Division 4.6.1 Overall environmental performance

United Kingdom

BAT 48. In order to improve the overall environmental performance of the thermal treatment of spent activated carbon, waste catalysts and excavated contaminated soil, BAT is to use all of the techniques given below.

Technique	Description	Applicability
a.	Heat recovery from the furnace off-gas	Recovered heat may be used, for example, for preheating of combustion air or for the generation of steam, which is also used in the reactivation of the spent activated carbon.	Generally applicable.
b.	Indirectly fired furnace	An indirectly fired furnace is used to avoid contact between the contents of the furnace and the flue-gases from the burner(s).	Indirectly fired furnaces are normally constructed with a metal tube and applicability may be restricted due to corrosion problems. There may be also economic restrictions for retrofitting existing plants.
c.	Process-integrated techniques to reduce emissions to air	This includes techniques such as: control of the furnace temperature and of the rotation speed of the rotary furnace; choice of fuel; use of a sealed furnace or operation of the furnace at a reduced pressure to avoid diffuse emissions to air.	Generally applicable.

Technique

Description

Applicability

Heat recovery from the furnace off-gas

Recovered heat may be used, for example, for preheating of combustion air or for the generation of steam, which is also used in the reactivation of the spent activated carbon.

Generally applicable.

Indirectly fired furnace

An indirectly fired furnace is used to avoid contact between the contents of the furnace and the flue-gases from the burner(s).

Indirectly fired furnaces are normally constructed with a metal tube and applicability may be restricted due to corrosion problems.

There may be also economic restrictions for retrofitting existing plants.

Process-integrated techniques to reduce emissions to air

This includes techniques such as:

control of the furnace temperature and of the rotation speed of the rotary furnace;
choice of fuel;
use of a sealed furnace or operation of the furnace at a reduced pressure to avoid diffuse emissions to air.

Generally applicable.