The need to reduce industrial energy consumption and recover waste heat
Waste heat generated in industrial processes is pure potential. With clever engineering, this potential can be harnessed to reduce a facility’s carbon footprint and energy consumption. With a typical Return On Investment (ROI) of two to four years, JOA energy recovery systems are possibly the easiest step you can take towards a more environmentally-friendly and economical production process.
The importance of industrial energy reduction
Where production happens, energy is spent and costs are made. The amount of energy spent will vary from process to process and facility to facility, but spending less energy will always lead to cost reductions, while also contributing to your GHG Reduction and Sustainable Development Goals (SDG).
Excess heat can be reused in various ways. In any scenario (air-to-air, air-to-water or air-to-steam), a closed loop solution is preferable to any other solutions. A selection matrix answers the following questions in respect of each of the possible reuse scenarios:
- How much heat can be reused?
- What kind of investment is needed to efficiently collect and reuse this heat?
- What is the ROI?
- Is the heat source easily accessible, or are there physical obstructions that make access difficult?
- Is it feasible to split a stream of heat and reuse it in two or more secondary processes?
How to recover energy from industrial processes
The generation of electricity and steam are important cost factors in production processes and key factors in reducing a factory’s carbon dioxide footprint. The design rule that JOA, generally applies to make the control system as direct and easy as possible is to make the energy provider the consumer of the generated (recovered) steam or hot water as well. The Energy Recovery Scrubber skid, due to its large turn-down ratio, is capable of handling condensing exhaust air streams. Condensation is targeted so that it takes place in the scrubber only, preventing fouling in the piping network.
Energy Assessment in advance of creating an overview of possibilities:
- Site Visits
- Interviews with operators/technicians
- Measurements of Air Flows & Data Collection
- Determining sensible and latent Heat Content for every available source
- Identify pollutions risks
- Determine potential consumers, where closed-loop systems are prefered
JOA investigates thoroughly how energy is created and what consumers are available. In many vapor extraction applications, such as (spray) dryers, the surplus energy in the exhaust stream requires treatment prior to entering the filter- or scrubbing unit (e.g. a quench chamber). Using the phase transition (condensation) of the humid air could provide a great opportunity for the direct generation of steam and hot water. This can be achieved by using energy recovery skids and scrubbers.
As we both build as integrate equipment in our designed systems, we are able to recover energy in exhaust-air effectively while also realizing a healthy industrial work environment and compliant emission levels.
Fume elimination in dryers, flash towers, roofing mills, etc. often results in an exhaust air stream with high temperatures and high absolute humidity levels. This means a large energy recovery potential. For the extraction system a key factor is the prevention of condensation of high temperature fumes as this facilitates the buildup of combustible dust in the extraction system piping.
Occasionally we also advise performing smoke tests in order to determine the possible effectiveness of the existing hood of the exhaust system at various fan speeds.
What Energy Recovery Systems can be integrated
Streams of heat can be recovered in several ways:
- Closed loop air-to-air: In this solution, the heat carrying agent is the same in both the source and consumer. Closed loop air-to-air solutions are very easy to implement: heat is recovered from the source and transferred to a different heat exchange point, where air for the secondary process is preheated and used.
- Closed loop air-to-steam: Sources with a high heat content can be used to create steam. When heat at 300°C is recovered, it’s feasible to create high pressure steam. Even an exhaust temperature of 100°C can be used to create low pressure steam up to 3 bar. In regular processes this may not seem like much, but in our experience 2 or 3 bar is often sufficient in a closed loop solution.
- Air-to-water: Often heat can be recovered in inline wet scrubbing systems like the JOA inline venturi scrubber. We have successfully recovered exhaust air from driers and flash towers for direct steam or hot water. Energy recovery using this method ranges from 70% to 85%.
JOA offers the following systems related to Energy Reduction
- Heat Recovery Units
- Heat pump
- Heat exchangers
- Energy Recovery Scrubbers
- Efficient dust removal by Inline Venturi Scrubber
Design Considerations for tailor-made equipment
Any JOA system is designed based on data. Thorough data collection at the beginning of the design phase leads to extremely efficient systems upon delivery.
- Extraction velocity and capacity
- Static Pressure
- Relative Humidity
- Absolute Humidity
- Dew Point
Benefits of JOA Energy Recovery Solutions
- Tailormade solution. We truly understand your process.
- High efficiency scrubbers and system designs
- Solutions including all potential heat suppliers and consumers
- We truly understand air. Top notch specialist within Emission Control and Air Filtration
- Able to recover potential energy, also from low grade waste heat sources
- Lowest ROI time. Clear scenarios provided. Typically our solutions have a ROI period of 2-4 years an a lifecycle far beyond that.