Dennis Long , chief system designer at industrial electric heater manufacturer , Watlow , explores the possibilities of electric process heaters
EDITOR ’ S CHOICE ELECTRIC PROCESS HEATERS
WATLOW
Dennis Long , chief system designer at industrial electric heater manufacturer , Watlow , explores the possibilities of electric process heaters
Processing and refining hydrocarbons requires high heat for a number of critical steps , and heaters based on fossil fuels have traditionally filled those roles . But with mounting pressure to mitigate carbon dioxide emissions and advance long-term decarbonization goals , engineers have been exploring the potential for electric process heaters . This would allow several heating steps to be completed using “ clean ” electricity from renewable sources .
Replacing fossil fuel heaters with electric heaters would allow for a reduction in “ Scope one ” carbon dioxide emissions . As defined by Buehler , Scope one emissions are the direct result of burning fuels like natural gas or fuel oil for process heating . Scope two emissions result from the need to import energy , while Scope three emissions are produced while using a product . For example , emissions from vehicles on the road . All three types must be reduced to hit decarbonization targets .
What ’ s holding back Scope one emission reduction ?
A survey conducted by Watlow for its customers and prospects has revealed that a full 90 per cent of oil and gas leaders are already actively engaged in decarbonization efforts . Hydrocarbon processors are no longer focused on if they should decarbonize , but how they will decarbonize .
So why aren ’ t electric process heaters more ubiquitous in the energy sector today ? Surprisingly , familiarity might be the main reason . Until now , such heaters have played only very narrow roles in hydrocarbon processing and were usually smaller , operating at lower voltages . Although larger heaters are easily imaginable , engineers recognize that a number of questions arise when it comes to their control and maintenance . In short , no one wants to be first into the water when it comes to running larger medium-voltage thermal systems .
The good news for industry is that modern electric heaters can provide the same , or improved , performance that hydrocarbon engineers have come to expect from fossil fuel powered heaters and can therefore play a key role in decarbonization efforts .
Ensuring consistent control
Some of the most common questions about larger process heaters have to do with control . What additional elements are needed to ramp up the heater ? How is temperature monitored and controlled ? What additional safety precautions are needed ?
Just because larger electric heaters have not traditionally been used to heat all processes in the petrochemical industry does not mean that the technology is untested . In fact , field-proven power switching devices have been in use for low voltage electric process heaters and electric medium voltage motors in numerous industries for years , and the ability to control voltage is well established .
PLCs and similar power management systems bring heaters online in ways that prevent problems for other devices connected to the same power source . The heater and controller are part of one closedloop system , which streamlines integration and yields more control over the entire system .
12 PECM Issue 62