Adsorption and Absorption

Absorption is the process in which a fluid is dissolved by a liquid or a solid (absorbent).

Adsorption is the process in which atoms, ions or molecules from a substance (it could be gas, liquid or dissolved solid) adhere to a surface of the adsorbent. Adsorption is a surface-based process where a film of adsorbate is created on the surface while absorption involves the entire volume of the absorbing substance.

Items	Absorption	Adsorption
Definition	Assimilation of molecular species throughout the bulk of the solid or liquid is termed as absorption.	Accumulation of the molecular species at the surface rather than in the bulk of the solid or liquid is termed as adsorption.
Phenomenon	It is a bulk phenomena	It is a surface phenomena.
Heat Exchange	Endothermic process	Exothermic process
Temperature	It is not affected by temperature	It is favored by low temperature
Rate of Reaction	It occurs at a uniform rate.	It steadily increases and reach to equilibrium
Concentration	It is same throughout the material.	Concentration on the surface of adsorbent is different from that in the bulk

Process

Gas-liquid absorption (a) and liquid-solid adsorption (b) mechanis.

Blue spheres are solute molecules

Adsorption and absorption are both sorption processes.

Absorption occurs when atoms pass through or enter a bulky material. During absorption, the molecules are entirely dissolved or diffused in the absorbent to form a solution. Once dissolved, the molecules cannot be separated easily from the absorbent.

Adsorption is generally classified into physisorption (weak van der Waal’s forces) and chemisorption. It may also occur due to electrostatic attraction. The molecules are held loosely on the surface of the adsorbent and can be easily removed.

 

 

Uses

Adsorption: Some of the industrial applications for adsorption are air-conditioning, adsorption chillers, synthetic resin and water purification. An adsorption chiller does not require moving parts and hence is quiet. In pharmaceutical industry applications, adsorption is used as a means to prolong neurological exposure to specific drugs or parts thereof. Adsorption of molecules onto polymer surfaces is used in various applications such as in the development of non-stick coatings and in various biomedical devices.

Absorption: The common commercial uses of absorption cycle are absorption chillers for space cooling applications, ice production, cold storage, turbine inlet cooling. High efficiency operation, environmentally friendly refrigerants, clean-burning fuels and few moving parts that require maintenance make absorption a very good choice for consumers. 

The process of gas absorption by a liquid is used in hydrogenation of oils and carbonation of beverages.

Video Link for comparison of adsorption and absorption http://v.youku.com/v_show/id_XNjIxNzAxOTc2.html

 

 

Gold APP Instruments Corporation China

www.jinaipu.com

www.app-one.com.cn

Mobile: +86-18210009838

Langmuir Surface Area|Pore Size Analyzer|Gas Pycnometer True Density Tester|High Pressure Volumetric Analyser|BET/BJH/MP/HK/T-Plot Analyzing--Gold APP Instruments

pressure vs composition diagram and the equipment to measure it

Gas sorption analysis is important in many fields of materials science and consumer product development. Some examples of current hot areas of technology involving gas-solid (or gas liquid) interactions include the development of energy storage materials, improved catalysts for petrochemical processing, advanced pharmaceuticals and food industries. At present, there is tremendous interest in the development of innovative materials for the transition to renewable energy. The science of gas sorption has become particularly critical in the advancement of materials for storing fuel gases such as hydrogen or natural gas, as well as for sequestration of greenhouse gases. Some exciting prospects for the chemical storage of gases include high-surface area and nanomaterials (graphitic carbons, CNT, zeolites, Metal-Organic-Framework MOFs). In the field of hydrogen-storage, a host of novel materials are being developed including high-pressure metalhydrides, light-weight complex hydrides, destabilized multicomponent chemical hydrides and amides, and other crossover materials such as ammonia borane encapsulated into mesoporous silica scaffolding.

