Explosive increase in waste

The volume of waste (nonindustrial waste) has grown explosively due to the prevalence of the "throw away" culture of recent years. Furthermore, the increase in plastic consumption has led to a rise in calories. Plastic consumption stood at 1,000 kcal per 1 kg around 1970 but now amounts to about 2,000 kcal. Since each person generates 1.1 kg of waste per day, roughly speaking the number of calories consumed per day (1 eu) by each Japanese is equal to the number of calories of waste generated (1 eu).

In the past, people did not throw away things readily. As such, the majority of waste primarily consisted of kitchen refuse. Since there are concerns that such refuse would emit an offensive odor and cause infectious diseases if left alone, most of the waste in Japan are collected by municipalities and burned at waste disposal facilities. In addition, prompted by the need to reduce the volume of waste, which has been increasing gradually, incineration facilities have become prevalent. In the past, waste was burned by pouring fuel on it. But given the rise in calories today, waste is burned by making sure that the temperature does not rise too much.

Waste power generation

Prompted by an effort to prevent the excessive disposal of energy, "waste power generation" which generates power by means of remaining heat from incineration has become widespread in recent years. Most of the large-scale facilities being built recently have power generation functions.

Nevertheless, there are various problems with power generation. One problem is that the power generation efficiency is low. While thermoelectric power plants have an efficiency of nearly 40%, ordinary waste power generation is said to have an efficiency of only 10-15%. This can be attributed to the fact the combustion temperature is lowered to about 300 °C because waste is burned by reducing emissions of nitrogen oxides and without damaging the furnace.

Recently, facilities called "Super Waste Power Generation" facilities have been built. At these facilities, the power generation efficiency is raised to more than 20-30% by burning waste with natural gas. Meanwhile, as the production of dioxin resulting from incomplete combustion now constitutes a major social problem, it has become necessary to set the combustion temperature above 850 °C and operate facilities around the clock. Since the old furnaces cannot meet these requirements, large new-generation furnaces need to be built. The "gasification fusion furnace" burns waste at a high temperature of nearly 1,000 °C and compresses the incineration ash. It therefore is attracting attention as a next-generation furnace. In addition, it has a high power generation efficiency.

Since round-the-clock waste incineration at a high temperature calls for a large volume of waste, it cannot be implemented in sparsely-populated areas. As such a method that transports waste by rail after converting it into solid fuel (RDF) and collectively burns it at a high temperature is drawing much attention.

Nonetheless, it would be getting the priorities wrong to build high-performance waste disposal plants by using a vast amount of taxes without making an effort to recycle waste. There is no such thing as waste from the beginning. Ideally speaking, most goods can be used for some purpose if they are recycled. Actually, waste should consist of only kitchen refuse and chipped chinaware as in the past.

Today, local residents throughout Japan are launching campaigns against the construction of final disposal plants for nonindustrial and industrial waste. Every citizen who disposes of waste needs to feel responsible for this problem rather than play a bystander role.