Catalytic activity of facilely synthesized mesoporous HZSM-5 catalysts for optimizing the CO2 desorption rate from CO2-rich amine solutions

Direct decomposition of nitric oxide (NO) proceeds over Co–Mn–Al mixed oxides promoted by potassium. In this study, answers to the following questions have been searched: Do the properties of the K-promoted Co–Mn–Al catalysts prepared by different methods differ from each other? The K-precipitated Co–Mn–Al oxide catalysts were prepared by the precipitation of metal nitrates with a solution of K2CO3/KOH, followed by the washing of the precipitate to different degrees of residual K amounts, and by cthe alcination of the precursors at 500 °C. The properties of the prepared catalysts were compared with those of the best catalyst prepared by the K-impregnation of a wet cake of Co–Mn–Al oxide precursors. The solids were characterized by chemical analysis, DTG, XRD, N2 physisorption, FTIR, temperature programmed reduction (H2-TPR), temperature programmed CO2 desorption (CO2-TPD), X-ray photoelectron spectrometry (XPS), and the species-resolved thermal alkali desorption method (SR-TAD). The washing of the K-precipitated cake resulted in decreasing the K amount in the solid, which affected the basicity, reducibility, and non-linearly catalytic activity in NO decomposition. The highest activity was found at ca 8 wt.% of K, while that of the best K-impregnated wet cake catalyst was at about 2 wt.% of K. The optimization of the cake washing conditions led to a higher catalytic activity.

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Efficient nickel-based catalysts for amine regeneration of CO2 capture: From experimental to calculations verifications

10.22541/au.162603766.62490342/v1 ◽

2021 ◽

Author(s):

Qiang Sun ◽

Yu Mao ◽

Hongxia Gao ◽

Teerawat Sema ◽

Sen Liu ◽

...

Keyword(s):

Catalytic Activity ◽

Co2 Capture ◽

Density Functional ◽

Catalytic Mechanism ◽

Theoretical Calculations ◽

High Heat ◽

Catalytic Performance ◽

Industrial Applications ◽

Co2 Desorption ◽

The Density Functional Theory

High heat duty is an urgent challenge for industrial applications of amine-based CO2 capture. In this work, we report a novel, stable, efficient, and inexpensive Ni-HZSM-5 catalyst to reduce the heat duty. The density functional theory (DFT) calculations successfully explain the catalytic performance. The catalytic activity associates with the combined properties of MSA × B/L × Ni2+. The 7.85-Ni-HZ catalyst presents an excellent catalytic activity for the CO2 desorption: it increases the amount of desorbed CO2 up to 36%, reduces the heat duty by 27.07% compared with the blank run, and possesses high stability during five cyclic tests. A possible catalytic mechanism for the Ni-HZSM-5 catalysts through assisting carbamate breakdown and promoting CO2 desorption is proposed based on experimental results and theoretical calculations. Therefore, the results present that the 7.85-Ni-HZ catalyst significantly accelerates the protons transfer in CO2 desorption and can potentially apply in industrial CO2 capture.

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Utilization of tertiary amine solutions and ultrasound irradiation for CO2 desorption at low temperature in a CCS process

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/abe2e8 ◽

2021 ◽

Vol 60 (SD) ◽

pp. SDDD01

Author(s):

Hirokazu Okawa ◽

Hiroyasu Ito ◽

Tatsuo Fujiwara ◽

Yuya Kitamura ◽

Takahiro Kato ◽

...

Keyword(s):

Low Temperature ◽

Tertiary Amine ◽

Ultrasound Irradiation ◽

Co2 Desorption ◽

Amine Solutions

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Desorption rate of volatile compounds in polishing ponds

Water Science & Technology ◽

10.2166/wst.2011.104 ◽

2011 ◽

Vol 63 (6) ◽

pp. 1177-1182

Author(s):

Eudes M. Alves ◽

Paula F. C. Cavalcanti ◽

Adrianus van Haandel

Keyword(s):

