Optimising the production cost of urea from black liquor

摘要

A conceptual design of an integrated facility for the co-production of ammonia and electricity from black liquor gasification has been studied. The integrated process exchanges black and green liquor, steam, electricity and sulfur with the adjacent Kraft pulp mill. A triple bottom line analysis has indicated that a competitive ammonia price (A$516/t) can be realized for a relatively small scale production 20ktpa of NH_3 with an internal rate of return of 13.7%. This is achieved through a novel process design which also produces electricity and steam for the pulp mill. The plant has a carbon footprint at 50% of the average and 33% below world best practice for NH_3. Social benefits are also predicted for the regional community.