Getting Off Gas: A Guide to Decarbonizing Processing Heat Beyond Natural Gas
A report from the Grattan Institute has found that manufacturers striving to hit net-zero targets in Australia must shift away from natural gas to lower their environmental impact.
According to the report around 22% of Australia’s emissions come from producing or burning gas, of which industrial usage accounts for 30-75% depending on the state.
At Enaxiom we focus on decarbonizing process heat within industry, this is because 52% of industries energy end use is for heat processes, 90% of which are still powered using fossil fuels. For this reason this article will focus on strategies to get off gas from the lens of decarbonising heat processes within industry.
Why get off gas?
Natural gas combustion releases carbon dioxide (CO2) and methane, potent greenhouse gases that contribute significantly to climate change. According to the Intergovernmental Panel on Climate Change (IPCC), methane's warming effect over a 20-year period is approximately 84-87 times greater than CO2. Transitioning away from natural gas is crucial for mitigating these adverse effects and achieving global climate targets. Additionally, a report by the World Health Organization (WHO) highlights the severe air quality issues linked to industrial gas use, leading to respiratory problems and premature deaths. By embracing cleaner alternatives manufacturers can reduce their carbon footprint and contribute to a healthier, more sustainable planet.
How to get off gas?
A key strategy to getting off gas is to electrify everything, however, for the industry in Australia, this only works for low-temperature heat processes such as water heating, spacing heating, cooking, and drying. It also means that as a decarbonization strategy, the electricity mix or source should have a lower carbon footprint than the equivalent gas it replaces if the aim is to reduce your carbon footprint.
In the case of medium to high temperatures, electrification may not be feasible either from a physical point of view or an economical one, and thus solutions such as solar thermal need to be considered.
When we talk about different industrial temperatures the general definitions below are considered for this article.
Low temperature: Up to 200°C (392°F) or 500°C (932°F), depending on the context.
Medium temperature: 200°C (392°F) to 800°C (1472°F).
High temperature: Above 800°C (1472°F).
Low- temperature options to replace gas
Heat Pumps:
Heat pumps are versatile devices that can extract heat from the air, water, or ground and amplify it for industrial processes. They work efficiently even at lower temperature differentials, making them suitable for low-heat applications.
Resistance Heating:
Electric resistance heating, using heating elements, is a straightforward and adaptable method for low-temperature industrial processes. It is commonly used for applications like drying, curing, and maintaining specific temperatures in enclosed spaces.
Induction Heating:
Induction heating is a highly efficient and precise method that uses electromagnetic fields to generate heat within the material itself. It is suitable for various industrial processes, including metal heating, drying, and cooking.
Microwave Heating:
Microwaves can be employed for selective and rapid heating in certain low-heat industrial processes. This method is particularly effective for drying, curing, and heating food products.
Infrared Heating:
Infrared heating relies on electromagnetic radiation to directly heat the surfaces of materials. It is well-suited for applications such as drying, curing coatings, and pre-heating before further processing.
Thermoelectric Generators:
Thermoelectric generators can convert low-grade waste heat into electricity. While not a direct replacement for low-heat processes, they can contribute to overall energy efficiency in an industrial setting.
Combined Heat and Power (CHP) Systems:
CHP systems, also known as cogeneration, generate both electricity and useful heat from a single energy source. By capturing and utilizing waste heat, CHP systems can significantly improve overall efficiency in industrial processes.
Electric boilers:
Embracing electric boilers is a pivotal step toward decarbonization. Unlike traditional gas boilers, electric alternatives produce heat without emitting harmful greenhouse gases. Manufacturers can integrate electric boilers seamlessly into existing infrastructure, minimizing the need for extensive overhauls.
Steam Electrode Boilers:
Electrode boilers that produce steam using electricity are an alternative to traditional fossil fuel boilers. They can be efficient for low-temperature steam requirements in various industrial applications.
Electric Infrared Emitters:
Electric infrared emitters use electrical energy to produce infrared radiation, which directly heats the surfaces of objects. This method is suitable for drying, curing, and heating processes in industries such as printing, textiles, and plastics.
Advanced Electric Resistance Heating:
Utilize advanced electric resistance heating technologies, such as high-efficiency electric infrared heaters or advanced resistance heating elements, to improve energy efficiency in low-temperature industrial processes.
