Incineration

Within waste terms Incineration is a form of thermal treatment of waste for disposal or recovery which can be described by waste origin (e.g. Municipal Incinerators), by the nature of the waste (e.g. Hazardous Waste Incinerators) or by the method/type of incineration (e.g. High Temperature Incinerators)(adapted from most recent BREF guidance).

Context and Definition

Definitions in Legislation			Types	Temp. Range °C	Category		Kiln/Furnace/Reactor
Incineration	With Energy Recovery		Combustion	800 - 1450	Thermal Treatment		Grate
							Fluidised Bed
			Gasification	500 - 1600	Advanced Thermal Treatment (ATT and ACT)		Reciprocating & Rotary
	Without Energy Recovery						Plasma
			Pyrolysis	250 - 700	Advanced Thermal Treatment (ATT and ACT)		Heated Tube
							Surface contact

In legal terms, a ‘waste incineration plant’ means any stationary or mobile technical unit and equipment dedicated to the thermal treatment of waste, with or without recovery of any energy generated. If the Incinerator can be shown to meet the energy efficiency measurement of R1 it can be classified as a recovery facility, if it cannot it is classified as a disposal facility. This means that an incinerator that generates power, and is a net exporter of power, but does not meet the energy efficiency of R1, can be described as an Energy from Waste (EfW) facility, even though it is legally classified as a disposal facility. An incinerator that does meet the R1 criteria is the only type of incinerator under the legislation that can legitimately describe itself as an Energy Recovery Facility (ERF).

Therefore, the activity is termed Incineration, regardless of the amount of energy generated, or whether the thermal treatment is of the waste, or whether the gases resulting from the thermal treatment are subsequently incinerated . The three main types of thermal process are:

• Combustion,
• Gasification
• Pyrolysis

The large majority of incinerators built and operating to date in the UK are based on 'conventional' combustion, with some development of Gasification and Pyrolysis over the last 10 to 15 years in the UK, with varying degrees of success. These ATT/ACT types of technology were encouraged by the subsidies available for power generation under the Renewables Obligation. The three types of incineration can have a variety of different furnaces (also termed kilns and reactors) and associated systems to ensure the uniform treatment and residence time of the waste in the kiln/reactor. The most common systems for Municipal Solid Waste (and similar Residual Waste) are Grate based (there are at least five different type of Grate). For the treatment of Hazardous Waste the more common systems are based on Rotary Kilns.

Emissions

The standards for emissions limits, monitoring, waste reception and treatment standards that are acceptable for waste incineration plants were set in the Waste Incineration Directive (2000/76/EC) and updated in the Industrial Emissions Directive (2010/75/EU). The Industrial Emissions Directive provides the framework for regulating across the EU and requires such installations to hold a Permit based on the use of Best Available Technique (BAT).

On the 3rd December 2019 new EU standards were published for waste incineration for new emissions, monitoring and efficiency standards. The new specifications stem from a review of Best Available Technique (BAT) Reference Document (BREF) for Waste Incineration.