Carbon Dioxide ◽

Experimental Investigation ◽

Volatile Compounds ◽

Rate Constants ◽

Driving Force ◽

Co2 Removal ◽

Desorption Rate ◽

Order Process ◽

First Order ◽

Co2 Desorption

Increase of pH in polishing ponds can be predicted quantitatively from variations in alkalinity and acidity. These variables are affected by processes that develop simultaneously in ponds: (1) CO2 desorption, (2) biological CO2 removal by photosynthesis and (3) NH3 desorption. An experimental investigation was carried out to determine the desorption rate of carbon dioxide and ammonium. It is shown that CO2 and NH3 desorption can be described by Fick’s law, which describes desorption of a gaseous compounds from water as a first order process with respect to the degree of oversaturation, which is the driving force of the process. An experimental investigation was carried out to determine the desorption rate constants. The value of the constant proved to be inversely proportional to the depth of the pond (H) and its value for H=1 m and at 26°C was established as KCO2=0.34/H d−1 for carbon dioxide and KNH3=0.33/H d−1 for ammonium.

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Advantages of high surface area niobium oxide catalysts on MgH2 sorption properties

MRS Proceedings ◽

10.1557/proc-0927-ee04-02 ◽

2006 ◽

Vol 927 ◽

Author(s):

Vinay V Bhat ◽

Aline Rougier ◽

Luc Aymard ◽

Gholam A Nazri ◽

Jean-Marie Tarascon

Keyword(s):

Catalytic Activity ◽

Low Temperature ◽

Surface Area ◽

Niobium Oxide ◽

High Surface ◽

High Surface Area ◽

Hydrogen Desorption ◽

Sorption Properties ◽

Desorption Rate ◽

Nano Crystalline

ABSTRACTWe report the synthesis by ‘chimie douce’ route of high surface area (200 m2/g) nano crystalline Nb2O5 (so called p-Nb2O5) and the importance of its addition to enhance the hydrogen sorption properties of MgH2. All of the prepared Nb2O5 catalysts induce faster kinetics, up to twice the desorption rate, than commonly used commercial Nb2O5. Among them, both p-Nb2O5 and Nb2O5:350 (p-Nb2O5 heated to 350 °C) exhibit the best catalytic activity, since a 5.2 wt% hydrogen desorption was achieved at 300 °C for (MgH2)p−Nb2O5, as compared to less than 4 wt.% for commercial Nb2O5 added MgH2, (MgH2)c−Nb2O5, within 12 min. Furthermore, due to the addition of high surface area Nb2O5, the desorption temperature was successfully lowered down to 200 °C, with a significant amount of desorbed hydrogen (4.5 wt%). In contrast at this “low” temperature, (MgH2)c−Nb2O5 shows no desorption.

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Selective Electrochemical Regeneration of Aqueous Amine Solutions to Capture CO2 and to Convert H2S into Hydrogen and Solid Sulfur

Applied Sciences ◽

10.3390/app11219851 ◽

2021 ◽

Vol 11 (21) ◽

pp. 9851

Author(s):

Frédérick de Meyer ◽

Charles Bignaud ◽

Bénédicte Poulain

Keyword(s):

Renewable Energy ◽

Proof Of Concept ◽

Desorption Energy ◽

Thermal Regeneration ◽

Electrochemical Regeneration ◽

Capture Process ◽

Amine Solution ◽

Co2 Desorption ◽

Separation Of Co2 ◽

Amine Solutions

Removing CO2 from natural gas or biogas in the presence of H2S is technically challenging and expensive as it often requires separation of both acid gases from the gas, typically using an aqueous amine solution, followed by separation of CO2 from H2S and conversion of H2S into solid S. In this work, the proof of concept of electrochemical, instead of thermal, regeneration of an aqueous amine solution is developed. This invention might be a very promising technology and has several advantages. It has H2S versus CO2 selectivity of 100%, can directly convert H2S into S and H2, and is economically competitive with CO2 desorption energy around 100 kJmol−1 and H2S conversion around 200 kJmol−1. If renewable energy is used for electrochemical regeneration, CO2 emissions due to the CO2 capture process can be significantly reduced.

