Coffee Roaster Waste Heat Recovery Systems

: Boost Efficiency and Cut Costs

Coffee roasters can save energy and money by using waste heat recovery systems. Here’s what you need to know:

• Waste heat recovery captures and reuses excess heat from roasting
• Systems can cut energy bills by up to 80% and reduce CO2 emissions by 90%
• Main types: air-to-air, air-to-water, and thermal oil systems

System Type	Heat Source	Main Use	Key Benefit
Air-to-Air	Exhaust gases	Pre-heating air	Simple, direct
Air-to-Water	Exhaust gases	Heating water	Versatile heat use
Thermal Oil	High-temp processes	Multiple applications	Handles high temps

To get started:

1. Measure your current energy use
2. Identify heat recovery options
3. Set energy saving goals
4. Plan and install a system
5. Maintain it regularly
6. Track energy savings and environmental impact

With the right system, you can slash energy costs while making your roastery more eco-friendly.

Related video from YouTube

Types of Heat Recovery Systems

Coffee roasters can choose from several waste heat recovery systems to boost energy efficiency. Let’s look at the main types:

Air-to-Air Systems

These systems use hot exhaust gases from the roasting process to heat incoming air. They’re simple and effective for many roasters.

For example, a roaster might use hot air from the cooling tray to pre-heat green coffee beans before roasting. This cuts down on the energy needed to start the roast.

Air-to-Water Systems

Air-to-water systems transfer heat from exhaust gases to water. This hot water can then be used for various purposes in the roastery.

Paulig’s Vuosaari roastery in Finland uses this type of system. Timo Tuukkanen, their Facility & Security Manager, explains:

"We primarily utilise the recovered heat for our own heating. Excess heat will be directed to Helen’s district heating network."

This approach has helped Paulig cut their yearly greenhouse gas emissions by up to 90%, equal to about 2,700 tonnes.

Thermal Oil Systems

For high-temperature heat recovery, thermal oil systems are often the best choice. They can handle higher temperatures than water-based systems and distribute heat effectively across multiple locations in a roastery.

A case study of a major Italian roasting plant with a 3,000 kg per hour coffee production capacity explored using an Organic Rankine Cycle (ORC) engine coupled with a thermal storage system. This setup can recover intermittent waste heat from hot flue gases, turning it into usable energy.

System Type	Heat Source	Main Use	Key Benefit
Air-to-Air	Exhaust gases	Pre-heating air	Simple, direct
Air-to-Water	Exhaust gases	Heating water	Versatile heat use
Thermal Oil	High-temp processes	Multiple applications	Handles high temps

When choosing a system, consider your roastery’s specific needs, energy costs, and production capacity. The right system can significantly cut energy use and costs while reducing your carbon footprint.

Check Your Roastery’s Needs

To upgrade your coffee roaster with a waste heat recovery system, you first need to understand your current energy use and potential for savings. Here’s how to do it:

Measure Energy Use

1. Document current consumption: Start by recording your roastery’s energy use. This includes electricity and gas consumption for roasting and other processes.
2. Use an Energy Calculator: Employ tools like the Energy Calculator to estimate energy consumption and CO2 emissions for each batch roasted. This tool considers:
   • Pre-heating phase
   • Between batches
   • Roasting process
   • Cooling phase
3. Record key parameters: Note down important details such as:
   • Power rating of roaster’s energy loads
   • Burner settings
   • Machine specifications
4. Analyze exhaust gases: Examine the temperature and flow rates of gases exiting from roasting and cooling stacks.

"As you think about your carbon footprint, can I encourage you to do this: use good information and good data." – Toby Weedon, Oatly

Find Heat Recovery Options

Once you’ve measured your energy use, explore heat recovery possibilities:

1. Identify waste heat sources: Look for areas where heat is being lost, such as:
   • Exhaust gases from roasting
   • Cooling processes
   • Other high-temperature operations
2. Consider recovery methods: Based on your roastery’s setup, think about:
   • Transferring heat from stack gas to incoming gas streams
   • Using waste heat to pre-heat green coffee beans
3. Evaluate system types: Assess which heat recovery system might work best for your needs:

System Type	Heat Source	Main Use	Key Benefit
Air-to-Air	Exhaust gases	Pre-heating air	Simple, direct
Air-to-Water	Exhaust gases	Heating water	Versatile heat use
Thermal Oil	High-temp processes	Multiple applications	Handles high temps

4. Calculate potential savings: Use the data you’ve gathered to estimate:
   • Energy savings
   • Cost reductions
   • CO2 emission cuts
5. Check economic feasibility: Factor in:
   • Natural gas prices
   • Electricity costs
   • Your roastery’s production capacity

sbb-itb-b8931c3

Plan and Install a Heat Recovery System

Set Energy Saving Goals

Before installing a heat recovery system, set clear targets for energy savings and eco-friendliness:

1. Analyze your current energy use and costs
2. Set realistic goals for reducing energy consumption (e.g., 25% reduction in the first year)
3. Define targets for cutting greenhouse gas emissions

Budget and Payback

Plan your costs and calculate the system’s return on investment:

Factor	Consideration
Initial investment	Equipment, installation, and setup costs
Energy savings	Projected monthly and annual reductions in energy bills
Maintenance costs	Regular upkeep and potential repairs
Payback period	Time needed to recoup the initial investment through savings

For example, a heat recovery system for a roaster with a 4-ton/hour capacity could save around €60,000 annually, with a payback period of 2-3 years depending on energy prices and production volume.

