Modern Waste to Energy
Solution for Sustainable
Solid Waste Management
by Ir KennyWong
Chairman, Environmental Division of the Hong Kong Institution of Engineers (2012-13)
Vice-chairman, Hong Kong Waste Management Association (2012-13)
T
he Hong Kong Blueprint for
Sustainable Use of Resources
2 0 1 3 - 2 0 2 2 ( t h e B l u e p r i n t )
r e c e n t l y pub l i s h e d b y t h e
E n v i r o nme n t B u r e a u a i ms
t o de ve l op a comp rehen s i ve wa s t e
management plan and promote a new
social contract with the community to
conserve resources and reduce waste. A
number of key actions and specific targets
for recycling, landfilling and incineration
are clearly spelled out in the Blueprint.
Among all these aspects, incineration caused
much controversy among the public, yet
it is a potential solution for sustainable
solid waste management as it can reduce
waste significantly as well as turn waste into
energy.
Incineration: A Current Missing
Link
Landfilling is the major means of final
disposal of the municipal solid waste (MSW)
generated in Hong Kong. According to 2011’s
figure, MSW takes up 67% of the total waste
disposed at Hong Kong’s three strategic
landfills while 9,000 tonnes of MSW are being
dumped into landfills every day, an amount
that can fill up three Olympic-size swimming
pools. The startling waste production rate
and limitations in expanding landfill sites
mean that we need more effective and
sustainable ways to achieve waste reduction.
Incineration is adopted in many countries
and places for decades, but Hong Kong is
unique in a way that we have been using
landfilling as our final disposal means.
Compared to our counterparts, we are the
only place that relies so heavily on landfilling
as final disposal means, which is not a
sustainable way of waste management.
According to Government's current estimate,
the current three strategic landfills in Hong
Kong will be exhausted by 2019 the latest.
Hence an incinerator is urgently needed,
together with other means for reducing
waste, so as to extend the lifetime of
our precious landfills. Taipei and South
Korea’s experience in particular provide
insights for our strategic plan of solid waste
management due to similar lifestyle. Both
places adopted incineration since mid-90’s
to turn waste into energy, thereby reducing
waste residues going to the landfills.
Driving the Turbine: How it is
achieved?
A modern incinerator burns waste at high
temperature (normally at 850
o
C or above)
which reduces waste by approximately
90%, as well as generates electricity and
low pressure steam at the same time. The
daily treatment capacity of a typical waste
to energy incineration plant ranges from
100 – 3,000 tonnes. The high temperature
exhaust gases from the furnace pass through
the waste heat boiler, which generates
electricity (through steam turbine) and low
pressure steam as renewable energy. By
deducting the amount of power required
for the operation of the incineration plant,
the surplus electricity is normally fed into
the power grid and sold to nearby residents.
For a typical waste to energy incinerating
plant of approximately 800 tonnes of
treatment capacity per day, it can generate
tens of million kilowatt hours per year,
which can provide electricity for over 10,000
households.
轉廢為能—
處理固體廢物可持續之道
王小偉工程師
香港工程師學會環境分部主席 (2012-13)
香港廢物管理學會副主席 (2012-13)
Expert Corner
26
GreenMAG
