Application: Regenerative scrubbing system to recover SO2 from flue gas containing high SO2 levels such as gas from FCC regenerator or incinerated SRU tail gas and other high SO2 applications. The LABSORB process is a low pressure drop system and is able to operate under varying conditions and not sensitive to variations in the upstream processes.
Products: The product from the LABSORB process is a concentrated SO2 stream consisting of approximately 90% SO2 and 10% moisture. This stream can be sent to the front of the SRU to be mixed with H2S and form sulfur, or it can be concentrated for other marketable uses.
Description: Hot dirty flue gas is cooled in a flue-gas cooler or wasteheat recovery boiler prior to entering the systems. Steam produced can be used in the LABSORB plant. The gas is then quenched to adiabatic saturation (typically 50°C–75°C) in a quencher/pre-scrubber; it proceeds to the absorption tower where the SO2 is removed from the gas. The tower incorporates multiple internal and re-circulation stages to ensure sufficient absorption.
A safe, chemically stable and regenerable buffer solution is contacted with the SO2-rich gas for absorption. The rich solution is then piped to a LABSORB buffer regeneration section where the solution is regenerated for re-use in the scrubber. Regeneration is achieved using low-pressure steam and conventional equipment such as strippers, condensers and heat exchangers.
Economics: This process is very attractive at higher SO2 concentrations or when liquid or solid effluents are not allowed. The system’s buffer loss is very low, contributing to a very low operating cost. Additionally, when utilizing LABSORB as an SRU tail-gas treater, many components normally associated with the SCOT process are not required; thus saving considerable capital.
Licensor: Belco Technologies Corp.