Transcript What is Activated Carbon - Knudsen Beverage Consulting

MBAA-Rocky Mountain District
Meeting
Beth McCann
Application Engineer
August 15, 2007
www.norit-americas.com
Contents
What is Activated Carbon
Activated Carbon in the Brewing Process
• Granular Activated Carbon for Water Purification
• Powdered Activated Carbon to Decolorize Beer
• Extruded or Granular Activated Carbon for CO2 Purification
Sterilization Process
Introduction To Norit
Worldwide
Leader in Activated
Carbon
5 Activation
4
Reactivation Plants
Broadest
7
Plants
Product Line
Different Raw Materials
Turnkey Approach
Systems
Capability
Turnkey Capability
Technical
•
Service
Laboratory Design
Systems
•
•
PAC Dosing and Silo Systems
GAC Adsorbers
Change-out
Reactivation
Service
What is Activated Carbon ?
What is Activated Carbon?
A Microcrystalline and / or Amorphous Form of
Carbon
A Rigid “Sponge” of Carbon
The Active Agent in a Separation Process
Network of Pores Surrounded by Carbon
An Adsorbent
It Is NOT a Chemical Compound
Activation Methods
Steam Activation: “Burn out” the internal pore structure
by reaction with steam in a controlled environment at
900°C to 1000°C
Chemical Activation: Mixing
of milled wood and phosphoric
acid then activate
Raw Materials
Lignite
Coal
Bituminous
GAC & PAC
Coal GAC & PAC
Wood
GAC & PAC
Peat
GAC & PAC, EXT
Olive
Pits
Coconut
EXT
GAC & PAC
Activated Carbon Pore Structure
Pore Diameter
Micropores:
<2 nm
Mesopores:
2-50 nm
Macropores:
>50 nm
Pore Volume, ml/g
Pore Size Comparison
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
Bituminous
Lignite
Wood
Peat
<2 nm
2-50 nm
Pore Diameter
>50 nm
Forms of Activated Carbon
Powdered (PAC)
100% Less Than 180 Microns
Granular (GAC)
US Std. Mesh Sizes
Extruded Pellets (EXT)
Diameter in mm
Choosing the Right Carbon
Adsorption
Adsorption
* Surface Phenomenon
* Accumulation of Substance at a Surface
* Two Types - Physical (Van Der Waals Forces)
- Chemisorption (Chemical Bond)
* Capacity vs. Rate
Adsorption process
Step 1 : Mass Transport of an impurity (solute or adsorbate) from the
fluid to the carbon particle surface film;
Step 2 : Diffusion of adsorbate into the pore;
Step 3 : Adsorption on interior surface or pore wall.
What Controls Adsorption?
1. Fluid Contacted (Solution or Gas)
pH, viscosity, temperature, chemical composition
2. Type of Impurity
concentration, solubility, molecular size, polarity,
competitive adsorption
3. Carbon Type
pore volume, dosage, particle size, activation method
4. Process Design
liquid or gas phase, PAC or GAC, contact time,
temperature
Activated Carbon in the
Brewing Process
Water Purification
Decolorization of Beer
CO2 Purification
Water Purification
Water Purification
Topics
Organic contaminants
Disinfection by-products
Residual disinfectants
Backwashing
Sterilization of bed
Water Purification
Removal of organic contaminants
Organics (taste and odor components)
Volatile Organic Compounds
(VOCs)
Synthetic Organic Compounds
(SOCs)
Natural Organic Compounds
(NOCs)
Water Purification
Removal of disinfection by-products
Disinfection by-products (DBPs)
Trihalomethanes
Cl
H C Cl
Cl
Chloroform
Cl
H C Br
Br
Dibromochloromethane
Haloacetic Acids
(THMs)
Br
H C Cl
Cl
Dichlorobromomethane
Br
H C Br
Br
Bromoform
(HAAs)
Water Purification
Removal of disinfectants
Dechlorination
1. Oxidation of carbon surface
C* + HOCl + H2O
C* O + H3O+ + Cl-
C* H + OCl- + H2O
C* O + H3O+ + Cl-
2. Surface oxide formation
HOCl + C*
C* HOCl
3. Reduction of hypochlorite
2HOCl + 2H2O
C* represents activated carbon
2H3O+ + 2Cl- + O2
Water Purification
Removal of Disinfectants
Chloramine removal
pH < 5 = Monochloramine (NH2Cl) formation
C* + NH2Cl + H2O
NH3 + C*O + H+ + Cl-
C* + 2NH2Cl + H2O
N2 + 2HCl + C* + H2O
pH > 5 = Dichloramine formation
NHCl2 + H2O + C*
C* represents activated carbon
NH3 + H+ + Cl- + C*O
Water Purification
Backwashing of GAC Bed
Initial
Removes dust and fines
In-service
Removes trapped suspended
solids
Stratifies the GAC bed
Removes inactive biomass
following steaming
Maintains good hydraulics
Water Purification
Steam Sterilization of GAC Bed
• Backwash to remove solids
• Sterilize with steam
• Maintained for 15 minutes after reaching 140°F
• Backwash with ambient water
Water Purification
Caustic Sterilization of GAC Bed
• Backwash to remove solids
• Sterilize with 2% by wt NaOH or Na2CO3
• Same solution can clean lines downstream
• Rinse filter, carbon and lines downstream
Beer Decolorization
Beer Decolorization
Production of Malternatives
Removal of Color and Taste from Beer
• Decolorization - chemically activated carbon
• Flavor removal - steam activated carbon
Powdered Activated Carbon Used
Batch Operation
CO2 Purification
CO2 Purification

In breweries, CO2 is recovered as a by-product of fermentation. It can then
be purified, compressed and liquefied for further use in packaging, tank
counter-pressure, carbonation, or the preparation of dry ice block or pellets.
Its many uses include:
 The carbonation of beer, wine, soft drinks and mineral water;
 The bottling beverages for preservation during transportation and shelf
storage;
 Tank pressurization
CO2 Purification
Carbon dioxide gas is passed through a CO2 water wash scrubber to
remove water soluble fermentation impurities.
The gas then passes through an activated carbon bed to remove nonwater soluble fermentation impurities - aldehydes, hydrogen sulfide,
ketones, mercaptans, etc.
After purification, the carbon dioxide is then compressed and dried to
remove the water vapor.
In the liquefying condenser, the CO2 gas is liquefied to remove any
remaining non-condensables (O2, N2).
Courtesy of The Wittemann Company, Inc.
Are there any questions