Oxidative coupling of methane in a fluidized bed reactor: Influence of feeding policy, hydrodynamics, and reactor geometry

Jašo, S.; Arellano‐García, Harvey; Wozny, Günter

doi:10.1016/j.cej.2011.03.077

Cited by 48 publications

(36 citation statements)

References 59 publications

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“…Despite of these advantages, the formation of the target products (C 2 þ ) is always accompanied by further oxidations to carbon oxides, which limits the overall process efficiency [1]. Since the pioneering work by Keller and Bhasin [4], extensive studies have been carried out on various aspects of the OCM reaction, such as catalyst composition and design [5][6][7][8], reaction mechanism [1,9] and reactor design [10][11][12]. Nevertheless, after over 40 years, this process is not yet commercialized.…”

Section: Introductionmentioning

confidence: 98%

An oxygen permeable membrane microreactor with an in-situ deposited Bi1.5Y0.3Sm0.2O3− catalyst for oxidative coupling of methane

Othman

2015

Journal of Membrane Science

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Section: Introductionmentioning

confidence: 98%

An oxygen permeable membrane microreactor with an in-situ deposited Bi1.5Y0.3Sm0.2O3− catalyst for oxidative coupling of methane

Othman

2015

Journal of Membrane Science

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“…By integrating hydrogen separation with reforming reactions, higher reactant conversions were achieved at mild operating temperatures and ultrapure hydrogen flow with purity >99.995% was obtained in the permeate lines . Selective dosing of reactants—mostly oxygen—via membranes is another interesting application of FBMR . Benefits such as the suppression of undesired side reactions, higher yields and conversions, and the expansion of the safe operating range of the reactant compositions can be achieved with species dosing via membranes.…”

Section: Introductionmentioning

confidence: 99%

“…The efficiency of the membrane units is commonly low in practical applications, and the stability of the membrane in long‐term operation at high temperatures is far away from satisfactory . The fundamental principles guiding the design and manufacture of FBMR are not yet clear . All the aforementioned challenges depend greatly on the knowledge of hydrodynamics in FBMR.…”

Section: Introductionmentioning

confidence: 99%

“…The abrasion and erosion effects of the particles on the membranes strongly depend on the dynamics of the moving solids in the bed . An improper arrangement of the membrane units causes significant channeling to occur, thus resulting in dominant and undesired side reactions . Additionally, the bubble‐to‐emulsion phase mass transfer limitation also tends to become more pronounced in an FBMR .…”

Section: Introductionmentioning

confidence: 99%

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Effect of gas extraction on the hydrodynamics in a fluidized bed membrane reactor at elevated temperatures

Xiao

Chun

Chen

et al. 2019

Asia-Pacific J Chem Eng

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This study describes experimental explorations on the effects of gas extraction on hydrodynamics in a pilot-scalegas fluidized bed membrane reactor (FBMR) at high temperatures. Differential pressure signals were measured at different vertical intervals in bed and were then characterized by multiscale resolution and power spectra analysis. The experimental results showed that the relative amplitude of σ r (σ/x av ) of pressure signal tended todecrease with the increase of gas extraction fraction.At room temperature, 20% gas extraction caused defluidization at an inlet velocity of 2U mf . However, athigh temperatures the gas extraction simultaneously decreased the magnitude of the low-frequency components and the numbers of the medium-to small-sized structures, mainly due to the decreased number of small-sized structures and the integration of bubbles. This effect of gas extraction increased with increase of gas extraction fraction and slightly decreased at higher inlet gas velocities. At elevated temperatures, the D6 sub-signals (0.781~1.562Hz) possessed the highest wavelet energy distribution percentage of the pressure signals, which meant that the medium-to small-sized bubbles dominated the gas-solid flow dynamics. Gas extraction was observed to enhance the dominance of the D6 scale components..

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“…Similar operations, such as distribution of secondary air can also be facilitated by using porous ceramic membranes or side ports instead of selective membranes. The distribution of the oxidative reactant on the membrane was experimentally found to reduce the unwanted side reactions [9], improve yields [10], and benefit the safe operation with a wide range of reactant compositions, mainly due to the possible proper alteration of the concentration profile along the reactor by this method. Consequently, axial gas back-mixing was efficiently decreased [11][12][13], and the interphase mass transfer could be enhanced [14].Despite the demonstrated advantages of integrating the membrane processes with a fluidized bed reactor, there are still several issues hindering the industrial application of FBMRs.…”

mentioning

confidence: 99%

Analysis of the Hydrodynamic Effects of Gas Permeation in a Pilot-Scale Fluidized Bed Membrane Reactor

et al. 2018

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This study experimentally investigates the effects of gas extraction/addition, via multiple vertical membrane panels, on the hydrodynamics in different regions of a pilot-scale gas fluidized bed membrane reactor (FBMR), based on differential pressure signals measured at different vertical bed sections at high temperature. In a bed section where membrane panels were installed and activated, the extraction of gas caused the average bubble size to increase, but decreased the number of small- and medium-sized bubbles. This effect of gas extraction penetrated into bed sections above the active membrane panel, but attenuated with increasing distance away from the extraction location. The attenuation rate was much faster in FBMR with lower bed voidage, mainly due to the large decrease of the drag force exerted by gas extraction on fluidizing gas in a denser bed. With the same inlet gas velocity, gas addition favored the growth of bubbles, especially in the upper bed sections compared with operation without gas permeation. The increase of the effective fluidizing velocity was the major reason for the increase of the bubble size during gas addition. These findings preliminarily suggest that membrane units should not be installed in or below fast-reacting zones in a scale-up FBMR, and operation with a lower bed voidage is preferable to avoid the formation of large bubbles enhanced by gas extraction.

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Oxidative coupling of methane in a fluidized bed reactor: Influence of feeding policy, hydrodynamics, and reactor geometry

Cited by 48 publications

References 59 publications

An oxygen permeable membrane microreactor with an in-situ deposited Bi1.5Y0.3Sm0.2O3− catalyst for oxidative coupling of methane

An oxygen permeable membrane microreactor with an in-situ deposited Bi1.5Y0.3Sm0.2O3− catalyst for oxidative coupling of methane

Effect of gas extraction on the hydrodynamics in a fluidized bed membrane reactor at elevated temperatures

Analysis of the Hydrodynamic Effects of Gas Permeation in a Pilot-Scale Fluidized Bed Membrane Reactor

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