The concept of circular economy replaces the conventional thinking of linear economy in the past. Understanding the importance of Solid Recovered Fuel (SRF) enables business owners to have a common goal to implement renewable energy, which is beneficial to the sustainable development of energy and the environment.
What are SRFs?
Solid recovered fuel is made from a variety of wastes. These wastes include general waste and industrial waste, and the composition properties include not only biodegradable organic matter but also various plastics. After the waste is collected, it is processed through a special treatment site. The procedure usually includes steps such as drying, filtering, crushing, and optical sorting. The most important thing is to remove all non-combustible substances such as stone, glass, metal, and harmful substances, especially chlorine.
The conversion of waste into SRF is to sort out combustible paper, plastic, or fiber from waste from various sources that may be mixed with various substances, and homogenize to form a single-quality fuel. And these SRF renewable fuels can be used with special boilers or cement kilns, with no need to burn coal, oil or natural gas, and other fuels, and truly turn garbage into gold. Moreover, the combustion calorific value and efficiency of SRF are higher, which is helpful to the production process. The emission of greenhouse gases is lower, which is beneficial to the environment so that the substances that can only be discarded and cannot be recycled can have the opportunity to be reused.
This fuel can be used in cement plants, coal-fired power plants, or industrial boilers to replace traditional fossil fuels. The generated electricity and heat can be used for industrial or domestic use. By replacing traditional coal combustion, greenhouse gas emissions can be reduced and the boiler's carbon footprint can be reduced. The type of fuel production and consumption is particularly prevalent in Europe, such as the Netherlands, the United Kingdom, and Germany. Taking Germany as an example, the production and use of SRF began as early as the 1990s. To reduce fuel costs, the cement industry took the lead. In Taiwan, the production and use of alternative fuels such as SRF have just started.
What is the Purpose of Solid Recovered Fuel (SRF)?
- Sorting out combustible paper, plastic, or fiber from various wastes mixed with various substances, and homogenizing them to form a single-character fuel.
- Instead of burning coal, oil, or natural gas, these SRF regenerative fuels can be used in conjunction with dedicated boilers or cement kilns.
- It is flammable and can be manufactured as fuel directly or after treatment. The types, names, and applicable items of waste that can be used as SRF.
- Does not contain hazardous industrial waste or medical waste plastics identified by relevant laws and regulations.
- Excluding electrical waste (R-1901~R-1908), metal products, ash (D-1101~D1199), solidified fly ash (D-2002), waste catalyst (D-1499), inorganic pollution Mud (D-0902) and other non-combustible-wastes-designated-by-the-competent-authority.
Advantages of Solid Recovered Fuel (SRF):
- Low environmental impact.
- Low fuel costs.
- Used in high energy efficiency boilers and combustion facilities.
What are the Quality Inspection Standards for Solid Recovered Fuel (SRF)?
SRF must be regularly tested and analyzed to confirm compliance with SRF quality standards. The SRF sampling method refers to the European Union EN 15442 (Solid recovered fuels-Methods for sampling). Every 1,500 metric tons is a batch. The sampled samples are mixed and analyzed as a batch of samples.
The SRF produced by the SRF manufacturer must be properly purified or homogenized, and the weight ratio of unavoidable natural inclusions of non-combustible waste contained in it must not exceed 1%.
Boilers Should Use SRF:
If you operate a coal-fired boiler, you know that every ton of coal burned produces a lot of carbon emissions. According to the U.S. Energy Information Administration, every ton of coal burned completely produces 2.86 tons of carbon dioxide. Carbon dioxide is a major culprit of climate change, leading to extreme climates around the world and affecting the quality of living. It is important to find ways to reduce the use of coal to achieve the purpose of reducing carbon emissions.
Is it Safe to Use SRF on a Boiler?
Chimney of SRF coal-fired co-fired boiler:
Since the fuel source is generated from waste, it is natural for someone to ask this question. After all, keeping the boiler at maximum load is the most important consideration for the operation of the plant. Corrosion in boiler steam generation is one of the greatest concerns for boiler operators for any fuel. The degree of corrosion varies according to the combustion environment, such as the temperature of the pipe wall and the content of corrosive substances in the SRF. Alkali metal chlorides are easy to accumulate in the superheater and cause corrosion repeatedly by reacting with the boiler metal surface, so the reduction control of the chlorine content in SRF is important.
The effective quality control of SRF manufacturing can ensure that the fuel does not exceed the specified chlorine and sulfur content: Remands conducts regular inspections and quality monitoring of our SRF through a third-party laboratory to ensure stable and high-quality fuel supply. Its total chlorine content can be controlled below 0.5%. In most cases, boilers still need to be refitted to handle the combustion of SRF. There are many sources of raw materials for SRF, and it is impossible to guarantee that the chlorine and sulfur in the fuel can be completely removed. Furthermore, the physical properties of SRF are different from those of coal, and it is difficult to directly feed them into the boiler using the same feed system.
Here are a Few Operational Recommendations that can Reduce Boiler Corrosion:
- Avoid excessive chlorine content and heavy metal pollutants in SRF by improving quality control.
- By mixing and homogenizing, avoid a small part of the fuel that is particularly high in chlorine.
- Avoid fuels with high chlorine content, and pay special attention when restarting the furnace after shut down for maintenance.
- Add additional agents or materials.
