Catalytic Effects at Pyrolysis of Wheat Grains Impregnated with Nickel Salts

Pyrolysis was performed on wheat grains untreated or impregnated with nickel nitrate solutions, into a fixed bed column, in the presence of a carbon dioxide stream. This produced a char with or without nickel, pyrolytic oil and a gaseous fraction. The distribution of these fractions was dependent on variations in heat flux, carbon dioxide superficial velocity and nickel nitrate solution concentration. The paper focused on establishing the qualitative and quantitative influence of these experimental variables on pyrolysis dynamics. In order to obtain a process characterization, a factorial experiment was used, wherein the pyrolysed material mass, collected oil mass, operating time, material bed temperature, volatiles temperature and column wall temperature were the evaluated process responses. A model reproducing pyrolysis curves was proposed considering the process dynamics as a result of competition between the appearance and extension of local pyrolysis points.

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Slow Pyrolysis of Cystoseira Barbata Brown Macroalgae

Revista de Chimie ◽

10.37358/rc.18.3.6147 ◽

2018 ◽

Vol 69 (3) ◽

pp. 553-556 ◽

Cited By ~ 1

Author(s):

Doinita Roxana Cioroiu ◽

Oana Cristina Parvulescu ◽

Tanase Dobre ◽

Cristian Raducanu ◽

Claudia Irina Koncsag ◽

...

Keyword(s):

Carbon Dioxide ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Bet Surface Area ◽

Heat Flow Rate ◽

Slow Pyrolysis ◽

Process Factor ◽

Bed Temperature ◽

Cystoseira Barbata ◽

Bio Oil

Slow pyrolysis of algal biomass of Cystoseira barbata was performed in a fixed bed reactor using carbon dioxide as a sweeping gas and a reactant in the process. Pyrolysis products consisted of a biochar, a bio-oil, and pyrolytic gases. According to a 23 factorial experiment, 8 tests were conducted for 1 hr at two levels of each process factor, i.e., specific heat flow rate (7540, 9215 W/m3), carbon dioxide superficial velocity (1.3, 2.6 cm/s), and bulk density of fixed bed biomass (221, 332 kg/m3). Correlations between these factors and final process responses in terms of mean bed temperature (461-663 oC), biochar yield (15.2-26.7%), bio-oil yield (29.9-34.8%), and BET surface area of biochar (45.17-91.12 m2/g) were established.

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Dynamic Modeling of CATOFIN® Fixed-Bed Iso-Butane Dehydrogenation Reactor for Operational Optimization

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2015-0087 ◽

2016 ◽

Vol 14 (1) ◽

pp. 491-515 ◽

Cited By ~ 3

Author(s):

Zeeshan Nawaz

Keyword(s):

Coke Formation ◽

Fixed Bed ◽

Process Intensification ◽

Operating Conditions ◽

Catalytic Dehydrogenation ◽

Heating Rates ◽

Reactor Model ◽

Fuel Gas ◽

Bed Temperature ◽

Operational Optimization

AbstractThe catalytic dehydrogenation of iso-butane to iso-butylene is an equilibrium limited endothermic reaction and requires high temperature. The catalyst deactivates quickly, due to deposition of carbonaceous species and countered by periodic regeneration. The reaction-engineering constraints are tied up with operation and/or technology design features. CATOFIN® is a sophisticated commercialized technology for propane/iso-butane dehydrogenation using multiple adiabatic fixed-bed reactors having Cr2O3/Al2O3 as catalyst, that undergo cyclic operations (~18–30m); dehydrogenation, regeneration, evacuation, purging and reduction. It is always a concern, how to maintain CATOFIN® reactor at an optimum production, while overcoming gradual decrease of heat in catalyst bed and deactivation. A homogeneous one-dimensional dynamic reactor model for a commercial CATOFIN® fixed-bed iso-butane dehydrogenation reactor is developed in an equation oriented (EO) platform Aspen Custom Modeler (ACM), for operational optimization and process intensification. Both reaction and regeneration steps were modeled and results were validated. The model predicts the dynamic behavior and demonstrates the extent of catalyst utilization with operating conditions and time, coke formation and removal, etc. The model computes optimum catalyst bed temperature profiles, feed rate, pre-heating, rates for reaction and regeneration, fuel gas requirement, optimum catalyst amount, overall cycle time optimization, and suggest best operational philosophy.

