Verfahren zur trockenen Entschwefelung eines Verbrennungsabgases

摘要

A process is proposed for the dry desulphurisation of a combustion gas. Dust is removed from the combustion gas produced in a combustion chamber and contaminated with fly ash and toxic gases; the combustion gas is then cooled with water to between 50 and 90 DEG C, mixed with an absorbent consisting of CaO and/or Ca(OH)2 and fed into a circulating fluidized bed comprising a fluidized bed reactor, a separator and a recycling duct; a portion of the solids particles caught in the separator is fed into the fluidized bed reactor and another portion is led into the region of the combustion chamber in which the prevailing temperature is 850-1050 DEG C. It is proposed with this process that: the combustion gas loaded with ash, toxic gases and recycled solids particles should undergo dust extraction in an electrofilter at 100-180 DEG C or in a centrifugal separator at 100-700 DEG C only until a solids content of between 5 and 40 g/Nm<3> is obtained; and that the absorbent loaded with toxic gases together with fly ash should be discharged from the process loop via the outlet of the electrofilter or centrifugal separator.