2E345 ENERGY & ENVIRONMENT

Energy:
Renewable Energies
and Energy Efficiency

Biomass 1.4
2E a division of

gunt Introduction Bioethanol

l Subject Areas
Biomass
090
b Basic Knowledge
Bioethanol
092

This product area is one of GUNT’s current CE 640

094
areas of development. If you have any ideas for Biotechnical Production of Ethanol
future teaching and research equipment
in this field, please get in touch. We would love
to work with you.

Biogas

b Basic Knowledge
Biogas
098

CE 642
100
Biogas Plant

Biodiesel

b Basic Knowledge
Biodiesel
104

CE 650
106
Biodiesel Plant

F
Visit our website at:
www.gunt.de
Energy 1.4 Biomass 089
2E345 ENERGY & ENVIRONMENT

Subject Areas l
Biomass
i Subject Areas 2E345 Products

General biomass is an extremely versatile starting

material. You can use the various plants and fruits CE 640
as food, as animal feed, as fuel for heat generation, Bioethanol Biotechnical Production of Ethanol
as fertiliser, as an additive or base of creams and The anaerobic degradation of plant
components (e.g. pota-toes)
lotions and as fuel for mobility purposes. through enzymes and yeasts
can produce bioethanol,
Many of the uses listed overlap with other areas, so which can be used as a fuel.
The waste gas is in turn
that any by-products created may be used as start- absorbed by the plants and
ing material in another branch. the circuit is closed.

We offer three devices in the biomass field, which

provide a practical representation and illustration
of the fundamental processes. Use of any by-prod- CE 642
ucts created is also possible. For example, with Biogas Biogas Plant
CE 640 on the biotechnical production of ethanol, Biogas can be produced by the anaerobic
you gain ethanol as the main product and mash as degradation of plant components
(e.g. maize) through biomass and,
the by-product. You can either discard the mash or for example, be converted into
use it as substrate in the CE 642 biogas plant. When electricity in combined heat
and power plants and the waste
you operate the biogas plant, you receive biogas as heat used for heating purposes.
the main product and a high-quality fertiliser, the The waste gas is in turn absorbed
digestate, as a by-product. This digestate is low in by the plants and the circuit is closed.

odour compared to manure and the nutrients are

better absorbed by plants.
CE 650
Biodiesel Biodiesel Plant
The main product of the CE 650 Biodiesel Plant
Both glycerin and the desired biodiesel
after the optional purification process is biodiesel. are obtained with the
With optional treatment of the by-products you can transesterification of
plant-based oils, and with
also obtain glycerin, which is used in the food and
the help of a few additives.
cosmetics industries, and a portion of additives. The waste gas is in turn
absorbed by the plants
and the circuit is closed.

Energy F 1.4 Biomass Introduction 091

2E345 ENERGY & ENVIRONMENT

Basic Knowledge B
Bioethanol
The consumption of fossil fuels (coal, petroleum, natural The CO2 cycle of bioethanol
gas) has risen sharply in recent decades. The outputs re- CO2 in the CO2 absorption through
quired to cover the energy demand are leading to an ever Photosynthesis, with the aid of sunlight, enables plant atmosphere photosynthesis
more rapid depletion of deposits. Newly discovered depos- growth. In this process CO2 from the atmosphere, as well
its are difficult to extract due to the location and frequent as water and inorganic substances from the plants, are
impurities. Therefore alternatives are being sought. absorbed and converted into energy-rich organic com-
pounds. This biomass can be regarded as the product of
Replenishable biomass can be used to produce storable a biochemical process, in which a portion of the absorbed
carbon neutral energy sources. These energy sources play sunlight is stored in the form of chemical energy. Being able
an important role alongside discontinuous sources such as to use the biomass as an energy source in various techni-
solar and wind in realising a carbon-neutral and renewable cal processes requires special treatment processes. These
energy supply. include simple physical process-es as well as more complex
Different biological and thermal processes are used to thermochemical and biological processes.
convert the biogenic energy feedstock into a storable Output Biogenic
energy source. of CO2 fuels