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BENTONITE-QUARTZ SAND AS THE BACKFILL MATERIALS ON THE RADIOACTIVE WASTE REPOSITORY

Indonesian Journal of Chemistry ◽

10.22146/ijc.21816 ◽

2010 ◽

Vol 5 (2) ◽

pp. 115-120

Author(s):

Raharjo Raharjo

Keyword(s):

Radioactive Waste ◽

Quartz Sand ◽

Nitrate Solution ◽

Fixed Bed ◽

Weight Percent ◽

Retardation Factor ◽

Backfill Materials ◽

Uranium Migration ◽

Water Saturated ◽

Bentonite Particle

An investigation of the contribution of quartz sand in the bentonite mixture as the backfill materials on the shallow land burial of radioactive waste has been done. The experiment objective is to determine the effect of quartz sand in a bentonite mixture with bentonite particle sizes of -20+40, -40+60, and -60+80 mesh on the retardation factor and the uranium dispersion in the simulation of uranium migration in the backfill materials. The experiment was carried out by the fixed bed method in the column filled by the bentonite mixture with a bentonite-to-quartz sand weight percent ratio of 0/100, 25/75, 50/50, 75/25, and 100/0 on the water saturated condition flown by uranyl nitrate solution at concentration (Co) of 500 ppm. The concentration of uranium in the effluents in interval 15 minutes represented as Ct was analyzed by spectrophotometer, then using Co and Ct, retardation factor (R) and dispersivity () were determined. The experiment data showed that the bentonite of -60+80 mesh and the quartz sand of -20+40 mesh on bentonite-to-quartz sand with weight percent ratio of 50/50 gave the highest retardation factor and dispersivity of 18.37 and 0.0363 cm, respectively. Keywords: bentonite, quartz sand, backfill materials, radioactive waste

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Mathematical Modelling of Catalytic Fixed-Bed Reactor for Carbon Dioxide Reforming of Methane over Rh/Al2O3 Catalyst

BULLETIN OF CHEMICAL REACTION ENGINEERING AND CATALYSIS ◽

10.9767/bcrec.3.1-3.19.21-29 ◽

2010 ◽

Vol 3 (1-3) ◽

Author(s):

Nor Aishah Saidina Amin ◽

Istadi Istadi ◽

New Pei Yee

Keyword(s):

Carbon Dioxide ◽

Mathematical Modelling ◽

Fixed Bed ◽

Fixed Bed Reactor ◽

Carbon Dioxide Reforming ◽

Al2o3 Catalyst

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Start-up Time and Load Range for the Methanation of Carbon Dioxide in a Fixed-Bed Recycle Reactor

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.8b00755 ◽

2018 ◽

Vol 57 (18) ◽

pp. 6391-6400 ◽

Cited By ~ 27

Author(s):

Steffi Matthischke ◽

Stefan Roensch ◽

Robert Güttel

Keyword(s):

Carbon Dioxide ◽

Fixed Bed ◽

Load Range ◽

Start Up ◽

Recycle Reactor

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Efficient Recovery of Carbon Dioxide from Flue Gases of Coal-Fired Power Plants by Cyclic Fixed-Bed Operations over K2CO3-on-Carbon

Industrial & Engineering Chemistry Research ◽

10.1021/ie9704455 ◽

1998 ◽

Vol 37 (1) ◽

pp. 185-191 ◽

Cited By ~ 133

Author(s):

Hiromu Hayashi ◽

Jun Taniuchi ◽

Nobuyoshi Furuyashiki ◽

Shigeru Sugiyama ◽

Shinichi Hirano ◽

...

Keyword(s):

Carbon Dioxide ◽

Power Plants ◽

Fixed Bed ◽

Flue Gases ◽

Efficient Recovery

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Supported CuO and ZnO Catalyst for Hydrogenation of Carbon Dioxide to Methyl Alcohol

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.396 ◽

2012 ◽

Vol 550-553 ◽

pp. 396-399

Author(s):

Chul Min Park ◽

Won Ju Ahn ◽

Woong Kyu Jo ◽

Jin Hun Song ◽

Chang Yeop Oh ◽

...