Of prime interest in the discovery of these and many other new materials is the characterization of gas absorption, adsorption and desorption kinetics, capacity, thermodynamic properties, as well as cycling performance of reversible materials. Also important is the ability to measure the tolerance of catalyst, chemicals, and consumer products to air, moisture and low-level contaminants. These wide-ranging requirements and the need to perform analysis at both a research and a production level (milligrams to kilograms) have driven the development of the H-Sorb 2600, the ultimate tool for gas sorption analysis.

 

 

H-Sorb 2600 high pressure gas adsorption parameters

1. Analysis Method: static volumetric, high pressure gas sorption
2. Versatility: adsorption/desorption isotherms measurement (atmospheric to 500℃), Gibbs supercritical adsorption measurement
3. Data Reduction: Langmuir model regression isotherm, PCT(Pressure-Composition-Temperature) or PCI (Pressure-Composition-Isotherm) diagram/curve/isotherm measurement, Langmuir maximum adsorption constant L and adsorption pressure constant B measurement; Langmuir correction model loading-ratio correlation regression (LCR) isotherm; Ono-Kondo (OK) lattice model isotherm regression; adsorptive gas density and vapor-liquid equilibrium accuracy calculation under different pressures and temperatures
4. Measuring Ranges: continuous adsorption and desorption measurement from atmospheric to 200Bar pressure
5. Accuracy: repeatability errors <3%
6. Temperature Range: cryogenic to 500℃, accuracy±0.1℃
7. Sample Ports: two samples analyzing and two degassing, stainless-steel micro welding sample cells, software integrated temperature PID adjustment
8. Transducer Accuracy: imported high precision transmitter, accuracy can reach 0.05% of F.S. (full-scale), long-duration usage stability is 0.025% of F.S.
9. Ultimate Vacuum: 4x10^-2 Pa (3x10^-4 Torr), molecular pump system (1x10^-6 Pa) is optional
10. Adsorbate Gas: high purity nitrogen, CO₂ or others (Ar, Kr, H₂, CH₄ etc.)
11. Data Acquisition: high-precision and high integration data acquisition modules, minimal error, strong anti-interference ability
12. Specifications: Height 22.05 inches (56cm)* Width 20.87 inches (53cm)*Depth 23.62 inches (60cm); 132 pound (60kg); 220V/5A

H-Sorb 2600 high pressure gas adsorption features:

1. Control System: imported VCR interface high pressure pneumatic valve can realize auto on-off within 200Bar, sealing performance is top to 1x10^-10 Pa.m3/s, can be used more than 500 million times; programmable logic controller (PLC) system, high integration and sound anti-interference, improve stability and prolong life
2. Analysis Management: parameters be set by software, fully automated, unattended operation at night; H-Sorb mode is available for accurate control gas charging pressure points, gain ideal data points
3. Manifold System: imported 316L stainless steel thick-walled manifolds, micro welding sealing can reduce dead space largely; metal VCR connection is convenient for installation and uninstallation
4. Safety Measures: H-Sorb asymptotic technology realizes auto gas-charging and degassing, prevents high pressure dangers caused by artificial misoperation, and also minimizes large differential pressure’s impact to pressure transducer

 

 

H-Sorb 2600 high pressure gas adsorption application

1.       Study and research in high temperature and pressure gas sorption, supercritical gas performance, microporous materials, hydrogen storage materials, coalbed gas, oil exploration, methane etc.

2.       Catalysts, molecular sieves, active carbon, carbon nano-tube, fuel cell, hydrocarbon and other materials

Our policy of continuous development may cause the information and specifications contained herein to change without notice or liability.

Contact info:

Web: www.jinaipu.com     www.app-one.com.cn

Email: sales@jinaipu.com

Tel.: 0086-10-82132122

Fax: 0086-10-82118197

Mobile: 0086-18210009838

IMs:

Skype: Gold-APP-Instruments

Yahoo Messenger: goldappinstruments@ymail.com

Google Talk: goldappinstruments2008@gmail.com