Duluth Recycled Pulp Mill is a POWER POINT presention on the "Two Stage", 2002 Fall Technical Conference

Emissions from the main stack of a modern recovery boiler are very well under control. However, a major source of TRS and particulate emissions is still the dissolving tank vent stack. This vent stack is also often the only visible plume coming from the recovery boiler. Until recently, due to their difficult nature, there was no effective technology for eliminating these vent gases.

Due to extremely tight overall TRS emission limits, dissolving tank vent stack emissions posed a serious problem for Aracruz. During the recent retrofit of existing recovery boiler “C,” they decided to incorporate Andritz dissolving tank vent cooler technology.

The new dissolving tank vent cooler technology solves vent stack emission problems by conditioning the dissolving tank vent gases and using them as combustion air in the recovery boiler. With proper design, the potential operational issues and difficulties that could be expected can be mostly avoided.

This paper discusses the design and operational aspects of implementing dissolving tank vent stack cooler technology in an existing recovery boiler in Brazil. Mill operational experience with the system is discussed and information of actually achieved performance is given.