Waste heat recovery systems now an integral part of FLSmidth’s offerings

Facing rising operating costs, industrial companies around the world are looking to cut down their power consumption. But cutting consumption is not the only option. Now FLSmidth is offering comprehensive waste heat recovery (WHR) systems that can be applied to new or existing cement or minerals plants. Although a new part of FLSmidth’s offerings, the WHR system is proven technology that supplies a significant part of a plant’s power needs at no extra fuel cost, reduces its carbon footprint and saves precious water.

WHR systems transform the hot gases produced by manufacturing processes into useable power. As an example, for a typical cement plant producing 5,000 tpd, a WHR cogeneration system can reliably supply about a third of the plant’s power needs. Based on an average electric grid price of 0.12 USD/kWh and a cost of operating a cogeneration unit at 0.01 USD/kWh, the plant stands to save a massive USD 6 million a year.

CO2 reduction
Depending on the carbon emission intensity of the grid power being replaced, WHR can save a 5,000 tpd cement plant more than 60,000 tonnes of CO2 a year. National governments all over the world are introducing more and more legislative mandates, tax initiatives and subsidies to encourage manufacturers to reduce their carbon footprints. Not surprisingly, the global demand for WHR installations is rising.

Reduced water consumption
As industrialisation accelerates in China and India, natural water resources are coming under increasing pressure. And as clean water becomes less abundant, its price rises. In the arid climates of the world, water consumption is a key design issue for new plants – often requiring contractors to dig extremely deep wells. Installing a waste heat boiler in a typical 5,000 tpd cement plant can save around 100 million litres of water a year by bypassing the conditioning tower. This relieves pressure on the environment and lowers production costs.

The payback period for a waste heat recovery project is attractive. In fact, savings in production costs and emissions can lead to a return on investment after only a few years, depending on the cost of electricity and scale of the plant. FLSmidth is working with key suppliers in the WHR industry to offer a complete, packaged WHR solution that is tailored to each plant’s unique requirements.

Drawing on extensive knowledge of process and layout design, FLSmidth treats each plant as an entire system. As a result, process flow is optimal and maintenance is kept as simple and cost-effective as possible.

Steam cycle systems
Most of the WHR solutions supplied in industry today employ Rankine steam cycle systems. The technology is tried, tested and, above all, safe – and is used to meet about 80 percent of all the world’s electricity needs. In cement and minerals processes, excess gas is used to generate steam in a boiler. The steam drives a turbine which generates electricity. The remaining steam then condenses in a cooling tower before it is recycled through pumps back to the boilers.

The Rankine steam cycle system is particularly well-suited to cement plants in which the temperature of the exhaust gas is higher than 300˚C, and the moisture content of the raw materials is less than eight percent. However, FLSmidth’s R&D is working on waste heat recovery solutions that are efficient and reliable under a wide range of demanding conditions for both cement and minerals plants – and that promise a quick return on investment.

So, you could let your plant’s hot gases go up in smoke. Or you could talk to FLSmidth and find out how to turn your plant’s waste heat into energy, reduce your running costs and lower your carbon footprint.

Contact Ravisher Sidhu