Short Notes #2

Isothermal Process Vs. Adiabatic Process

Isothermal and adiabatic processes are important concepts with thermodynamics and chemical engineering students should grasps these concepts, Below are some basic differences between the two processes:

Isothermal Process	Adiabatic Process
It is a thermodynamic process that occurs under a constant temperature	It is a thermodynamic process that occurs without any heat transfer between a system and its surroundings
The temperature is constant	The temperature can change
Heat transfer can be observed	No heat transfer
Work done is due to the change in the net heat content of the system	Work done is due to the change in its internal energy

Absorption vs Adsorption

Both are some of the most important mass transfer processes used in chemical and process industries and are called sorption process. A Sorption Process is a physical or a chemical process by which one substance becomes attached to another substance. Another sorption process is Ion Exchange process.

Absorption is a process where components from a gas phase transfer into a liquid phase when the gas phase and liquid phase are brought into contact. On the other hand. 

Adsorption is a process where components from a gas phase or a liquid phase are attached to the surface of a solid phase when the gas phase or the liquid phase is brought in contact to the solid phase. Adsorption is a surface phenomenon.

Absorption	Adsorption
The substance penetrates the surface	It is a surface phenomenon
Occurs at a uniform rate	Initially the rate increases then decreases
Unaffected by temperature	Affected by temperature
It is the same throughout the material	Concentration on the surface of absorbent is different from that in the bulk
It is an endothermic process	It is an endothermic process