Waste heat recovery

1st July, 2015

Waste heat recovery: A solution for the future

UltraTech Cement is one of the earliest proponents of waste heat recovery, alternative fuels and other environmental practices among cement manufacturers in India. It has undertaken a voluntary strategy to reduce the impact of its operations on Climate Change. As a member of the Cement Sustainability Initiative, it is committed to publishing its emission data and set environmental performance targets.

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Cement manufacturing is an energy-intensive process. The present situation of scarcity of natural fuels is an ever growing concern for the cement industry. Given these dynamics, it makes sense for cement manufacturers to adopt waste heat recovery systems (WHRS) to meet a portion of their energy requirements.  

WHRS makes economic sense for cement companies as it enables greater energy security, (capability to meet 20% of power requirement), improves competitive positioning, and ensures compliance to regulatory policies (push towards use of minimum 5-10% renewable/WHR energy in several states in India).

Establishing its footprint

With improvements in technology, increased cost of power, and the pressing need to reduce energy consumption and CO2 footprint, waste heat recovery systems have emerged as a feasible option. However, the challenge lies in integrating a system for waste heat recovery into the existing site without affecting the process. And this is exactly what UltraTech Cement has successfully done. Rising energy prices and depleting energy sources are a major challenge for the industry. UltraTech Cement is always looking for technologies and solutions that can lower its environmental footprint as well as be economically viable. The company is in the process of installing waste heat recovery power plants wherever feasible.  
 

As part of its commitment to reduce its carbon footprint, UltraTech Cement has commissioned Waste Heat Recovery Systems at some of its units in India. It has recently commissioned Waste Heat Recovery Systems (WHRS) at Rawan Cement Works in Chhattisgarh, Awarpur Cement Works in Maharashtra, Rajashree Cement Works in Karnataka and Aditya Cement Works in Rajasthan. UltraTech also has a 3.5 MW waste heat recovery plant operational at Andhra Pradesh Cement Works, Tadipatri.  

The current capacity of WHR systems at these units is as under:

• Awarpur Cement Works: 13 MW commissioned in April 2014

• Rajashree Cement Works: 10.7 MW commissioned in April 2015

• Rawan Cement Works: 13 MW (Pre-Heater Boiler for additional 2 MW to be commissioned by June 2015)

• Aditya Cement Works: 10 MW (Boiler for additional 6 MW to be commissioned by March 2016)

Post the complete commissioning of the WHR power projects in these four plants, UltraTech Cement will be one of the leaders in India in waste heat recovery systems in cement manufacturing with a combined capacity of about 58 MW. UltraTech has adopted the strategy of installing WHR power projects in all its operating integrated plants and will be considering WHR right from the beginning for its upcoming projects.

Waste heat recovery is not only the cheapest source of energy but it also reduces carbon footprint. WHR systems are now part of all new projects at UltraTech Cement.

A feasible option for the future

The average cost of a WHR plant is approximately Rs 10 crore per MW. Carbon footprint reduction and PAT (perform achieve trade) benefit of waste heat recovery across the five systems can be estimated after complete commissioning.

The benefits of WHR systems include carbon footprint reduction and PAT benefits, and cost benefits with reduction in cost per unit. Thermal power cost is about Rs 4 per unit, and WHR can bring it down to Rs 0.5 per unit. As fossil fuels become scarcer and power costs edge higher, waste heat recovery is going to be a strategic option to gain cost leadership in manufacturing.