Engineering Software from ANSYS Enables Replacement of Fossil Fuels with Green Alternatives

By DE Editors

ANSYS, Inc. software is helping aixprocess, a German engineering consultancy, to explore process improvements that will make cement manufacturing more profitable and more environmentally responsible. The business has been investigating replacing traditional fossil fuels—which are becoming increasingly difficult to extract,  expensive to use, and are of limited quantity—with alternative fuels. The efforts of aixprocess are part of a collaborative project sponsored by the German Federal Ministry of Education and Research, aimed at using fluid dynamics modeling tools to identify process improvements needed to help cement manufacturers remain competitive in today’s business world.

Cement manufacturing is a resource-intensive process in which limestone and other materials are crushed and milled, preheated to separate glass from solids, and then heated in a kiln at temperatures up to 1,450 degrees Centigrade. Large quantities of fuel are needed for preheating raw materials and keeping kiln temperatures high enough to produce the calcium silicate and aluminates that represent modern cement mixtures. Traditionally,  the fuels used in cement making have been coal, oil, and gas. However, due to the increasing financial costs associated with fossil fuels—as well as the negative environmental impacts—cement manufacturers around the world are beginning to explore the use of nontraditional fuels such as scrap tires, paper waste, and plastic waste.

These secondary fuels differ greatly from conventional fuels in terms of their physical characteristics and combustion processes, which can disrupt the complex cement-making process if they fail to maintain the proper temperatures, material concentration, and other conditions required for a high-quality cement product. To successfully replace fossil fuels with alternative fuels in cement production facilities—without costly physical testing and process—engineers at aixprocess have used engineering simulation software from ANSYS to analyze the real-world impacts of these “green” fuels. The company used fluid dynamics to simulate the effects of these fuels on combustion rates and outputs, heat, and mass transfer processes, and chemical reactions within cement kilns. By relying on ANSYS software instead of physical tests, the team of engineers estimates it was able to cut 30 percent of its analysis costs.

“By using software from ANSYS, we have been able to analyze the effects of replacing 40 percent of the traditional fuels used in an existing cement factory with alternative fuels. Specifically, we worked on determining the process modifications needed to maintain high kiln temperatures and to stay within other operating critical parameters,” said Martin Weng,  co-founder of aixprocess. “We have learned that to use these new fuels, we must compensate with increased oxygen pressure and an intensified materials blending process. Real-world testing to reach this same conclusion would have taken much longer and been far more expensive.”

Based on their simulations, engineers at aixprocess have a high degree of confidence that cement manufacturers can successfully replace traditional fossil fuels with alternative secondary fuels, leading to both economic and environmental benefits. Next, they plan to use software from ANSYS to analyze and optimize other aspects of the cement-making industry, including chemical reactions within kilns and the separation processes used to isolate gases and solids during the preheating phase.

For more information, visit ANSYS,  Inc.

Sources: Press materials received from the company and additional information gleaned from the company’s website.