EVATool: A novel software for aiding in operational decision-making of evaporation plants in kraft pulp mills

Abstract

The energy recovery capability of a kraft pulping process is crucial for its feasibility, and the evaporation process of black liquor is very important for a successful energy recovery since it is the first stage of the recovery system. Despite the apparent simplicity of the process, black liquor evaporation involves multiple evaporators and complex unit operations. Therefore, analyzing and simulating different operational scenarios is essential before proposing changes. A new software tool was developed to address the limited offer of specific software for analyzing black liquor evaporation plants. It focuses on fast analysis of these plants by estimating the heat transfer coefficient, steam consumption, steam economy, black liquor mass fraction between effects, and others. The tool was developed in Python and provides an interface resembling the supervisory system used by operators and offers equipment widgets for creating plant diagrams. EVATool also presents a dashboard for easy visualization of the main results. Software validation using examples of evaporation plants has confirmed its capability to simulate plants in different modes. In an industrial setting, the dashboard enables the comparison of simulated values with project indicators unavailable through operational instrumentation. While improvements are possible, this software shows great potential for industrial implementation, contributing to operational decision-making in daily operations of the evaporation process in pulp mills.