Keyword(s):

Carbon Dioxide ◽

Methyl Alcohol ◽

Nitrate Solution ◽

Catalyst Support ◽

Zinc Nitrate ◽

Zinc Nitrate Solution ◽

Cupric Nitrate ◽

Air Atmosphere ◽

Co Precipitation ◽

Hydrogenation Of Carbon Dioxide

If the surface of the titanium chips (TC) was modified by thermal treatment under air atmosphere, it could be reused as catalyst support or photocatalytic materials. TC-supported CuO and ZnO catalysts were prepared by impregnation (IMP) method and co-precipitation (CP) method using cupric nitrate and zinc nitrate solution as precursors. Loading of CuO and ZnO on TC was 40.6wt% and 50.3wt%, respectively. The catalytic activity for CO2 hydrogenation was investigated using a flow-typed reactor under various pressures. Conversion of carbon dioxide to methyl alcohol over the CuO-ZnO/TC catalyst by CP and IMP methods were ca. 22% and ca. 10%, respectively. Conversion of carbon dioxide over CuO-ZnO/TC catalyst by CP method was increased with increasing reaction temperature in ranging of 15atm to 30 atm. Maximum selectivity and yield to methyl alcohol over CuO-ZnO/TC catalyst at 250°C were ca. 90% at 20 atm and ca. 18.2% at 30 atm, respectively.

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Cyclic Fixed-Bed Operations over K2CO3-on-Carbon for the Recovery of Carbon Dioxide under Moist Conditions

Bulletin of the Chemical Society of Japan ◽

10.1246/bcsj.68.1030 ◽

1995 ◽

Vol 68 (3) ◽

pp. 1030-1035 ◽

Cited By ~ 45

Author(s):

Shinichi Hirano ◽

Naoya Shigemoto ◽

Shinichi Yamada ◽

Hiromu Hayashi

Keyword(s):

Carbon Dioxide ◽

Fixed Bed

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Australian grains free-air carbon dioxide enrichment (AGFACE) facility: design and performance

Crop and Pasture Science ◽

10.1071/cp08354 ◽

2009 ◽

Vol 60 (8) ◽

pp. 697 ◽

Cited By ~ 77

Author(s):

Mahabubur Mollah ◽

Rob Norton ◽

Jeff Huzzey

Keyword(s):

Carbon Dioxide ◽

Atmospheric Carbon Dioxide ◽

Operating Time ◽

Carbon Dioxide Concentration ◽

Growth Yield ◽

Triticum Aestivum L ◽

Interactive Effects ◽

Temporal And Spatial Distribution ◽

And Performance ◽

Carbon Dioxide Co2

The AGFACE project commenced in June 2007 at Horsham (36°45′07″S, 142°06′52″E; 127 m elevation), Victoria, Australia. Its aim is to quantify the interactive effects of elevated atmospheric carbon dioxide concentration (e[CO2]), nitrogen, temperature (accomplished by early and late sowing times), and soil moisture on the growth, yield, and water use of wheat (Triticum aestivum L.) under Australian conditions. The main engineering goal of the project was to maintain an even temporal and spatial distribution of carbon dioxide (CO2) at 550 μmol/mol within AGFACE rings containing the experimental treatments. Monitoring showed that e[CO2] at the ring-centres was maintained at or above 90% of the target (495 μmol/mol) between 93 and 98% of the operating time across the 8 rings and within ±10% of the target (495–605 μmol/mol) between 86 and 94% of the time. The carbon dioxide concentration ([CO2]) measured inside the rings declined non-linearly with increasing distance downwind of the CO2 source and differed by 3–13% in concentration between the two canopy heights in each ring, but was not affected by wind speed or small variations in [CO2] at the ring-centres. The median values for model-predicted concentrations within the inner 11-m-diameter portion of the rings (>80% of the ring area) varied between 524 and 871 μmol/mol but remained close to target near the centres. The design criteria adopted from existing pure CO2 fumigating FACE systems and new ideas incorporated in the AGFACE system provided a performance similar to its equivalent systems. This provides confidence in the results that will be generated from experiments using the AGFACE system.

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