Advanced Control Systems:
Implement advanced control systems, including sensors and automation, to optimize the use of electricity in industrial processes. This can improve efficiency and reduce energy consumption during low-heat operations.
Solar Thermal Systems:
Combine solar thermal systems with electrical heating elements to provide low-temperature heat for industrial processes. This hybrid approach can harness renewable energy while ensuring a consistent heat supply.
A great option for Australian industry is the Linear Fresnel technology, which offers a solar-powered solution to heat generation. By concentrating sunlight onto a linear receiver, it efficiently produces high-temperature steam for industrial processes. This not only reduces reliance on fossil fuels but also taps into a clean and renewable energy source.
When electrifying low-heat industrial processes, it's essential to conduct a thorough analysis of the specific requirements and constraints of the process in question. The chosen strategy should align with energy efficiency goals, cost considerations, and the overall sustainability objectives of the industrial facility.
To address intermittency challenges associated with renewable sources, manufacturers can integrate energy storage systems. Batteries and other storage solutions enable the smooth operation of electric boilers and linear Fresnel systems, ensuring a consistent and reliable energy supply.
Medium to high temperature options to replace gas
Induction Heating:
Induction heating is a method that utilizes electromagnetic induction to generate heat in a conductive material. This process is suitable for medium to high industrial heat applications such as metal hardening, brazing, and forging. Induction heating offers precise control over the heating process and can be highly efficient.
Resistance Heating Furnaces:
Resistance heating furnaces use electrical resistance to generate heat, making them suitable for various industrial applications, including heat treatment, annealing, and forging. These furnaces are versatile and can provide high-temperature heat for different materials.
Microwave-Assisted Processes for High-Heat Applications:
Extend the use of microwaves beyond low-heat applications by developing and implementing microwave-assisted processes designed for medium to high industrial heat. This could involve the development of specialized equipment and techniques tailored for processes like sintering, melting, or other high-temperature applications.
Plasma Heating Systems:
Plasma heating systems utilize ionized gas (plasma) to generate extremely high temperatures. These systems are suitable for applications requiring very high temperatures, such as metallurgical processes, ceramic production, and advanced material synthesis.
Magnetic Induction Heating:
Similar to induction heating, magnetic induction heating uses magnetic fields to induce heat in conductive materials. This method is applicable for medium to high-temperature industrial processes, such as metal melting, heat treatment, and welding.
Thermal Energy Storage Systems:
Implement thermal energy storage systems that store excess heat generated during periods of low demand and release it when needed. This approach ensures a continuous and reliable heat supply, making it suitable for industries with fluctuating heat requirements.
Hybrid Systems:
Combine different electric heating technologies, such as induction heating with resistance heating or microwave heating with infrared heating, to create hybrid systems tailored for specific industrial processes. This approach allows for flexibility and optimization of heat generation.
Advanced Electrothermal Technologies:
Explore and adopt advanced electrothermal technologies, including high-frequency induction heating or radiofrequency heating, to achieve efficient and precise heat generation for medium to high-temperature industrial applications.
Integration of Renewable Energy Sources:
Integrate renewable energy sources, such as wind or solar power, into the industrial heating process. This could involve using electric heaters powered by renewable energy or developing hybrid systems that combine electric heating with renewable sources to meet higher heat demands.
Optimization through Machine Learning and Artificial Intelligence:
Implement machine learning and artificial intelligence algorithms to optimize electric heating processes. These technologies can analyze data, predict heat demand patterns, and adjust heating parameters in real-time, enhancing overall system efficiency and reducing energy consumption.
It's important to note that the suitability of these alternatives may vary depending on specific industrial processes, energy requirements, and local conditions. A comprehensive assessment considering factors like cost, efficiency, and environmental impact is crucial when transitioning from gas to electric heating in medium to high industrial heat applications.
Take advantage of available government incentives and grants designed to encourage sustainable practices. Many regions offer financial support for businesses adopting eco-friendly technologies, making the transition to electric boilers and linear Fresnels more economically viable.
Manufacturers can effectively decarbonize and get off gas by embracing many existing technologies such as electric boilers, harnessing solar power with linear Fresnels, optimizing processes, and leveraging government support. These strategies not only reduce environmental impact but also position businesses for a sustainable and resilient future.
By implementing these eco-conscious solutions, manufacturers can contribute to a greener world while staying competitive in an increasingly environmentally conscious market.
