Environmental wins by optimised coke oven gas treatment

Purpose and goal

The objective of the project was to investigate the possibility of using statistical multivariate analysis and modelling and, in thereby ultimately reducing the content of ammonia and hydrogen sulphide in purified coke gas. The project also aims to improve the conditions for process optimization by further developing measurement technology in the field. The feasibility study has contributed mainly to the agenda item 6 "reduce the environmental impact of the life cycle," but also to the agenda item 7 "Increasing the competence and attractiveness".

Expected results and effects

The prediction models (MLR and PLS) created were able to confirm already known relationships, but also gave rise to new process knowledge. A possible method of measuring ammonia online in process water has been developed and can be further developed in a continuation project. In addition to the increased process understanding, the project has led to greater cooperation and an exchange of experience between the coke plants internally and the research institute Swerea MEFOS.

Planned approach and implementation

The project began with a survey of the coke plant processes and a review of previous work and research planning. Factorial experiments were conducted at SSAB´s Swedish coking plant for seven weeks at each plant. Process data and lab analysis were evaluated, and statistical models were developed in Simca (Principal Component Analysis and Partial Least Square) and MODDE (Multiple Linear Regression) software. Measurement technology was developed through field visits, world analysis, discussion with measurement technology companies and feedback to technicians at the coking plants.