Biofuels for carbon-neutral energy Starting materials for bioethanol are the carbohydrates
(sugars) contained in the plants, from which alcohol is Feedstock
In addition to the simple mechanical processes such as with appropriate engine technology. The basis of biofuel is created with the aid of enzymes and yeast fungus. While
comminution and press agglomeration used to produce ethanol for super unleaded fuel and vegetable oil for diesel plants containing sugar are fermented directly, in the case
solid energy sources (pellets), complex biological processes fuel. of starchy plants it is the actual alcoholic fermentation of
are used to produce biofuels and biogas. the enzymatic digestion of the plant material that comes Enzyme
For the field of biofuels, we supply a complete system that Condensation
first. Water
These methods are applications of natural processes on uses enzymes and yeasts to convert starch ethanol. The in-
an industrial scale. Factors such as temperature, pH value, tegrated distillation system is used to separate the ethanol Cooling
mixing and residence time play an important role in these from the digestate.
processes, so as to achieve the greatest yield of energy Enzyme
Another system for the conventional production of bio- Saccharification
sources from the biomass. Acid
diesel by means of transesterification is in development.
Biofuels are substitutes for super unleaded and diesel fu- Cooling
els, which are either mixed with fossil fuels or used directly
Yeast Fermentation

1400
Distillation
1200 production
1000 sales
The fermentation process is completed once either the
800 sugar is consumed or a maximum alcohol concentration is Raw alcohol Spent mash
600 reached. The resulting bioethanol is separated by distilla-
400
tion. The product of distillation is called raw alcohol.
Fundamental principle of bioethanol
200 production
0
2004
004 005
2005 006
2006 200
2007 008
2008 20
009
0 0
2009 20
010
0 1
2010 011
2011 201
012
2012 013
2013

Growth of bioethanol in Germany (in 1000 t) (Source: BDBe/FNR)

Energy F 1.4 Biomass Bioethanol 093

2E345 ENERGY & ENVIRONMENT

CE 640 Biotechnical Production

of Ethanol

Understand the production process Satisfied customers

of bioethanol in a laboratory experiment
The experimental plant on the biotechnical production of Using the CE 640 Biotechnical Production of Ethanol
ethanol is ideal for teaching professionals and students experimental plant, you can follow and investigate all
in the fields of chemical and bioprocess engineering. necessary process steps from condensation and saccha-
Bioethanol will be the world's leading biofuel in the future. rification of the feedstocks, through to the conversion of
Students learn the complete process from feedstock to sugar into ethanol and distillation. AGRICULTURAL
end product. RESEARCH INSTITUTE
Nicosia / Cyprus
Dr. Polycarpos Polycarpou
Agricultural Research
Officer Head of Soils and Water Use Department
Agricultural Engineering
Agricultural Research Institute

Chemical Engineering Department in

Steinfurt (Germany)

The production of ethanol with

CE 640 is offered as a practical
course in the laboratory for chemical
process engineering at the Münster
University of Applied Sciences.
Two sessions are scheduled so that
all participants can follow both the
preparation of the mash and the
results of fermentation in their own
experiments.

E Q U ENERG
I P M
E N T Y & EN
F O R
E N G VIR ONMEN
I N E
E R I
N G
T
E D U
C A T
I O N

CE 640
ProductioBiotechnical
n of Etha
Energy nol
Addition of the yeast Preparation of the yeast Addition of feedstocks from ren
ewa ble raw
materials
An interesting film and a
into the fermentation tank into the mash tank
brochure for CE 640 can
be found on our 2E website
www.gunt2e.de

© 2010 G.U.N.T.
Incl. Video
Operation and Experiments

Geräteba
u GmbH
with CE 640

2E a division
of
Energy F 1.4 Biomass Bioethanol 095
2E345 ENERGY & ENVIRONMENT

CE 640 Biotechnical Production

of Ethanol

From plant to biofuel

Using the CE 640 trainer you can go through the whole process After the material has been pumped over into the second tank
used to produce ethanol in the laboratory. Ethanol is produced and yeast has been added, the fermentation process takes
from raw materials containing starch and sugar, as a starting place sealed off from the outside atmosphere. The yeast con-
material for biofuels and many other products. When convert- verts the sugar into ethanol and carbon dioxide. The carbon
ing starch to ethanol, different conversion processes have to dioxide escapes into the environment via a fermentation lock. Thick-walled,
be conducted using enzymes and yeasts. The temperature in the fermentation tank is monitored and highly polished and
regulated throughout the process. hammered pure copper
The starch is converted into sugar in the first tank by glucoam- distillation kettle.
ylase and alpha-amylase enzymes. The temperature and pH Once the fermentation process has ended, the ethanol is
value are monitored and controlled while this process takes separated from the waste materials using a distillation unit
place. (still).
s Software

!(¡{
6 The software for CE 640 allows the most
important variables to be captured
!$
¡¢
1
!(¡{
6 • temperature
mash tank
• pH value
!$
¡¢
1
• fermentation
temperature fermentation
!(¡{
5 §(
¶{ • water temperature
tank
7
!(¡{
5
• boiler temperature
!$
¡¢
1 • bubble tray
temperatures
• dephlegmator still
temperature
!(¡{
2 !(¡{
3
!(¡{
4
• condenser
!(¡{
8
temperature

i Learning objectives

•
!(¡{
4
gelatinisation by steam injection
• liquefaction by use of
alpha-amylase
• saccharification by use of glu-
!(¡{
1 stirring machines co-amylase

