Most frequent questions and answers on Waste Heat to Power
Waste Heat to Power is a source of clean energy that captures energy as heat and converts it into valuable electricity. This is done using an Organic Rankine Cycle which turns a turbine to generate clean baseload power. While waste heat is ubiquitous, waste heat from industrial processes provides the best use for WHP because of the regularity of the heat source and relatively high temperatures of exhaust to make projects viable.
CHP and WHP both use Organic Rankine Cycle technology to generate electricity; however, there are critical differences that distinguish each system. Unlike CHP, WHP does not require fuel for generating. Instead, WHP integrates at the end of an industrial process, also known as the ‘bottoming cycle,’ where it captures waste heat for conversion into electricity. Because there are no incremental emissions in a WHP system, it is a clean source of baseload electricity.
WHP is emission-free because there are no incremental emissions in its production of electricity. In using exhaust heat from existing thermal processes, a WHP system does not generate emissions and instead offsets the need to generate additional electricity, which in many cases has a carbon fuel source.
Baseload electricity is readily available power that can meet the requirements of an electricity grid at any time of day. In contrast, intermittent electricity is power that is not continuously available. Wind and solar energy are examples of intermittent electricity generation because while they complement each other, on their own they are only able to generate when there are sun and wind available. WHP from industrial processes generates baseload electricity because the processes it connects to are in operation continuously. In electricity markets, clean baseload power is a valuable component of the power mix for utilities decarbonizing their grids.
An ORC is a technology used to convert waste heat to power. Typically, industrial processes vent exhaust flue gas through an exhaust stack without recapturing any of the energy used to create the heat. To convert this energy into electricity the exhaust can be diverted to pass over a heat exchanger, connected to an ORC. The ORC is a closed-loop system that pipes an organic fluid with a low boiling point through the heat exchanger to convert the fluid into a gas. The gas then passes through a turbine where electricity is generated.
There are no costs to the host facility. Kanin finances, develops, and manages the WHP systems deployed to sites, and provides industrials with electricity or an additional revenue stream depending on circumstances.
It depends; the smallest applications can be as small as a spare bedroom with the largest as big as a city block. The determining factor for size is the nature of the heat source, its temperature, and its flow rate. Kanin considers these along with other factors when it sizes an ORC system and selects an appropriate organic fluid for most efficient use. A hotter source or higher flow rate typically translates into a larger ORC system with greater generation capacity.
There are over 100 working fluids used worldwide. The choice of fluid depends on the temperature and nature of the heat source. Typical fluids utilized are pentanes, for lower temperatures, and various butanes.
There is no impact or potential impact on the existing industrial process, therefore, there is no risk to the client process. For example, any additional back pressure added to a turbine exhaust by Kanin’s heat exchanger will be mitigated by installing an ID fan (if required). The systems utilized are relatively low pressure, field-proven, and have been deployed for many years.
The temperature ranges used for ORC are more efficient and effective. There are more regulations and requirements for operating steam systems that do not exist for ORC.
The site equipment will immediately revert to the previous operation for exhaust before the ORC system was installed.
Kanin is responsible for any repairs or maintenance that would be required for the ORC equipment. Every 5 years the system gets inspected with a maximum week turnaround.
Kanin will arrange with the host facility to give a percentage back of the generated revenue.
While 100kW installations of waste heat recovery do exist, the viable project minimum for Kanin starts in the 4-5 MW range and can lead up as high as the waste heat results will allow.
Visual inspections can typically be incorporated into the rounds of the operators. Kanin will compensate for any additional workload taken on by the company. Kanin also provides the option to completely and independently manage the ORC system. Additionally, the ORC manufacturer also provides remote monitoring and preventative maintenance on a 24/7 basis.
We do not remove carbon from the atmosphere absolutely; however, we are considered a clean power generation source because there are no incremental emissions in the production of electricity through a WHP ORC system. The average project reduces CO2 emissions by 35,000 metric tonnes.