Regeneration of Sodium Hydroxide from a Biogas Upgrading Unit through the Synthesis of Precipitated Calcium Carbonate: An Experimental Influence Study of Reaction Parameters

This article presents a regeneration method of a sodium hydroxide (NaOH) solution from a biogas upgrading unit through calcium carbonate (CaCO3) precipitation as a valuable by-product, as an alternative to the elevated energy consumption employed via the physical regeneration process. The purpose of this work was to study the main parameters that may affect NaOH regeneration using an aqueous sodium carbonate (Na2CO3) solution and calcium hydroxide (Ca(OH)2) as reactive agent for regeneration and carbonate slurry production, in order to outperform the regeneration efficiencies reported in earlier works. Moreover, Raman spectroscopy and Scanning Electron Microscopy (SEM) were employed to characterize the solid obtained. The studied parameters were reaction time, reaction temperature, and molar ratio between Ca(OH)2 and Na2CO3. In addition, the influence of small quantities of NaOH at the beginning of the precipitation process was studied. The results indicate that regeneration efficiencies between 53%–97% can be obtained varying the main parameters mentioned above, and also both Raman spectroscopy and SEM images reveal the formation of a carbonate phase in the obtained solid. These results confirmed the technical feasibility of this biogas upgrading process through CaCO3 production.

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Synthesis and Characterization of Hydroxyapatite from Duck Eggshell by Wet Precipitation Process

Journal of Applied Materials and Technology ◽

10.31258/jamt.3.1.8-11 ◽

2021 ◽

Vol 3 (1) ◽

pp. 8-11

Author(s):

Yelmida Azis ◽

Cory Dian Alfarisi ◽

Komalasari Komalasari ◽

Khairat Khairat ◽

Yusnimar Sahan

Keyword(s):

Xrd Analysis ◽

Precipitation Method ◽

Molar Ratio ◽

Precipitation Process ◽

Stable Form ◽

X Ray Diffraction ◽

Precipitated Calcium Carbonate ◽

X Ray ◽

Inorganic Mineral

Hydroxyapatite (HAp, Ca10(PO4)6(OH)2) is the most stable form of calcium phosphate and widely used in various medical applications, mainly in orthopedics and dentistry due to its close similarities with the inorganic mineral component of bone and teeth. This study aims to synthesize hydroxyapatite from duck eggshell using the precipitation method. The duck eggshell was calcined, hydrated (slaking) and underwent carbonation to form Precipitated Calcium Carbonate (PCC). Afterwards, (NH4)2HPO4 was added to produce HAp by varying the molar ratio of Ca/P by 1.67, 1.77 and 1.87 and stirring speed by 200, 250, 300rpm under basic condition (pH 10 – 11). The best results were obtained at a molar ratio of 1.77 with 200rpm stirring speed. Furthermore, the X-ray Diffraction (XRD) analysis showed that its crystals were hexagonal with sizes of 23.062nm, in the absence of other crystalline phases. Therefore, the hydroxyapatite was obtained in the agglomerates form with a specific surface area of ??55.929m2/g.

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The Effect of Molar Ratio Ca/Al on Synthesis of Aragonite Precipitated Calcium Carbonate

Geosystem Engineering ◽

10.1080/12269328.2004.10541228 ◽

2004 ◽

Vol 7 (4) ◽

pp. 103-106

Author(s):

Jeong-Hwan Kim ◽

Ji-Whan Ahn ◽

Sang-Bop Lee ◽

Hwan Kim

Keyword(s):

Calcium Carbonate ◽

Molar Ratio ◽

Precipitated Calcium Carbonate

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Effect of Calcium Carbonate on the Mechanical Properties and Microstructure of Red Clay

Advances in Materials Science and Engineering ◽

10.1155/2020/5298186 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Lijie Chen ◽

Xuejun Chen ◽

Xin Yang ◽

Pengyan Bi ◽

Xiang Ding ◽

...

Keyword(s):

Mechanical Properties ◽

Calcium Carbonate ◽

Carbonate Content ◽

Shear Tests ◽

Red Clay ◽

Precipitated Calcium Carbonate ◽

Sem Images ◽

Clay Particles ◽

Calcium Carbonate Content ◽

Analysis System

The influence of precipitated calcium carbonate on the strength and microstructure of red clay was studied. Precipitated calcium carbonate was added to red clay at ratios of 0%, 5%, 10%, 15%, and 20%. Shear tests were carried out on the samples to observe the effect of calcium carbonate on the mechanical properties of red clay. The results showed that, with increasing calcium carbonate content, the strength of red clay first decreased and then increased. The maximum strength was obtained for the sample with 20% calcium carbonate. Scanning electron microscopy (SEM) was used to observe the changes in microstructure caused by addition of calcium carbonate. The pores and cracks analysis system (PCAS) was used to quantitatively characterize the microstructure changes detected in SEM images. The addition of calcium carbonate decreased the pore area and increased the total number of pores of red clay. The incorporation of calcium carbonate caused the red clay particles to agglomerate. The higher the calcium carbonate content, the stronger the agglomeration of red clay particles in the soil samples.