!(¡{
2 mash tank • fermentation: conversion of sugar
into ethanol by yeast cultures
!(¡{
3 fermentation tank under anaerobic conditions
!(¡{
4 distillation kettle • distillation: separation of ethanol
!(¡{
5 column still from the mash

!(¡{
6 dephlegmator

!(¡{
7 PLC with touch panel
Product No.
083.64000
!(¡{
8 metering pumps for acid
or caustic solution
More details and technical data:

F
gunt.de/static/s3336_1.php
Energy 1.4 Biomass Bioethanol 097
2E345 ENERGY & ENVIRONMENT

Basic Knowledge B
Biogas
Rising energy requirements and the limited availabil- In a biogas plant, microorganisms biologically de- Ambient conditions then converts this mechanical energy into electric power.
ity of fossil energy sources make new energy supply grade the organic starting substances (substrate) In addition to electrical energy, a combined heat and power
The microorganisms involved in the anaerobic degrada- plant also produces heat which can, for example, be used to
concepts necessary. Energy production from biomass under exclusion of light and oxygen. The product of
tion have different requirements regarding the ambient heat the reactor or buildings.
plays an important role in future energy concepts this anaerobic degradation is a gas mixture which conditions. This applies primarily to the pH value and the
besides solar and wind energy. primarily consists of methane. This gas mixture is temperature. Especially methanogens are very sensitive
called biogas. to deviations of these two process variables from their
respective optimal value.
How a biogas plant works:
If all 4 phases of the degradation take place in one reactor,
a compromise regarding the pH value and temperature
!(¡{
1 slurry from livestock husbandry

needs to be found. This results in a lower biogas yield. From !(¡{

2 renewable raw materials (e.g. maize)
a process engineering point of view, a two-stage process !(¡{
3 storage for shredded raw materials
in two separate reactors is more practical as this enables
the ambient conditions to be adjusted more specifically to !(¡{
4 storage for feeding the bioreactor
the respective bacteria. !(¡{
5 bioreactor (fermenter)
!(¡{
6 storage for digestate
Use of biogas !(¡{
7 biogas treatment
The biogas produced can now be combusted in a combined !(¡{
8 combined heat and power plant
!(¡{
heat and power plant. This converts the energy stored in
9 water circuit to heat the bioreactor
the biogas to mechanical energy. A connected generator
The complex processes of anaerobic degradation can be
simplified as four consecutive phases. Proteins, fats, carbohydrate !(¡{
10 feed of the current into the public power grid
!(¡{
11 digestate (use as fertilizer)
Phase 1: Hydrolysis Phase 1
The substrate used in biogas plants is available as undis-
solved, high-molecular compounds such as proteins, fats Amino acids !(¡{
2 !(¡{
1
and carbohydrates. Therefore these compounds first have fatty acids, sugar
to be broken down into their individual components. Hydro-
lysis products are amino acids, sugars and fatty acids. Phase 2

Phase 2: Acidification H2 CO2 Butyric acid !(¡{

10 !(¡{
11
The hydrolysis products are then biochemically decom- propionic acid
posed further, primarily into propionic acid, butyric acid, Acetic acid alcohols
acetic acid, alcohols, hydrogen and carbon dioxide. !(¡{
7 !(¡{
8 !(¡{
9
Phase 3
Phase 3: Formation of acetic acid
The products of the previous phase are now converted into H2 CO2 !(¡{
6
acetic acid, hydrogen and carbon dioxide.
Acetic acid !(¡{
3

Phase 4: Formation of methane

Methanogens can use either acetic acid (CH3COOH) or car- Phase 4 !(¡{
5
bon dioxide and hydrogen for their metabolism. So methane !(¡{
4
(CH4) can be produced in the following two reactions:
Biogas
CH3COOH CH4 + CO2 CH4
CO2
4H2 + CO2 CH4 + 2H2O

F
Fundamental principle of anaerobic degradation
Energy 1.4 Biomass Biogas 099
2E345 ENERGY & ENVIRONMENT

