Advances in recycling have enabled all 24 trash incinerators around the country to double as biomass electricity plants, Environmental Protection Administration (EPA) officials said yesterday, adding that the efficiency of these plants was expected to increase with time.
Trash incinerators already contribute a small percentage of domestic electricity output, EPA Deputy Inspector-General Huang Hui-yuan (黃輝源) said.
“Last year alone, about NT$5 billion in electricity was generated from burning trash,” he said.
Huang said: “From analyses of trash composition in recent years, we found that although the total amount of [unrecyclable] paper, plastic and kitchen waste in the trash has decreased, the percentage of these three types of trash among all trash has increased.”
The change in trash composition has resulted in an increase in the so-called lower heating value (LHV) of the trash, EPA Bureau of Environmental Inspection section chief Lin Mao-yuan (林茂原) said.
LHV refers to the total amount of heat emitted by trash that is being incinerated, minus the heat generated by water contained in the trash, Lin said.
“About five years ago, the LHV of the nation’s trash was about 1,600Kcal per kilogram, but now it is about 2,100Kcal/kg,” Lin said.
The increase in LHV is the result of growing recycling efficiency, which means that the unrecyclable waste that ends up in incinerators contains large quantities of unrecyclable types of paper and plastic such as paper diapers, tissues and plastic film, Huang said.
Although the LHV of trash is relatively low compared with that of coal, which has an LHV of about 4,000Kcal/kg, the current trend indicates a steady increase in the nation’s trash LHV, which would in turn increase the output of incinerator biomass electricity plants, Lin said.
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