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Comparison of experimental techniques for biocementation of sands considering homogeneous volume distribution of precipitated calcium carbonate

E3S Web of Conferences ◽

10.1051/e3sconf/202019505004 ◽

2020 ◽

Vol 195 ◽

pp. 05004

Author(s):

Francisco Centeno Dias ◽

Inês Borges ◽

Sofia O. D. Duarte ◽

Gabriel A. Monteiro ◽

Rafaela Cardoso

Keyword(s):

Calcium Carbonate ◽

Small Samples ◽

Volume Distribution ◽

Compression Tests ◽

Precipitated Calcium Carbonate ◽

Sem Images ◽

Entire Volume ◽

Dissolution Tests ◽

Microbially Induced Carbonate Precipitation ◽

Preparation Techniques

Microbially induced carbonate precipitation (MICP), or biocementation, consists in using microorganisms living in the soil to produce calcium carbonate (biocement). This mineral bonds the grains and therefore improves the soil hydro-mechanical properties. When using this technique, one of the challenges is to ensure homogeneous treatment in the entire volume. In this study, an experimental device was developed to apply this treatment in cylindrical soil samples with 7.2 cm diameter and 12 cm height. Two distinct sample preparation techniques were tested: (i) pre-mixing the soil with bacteria, and then inject the feeding solution; (ii) inject bacteria followed by injecting the feeding solution. In both, the injection conditions varied in two distinct ways: (i) infiltration column, from the top and (ii) injecting through a perforated central tube. The homogeneity of the biocement in the volume was evaluated using X-ray and SEM images from small samples taken from different locations in the specimens and analysing different parameters. Mercury intrusion porosimetry (MIP) and CaCO3 dissolution tests revealed uneven distribution of CaCO3 content between the top and bottom sections, as well as along radial direction. The most homogeneous samples were found when bacteria were premixed with the soil before injecting the feeding solution. Unconfined compression tests (UCS) were also performed in samples with and without treatment. The treatment increased stiffness and strength significantly and soil rupture occurred mostly near the bottom, where the lowest CaCO3 contents were detected.

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Cellulose-precipitated calcium carbonate composites and their effect on paper properties

Chemical Papers ◽

10.2478/s11696-013-0513-7 ◽

2014 ◽

Vol 68 (6) ◽

Cited By ~ 7

Author(s):

Kamel Mohamadzadeh-Saghavaz ◽

Hossein Resalati ◽

Ali Ghasemian

Keyword(s):

Calcium Carbonate ◽

Reaction Temperature ◽

Crystal Habit ◽

Precipitated Calcium Carbonate ◽

Sem Images ◽

Paper Properties ◽

Xrd Pattern ◽

Cellulose Fibrils ◽

Softwood Kraft Pulp ◽

Alkaline Conditions

AbstractA cellulose-PCC composite was synthesised using the CaCl2 reaction with dimethyl carbonate (DMC) under alkaline conditions and in the presence of cellulose fibrils made from highly refined bleached softwood kraft pulp. The results showed that the ash content in the synthesised cellulose-PCC composite increased by increasing the reaction temperature from 25°C to 70°C, the reaction time from 3.5 min to 7.5 min and the cellulose consistency from 0.05 % to 0.1 %. The ratio of calcium carbonate generated to the calcium chloride used initially was increased by increasing the reaction temperature and time. The XRD pattern of the cellulose-PCC composite indicated no modification micro-crystal habit of the deposited CaCO3. The SEM images showed that the cellulose-PCC composite filler had a rhombohedral shape as opposed to the scalenohedral shape of common PCC. The paper filled with the cellulose-PCC composite had much higher bursting and tensile strengths, at a tearing strength similar to common PCC.

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Study of Culture Paper Making with P-RC APMP by Different Papermaking Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.629.347 ◽

2012 ◽

Vol 629 ◽

pp. 347-351

Author(s):

Tao Lin ◽

Jian Wei Song ◽

Xue Feng Yin ◽

Zhi Jie Wang

Keyword(s):

Calcium Carbonate ◽

Raw Materials ◽

Strength Properties ◽

Precipitated Calcium Carbonate ◽

Sem Images ◽

Paper Properties ◽

Fiber Network ◽

Paper Making ◽

Flocculation Process ◽

Ground Calcium Carbonate

Using Poplar P-RC APMP as raw materials for culture paper making, the effect of conventional papermaking process and P-RC APMP fines-calcium carbonate co-flocculation process on the P-RC APMP culture paper properties were studied. The result showed that, comparing to the conventional papermaking process, co-flocculation process can supply paper with better strength properties, bulk and whiteness. When precipitated calcium carbonate (PCC) or ground calcium carbonate (GCC) were added respectively in conventional papermaking process, the PCC supplied handsheets with better bulk and whiteness, while GCC supplied handsheets with better strength properties. In the co-flocculation process, the effects of PCC and GCC were nearly the same in strength properties and bulk of handsheets, but PCC was more beneficial for whiteness. SEM images showed that PCC distributed more evenly in the fiber network, and well-bonded with fiber network. The particle size of GCC is relatively small, mainly filled in the fiber network and wrapped on the fiber.

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Physicochemical comparison of precipitated calcium carbonate for different configurations of a biogas upgrading unit

Journal of Chemical Technology & Biotechnology ◽

10.1002/jctb.6013 ◽

2019 ◽

Cited By ~ 1

Author(s):

Francisco M Baena‐Moreno ◽

Cameron AH Price ◽

Estelle le Saché ◽

Laura Pastor‐Pérez ◽

Daniel Sebastia‐Saez ◽

...

Keyword(s):

Calcium Carbonate ◽

Biogas Upgrading ◽

Precipitated Calcium Carbonate

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A method for measuring the in-plane compressive strength and the compression behavior of coating layers

TAPPI Journal ◽

10.32964/tj10.7.29 ◽

2011 ◽

Vol 10 (7) ◽

pp. 29-34

Author(s):

TEEMU PUHAKKA ◽

ISKO KAJANTO ◽

NINA PYKÄLÄINEN

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Calcium Carbonate ◽

Coating Layer ◽

Test Methods ◽

Coating Films ◽

Precipitated Calcium Carbonate ◽

Coating Color ◽

Mineral Coatings ◽

Styrene Butadiene

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.

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