MASS-INTEGRATION ANALYSIS - A TECHNIQUE FOR REDUCING METHANOL AND EFFLUENT DISCHARGE IN PULP-MILLS

This work illustrates the use of mass-integration methodology, a holis tic approach to process design and operation. The method's utility der ives from its ability to develop global insights about mass flow withi n a process. The design engineer can then use these insights to identi fy optimal strategies for allocating, routing, and separating process streams and targeted species. A case study is presented to illustrate the effectiveness of this approach in reducing methanol and wastewater discharges from a kraft pulp mill. The method targets all sources of a given pollutant simultaneously, allowing the engineer to evaluate op portunities for segregation, mixing, recycling, and interception of in -plant and terminal streams. Several visualization tools are described . These graphs are used to understand the global mass flow and to iden tify optimal allocation, interception, and recycle/reuse opportunities .