Decarbonisation Technology May 2025 Issue

Solutions for heat tracing in the decarbonisation of cement Heat tracing solutions are instrumental in addressing several challenges in the cement industry, playing a pivotal role in reducing its carbon footprint

Koen Verleyen Chemelex

T he cement industry is at a critical juncture in its journey towards net-zero emissions. As one of the most energy-intensive and carbon-emitting industries (~8% of global CO₂ emissions ( Facts on climate, 2019 ), cement manufacturing faces numerous technical challenges in reducing its carbon footprint ( Lehne & Preston, 2020 ). These challenges are primarily related to the inherent nature of cement production, which involves high- temperature processes and significant CO₂ emissions. Heat tracing solutions are emerging as a key technology to enhance process efficiency, reduce energy consumption, and facilitate the integration of low-carbon technologies. Technical challenges in cement industries: u High-temperature process requirements Cement production involves several high- temperature steps, particularly in the kiln, where raw materials are heated to 1,450°C (2,642°F) to produce clinker. This process is not only energy-intensive but also results in significant

v Energy efficiency and heat loss The high-temperature processes generate significant heat, much of which is lost to the environment due to poor insulation and process inefficiencies. Improving energy efficiency is essential to reducing the carbon footprint of cement production, but this requires innovative solutions to capture and utilise the excess heat generated during the process. alternative fuels, such as biomass, waste-derived fuels, and hydrogen, to replace traditional fossil fuels. However, these alternative fuels often have different combustion characteristics, affecting the stability and efficiency of the kiln operation. Biomass and waste-derived fuels have lower w Integration of alternative fuels The cement industry is exploring the use of calorific values and higher moisture content, which can lead to incomplete combustion and higher energy consumption. Ensuring consistent and efficient combustion of alternative fuels is a significant technical challenge.

67% Process emissions 33% Energy

CO₂ emissions due to the decomposition of limestone (calcination) and the combustion of fossil fuels. The challenge lies in finding ways to reduce energy

Chemical reaction releases CO from the heated limestone

emissions

CaCO

CaO + CO

consumption and emissions without

Limestone & clays

Output Clinker

Heated to 1 , 450˚C

compromising the high temperatures required for clinker production.

Feedstock

Figure 1 Process emissions during concrete production