How Artisan Distillation Works

Kris Arvid BerglundUniversity Distinguished Professor

of Forestry and Chemical EngineeringMichigan State University

East Lansing, MI 48824 USAand

Professor of Biochemical & Chemical Process EngineeringLuleå University of Technology

SE-971 87 Luleå SWEDEN

MSU/ LTU ARTISAN DISTILLING PROGRAM

• Established to promote the establishment and expansion of artisan distillers

• Activities include: education, service, and research

• Designed as a dedicated program for distilled spirits

FACILITIES

• Michigan Brewing Company-houses program, alternating premises license

• A150l Christian Carl still equipped with a three tray side column and a packed column is for high rectification work. (120l to be added at LTU)

• A 450l Christian Carl still for stripping and botanicals• An 800l, 38-tray Christian Carl still (on line in March

2009)• A 10l Christian Carl still for experimental work• Comprehensive analytical instrumentation: GC,

HPLC, Anton Paar DMA 5000 densitometer

EDUCATIONAL ACTIVITIES

• Workshops- two day– MSU, Webberville, MI– WSU, Mt. Vernon, WA– Cornell University, Geneva, NY

• Coursework at MSU, CHE 491• Book entitled, “Artisan Distilling” on CD-

ROM, internet download (free) at www.artisandistilling.org

RESEARCH ACTVITIES

• Develop quality indicators- congener monitoring and control

• Control of regulated compounds

• Yeast screening for congeners

• Activated carbon finishing

Some definitions

• The agency that licenses at the Federal level is Alcohol and Tobacco Tax and Trade Bureau, the Department of Treasury (TTB), not the Bureau of Alcohol, Tobacco and Firearms, the Department of Homeland Security (BATF).

• All spirits are defined in the Code of Federal Regulations-27 CFR Part 5.21

• Make sure anything you wish to make is defined!

Recognized classes of spirits• Class 1; neutral spirits or alcohol.• Class 2; whisky.• Class 3; gin.• Class 4; brandy.• Class 5; blended applejack.• Class 6; rum.• Class 7; tequila.• Class 8; cordials and liqueurs.• Class 9; flavored brandy, flavored gin, flavored rum,

flavored vodka, and flavored whisky.• Class 10; imitations.• Class 11; geographical designations.• Class 12; products without geographical designations

but distinctive of a particular place.

DISTILLATION- MOTIVATION

• Concentrate aromas, flavors, and alcohol

• Several operational parameters possible

• Remove the negative compounds

DISTILLATION

• A process involving an equilibrium between two phases - liquid and vapor.

• For a pure compound, a sharp boiling point usually exists.

• For a mixture, however, a phase equilibrium exists over a range of temperatures.

UNIQUE VLE OF ETHANOL-WATER SOLUTIONS

• For ideal mixtures, the mvc is always at a higher concentration in the vapor phase than the lvc

• The boiling point of the mixture should be a continuously increasing value as the concentration of the lvc is increased

• This is not the case for ethanol-water• The boiling point has a minimum value for a

mixture• This is called a minimum boiling azeotrope

Boiling Point Diagram

76

81

86

91

96

101

0 0.2 0.4 0.6 0.8 1

Mole Fraction

Bo

ilin

g P

oin

t, C DEW CURVE

BUBBLE CURVE

vapor

liquid

mixture

Boiling Point Diagram Near Azeotrope

78

78.2

78.4

78.6

78.8

79

79.2

79.4

79.6

79.8

80

0.5 0.6 0.7 0.8 0.9 1

Mole Fraction

Bo

ilin

g P

oin

t

AZEOTROPE

Ethanol Water VLE

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Liquid Mole Fraction EtOH

Vap

or

Mo

le F

ract

ion

EtO

HINCREASING TEMP.

EtOH Water VLE

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Liquid Phase

Va

po

r P

ha

se

COMPARISONOF UNITS- MOLE, WEIGHT, ANDVOLUME FRACTIONS

VOLUME

WEIGHTMOLE

TYPES OF DISTILLATION

• Simple batch- no rectification

• Alambic- some rectification

• Column- active rectification

BATCH DISTILLATION

• Use “cuts”• “Heads”- remove acetaldehyde, methanol• “Hearts”- product rich in aromas and flavors• “Tails”- fusel oils, dilute

RECTIFICATION- EQUILIBRIUM CONTACT

• Rectification is the result of equilibrium contact between two phases

• The liquid and vapor leaving the contact are in equilibrium

• Rectification, also called enrichment, results in a higher concentration than would occur in a single equilibrium contact

contact n

Vn, yn

Vn+1, yn+1Ln, xn

Ln-1, xn-1

SIMPLE BATCH (RAYLEIGH) DISTILLATION                                                                                                                                                                                     

       

