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Research draft

adsorption

vr.tr.adsorption · ACT.PRC

Let an agent explain adsorption and distinguish it from absorption, describe physisorption and chemisorption and the main isotherm models, relay applications and measurement methods, and route design questions to engineering references.

Thing Registry Activities and processes

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent explain adsorption and distinguish it from absorption, describe physisorption and chemisorption and the main isotherm models, relay applications and measurement methods, and route design questions to engineering references.

The adhesion of atoms, ions or molecules from a gas or liquid to a surface, forming a film on the adsorbent, either by weak physical forces or by chemical bonding; adsorption underlies activated carbon filters, catalysis, chromatography, gas storage and many separation processes, and is described by isotherms that relate the amount adsorbed to pressure or concentration.

What it is for: Separation, purification, catalysis and storage.

It can be explain the process and its kinds; distinguish adsorption from absorption; explain isotherms and measurement; describe applications.

Distinguishing features

Surface phenomenon

Physical versus chemical binding

Described by isotherms

Reversible by desorption in many cases

What it looks like

Not visible; a surface layer of molecules on a solid or liquid.

Physical character

physisorption enthalpy: about 5-40 kJ per mole - typical

chemisorption enthalpy: about 40-400 kJ per mole - typical

activated carbon surface area: about 500-1500 square metres per gram

How it is recognised

Accumulation on a surface

Physisorption by weak forces or chemisorption by bonds

Absorption takes material into the bulk

Related models

is a kind of - a surface form

sorption

is a kind of - in engineering

separation process

is contrasted with - uptake into the bulk

absorption

is described by - the relation

adsorption isotherm

In practice

Families and kinds

physisorption

chemisorption

gas adsorption on solids

adsorption from solution

isotherm models such as Langmuir, Freundlich and BET

pressure and temperature swing adsorption processes

Standards and regulation

ISO 9277 for surface area by gas adsorption

IUPAC recommendations on adsorption terminology

Failure modes and hazards

Confusing adsorption with absorption

Saturation and breakthrough of adsorbents

Heat release in adsorption beds

Also called

adsorption isothermphysisorptionchemisorption

Where this came from

wikidata · CC0 1.0

Also registered as vr.tr.adsorption

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Concept What adsorption is.

Definition.

Definition

Definition and kinds.

Definition

Definition.

  1. What is adsorption, and how do physisorption and chemisorption differ? definition
  2. Is the question about adsorption or absorption? boundary

Isotherms

Isotherms.

Isotherms

Isotherms.

  1. What do the Langmuir, Freundlich and BET isotherms describe? definition
  2. Which entry fits a specific isotherm? action
Measure Measurement.

Method.

Methods

Methods.

Methods

Methods.

  1. How are adsorption capacity and surface area measured? measurement
  2. Which standards apply? provenance

Data

Data.

Data

Data.

  1. What typical values do common adsorbents show, with sources? measurement
  2. Which references are standard? provenance
Apply Applications.

Engineering.

Separation

Separation and purification.

Separation

Separation.

  1. How is adsorption used in water and air purification, gas separation and chromatography? provenance
  2. Which entry fits activated carbon? action

Catalysis

Catalysis and storage.

Catalysis

Catalysis.

  1. What role does adsorption play in catalysis and gas storage? provenance
  2. Which entry fits heterogeneous catalysis? action
Learn Theory and teaching.

Study.

Theory

Theory.

Theory

Theory.

  1. How do thermodynamics and kinetics describe adsorption? provenance
  2. Which entry fits surface science? action

Teach

Teaching.

Teach

Teaching.

  1. How is adsorption taught, and which misconceptions arise? provenance
  2. Which entry fits physical chemistry? action

What the second pass must settle

  • Should isotherm models be separate entries?
  • How should standards be linked?
  • The registry entry has merged aliases for isotherms and kinds; should they be split off?