This document summarizes the key processes in an organic waste treatment facility. It begins with the reception of organic biomass feeds and includes pre-treatment like sterilization or hygenization. The materials are then mixed and sent to bioreactors where biogas is produced. The biogas undergoes desulphurization before storage. Post-treatment separates the effluent into liquid and solid fractions. The liquid is further treated to extract ammonia and clean water. The solid fraction undergoes composting to produce soil conditioner. The overall process converts organic waste into biogas for energy production and compost for agricultural use.

1. Reception
1.0
Organic biomass
By-products Cat. 2
By-products Cat. 3
Mix tank
3.0
Pre- Separation
4.0
Heat Electricity
Sediment
5.1
DENMEK BG
Bioreactor
5.0
De-sulphurizer
6.1
Biogas
6.0
Gas Storage
6.2
Energy
7.0
Pre-treatment
2.0
Sterilisation
2.1
Hygenisation
2.2
Composting
9.0
Compost
Soil conditioner
PK N
Process
water
Concentrates
Post treatment
8.0
NH3 Separator
8.1
RO
8.2
The DENMEK Solution
We turn organic waste into valuable
new resources

2. Underground reception tank Covered over ground reception tanks
The reception system has one or more tanks.
There is a reception tank for every type of biomass.
This allows for the best possible optimizing of the process. Generally, the
reception system is dimensioned with a capacity equivalent of 4- 5 days of
operation.
1.0. Reception system

3. 2.0. Pre-treatment
Depending on the category of biomass in question the pre-treatment system
provide pre-treated biomass to either;
(2.1.) the pressure sterilisation unit or
(2.2.) the hygenisation unit or
(3.0.) the mixing system directly if there are no requirements of hygenisation or
sterilization.

4. 2.1. Sterilisation unit
Category 2 materials used as raw
material in a biogas plant must be
submitted to pressure sterilisation
to the following minimum treatment
requirements;
(a) maximum particle size before
entering the unit: 50 mm
(b) minimum temperature in all
material in the unit: 133°C at an
absolute pressure of 3 bar (Steam)
(c) minimum retention time in the
unit without interruption: 30 minutes.
DENMEK Batch
sterilizer

5. 2.2. Hygenisation unit
Category 3 materials used as raw
material in a biogas plant must be
submitted to hygenisation to the
following minimum treatment
requirements:
(a) maximum particle size before
entering the unit: 12 mm
(b) minimum temperature in all
material in the unit: 70 °C
(c) minimum retention time in the
unit without interruption: 60
minutes.
From engineering…
To reality!

6. 3.0. Mixing
The purpose of the mixing system
is to deliver a homogeneous
biomass to the digesters.
The mixing system receives the
raw feed material from;
3.0. the pre-treatment system or
2.2. the hygenisation unit or
2.1. the Sterilizer unit.
Open Mix tank
Closed Mix tank

7. 4.0. Pre-separation
The pre-separation system serves the purpose of preventing straw, sand and
other kinds of indigestible material in the biomass to enter the digesters.
If this indigestible materials are not removed it will consequently build up a
sedimentation layer in every tank in the biogas plant, reducing tank capacity,
blocking pipes and pumps and inducing the need for more or less frequent total
plant shutdown while cleaning out the sediment.

8. 5.0. DENMEK BG Bioreactor
The DENMEK BG Bioreactors are Biogas digesters can either operate at 37°C
(Mesophilic operation) or at 52 °C (Thermophilic operation) depending on the
biomass to be treated.
The DENMEK BG Bioreactor is a high-rate fixed film, plug flow biogas production
system, designed for continuous operation with minimal service downtime.
The DENMEK technology can operate with retention time from 2 days – 5 days
depending on the raw material to be processed

9. 6.0. Biogas system
Composition %
CH4 Methane 50-75
CO2 Carbon dioxide 25-50
CO Carbon monoxide 0-0,03
N2 Nitrogen 0-10
H2 Hydrogen 0-1
H2S Hydrogen sulphide 0-3
H2O Water vapour 2-4

10. 6.1. De-sulphurizer
Fixed film technology
No chemicals needed
Troublefree operation
H2S reduction 95-99 %
Condense reduction 90-95 %
Numerous installations
The DENMEK de-sulphurizer removes Hydrogen sulphide and water vapour
as those creates the primary operational difficulties in biogas utilization

11. 6.2. Gas storage
The gas store ensures a stable
operation of the gas engines, as the
biogas production vary over time.
The gas store has a designed
capacity that can accumulate the
produced biogas when the gas
engine is undergoing service and
maintenance work.
DENMEK is using two different types of gas stores depending on
produced volume of biogas.
1/ Pressurized gas tanks: max. 10 bar.
2/ Low pressure gas balloons or gas sacks; max. 20 mbar

12. 7.0. Energy system
The energy system utilize the biogas
for production of;
1/ electricity
that can be sold to the public grid
and/or used at the processing facility.
2/ heat
used at the process plant. Surplus
heat can be used in stables, industrial
buildings, and houses and it can also
be sold to district heating systems.
3/ steam
to be used at the process plant.
Among other things it can be used in
combination with a pressure
sterilization unit.

13. 8.0. Post-treatment
The post-treatment system
is the separation section of
the plant.
It is designed to separate
and convert the de-gassed
effluent stream from the
digester into valuable
products.
- The Liquid fraction is to be further processed in the ammonia separator.(8.1)
- The humus fraction is to be further processed in the compost unit.(9.0)
First, a decanter centrifuge
separates the de-gassed
biomass into a humus
fraction and a liquid
fraction

14. 8.1. Ammonia separator
The DENMEK ammonia
separator removes ammonia
from the separated liquid
fraction.
In the first column the
dissolved ammonia gas is
released by an air stream.
The released ammonia is led
to the second column where
sulphuric acid is sprayed into
the airstream, forming
ammonium sulphate that is
collected in a buffer tank. The remaining waterish liquid is led to a buffer
tank for further treatment in the RO unit.

15. 8.2. RO Unit
The RO unit consists of one or more semi
permeable membranes that are capable of
separating clean water from various salts and
nutrients.
The waterish liquid from the ammonia separator
is pumped into the RO-unit where it is first pH
adjusted, thereby reducing the risk of a calcium
carbonate CaCO3 build-up in the RO filter.
The pressure is then raised to 40 bars and
pumped through the membranes whereby the
liquid is separated into cleaned water and a
PK concentrate.
The RO water can be used as process- or
washing water.

16. 9.0. Compost unit
The compost unit solves environmental
problems by converting otherwise
problematic organic materials into a new
valuable product:
Rich Organic Soil conditioner.
It takes approximately 4 weeks to produce
the compost/soil conditioner including
hygenisation of the product.
The treatment solution is based on
modulized composting reactors.
Each module has a capacity of 17
tonnes.

17. The result:
oElectricity
oHeat
oCleaned water
oPK Fertilizer Concentrate
oAmmonia Sulphate
oOrganic Soil Conditioner (Compost)

18. Where to get it?
www.denmek.dk