scholarly journals Quantitative Comparison of Binary Mix of Agro-Industrial Pozzolanic Additions for Elaborating Ternary Cements: Kinetic Parameters

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2944
Author(s):  
Ernesto Villar-Cociña ◽  
Moisés Frías ◽  
Holmer Savastano ◽  
Loic Rodier ◽  
María Isabel Sánchez de Rojas ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Sugar Cane ◽  
Research Work ◽  
Pozzolanic Reaction ◽  
Reaction Rate Constant ◽  
Pozzolanic Activity ◽  
Binary Blend ◽  
Activation Free Energy ◽  
Pozzolanic Reactivity ◽  
Bamboo Leaf Ash

In this research work, the quantitative characterization of a binary blend comprised of two pozzolans (sugar cane straw (SCSA)–sugar cane bagasse ashes (SCBA), bamboo leaf ash (BLAsh)–SCBA and paper sludge (PS)–fly ash (FA)) taking into account the calculated values of the kinetic parameters of the reaction in the pozzolan/calcium hydroxide system is shown. The paper shows the most significant and important results obtained by the authors in the quantitative assessment (calculation of kinetic parameters) of the pozzolanic reaction of different mixtures of pozzolanic materials that are residues from agriculture or industrial processes. This allows a direct and rigorous comparison of the pozzolanic activity of the binary combinations of materials. The values of the kinetic parameters (reaction rate constant or activation free energy) constitute a very precise quantitative index of the pozzolanic activity of the binary combinations of materials, which is very useful for its employment in the elaboration of ternary cements. This paper shows that the binary blends 1SCBA60Blash40, 1SCBA50Blash50, 1SCBA70Blash30 have a very high pozzolanic reactivity followed by PSLSFA, 2SCBA50SCSA50, PSISFA and SCWI.

scholarly journals Not Reacted Core Model Applied in Palm Nut Shell Pyrolysis

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ernesto de la Torre ◽  
Sebastián Gámez
Keyword(s):  
Kinetic Parameters ◽  
Elaeis Guineensis ◽  
Effective Diffusion ◽  
Reaction Rate Constant ◽  
Core Model ◽  
Scanning Calorimetry ◽  
Differential Scanning Calorimetry Study ◽  
Different Temperatures ◽  
Char Conversion ◽  
Pyrolysis Of Biomass

One of the main sources of activated carbon is biomass which can be transformed into char by pyrolysis. Apart from the obtaining coal, the pyrolysis of biomass can be used for the preparation of fuels, and this is why it is very important to determine its kinetic parameters for modelling. In the present research, the pyrolysis enthalpy of palm nut shells (Elaeis guineensis) was determined with the use of a differential scanning calorimetry study (DSC). To determine the kinetic parameters, the Not Reacted Core model was employed. This model considers that there is a heat and mass gradient between the furnace atmosphere and the interface formed during pyrolysis. To obtain the required data for the model, palm nut shells were submitted to pyrolysis in a Nichols furnace under reducing atmosphere. Samples were taken every 10 minutes to calculate char conversion. The experimental pyrolysis enthalpy resulted to be 301.81 J/g and then the monomeric units of cellulose, hemicellulose, and lignin were employed in order to determine the pyrolysis enthalpy per mole. The three biopolymers react with different mechanisms at different temperatures. The molecular weight resulted to be 172.38 g/mole, and the enthalpy for pyrolysis was 52.03 kJ/mol. For the application of the Not Reacted Core model, the amorphous char heat transfer coefficient was selected, and the value is 1.6 J/s·m·K. The reaction rate constant was 6.64 × 10−9 1/s assuming a first-order reaction, whereas the effective diffusion across the char layer was 4.83 × 10−7 m2/s.

scholarly journals Experimental investigation of soil blended with lime and lignosulphonate

2018 ◽  
Vol 7 (2.25) ◽  
pp. 74
Author(s):  
Soundarya M.K ◽  
Bhuvaneshwari S ◽  
Prasanna Kumar.S
Keyword(s):  
Expansive Soils ◽  
Research Work ◽  
Expansive Soil ◽  
Pozzolanic Reaction ◽  
Clay Particles ◽  
Bearing Strength ◽  
Pulp Industry ◽  
Saw Dust ◽  
Change Behavior ◽  
Volume Change Behavior

The deterioration of the structures which are built on the expansive soils is due to its volume change behavior, due to the presence of Mont-morillonite minerals in soil. Hence this soil requires adequate stabilization before commencement of any construction activities. The stabili-zation phenomenon in which addition suitable additives completely alters the behavior of the soil by changing the basic properties and there-by increasing the bearing strength of soil. The choice of the additives depends on the ease and permanence of the stabilizing characteristics achieved for the expansive soil. In this paper, an attempt is done to evaluate the behavior of soil when blended with additives like saw dust ash, lime and lignosulphonate at varying blending ratio. The objective of the research work is to focus on the change in the plasticity charac-teristics by utilizing the industrial waste as additive due to its cementitious value, making it eco-friendly and reduction in cost. Lignosulpho-nate is a by-product of paper pulp industry, generated during the sulphite process. From the literature, the optimum percentage for stabilizing works for lime and lignosulphonate was found to be two to eight percent and one to three percent respectively. Basic Index properties and compaction characteristics test were determined for both virgin and treated soil. The additives decreased the plasticity index, causing ag-glomeration of clay particles involving pozzolanic reaction. 

Determination of Some Kinetic Parameters by Respirometry

1992 ◽  
Vol 26 (9-11) ◽  
pp. 2535-2538 ◽  
Author(s):  
M. Roš ◽  
M. Dular
Keyword(s):  
Reaction Time ◽  
Activated Sludge ◽  
Kinetic Parameters ◽  
Oxygen Transfer ◽  
Dynamic Method ◽  
Research Work ◽  
Substrate Utilisation ◽  
Relative Standard ◽  
Temperature Constant

Individual kinetic parameters such as BOD, biodegradation of wastewater, reaction time, maximal substrate rate can be determined by respirometry. For the determination of main respirometric parameters (STBOD, BODr, reaction time, etc.) overall oxygen transfer coefficient, KLa, is needed. This parameter can be determined with dynamic method in an open respirometer at limited conditions (constant temperature, constant stirring conditions). It was found out that KLa is dependent upon concentration of the activated sludge; it can be determined with about 2% of relative standard deviation. The objective of our research work was determination of maximal exogenous oxygen uptake, re max and maximal substrate utilisation, µmax, which is very important kinetic parameter at wastewater treatment. These parameters show us the maximal substrate (wastewater) utilisation for appointed activated sludge.

Assessing the pozzolanic activity of cements with added sugar cane straw ash by synchrotron X-ray diffraction and Rietveld analysis

2015 ◽  
Vol 98 ◽  
pp. 44-50 ◽  
Author(s):  
Guilherme A. Calligaris ◽  
Margareth K.K.D. Franco ◽  
Laurence P. Aldrige ◽  
Michelle S. Rodrigues ◽  
Antônio Ludovico Beraldo ◽  
...  
Keyword(s):  
Sugar Cane ◽  
Rietveld Analysis ◽  
Pozzolanic Activity ◽  
X Ray Diffraction ◽  
Added Sugar ◽  
X Ray ◽  
Straw Ash
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