 mM H2O2, 70 °C) in a batch reactor. Kinetic studies showed that two different reaction regions existed, and an activation energy of 51.9 kJ/mol for the second region was found. Under the optimal operating conditions found (namely, catalysts filling amount of 3.5 g, feed flow rate of 4 mL/min), the Fe-13X catalysts displayed high MO conversion (99.4%) and COD elimination ratio (77.1%) after continuously ran for 200 min in a fixed bed reactor.

Sign in / Sign up

Export Citation Format

Share Document