METHANOL PURIFICATION SYSTEM

摘要

Methanol is formed as a by-product of the kraft pulping process. Due to its high relative volatility to water, a large fraction of this methanol will be present in the vapour phase and therefore can be captured in a relatively small foul condensate stream. Many kraft facilities, including the Alberta Pacific Forest Industries (Al-Pac) mill, operate a foul condensate steam stripping system, producing methanol rich stripper off gas (SOG). At Al-Pac, SOG is currently disposed of through incineration in the lime kiln or power boiler; this flow is to be diverted to the new methanol purification system designed and supplied by A.H. Lundberg Systems Limited. The methanol is recovered by separating it from water and other contaminants through distillation, producing a methanol product at a minimum of 99.85wt% purity. Some of the purified methanol is to be used internally for the production of chlorine dioxide with the balance for external sale.