Catalyst Paper hired Allnorth to evaluate the potential of their Crofton pulp and paper mill to generate incremental electrical power.
Allnorth completed a process and energy simulation of the pulp mill and steam plant. This simulation was verified against actual mill operation for both winter and summer operating periods. A number of process changes were identified to reduce steam consumption and hot water consumption in the process, consistent with current industry benchmark data for similar operating processes. The process changes were modeled to evaluate the potential for steam reduction and resultant incremental power generation provided by a new condensing steam turbine generator.
The proposed process modifications, including a major reconfiguration of the evaporator plant were prioritized and grouped into six areas – evaporator reconfiguration, heat exchanger network, brownstock washing, A-bleach, B-bleach, kraft machines. The engineering and design was developed in sufficient detail for the preparation of an AACE Class 3 capital cost estimate. A significant portion of the work was in the evaporator plant, including reconfiguration of the No.3 evaporator train as a pre-evaporator to improve steam economy and replacement of the No. 3 evaporator surface condenser.
3D scanning was used in the mechanical, piping and structural design associated with the evaporator plant process modifications as the area was very congested.