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Turn up the heat, turn down plant emissions

Electric heating in food processing offers many advantages over more traditional steam or hot oil, making it a sustainable option for manufacturers seeking efficiency and flexibility.

In today’s industrial landscape, sustainability and energy efficiency are driving technological advancements, especially within the food ingredient manufacturing sector. One such development is the increasing adoption of electric heating in indirect thermal processing, replacing traditional combustion-based methods. While steam and hot oil have long been used as heat transfer mediums, electric heating is gaining traction due to its environmental and economic advantages.

But is this shift towards electric heating right for your process? Let’s explore the key factors and considerations for making the switch.

Heat transfer mediums in thermal processing

Indirect thermal processes rely on a heat transfer medium, most commonly steam or hot thermal oil. The heat transfer medium conveys heat via conduction through a vessel wall, never coming in contact with the process materials.

When choosing a heat transfer medium, key considerations include:

1. Process temperature requirements.
2. Existing utilities and infrastructure.
3. Safety and reliability.
4. Mechanical and operational needs.

Each medium has its strengths, depending on the specific application.

Traditional mediums: Steam and Hot Oil

1. Steam: Widely used due to its excellent heat conduction, steam is ideal for applications requiring temperatures up to 185°C (360°F). It heats and cools quickly, making it suitable for processes with frequent start-stop operations. However, steam systems require boilers, specialized personnel, and regular maintenance. For food manufacturers already equipped with steam systems, the transition might not seem immediately necessary. However, those seeking efficiency improvements or lower emissions should consider alternatives.


2. Hot Oil: Capable of reaching up to 350°C (660°F), hot oil systems are often used in applications requiring higher temperatures. While less efficient at conducting heat through metal compared to steam, hot oil’s ability to maintain stable temperatures can enhance certain food processes, especially those that require longer, consistent heating. However, hot oil systems heat and cool slowly, making them less ideal for batch processing common in food manufacturing. They also carry additional safety concerns due to the high temperatures and fire risk.

New medium: Electric Heating

Electric heating is becoming a competitive alternative, especially for food manufacturers looking to reduce emissions and streamline operations. Electric elements can achieve much higher temperatures – up to 800°C (1,600°F) – making them suitable for extreme heat applications. They offer simpler installation, as they do not require the extensive infrastructure of boilers, burners, or pressurized lines.

For food manufacturers, the benefits of electric heating include:

• Lower emissions: Eliminating onsite combustion reduces the environmental footprint.
• Simplified infrastructure: No need for complex piping or steam boilers, reducing installation costs.
• Safety: Electric systems minimize risks associated with fuel combustion.
• Temperature control: Electric elements offer precise control, crucial for maintaining consistency in processes such as drying, crystallization, or pasteurization.

However, electric elements do have a finite lifespan and may require special materials (e.g., exotic alloys) for extreme temperatures. Additionally, they may not be as efficient at conducting heat through metal compared to steam.

How electric heating compares

Here’s a quick comparison of the three mediums:

• Process Temperature Limits:
• Steam: Up to 185°C (360°F).
• Hot oil: Up to 350°C (660°F).
• Electric: Up to 800°C (1,600°F).
• Installation Requirements:
• Steam and hot oil systems require code vessels and certified personnel.
• Electric systems simplify installation with basic wiring and typically avoid complex regulatory requirements.
• Efficiency:
• Steam is the most efficient in conducting heat through metal.
• Electric and hot oil systems can achieve higher temperatures but are less efficient in heat conduction.
• Response Time:
• Steam heats and cools quickly, ideal for batch operations.
• Hot oil and electric systems take longer to heat up and cool down, and are therefore better suited for continuous processes.

Electric heating in food manufacturing

At Bepex, we’ve integrated electric heating into several technologies, offering food manufacturers a pathway to more sustainable and efficient operations. Our Solidaire thin-layer paddle dryer, for example, is fully heated by electric elements, providing precise temperature control essential for delicate food products. Similarly, our PCX Dispersion Flash Dryer can now be equipped with electric heaters for process gas, reducing carbon emissions without sacrificing performance.

Is electric heating right for your process?

For food ingredient manufacturers, switching to electric heating can offer significant advantages, particularly in achieving higher temperatures, reducing emissions, and simplifying installation. However, it’s important to consider the specific needs of your process. While electric heating may not be the best solution for every application, especially in processes that prioritize efficiency over extreme temperature capability, it’s an attractive option for manufacturers aiming to enhance sustainability and operational simplicity.

By partnering with experts who understand both traditional and electric heating systems, food manufacturers can make informed decisions tailored to their unique process requirements.