Cement Plant Energy Saving & Emission Reduction

Waste Heat Recovery Boiler

whrb boiler

What Is a Waste Heat Recovery Boiler (WHRB)?

A Waste Heat Recovery Boiler (WHRB) is a specialized boiler designed to recover heat from high-temperature exhaust gas. The WHRB boiler full form is “Waste Heat Recovery Boiler,” and it captures thermal energy that would otherwise be lost and converts it into steam for power generation or process heating — all without requiring any additional fuel. A waste heat boiler is a key component of a WHR plant (Waste Heat Recovery Power Plant). It enables cement plants to turn “wasted thermal energy” into “valuable steam,” which can then be further converted into electricity.

Waste Heat Recovery Boiler

WHRB Boiler Working Process

Exhaust gas heats boiler water

High-temperature flue gas from the preheater (PH) and air-cooled condenser (AQC) flows through the boiler’s heating surfaces, transferring heat to the boiler water.

Steam generation

The boiler water absorbs heat and is converted into saturated or superheated steam.

Steam drives turbine for power generation

The steam generated by the waste heat boiler is sent to a steam turbine, which drives a generator to produce electricity, providing clean and fuel-cost-free power for the cement plant.

our products

Two Types of WHR Boilers in Cement Plant

Since the two typical sources of waste heat in cement production lines are:

PH (Preheater) exhaust gas from the preheater outlet

AQC (Air Quenching Cooler) exhaust gas from the grate cooler

Therefore, cement plants usually need to install two types of waste heat boilers:

PH Boiler for the kiln preheater exhaust gas

AQC Boiler for the clinker cooler vent air

Because the two gas streams have different temperatures, dust content, and flow characteristics, the boilers must be designed separately and cannot be interchanged.

WHR Boilers

PH Boiler

Waste heat source: Preheater and decomposition system

Exhaust gas temperature range: generally 280-380°C

Features:

Stable heat output, large volume of flue gas

Mainly responsible for the evaporation section and part of the superheating section

AQC Boiler

Waste heat source: Clinker cooler

Exhaust gas temperature range:  450–650°C, generally higher than the preheater

Features:

Heat is concentrated but fluctuates significantly

High proportion of steam production (approximately 40–60%)

Parameter PH Boiler (Preheater WHRB) AQC Boiler (Grate Cooler WHRB)
Typical Application Recovery of preheater exhaust heat Recovery of grate cooler exhaust heat
Gas Flow 180,000 – 320,000 Nm³/h 150,000 – 280,000 Nm³/h
Steam Output 11 – 36 t/h 8 – 30 t/h
Design Steam Pressure 1.2 – 2.5 MPa 1.2 – 2.5 MPa
Design Steam Temperature 300 – 380 ℃ 300 – 380 ℃
Heat-Exchange Arrangement Vertical/suspended tube bundles Water-cooled walls or horizontal ducts
Materials & Protection Anti-wear & anti-corrosion coatings, heat-resistant alloys Wear-resistant liners, alloy tubes, ceramic coatings
Typical Structure Vertical tower-type structure Vertical or box-type structure
Design Notes Customized according to preheater gas conditions Customized based on grate cooler gas abrasiveness

Tips

Waste heat boilers are non-standard, custom-designed equipment. The parameters above are general industry reference ranges and are only intended to help you quickly estimate equipment size and capacity. 

To provide you with accurate design parameters and a quotation, we need your site-specific operating data (such as preheater/grate cooler outlet flue gas temperature, flue gas flow rate, dust content and composition, clinker production capacity, electricity price, etc.).

Please reach out to us to get a free heat balance and ROI estimation.

WHY CHOOSE US

AGICO WHRB Boiler Key Performance Advantages

1. Vertical Inverted-π Structure

The compact vertical inverted-π arrangement makes the overall boiler structure more concentrated, significantly reducing the footprint and effectively lowering civil engineering costs. This structure also features a more rational gas flow organization, resulting in high heat exchange efficiency and stable and reliable operating performance.

2. High-Strength Steel Tube Economizer

The economizer utilizes a high-strength steel tube structure, possessing excellent impact resistance and wear resistance, and can adapt to the varying flue gas loads during cement production. The system features a flexible layout and is easy to install and maintain, contributing to improved overall thermal efficiency.

3. Fully Automatic Sonic Soot Blower

Equipped with a sonic soot blowing system, it can continuously clean the ash deposits on the heating surfaces without shutting down the boiler, reducing the risk of ash blockage. Compared with traditional vibration or steam soot blowing methods, sonic soot blowing does not cause additional impact or wear on the pressure-bearing components, thus effectively extending the boiler’s lifespan and maintaining efficient operation.

Need WHRB Power Plant?

AGICO not only sells waste heat boilers, but we are also a supplier of waste heat recovery power plant solutions. To learn more about our complete cement plant waste heat power generation system, please visit the Waste Heat Recovery Power Plant details page.

success cases

Overseas Cement Plant WHRB Boiler Reference Project (Typical Configuration)

Case 1: 2×9MW Cement Waste Heat Recovery Power Plant in Southeast Asia (WHR Power Plant)

Project Overview:

A major cement group in Southeast Asia constructed two new 5000 t/d clinker production lines in the Ho Chi Minh region of southern Vietnam. To reduce electricity costs and improve overall energy efficiency, the plant implemented a 2×9MW pure low-temperature Waste Heat Recovery (WHR) power generation system.

The project was delivered under a full EPC contract by AGICO, covering engineering, supply, and construction of the PH & AQC boilers, steam turbine generator units, and all auxiliary systems.

Completed on schedule within 6 months, the WHR system was successfully connected to the grid and now provides significant annual power savings for the cement plant. It has become a benchmark WHR project in the regional cement industry.

Project Item Value / Information
Project Location Southern Vietnam (Ho Chi Minh Region)
Clinker Line Capacity 2 × 5000 t/d
Number of WHRBs 4 units (2 × PH + 2 × AQC)
Steam Turbine Generator Sets 2 × 9 MW
System Type Pure low-temperature WHR power generation (WHRB + Steam Turbine)
EPC Mode Turnkey EPC
Construction Period 6 months
Client Objectives Reduce electricity costs, improve energy efficiency, reduce CO₂ emissions

Case 2: 9MW Low-Temperature Waste Heat Recovery Project in the Middle East (WHR System)

Project Overview:

AGICO built a 9MW low-temperature Waste Heat Recovery (WHR) power generation system for a cement plant located in northern Oman. The system was installed on the plant’s 5000 t/d new dry-process clinker production line and includes two waste heat boilers (PH boiler + AQC boiler) together with a 9MW steam turbine generator set.

As one of the first cement plants in the region to adopt WHR technology, the successful operation of this project has become an important demonstration model for energy saving and emission reduction in the Middle Eastern cement industry.

Project Item Value / Information
Project Location Oman
Clinker Line Capacity 5000 t/d
Number of WHRBs 2 units (1 × PH + 1 × AQC)
Steam Turbine Generator Set 1 × 9 MW
System Type Pure low-temperature WHR power generation (WHRB + Steam Turbine)
EPC Mode Turnkey EPC
Construction Period 7 months
Client Objectives Power self-sufficiency, lower operating costs, enhance market competitiveness