This article is all about sustainable food waste recycling solutions which can be achieved by eliminating grit and plastics from the organic soup output of the Twister™ and Seditank™ depackaging machinery manufactured, supplied and serviced by the Drycake™ company. The sustainable solutions considered to be the aim of the recycling/ waste processing plant operators are:
- diversion of organic waste from landfills: to reduce the odour of landfilling, and in the long term reduce the greenhouse gas which they produce which contributes to global warming
- efficient organic pulp production for high biogas output in AD plants, from food and similar organic waste streams
- use of digestate as a beneficial fertiliser in products for sale.
In the realm of food waste recycling, these sustainable practices are key to minimizing environmental impact and maximizing resource efficiency.
One of the major challenges faced by depackaging equipment operators is the presence of grit and plastics in the organic waste stream. This can lead to maintenance issues and compromise the quality of the final digestate reducing its value as a biogas plant feedstock.
However, with the introduction of the Drycake Seditank system combined with their Plastifloat plastics removal technology, such concerns can now be effectively addressed.
Not only that, but a real opportunity for income generation also arises from:
- the added value of the biogas plant feed (pulp) which is clean from plastic and grit and delivered to the digester at optimum water content
- the potential for the sale of plastic bottles and other selected high-value recyclable plastic waste streams for recycled resin production.
In this article, we will explore the role of the Seditank in eliminating grit and plastics from the organic soup output of the Twister, or any other depackaging machine, and how it contributes to sustainable food waste recycling solutions.
The Problem of Grit and Plastics in Organic Waste
When it comes to food waste recycling, the presence of grit and plastics poses a problem.
Grit, which includes sand, soil, and other heavy inert materials, can cause abrasion and wear in biogas reactors, leading to increased maintenance costs. Moreover, the presence of plastics, including microplastics, not only hampers the efficiency of the digestion process but also raises concerns about:
- raised viscosity in the biogas reactor and
- contamination of the final digestate.
If the depackaging/separation system grinds up metals into tiny pieces, the metal contamination may also be a problem for fertiliser production and will need to be removed with the grit.
Addressing these issues is crucial for achieving sustainable and effective food waste recycling.
Introducing the Seditank
The Seditank is an innovative solution developed by Drycake™ to tackle the problem of grit and plastics in the organic waste stream. It is a piped-in and weir-out/auger-conveyed grit removal system that can be easily integrated with the Twister, or any other depackaging machine. Its function is to remove grit and plastics prior to entering the biogas reactor.
This innovative system eliminates the need for high-wear-resistance grit pumps and enables the efficient separation of organic material from unwanted contaminants.
Enhancing Biogas Yield/Efficiency with the Seditank
The integration of the Seditank with the Twister offers numerous benefits to food processing professionals involved in recycling.
Firstly, by removing grit and plastics, it helps to maintain the longevity and performance of biogas reactors, reducing maintenance costs associated with abrasion and wear.
Secondly, the almost total elimination of plastics from the organic soup output ensures a cleaner and higher-quality digestate, which can be utilized as a valuable resource in various applications.
Additionally, by preventing the entry of plastics into the anaerobic digester, the Seditank plays a crucial role in addressing the growing concern about visible plastics in solids or liquids used in crop and horticultural/garden applications.
The Process: Grit and Plastic Removal
The Seditank-Plastifloat system works in conjunction with the Twister or any other depackaging machine to efficiently remove grit and plastics from the organic soup output.
The innovative auto-opening weir outlet, combined with a submerged outlet for the clean pulp, and separate low-level grit/sand/silt outlet allows the 3way separation of light/floating plastics, from the heavy/inert fractions, including grit, from the organics. Only the clean organics then proceed to the biogas reactor.
On the other hand, the Plastifloat component effectively removes all types of plastics, including microplastics, through a specialized separation process. This ensures that the organic waste stream entering the biogas reactor is free from undesirable contaminants, resulting in enhanced system efficiency and a higher quality of digestate.
According to local regulations, the digestate will normally be low in metal contamination and contain minimal microplastic making it suitable for land spreading and use in fertiliser products.
Promoting Sustainable Food Waste Recycling
By incorporating the Seditank system into food waste recycling processes, recycling and food processing professionals can significantly contribute to sustainable practices.
The efficient removal of grit and plastics not only reduces maintenance costs but also safeguards the environment by minimizing the release of microplastics and ensuring a cleaner digestate. Furthermore, the separated plastics can be reprocessed, promoting a circular economy approach and reducing the overall environmental footprint.