Waste Incinerator Meets Stringent Environmental Standards

A large household waste incinerator is comfortably meeting stringent new environmental standards, thanks to the introduction of Sorbacal® SP, the specialist hydrated lime product. Sorbacal® SP, made by Lhoist (Belgium), the world`s biggest lime producer, offers a cost effective solution to flue gas treatment without the need to invest in additional capital equipment.
Operators of the incinerator were faced with the problem of finding a new treatment to achieve flue gas emission levels of no higher than 10 mg HCI/Nm3 (previously 50 mg HCI/Nm3) and 50 mg SO2/Nm3 (previously 200 mg SO2/NM3). Achievements of these new lower limits were needed to bring the incinerator in line with both the EEC 2000/76/CE directive and the strict framework of local regulations.
Their choices were to replace the entire existing system with either a sodium based reagent process or a wet lime and/or a wet scrubber, or to adapt the existing equipment to dose at significantly higher levels to meet the new regulations.
Said Lhoist UK product manager James Ng: “We suggested the best route forward would be to use the existing equipment and
replace the reagent they were using with Sorbacal® SP within a dry flue gas treatment process where the injection point was made
before the fabric filter. Following this, the Lhoist research and development team assisted in the optimisation of the bag house filters
and the operating parameters including temperature to enhance the performance of Sorbacal® SP.
“The incinerator operators are more than satisfied with the results of this. The process now allows them to meet all the requirements
of acidic gas removal, and has proved to be one of the most efficient treatment processes used by incinerators. In fact, the results
in recent trials Lhoist UK carried out in the UK with four waste incinerators demonstrated a reduction in hydrated lime usage by
between 20 to 33% compared to standard ordinary hydrated lime.”
Another benefit, added James Ng, is that the incinerator operator’s use of Sorbacal® SP offers better control against acidic gas
“spikes” due to the higher reactive nature of this specialist hydrated lime. Some operators have managed to operate very near the
WID limit, so optimising the use of the reagent. In addition to the reduction in usage of Sorbacal® SP, the net effect is the reduction
of Air Pollution Control waste delivering a significant saving for the operator.