POWER September 2016 - 69

FUELS
4. A growing fuel source. As developing economies like India transition to fully industrialized
ones, their net waste generation could increase substantially. Courtesy: Una Nowling
copper (which acts as a catalyst for dioxin
formation), and rapid quenching of flue gas
to avoid time spent at temperatures between
250C to 400C. Activated carbon injection
can be used, with or without an activated
carbon reactor. These are somewhat uncommon
technologies. Conventional
selective
GW, processing in total 156,000 mt per day.
China's population-dense cities can yield concentrations
of waste that lend themselves to creative
use. One study found 956,300 mt per year
of expired and waste food are generated from
Beijing restaurants, which could be converted
via anaerobic digestion into 300 million Nm3
methane per year (about 3% to 4% of Beijing's
total natural gas consumption).
Despite both significant potential resources
and experience with waste incineration,
however, not all of China's projects
are successful. Public opposition to waste
incinerators has resulted in several project
cancellations. In 2013 a 12-MW incinerator
in Huizhou was closed after local residents
complained of noxious fumes and serious
health problems from the facility. In 2014
violent protests against a proposed incinerator
project broke out in Hangzhou, resulting
in the project's suspension.
Most MSW in China consists of food
waste, which tends to be very damp and have
low specific energy content. This results in
a low combustion temperature, which can
increase dioxin emissions in the flue gas. To
prevent this from occurring, fuel oil may be
cofired with the waste to maintain temperatures
above 1,742F (950C). One of the problems
at the aforementioned Huizhou station
was an admitted reluctance to burn highercost
fuel oil, resulting in elevated dioxin
emissions. Undeterred by the problems, the
local government is committed to developing
a new, much cleaner incinerator to replace
the canceled project.
Options for reducing dioxin emissions
consist of combustion options and postCIRCLE
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combustion options. Primary combustion
options include higher combustion temperatures,
separating out chloride-containing
materials (mainly, reducing plastics such
as PVC from the waste stream), reducing
of
catalytic reduction systems that operate at
cold temperatures (<200C) can reduce dioxins
as well.
India. Although it is the second-most
populous country on Earth, India's per capita
solid waste production is very low, resulting
in an annual MSW generation of only 68
million mt per year. More than 90% of this
waste is landfilled with almost no sanitary
measures, and leaching of heavy metals from
the waste is a problem in many coastal areas.
Landfill fires and open burning of waste are
a constant problem in the country, contributing
to 20% of Mumbai's particulate matter,
carbon monoxide, and hydrocarbon emissions.
What's more, the growing population
in India continues to reduce the land area
available for landfill space, giving impetus to
WTE projects as a means of reducing landfill
use (Figure 4).
However, Indian WTE projects face many
challenges. Segregated waste collection efficiency
is almost 0%, and nearly 50% of

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