As a result of the analysis carried out by both companies, it was identified that the greatest potential for heat recovery was in the process air leaving the fluidised bed monohydrate drying chamber at the Qemetica Soda Polska plant in Inowrocław. This dryer is one of the largest soda production lines in Europe with a capacity of up to 90 tonnes of soda per hour.
The modernisation of the dryer, which has been in operation since 2005, cost more than PLN 6 million and involved the development of a solution whereby a stream of energy from process air with a temperature of around 100 degrees and a flow rate of more than 120,000 kg/h was channelled back into the production process. Previously, prior to the upgrade, the hot air escaped into the atmosphere via a chimney.
- During the design phase, the biggest challenge was to develop a solution for placing the heat exchanger in the optimum location in terms of heat recovery efficiency, i.e. in the middle of the fluidised bed dryer exhaust air stack. The weight of the chimney itself, at 24 tonnes, made it impossible to base it directly on the heat exchanger. Therefore, a project was prepared to divide the chimney into two parts using an additional support structure dedicated to its upper half located just above the heat exchanger, says Damian Żórawski R&D manager at Qemetica.
The modernisation consisted of installing heat recovery equipment, as well as extending the dryer with new components. Currently, the installation consists of a pump system, three heat exchangers and an automated parameter control system with SCADA visualisation.
- Hot air flows are very high in the dryer, so returning the air to the production process represents a major saving in production and consumption of steam, a raw material essential in the manufacture of soda. Savings in steam consumption means less energy, which today we get from coal, and therefore less CO2 emissions from our CHP plants. This clearly also translates into financial savings and an improved competitive position of the Inowrocław plant, explains Piotr Kapuściński, vice-president of Qemetica Soda Polska.
The goal of Qemetica's soda business (production plants in Inowrocław, Janikowo and German Stassfurt) is energy transformation, including reducing the energy intensity of the soda production process and gradually excluding coal from energy production. According to Qemetia's latest strategy, coal will no longer be an energy resource at the Inowrocław and Janikowo plants in 2033. By 2029, the CO2 emissions of the entire Group are to fall by 45 per cent compared to 2019.