Water & Wastewater Asia March/April 2024

FOCUS
Fluidised Bed
Incineration (FBI)
technology for sewage
sludge waste-to-energy
By Lee Tze Kang, executive director, Novexx
FBI technology
SOLUTION FOR SEWAGE SLUDGE AND
HAZARDOUS WASTES
Integrated engineering solutions company
in Singapore, Novexx, is the authorised
representative of Raschka Engineering.
Raschka incineration technology is said
to be reliable, efficient and safe for
waste-to-energy, process chemicals and
pharmaceutical facilities. The technology is
designed for low calorific value scattered
solid wastes — such as sludge from
wastewater treatment plants (WWTPs) — to
achieve complete homogeneous burning
without the need for supplementary fuel
except for initial commissioning. It includes
an effective and efficient flue gas treatment
system to meet the stringent environmental
emission standards in Europe and Singapore.
We have also incorporated future-proofing
feature in our design to reduce nitrous
oxide (N2O) emission. N20 can remain in
the atmosphere for more than 100 years
and thus contributes largely to global
warming. According to the US Environmental
Protection Agency (EPA), the impact of 1
pound of N2O on warming the atmosphere is
almost 300 times that of 1 pound of carbon
dioxide. 1
Over the last 60 years, we have
completed more than 100 sludge FBI
and other hazardous waste incineration
waste-to-energy projects across
Europe and Asia. The projects include
the oldest operating FBI incineration
plant since 1976 in Switzerland, and the
largest sludge incineration in the world
in Germany. Raschka FBI technology has
also been adopted by Singapore’s National
Environment Agency (NEA) for the Tuas
Nexus Integrated Waste Management
Facility (IWMF) project, with a design
capacity of 800 tonnes per day of sludge.
WHY INCINERATION?
Firstly, it provides safe disposal.
Unincinerated or partially treated,
post-anaerobic digested WWTP sludge
has the potential to contaminate
underground water if not properly
managed. Some examples are leaching
to underground water sources, surface
runoff to nearby rivers, infiltration,
and contamination of soil and wells.
Incineration is considered a safe method
for sludge disposal as it destroys any
potential hazardous substances that may
be present in the sludge. This ensures
that the sludge does not pose a risk to
the environment or human health when
properly disposed of. Furthermore, WWTP
sludge can contain harmful pathogens,
including bacteria, viruses, and parasites.
Incineration at high temperatures helps to
kill these pathogens, reducing the risk of
disease transmission.
42 Water & Wastewater Asia | March-April 2024