Activated carbon, silica-gel and calcium chloride composite adsorbents for energy efficient adsorption cooling systems

2012 ◽  
Author(s):  
Chi Yan Tso
Keyword(s):  
Activated Carbon ◽  
Calcium Chloride ◽  
Silica Gel ◽  
Energy Efficient ◽  
Cooling Systems ◽  
Composite Adsorbents

Development of Composite Adsorbents of Activated Carbon and Hydrophobic Silica Gel for Gasoline Vapor Adsorption

2011 ◽  
Vol 396-398 ◽  
pp. 512-515 ◽  
Author(s):  
Wei Qiu Huang ◽  
Zhi Lun Hu ◽  
Juan Bai
Keyword(s):  
Activated Carbon ◽  
Adsorption Capacity ◽  
Silica Gel ◽  
Lower Layer ◽  
Optimum Ratio ◽  
High Concentration ◽  
Composite Adsorbent ◽  
Low Concentration ◽  
Hydrophobic Silica ◽  
Composite Adsorbents

A composite adsorbent with upper-layer activated carbon (TY) and lower-layer hydrophobic silica gel (HSG) was developed, based on the comprehensive consideration of both adsorption capacity and adsorption heat of activated carbon and hydrophobic silica. For the composite adsorbent, various volumetric ratio of activated carbon to silica gel was designed, and the adsorption capacity and heat effect of the composite adsorbent with different ratio were investigated. The experimental results showed that the optimum ratio was 1:1. Thus, the vapor with high concentration was early adsorbed by the lower-layer hydrophobic silica gel, and then the residual vapor with low concentration was late adsorbed by the upper-layer activated carbon. In this way, incombustibility of silica gel and high adsorption capacity of activated carbon were fully utilized; accordingly the adsorption operation safety was improved and the adsorption capacity of activated carbon was increased owing to that the activated carbon was only used to adsorb the vapor with low concentration.

Structure and Properties of Composite Adsorbents Salt Inside Porous Matrix

2021 ◽  
pp. 43-87
Keyword(s):  
Silica Gel ◽  
Sol Gel ◽  
Salt Content ◽  
Porous Matrix ◽  
Sodium Sulphate ◽  
Crystalline Hydrate ◽  
Host Matrix ◽  
Gel Method ◽  
Composite Adsorbents ◽  
Silicon Oxygen

The chapter is devoted to structure and properties of composite adsorbents ‘salt inside porous matrix'. Characteristics of adsorbents ‘salt inside porous matrix', such as ‘zeolite – crystalline hydrate', ‘vermiculite – crystalline hydrate', ‘silica gel – crystalline hydrate' were analysed. Main advantages of composite adsorbents are shown to be higher adsorptive capacity and lower regeneration temperature as compared with host matrix. Adsorptive capacities of composite materials are shown to be significantly enhanced by introduction of salts in host matrix such as zeolite, vermiculite, or silica gel. Water uptake by composite adsorbent is shown to be increased by rising the salt content in it. The drawback of most of existing impregnation technologies is shown to be impossibility of obtaining composite with salt content more than 40 – 60% along with complexity. Sol gel method is shown to be an alternative for conventional impregnation methods. Properties of adsorbents ‘silica gel – sodium sulphate' synthesized according to sol gel method developed by authors were considered. The composite ‘silica gel – sodium sulphate' composition and structure were studied by IR-spectroscopy and wide-angle x-ray scattering. Adsorptive properties of crystalline Na2SO4 when allocated in silicon oxygen matrix are shown to result from dispersion up to nanoscale. Adsorptive capacities and heat of adsorption of composites ‘silica gel – sodium sulphate' and ‘silica gel – sodium acetate' surpass almost by 30% the value calculated from the linear superposition of the sorption capacities of the sorbent and massive salt. Their adsorption properties are shown to be not a linear combination of properties of silica gel and salt. The formation of a unique structure promoting an increase in the rate of reaction between crystalline hydrates and water vapor in the developed pores of the silicon-oxygen matrix is confirmed. It leads to increasing the heat of adsorption and the heat energy storage density. Strong difference of water sorption kinetic curves of composite ‘silica gel – sodium sulphate' and massive sodium sulphate is revealed. The correlation of their composition, structure, water adsorption kinetic, and operating characteristic as heat storage material is stated.

Chitosan, alginate and other macromolecules as activated carbon immobilizing agents: A review on composite adsorbents for the removal of water contaminants

2020 ◽  
Vol 164 ◽  
pp. 2535-2549 ◽  
Author(s):  
Heloise Beatriz Quesada ◽  
Thiago Peixoto de Araújo ◽  
Daniel Tait Vareschini ◽  
Maria Angélica Simões Dornellas de Barros ◽  
Raquel Guttierres Gomes ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Water Contaminants ◽  
Composite Adsorbents

A method to circumvent the lot number of activated carbon affecting the performance of activated carbon silica gel columns used for cleanup of blood samples for analysis of 29 hazardous organochlorine compounds

The Analyst ◽  
2005 ◽  
Vol 130 (4) ◽  
pp. 557 ◽  
Author(s):  
Kimiyoshi Kitamura ◽  
Yoshikatsu Takazawa ◽  
Shunji Hashimoto ◽  
Jae-Won ChoiPresent address: Organic Chemis ◽  
Hiroyasu Ito ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Silica Gel ◽  
Organochlorine Compounds ◽  
Blood Samples

Desiccant Degradation in Desiccant Cooling Systems: An Experimental Study

1993 ◽  
Vol 115 (4) ◽  
pp. 212-219 ◽  
Author(s):  
A. A. Pesaran
Keyword(s):  
Thermal Cycling ◽  
Silica Gel ◽  
Molecular Sieves ◽  
Cooling System ◽  
Ambient Air ◽  
Activated Alumina ◽  
Humid Air ◽  
Cooling Systems ◽  
Degradation Data ◽  
Capacity Loss

We conducted experiments to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. The source of contamination was cigarette smoke, which is considered one of the worst pollutants in building cooling applications. We exposed five different solid desiccants to “ambient” and “contaminated” humid air: silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. We obtained the moisture capacity of samples as a function of exposure time. Compared to virgin desiccant samples, the capacity loss caused by thermal cycling with humid ambient air was 10 percent to 30 percent for all desiccants. The capacity loss because of combined effect of thermal cycling with “smoke-filled” humid air was between 30 percent to 70 percent. The higher losses occurred after four months of experiment time, which is equivalent to four to eight years of field operation. Using a system model and smoke degradation data on silica gel, we predicted that, for low-temperature regeneration, the loss in performance of a ventilation-cycle desiccant cooling system would be between 10 percent to 35 percent, in about eight years, with higher value under worst conditions.

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