Ethanol Water VLE

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Liquid Mole Fraction EtOH

Vap

or

Mo

le F

ract

ion

EtO

H

1

2

Boiling Point Diagram

76

81

86

91

96

101

0 0.2 0.4 0.6 0.8 1

Mole Fraction

Bo

ilin

g P

oin

t, C

vapor

liquid

mixture

1

2

DIRECT FIRED STILL (ALAMBIC)

Some vapor condenses to liquid and returns to the pot

Classic cognac distillation

INDIRECT STEAM HEATING (ALAMBIC)

Some vapor condenses to liquid and returns to the pot

SteamFigure courtesy of Christian Carl Ing. GmbH

INDIRECT HEATING WITH RECTIFICATION

INCREASING TEMPERATURE DOWN THE COLUMN, HIGHEST TEMPERATURE IS IN THE POT

Figure courtesy of Christian Carl Ing. GmbH

RECTIFICATION COLUMNS•

Figure courtesy of Christian Carl Ing. GmbH

SIEVE TRAY

Top View Side ViewCondensate Return

Vapor

CondensedLiquid

BUBBLE CAP TRAY

Condensate Return

Vapor

CondensedLiquid

BATCH COLUMN STILL

Boiler

Partialcondensor

D, xDL

D

LR Reflux

ratio

Ethanol Water VLE

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Liquid Mole Fraction EtOH

Vap

or

Mo

le F

ract

ion

EtO

H

1

23

45

6

XFEEDxDIST

The number of trays needed for a specific separation is determined by stepping off……..

Boiling Point Diagram

76

81

86

91

96

101

0 0.2 0.4 0.6 0.8 1

Mole Fraction

Bo

ilin

g P

oin

t, C

vapor

liquid

mixture1

23

4 5

Ethanol Water VLE

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Liquid Mole Fraction EtOH

Vap

or

Mo

le F

ract

ion

EtO

HIf the reflux ratio is constant,the product concentrationwill decrease during the batch

1

1

22

33

Ethanol Water VLE

0

0.2

0.4

0.6

0.8

1

0 0.2 0.4 0.6 0.8 1

Liquid Mole Fraction EtOH

Vap

or

Mo

le F

ract

ion

EtO

H

Since the concentration in the pot decrease during a bath, in order to keep the product concentration high, the reflux must be increased

1

2

3

1

23

T

REFLUX IS INCREASED BY INCREASING COOLING WATER

FLOWRATE TO PARTIAL CONDENSER TEMPERATURE SENSOR

WATER TO CONDENSER

Figure courtesy of Christian Carl Ing. GmbH

FLAVOR COMPOUNDS (CONGENERS) IN DISTILLED SPIRITS

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200Methanol

Higher alcohols

Carbonyl compounds

Ethyl acetate

Other esters

Vo

lati

le C

on

gen

ers

in t

he

Dis

till

ed

Sp

irit

s p

er 1

00

mL

of

Alc

oh

ol

TYPICAL COMPOUNDS BY GC

Chemical Name RetentionTime (min) Boiling point (deg. C)Acetaldehyde 2.5 20.8Acetone 3.4 56.2Ethyl Formate 3.6 54.0Ethyl Acetate 4.5 77.0Methanol 4.7 64.7Ethanol 5.8 78.01-propanol 8.7 97.0Isopentanol (isoamyl alcohol) 16.3 132.0Benzaldehyde 33.0 179.0

TYPICAL GC RESULTS

1000

mvolts

500

00

Minutes

40302010

Ethanol

Isoamyl Alcohol1-Propanol Benzaldehyde

50

25

mvolts

0

Minutes

05 10

Acetone

Acetaldehyde

Ethanol

Methanol

1-Propanol

Ethyl Acetate

ETHANOL RESULTS FROM PLUM DISTILLATION

50

60

70

80

90

0 2000 4000 6000 8000Distillate Volume (mL)

Eth

an

ol

Co

nc

. (%

v/v

)

HEADS HEARTS TAILS

CONGENER CONCENTRATIONS IN PLUM DISTILLATES

Congener Concentration vs Distillate Volume 2 Trays with Catalytic Converter

-0.05

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0 1000 2000 3000 4000 5000

Distillate Volume (mL)

Con

gen

er C

once

ntr

atio

n (

% v

/v)

0.10

0.15

0.20

0.25

0.30

0.35

0.40

0.45

0.50

0.55

0.60

Met

han

ol C

once

ntr

atio

n (

% v

/v)

Acetaldehyde

Ethyl Acetate

1-Propanol

Iso Amyl Alcohol

Methanol

HEADS HEARTS TAILS

CONTACT

Prof. Kris Arvid Berglund

Email: berglund@msu.edu

Email: kris.berglund@ltu.se

www.artisandistilling.org

ACKNOWLEDGEMENTS

• Christian Carl Ing. GmbH• Project GREEEN, State of Michigan• Michigan State University• Luleå University of Technology