Gas On Power Point

Gas Separation and Applications

By Rakesh Jaiswal

1

WHY GAS SEPARATION BY MEMBRANES – Low energy consumption, – No environmental pollution, – Space savings,

2

• Gas separation is important in many industries, e.g., – Development of natural gas and oil resources – Petrochemicals – Foodstuffs

• Separations are needed to:

– Purify products to required purity specifications – Remove toxic or environmentally damaging byproduct

3

Milestones in the Development of Gas Separation • Membranes: used extensively for separations since the 1960’s – Desalination – haemodialysis and separations of dairy proteins – pharmaceutical products – processing of alcoholic and soft drinks • Last 15 years: – Increased demand for new types of membranes for gas separations – low-energy consumption, environment-friendly separation solutions that cannot be obtained through the use of traditional approaches (e.g. distillation) • Beyond traditional polymeric membranes applications: – Development of membranes from new polymers, carbon, or sophisticated ceramics

4

A membrane is a selective semi permeable barrier that allows different gases, vapours, or liquids to move through it at different rates

5

6

Mechanisms for gas separation using membranes

7

PARAMETERS AFFECTING THE PERFORMANCE OF MEMBRANE GAS SEPARATION SYSTEMS

8

ROBSON PLOT

9

Gas separation permeability and selectivity

Upper bound relationship for O2/N2 separation

10

11

12

13

14

15

16

Membranes material and structures 1. Metal Membranes 2. Polymeric Membranes 3. Zeolite & Ceramic Membranes 4. Mixed Matrix 17

Mechanism of permeation of hydrogen through metal membranes

18

Two-layer composite membrane formed by coating a thin layer of a selective polymer on a micro porous support that provides mechanical strength

19

Gas permeation through mixedmatrix membranes containing different amounts of dispersed zeolite particles

20

G a s S e p a r a t io n M e m b r a n e A p p lic a t io n s HYDROGEN SEPARATION CARBON DIOXIDE REMOVAL SEPARATION OF OXYGEN AND NITROGEN NATURAL GAS SEPARATION DEHYDRATION OF NATURAL GAS SEPARATION OF HYDROCARBONS FROM AIR

21

HYDROGEN RECOVERY 1.Simplified flow schematic of the membrane system to recover hydrogen from an ammonia reactor purge stream 2. A two-step membrane system is used to reduce permeate compression costs

22

Approximate competitive range of current membrane nitrogen production systems.

23

Glassy membranes generally separate by differences in size Rubbery membranes separate by differences in condensability

24

Flow scheme of one-stage and two-stage membrane separation plants to remove carbon dioxide from natural gas

25

Issues and limitations

•Existing issues include: • •Plasticization •Compaction •Aging •Fouling • •Pre-combustion capture is likely to be viable, particularly for hydrogen separation within membrane reactors

•

•Post-combustion capture offers the greatest challenge for membranes

26

Reference Membrane Technology and Applications Richard W. Baker, McGraw-Hill Synthetic Membranes and Membrane Separation Precesses Takeshi Matsuura, CRC Press Membrane Handbook W. S. Winston. Ho Basic Principles of Membrane Technology Marcel Mulder, Kluwer academic publishers Membrane Science and Technology Yoshihito Osada, Marcel Dekker, Inc.

27

THANK YOU 28