CE 642 Biogas Plant

!(¡{
9 !(¡{
9
F Q3 Q2 T M
!(¡{
9 !(
¡{
9

!(¡{
6 !(¡{
8
!(¡{
7
In CE 642 we have developed a practical system for the pro- A suspension of comminuted organic solids is used as the sub- T T
duction of biogas under laboratory conditions. CE 642 allows strate. Hydrolysis and acidification of the substrate take place
!(¡{ !(¡{
Q1 L Q1 L
1 substrate tank F flow rate
you to study all important factors that influence biogas pro-
duction. The necessary process steps can be controlled and
in the first stirred reactor. Here, anaerobic microorganisms
convert the long-chain organic substances into short-chain !(¡{
2 reactor 1 !(¡{
L level
!(¡{
2 !(¡{
3
automated via the PLC. The plant is equipped with extensive organic substances. In the second stirred reactor, biogas is
!(¡{
3 reactor 2 !(¡{
M humidity
measurement technology and data acquisition in order to
capture all necessary process variables.
created in the final step of the anaerobic degradation. This
biogas primarily contains methane and carbon dioxide. This !(¡{
4 digestate tank !(¡{
Q1 pH value !(¡{
1 T L

two-stage method means you can adjust and optimise the !(¡{
5 heating water tank !(¡{
Q2 methane !(¡{
5
!(¡{
4
L

ambient conditions in the two reactors independently of each

!(¡{
6 acid dosing
concentration
other. The digestate is collected in a separate tank.
!(¡{
7 alkaline dosing
!(¡{
Q3 CO2 concentration

!(¡{ drying column

8
!(¡{
T temperature

!(¡{
9 biogas
i Learning objectives

Gas analysis: volumetric flow rate, PLC with • achieving a stable operating state
methane concentration, CO2 concentration touch panel
• influence of the following parameters on the
biogas generation:
· temperature
!(¡{
9 · substrate
· volumetric loading
· pH value
•
Industrial peristaltic pump !(¡{
8
influence of the operation mode on the
biogas yield
· single stage or dual stage
· with and without post-fermentation
· continuous and discontinuous

!(¡{
9 • determining the following parameters
depending on the operating conditions:
!(¡{
2 !(¡{
3 !(¡{
6 !(¡{
7 · biogas yield
· biogas flow rate
· biogas quality
!(¡{
1 !(¡{
4

!(¡{
5

!(¡{
8 !(¡{
9

Supply unit Trainer Secondary treatment unit

Silica gel in the drying column Connectors for biogas with gas
analysis

Product No.
083.64200
More details and technical data:

F
gunt.de/static/s5354_1.php
Energy 1.4 Biomass Biogas 101
2E345 ENERGY & ENVIRONMENT

CE 642 Biogas Plant

Each reactor can measure fill level, pH value and temperature.

Substrate and biomass are pumped by peristaltic pumps
typical of biogas plants. Temperature is controlled via a dou- Customer reference from Argentina
ble jacket with heating water. The biogas can be analysed or
passed directly for consumption.

&)
]} &)
]}
10 10
s Software

!(¡{
8 !(¡{
8
!(¡{
5 !(¡{
12
!(¡{
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[} !(¡{
3
!$
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11 7 11
%)
[}
7

!(¡{
1 !(¡{
2

!(¡{
6
In the gas analysis menu in the PLC user interface, you
!$
¡¢
9 are given a summary of the current flow direction of the
gas and the current measured values of the gas analysis.

!(¡{
6
Further-more, this menu is where you select the auto or
manual measuring mode, with the measurement times for
!(¡{
4
each tank. You can also retrieve saved measured values via
this menu.
!$
¡¢
9
The software for CE 642 allows the most important
variables to be captured:
• temperature
• pH value
!(¡{
4 • level per reactor
• speed of the stirring machines
!(¡{
1 reactor 1 !(¡{
4 outlet !(¡{
7 connector for inert gas !(¡{
10 acid and alkaline dosing • volumetric flow rate
!(¡{
2 reactor 2 !(¡{
5 fill opening !(¡{
8 level control !(¡{
11 stirring machine • methane concentration
• carbon dioxide concentration
!(¡{
3 inlet !(¡{
6 biomass !(¡{
9 double jacket for heating !(¡{
12 safety valve
• temperature gas analysis
Instituto Nacional de Technología Industrial

• humidity
• volumetric flow rate and quantity

Product No.
083.64200
More details and technical data:

F
gunt.de/static/s5354_1.php
Energy 1.4 Biomass Biogas 103
2E345 ENERGY & ENVIRONMENT

