Simulation and Optimization of a Generic Kraft Pulp Mill

Abstract

The Canadian pulp and paper industry is going through an economic crisis mainly due to a decrease of world demand and aggressive competition from emerging nations. In this context, the forest biorefinery which can be defined as the “full integration of the incoming biomass and other raw materials, including energy, for simultaneous production of fibres for paper products, chemicals and energy”, is one of the solutions for pulp and paper mills to diversify their core business and regain competiveness while continuing to produce traditional wood, pulp and paper products. Forest Biorefinery is one of the research areas in École Polytechnique within the E2D2BF laboratory (Efficacité Energétique et Développement Durable de la Bioraffinerie Forestière. This research unit mainly focuses on invesigating the technical and economic feasibility of the biorefinery implementation into pulp and paper mills, developping processes simulations of biorefinery technologies, proposing new methodologies for energy optimization of the biorefinery units and pulp and paper processes. The study performed during this internship is part of a BioKrEn project (Biorefinery, Kraft and Energy) which involves several Canadian industrial partners,3 partner mills , 2 research laboratory FPInnovations and CanmetEnergy laboratory, leader in innovation of clean and renewable energetic solutions as well as several universities. The objective of this project is to develop and demonstrate a methodology and criteria to evaluate the feasibility of bioenergy proposals for Canadian Kraft pulp mills and, to propose optimized process designs that best integrate biorefining into existing mills. The first part of the BioKrEn project was to develop a reference Kraft mill simulation model using CADSIM Plus (a pulp and paper simulation software) platform. This reference Kraft mill representative of the current situation of Canadian Kraft mill in terms of capacity production, utilities consumption and equipment used will be used as a basis for biorefinery implementation. The objectives of this internship were first to complete and tune the simulation, to validate it and then to optimize it in terms of mass and energy using pinch methodology. This methodology is based on a combined energy and water analysis of the process in order to optimize water use and to limit the energy consumption in the process. The analysis of a subsystem of the process, the water network, is required before a complete data extraction for the further analysis is performed. This report contains all data, graphs, tables and results of this study. It also reflects the approach that will be followed with some observations, remarks, difficulties and benefits that this work has generated. Resulting projects will be submitted to the partners in order to show a real average Canadian Energy consumption. Conclusions and future work are given at the end of the report.