Black Liquor gasification CFDModelling of Quench and counter

Black Liquor gasification: CFD-Modelling of Quench and counter current condenser L. Westerlund, L. Johansson Division of Energy Engineering Gas and smelt inlet Water spray Gas Outlet Water column Green liquor Sketch of the quench Black liquor is formed in the paper making process. It is a biomass based fuel that traditionally has been burnt in recovery boilers to generate electricity and steam and to recover the inorganic chemicals. Over the years lots of research have been made in Black liquor gasification. In this process the flue gases can be used in a combined cycle (gas-steam turbine) with increased efficency. Introduction of Black liquor gasification has the potential to increase the electricity production in Sweden with approximately 1000 MW. Sweden is one of the leading actors in Black liquor gasification today. The most famous high temperature gasification reactor, ”The Chemrec reactor”, designed and developed by Chemrec AB. Fluent calculations showing the spray inlets In this research project a CFD model of the quench, a part of the reactor and counter current condenser is developed. The objectives are to build a complete model that in a later stage can be used as a design tool for the Chemrec-reactor. Smelt and flue gases are entering the quench where it’s rapidly cooled by water sprays. The smelt is seperated from the gases by gravitation and the smelt is collected in the bottom of the quench. The gases bubbles through a water column and is cooled further before it exits the quench. The results consists of the gasflow and water sprays. The smelt has not yet been included in the model. The software FLUENT 5 is used in the project. Fluent calculation showing velocity pathlines through the quench Fluent calculation showing the temperature of the cooled gases The research is funded by Swedish National Energy Administration and Chemrec AB. Partners are: ETC, LTU, Umeå University and Chalmers Institute of Technology