The 4 R’s of Carbon Reduction

You’re taking steps to meet corporate sustainability goals, save energy and reduce emissions, but you’re unsure what other opportunities you have. Tracking and reporting your emissions with carbon accounting is an important overarching approach. Another framework to keep in mind is the 4 R’s: reduce, reuse, refuel and redesign.

Reduce

At a broad level, the best way to manage your carbon footprint is to manage your energy consumption. Seeking certification or recognition in strategic energy management programs, such as ISO 50001 or the U.S. Department of Energy’s 50001 Ready initiative; implementing energy improvement projects; and using tools like energy treasure hunts and energy assessments are all actions that can reduce energy consumption, and less energy use = a smaller carbon footprint.

Ensuring proper maintenance of your combustion systems will also improve operational efficiency and produce energy savings. Tuning burners, changing filters, monitoring stack exhaust, lubricating fans and motors, and more allow your combustion-based heat-treating processes to operate as efficiently as possible.

Reuse

In a combustion process with 0% excess air and an exhaust gas temperature of 1,500°F, about 50% of the thermal energy goes right up the stack and heats the surrounding neighborhood. For example, the temperature of your exhaust stack gases is likely around of 1,200–1,500°F, depending on the process. Consider whether there’s an effective way to reuse this waste heat for other processes, such as to preheat the combustion air feeding the heating process. Here are some possibilities for reusing waste heat:

• Space heating
• Ingredient preheating
• Hot water heating
• Boiler feedwater preheating
• Combustion air preheating

Refuel

Once you’ve squeezed all you can from reducing your process energy consumption and reusing waste heat, consider switching the fuel source of the process. If you use combustion to provide heat for a process, is it practical, and possible, to convert to electricity as the energy source? Electricity typically has lower carbon emissions than your existing direct combustion processes on-site and is also likely to get even cleaner over time.

Switching heating energy sources is complex, and you must ensure that you maintain process parameters and product quality. Typically, testing is required to make sure that the new electrical process keep the chemical properties and quality standards that your customer specifications demand. You’ll also need capital investment in new equipment. Still, this method has significant potential for reducing carbon emissions and is worth considering.

Redesign

Finally, when the time is right, you may consider starting with a blank sheet of paper and completely redesigning your processes to be carbon neutral. Redesigning will likely mean a significant process change and capital investment but could apply if you’re adding a new process line or setting up a new manufacturing plant at a greenfield site.