Combustion
Overview
Combustion is essentially the burning or thermal treatment of waste in a furnace/kiln of an incinerator under controlled conditions.
Of the Municipal Solid Waste (MSW) incinerators listed on the Residual Waste EFW page and operating in the UK, a large number (but not all), operate standard combustion technologies which either result in the net generation of power (electricity) or otherwise.
Context and Definition
If an Incineration facility 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[1]. This means that an incinerator that generates power, and is a net exporter of power, can be described as an Energy from Waste(EfW) facility. An incinerator that is an EfW facility that meets the R1 criteria is the only type of incinerator under the legislation that can legitimately describe itself as an Energy Recovery Facility (ERF).
The most recent recent BREF guidance[2] also sets out how incinerators can be described by:
- waste origin (e.g. Municipal Incinerators), and in WikiWaste includes Residual Waste EFW and Biomass Waste EFW,
- the nature of the waste (e.g. Hazardous Waste Incinerators), and in WikiWaste includes Hazardous Waste Incineration and Clinical Waste Incineration
- the method/type of incineration (e.g. High Temperature Incinerators).
However, there are a range of other terms used in the sector to describe different types of incineration, the kiln/furnace used, and the subsidy that may apply to them, and these are captured in the table below:
| 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) | Rotary | ||||
| Without Energy Recovery | Plasma | ||||||
| Pyrolysis | 250 - 700 | Advanced Thermal Treatment (ATT and ACT) | Heated Tube | ||||
| Surface contact | |||||||
Standard combustion technologies are well established within waste Incineration facilities operating not just in the UK but across the globe and benefit from being able to operate at lower temperatures (typically in the range off 800 - 1200°C). The combustion of waste does mean that carbon dioxide and other greenhouse gases are produced in the process and as such all waste incinerators operating throughout the UK must comply with the strict emissions requirements stipulated within the Industrial Emissions Directive (IED) which has been transposed in England and Wales by the Environmental Permitting (England and Wales) Regulations 2010 as amended which require all waste incineration faciliites to operate within the conditions imposed within their Environmental Permit.