Installation Steps

Follow these steps to set up your heat recovery system:

1. Choose the right system type (air-to-air, air-to-water, or thermal oil)
2. Hire a qualified installer with experience in coffee roasting equipment
3. Prepare your roastery for installation (e.g., clear space, update electrical systems)
4. Install the heat recovery equipment
5. Test and calibrate the system
6. Train staff on proper use and maintenance

"We currently use only 25% of the amount of gas we used to, even though the machine is three times the size. It is drastically more efficient." – Peter Mark, Owner of Kuma Coffee in Seattle

Keep Your System Running Well

To get the most out of your coffee roaster waste heat recovery system, focus on improving performance and regular upkeep.

Improve Performance

Adjust your system to work better and save more energy:

1. Monitor and optimize airflow: Keep ventilation systems clean and check for blockages regularly.
2. Fine-tune temperature control: Use sensors to track heat exchanger performance, flow rates, and pressure differentials.
3. Implement energy-saving strategies: Consider thermal energy storage (TES) or organic Rankine cycles (ORCs) for intermittent waste heat recovery.
4. Upgrade components: Replace outdated parts with more efficient alternatives to enhance overall system performance.

Regular Upkeep

Prevent problems and keep your system working well with these key tasks:

Task	Frequency	Details
Clean chaff collector	Every 3-5 roasts	Remove buildup to ensure smooth operation
Clean cooling tray	Daily	Maintain high coffee quality standards
Inspect airflow	Weekly	Check for obstructions in ventilation systems
Deep clean and calibrate	Monthly	Perform thorough cleaning and adjust components
Conduct detailed inspection	During shutdowns	Check for wear, corrosion, and other damage

Pro tip: Use Cropster‘s Task Management feature to set up, assign, and track maintenance tasks, making regular upkeep routine.

"A well-maintained roaster is your ticket to consistently excellent, freshly roasted coffee that keeps customers coming back for more." – CoffeeRoast Co.

Measure Energy Savings and Eco-Impact

To check if your coffee roaster waste heat recovery system is working well, you need to look at energy use and cost savings. Here’s how to do it:

Track Energy Use

To measure energy use before and after installing the system:

1. Set up energy monitoring

Install energy monitoring systems to get real-time data on your roaster’s energy consumption. This helps you make smart decisions to cut costs.

2. Collect baseline data

Before installing the heat recovery system, record your roaster’s energy use for at least a month. Use the Artisan Energy Calculator to estimate energy consumption and CO2 emissions for each batch.

3. Monitor post-installation performance

After installing the system, keep tracking energy use. Compare it to your baseline data to see the difference.

Metric	Before Installation	After Installation	Savings
Energy use (kWh/kg green coffee)	[Baseline value]	[New value]	[Difference]
CO2 emissions (g/kg green coffee)	[Baseline value]	[New value]	[Difference]

Figure Out Eco-Benefits

To measure reduced CO2 emissions and other eco-friendly results:

1. Calculate CO2 reduction

Use the Artisan Energy Calculator to figure out your CO2 savings. The calculator reports CO2 in grams per kg of green coffee.

2. Look at the big picture

Remember, roasting makes up a big part of coffee’s carbon footprint. As Toby Weedon from Oatly says:

"There is so much to be done! As you think about your carbon footprint, can I encourage you to do this: use good information and good data."

3. Track other benefits

Keep an eye on things like reduced smoke emissions and improved air quality in your roastery.

4. Do a full life cycle assessment

Consider doing a complete Life Cycle Assessment (LCA) of your roasting process. This gives you a fuller picture of your environmental impact.

Wrap-Up

Coffee roasters can make a big impact on their energy use and environmental footprint by adding waste heat recovery systems. These systems help roasters save money and cut down on emissions.

Here’s what roasters can achieve with heat recovery:

• Energy savings: Loring roasters offer up to 80% fuel savings compared to standard machines.
• Lower emissions: Bellwether Coffee claims their electric roasters cut carbon footprint by almost 90% per pound of coffee.
• Less gas use: Kuma Coffee in Seattle saw a 75% drop in gas use after switching to a Loring roaster.

"We currently use only 25% of the amount of gas we used to use, even though the machine is three times the size. It is drastically more efficient." – Peter Mark, Owner of Kuma Coffee

The coffee industry makes up about 15% of the carbon footprint in the UK food and drinks sector. By using heat recovery, roasters can help lower this number.

Roasters have options to fit their needs:

System Type	How It Works	Benefits
Air-to-Air	Reuses hot air from roasting	Cuts energy use
Air-to-Water	Turns waste heat into hot water	Provides hot water for other uses
Thermal Oil	Uses oil to transfer heat	Works well for larger roasters

Adding a heat recovery system takes some work, but it pays off. Roasters can save money on energy bills and help the environment at the same time.

Related posts

• 10 Tips for Energy-Efficient Coffee Roasting Profiles
• Coffee Roaster Heat Insulation: Best Practices
• Coffee roaster cafe upgrades for exceptional brews
• Eco-Friendly Commercial Coffee Roasters: Trends & Impact