Basic Knowledge B
Biodiesel
Biodiesel is an important element in the biofuels field. Biodiesel
can be produced from a wide variety of raw materials, which Vegetable oil
mainly vary by region.
It is mainly vegetable oils which are used, and these are chem-
The transesterification from rapeseed oil to biodiesel
ically or biologically converted into biodiesel. In temperate Alcohol
Base Transesterification is carried out in a reactor. Depending on the required
regions, rapeseed oil is used in many cases. In sub-tropical
quantity of biodiesel, either a beaker in the laboratory
regions on the other hand, palm oil is often used.
or a large-scale production plant operated 24/7 is
Furthermore, various input materials such as short-chain required for manufacture. The chemical reaction is the
alcohols and bases are required for the chemical process of By-products Separation stage same in each case.
transesterification.
After biodiesel has been successfully produced, it is necessary Cooling
to clean the biodiesel for use in engines. It is mainly water which Acids, additive
is separated out in the additional step. The main by-product is By-products Purification
glycerin. A variety of processes are currently being developed
to use this glycerin. Thanks to the high level of biodiesel pro-
duction, large quantities of glycerin which exceed the demand Separation of the biodiesel from the by-products can
from conventional use as antifreeze and a base for ointments Biodiesel be carried out using different plants, most of which
are available. operate based on the different densities. For example,
Fundamental principle the separating funnel shown is used in the laboratory.
of chemical biodiesel production For large quantities of biodiesel, centrifuges are used.

i Chemical reaction

H
O H
H C O C
O R1 Recovery of the alcohol used is an excellent method of
H H C OH H
O O reducing costs. Recovery of the alcohol is carried out
H C O C + 3· H O C H H C OH + 3· H C O C using distillation due to its lower boiling point; in large
O R2 O Ri production plant this can be done in multiple stages.
O H H C OH H
i = 1, 2, 3
H C O C
O R3 H
H

Vegetable oil + 3· Alcohol Alcohol + 3· Biodiesel

(triglyceride) (methanol) (glycerine) (FAME: fatty acid
methyl ester
The biodiesel produced contains by-products
and residual quantities of the catalyst. These
impurities are water-soluble and are washed
The reaction requires a catalyst, e.g. potassium hydroxide out using water.
C Carbon, O Oxygen, H Hydrogen, R Carbon chains of different lengths Carrier, Transition component, Solvent

Energy F 1.4 Biomass Biodiesel 105

2E345 ENERGY & ENVIRONMENT

CE 650 Biodiesel Plant

Phase separator
Phase separator Biodiesel washer

1st transesterification stage

PLC with
touch panel

2nd transesterification stage

Methanol recovery

Supply Storage

Biofuels for carbon neutral energy i Learning objectives

In addition to biotechnical manufacture of ethanol (CE 640), an ex- !(¡{
1 supply !(¡{
1 !(¡{
2 L
T
!(¡{
3 L
T
•
perimental plant for biodiesel manufacture from vegetable oils is also
available. The biodiesel is produced by a chemical reaction known as
production of biodiesel from
vegetable oil !(¡{ st
2 1 transesterification stage with F
F
L

F
L

phase separator L

transesterification. The raw material vegetable oil reacts with the · influence of dwell time
added alcohol, e.g. methanol, to form biodiesel and the by-product glyc- · influence of temperature !(¡{ nd
3 2 transesterification stage with F
F F

erine. The CE 650 replicates the classic chemical production method phase separator
• chemical transesterification L
F

for biodiesel. The experimental unit includes the following process steps:
• !(¡{
4 methanol recovery
1st Transesterification stage with return, 2nd Transesterification stage distillation
!(¡{ !(¡{
6
with return, methanol recovery and biodiesel washing. • liquid-liquid extraction
5 biodiesel washing !(¡{
5 !(¡{
4 L
T

!(¡{
L
L
6 storage T
• starting up a continuous process
consisting of several basic operations !(¡{
F flow rate L
F
F
T

!(¡{
L level L
P T F F

!(¡{
T temperature

Product No.
083.65000
More details and technical data:

F
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Energy 1.4 Biomass Biodiesel 107
2E345 ENERGY & ENVIRONMENT

CE 650 Biodiesel Plant

&(   Control of the chemical reaction

In the CE 650, transesterification of the vegetable
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3 !(¡{
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1 level sensor
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!(¡{
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Software *817
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$XWR $XWR
!(¡{
3 exhaust air connection

The PLC controls the electrical components of the experimental plant. !(¡{
4 !(¡{
5 !(¡{
4 electric heater
Entering individual values in the different screens specifies the operating !(¡{
5 temperature measuring
parameters for the components. The control parameters can be viewed and point
adjusted in secondary screens. The experimental unit is operated from the
start screen shown.

Vegetable oil Addition of Reaction to form biodiesel

Time
chemicals

Product No.
083.65000
More details and technical data:

F
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Energy 1.4 Biomass Biodiesel 109