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High resolution electron microscopy of lanthanum phosphate crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100108519 ◽

1978 ◽

Vol 36 (1) ◽

pp. 274-275

Author(s):

J. C. Wheatley ◽

J. M. Cowley

Keyword(s):

Electron Microscopy ◽

Catalytic Activity ◽

High Resolution ◽

Petroleum Industry ◽

High Resolution Electron Microscopy ◽

Lanthanum Phosphate ◽

Good Catalyst ◽

Resolution Electron ◽

Good Catalytic Activity ◽

Physical And Chemical

Rare-earth phosphates are of particular interest because of their catalytic properties associated with the hydrolysis of many aromatic chlorides in the petroleum industry. Lanthanum phosphates (LaPO4) which have been doped with small amounts of copper have shown increased catalytic activity (1). However the physical and chemical characteristics of the samples leading to good catalytic activity are not known.Many catalysts are amorphous and thus do not easily lend themselves to methods of investigation which would include electron microscopy. However, the LaPO4, crystals are quite suitable samples for high resolution techniques.The samples used were obtained from William L. Kehl of Gulf Research and Development Company. The electron microscopy was carried out on a JEOL JEM-100B which had been modified for high resolution microscopy (2). Standard high resolution techniques were employed. Three different sample types were observed: 669A-1-5-7 (poor catalyst), H-L-2 (good catalyst) and 27-011 (good catalyst).

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The design and catalytic performance of molybdenum active sites on an MCM-41 framework for the aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran

Catalysis Science & Technology ◽

10.1039/c8cy02291g ◽

2019 ◽

Vol 9 (3) ◽

pp. 811-821 ◽

Cited By ~ 7

Author(s):

Zhao-Meng Wang ◽

Li-Juan Liu ◽

Bo Xiang ◽

Yue Wang ◽

Ya-Jing Lyu ◽

...

Keyword(s):

Catalytic Activity ◽

Active Sites ◽

Aerobic Oxidation ◽

Catalytic Performance ◽

Mcm 41

The catalytic activity decreases as –(SiO)3Mo(OH)(O) > –(SiO)2Mo(O)2 > –(O)4–MoO.

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Prolonged Expression of Procoagulant Activity of Human Platelets Degranulated by Thrombin

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649855 ◽

1995 ◽

Vol 74 (03) ◽

pp. 958-961 ◽

Cited By ~ 6

Author(s):

Raelene L Kinlough-Rathbone ◽

Dennis W Perry

Keyword(s):

Catalytic Activity ◽

Thrombus Formation ◽

Annexin V ◽

Human Platelets ◽

Procoagulant Activity ◽

Prothrombinase Complex ◽

Arterial Thrombus ◽

Flowing Blood

SummaryPlatelets are exposed to thrombin when they take part in arterial thrombus formation, and they may return to the circulation when they are freed by fibrinolysis and dislodged by flowing blood. Thrombin causes the expression of procoagulant activity on platelets, and if this activity persists, the recirculating platelets may contribute to subsequent thrombosis. We have developed techniques to degranulate human platelets by treatment with thrombin, and recover them as single, discrete platelets that aggregate in response to both weak and strong agonists. In the present study we examined the duration of procoagulant activity on the surface of thrombin-degranulated platelets by two methods: a prothrombinase assay, and the binding of 125I-labeled annexin. Control platelets generated 0.9 ± 0.4 U thrombin per 107 platelets in 15 min. Suspensions of thrombin-degranulated platelets formed 5.4 ± 0.1 U thrombin per 107 platelets in this time. Binding of 125I-annexin V was also greater with thrombin-treated platelets than with control platelets (controls: 1.7 ±0.1 ng annexin/107 platelets; thrombin-degranulated platelets: 6.8 ± 0.2 ng annexin/107 platelets). With thrombin-degranulated platelets, increased procoagulant activity and annexin binding persisted for at least 4 h after degranulation and resuspension, indicating that the catalytic activity for the prothrombinase complex is not reversed during this time. These platelets maintained their ability to aggregate for 4 h, even in response to the weak agonist, ADP. Thus, platelets that have taken part in thrombus formation and returned to the circulation may contribute to the promotion of further thrombotic events because of the persistence of procoagulant activity on their surface.

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