Digitisation of temperature measurement holds the key to optimising composting plants

The global waste and recycling sector is undergoing a fundamental transformation. While larger operators are more likely to be ready for the digital revolution,  95% of the composting plants worldwide  employ less than ten people and have correspondingly few resources. compocheck24, from sense4elements GmbH provides a cost-effective path for the digitisation of these composting plants.

It is not a question of reinventing the established technologies. What is holding back the complete digitisation and networking of temperature monitoring processes at composting plants is not just about the acquisition of digital tools, but re-appraising structures, working methods and attitudes at every level.. 

The general waste sector needs modernising, while paper and all sorts of paperwork are stillubiquitous to this sector, the chances of errors occurring is high while efficiency is low. Between the management and the plant, the information circulates erratically. Delays, confusion and mistakes are commonplace, which has an adverse effect on productivity.  Over the last decade, waste management efficiency has risen by a mere 3 percent, in comparison to manufacturing sector as a whole, which has improved by over 30 percent.

Operators of composting plants have been crying out for a precise, reliable and user-friendly instrument to take away the burden of material monitoring. At the start of the composting process high temperatures, ideally between 60°C and 70°C, are needed to decompose the material and eliminate harmful organisms; however, operators need to avoid higher temperatures above 70°C, which can kill organisms necessary for fetilisation.

Temperature plays a key role in the production of biological fertiliser to ensure hygienic treatment of the waste materials in the process and to achieve quality that is both high in quality and sustainable. Disposed organic material typically contains plant and vegetable waste, agricultural manure, shrub/grass cuttings, feed residue and well as standard garden and kitchen waste and the material we put in our organic recycling bins. This waste is sorted at the composting plants and mixed to facilitate natural rotting by microoganisms.

During the composting process, particulalry during hygenisation, pathogenic microorganisms and molds are killed off and weed seeds lose their germination capabilities.

Optimal composting goes through 3 essential phases: phase 1 is fermentation, where the temperature rises to approximately 40°C – which results in what is known as ‘pre-rotting‘, this is followed by phase 2, which is hygenisation, where the temperature rises to 65°C – this is known as ‘hot rotting‘ and finally phase 3 where thematerial is cut, can rest and high-quality biological fertilizer is produced.

Hot rotting requires particularly close attention, because it is used for hygiene and needs continuous monitoring.  To ensure the requisite oxygen exchange or oxygen enrichment is reached, the composted material is regularly turned, usually every three days, or converted during controlled rotting. 

To ensure that hygiene standards are met, the rotting material’s temperature must be recorded at least once every day, to comply with the Biowaste Ordinance (BioAbfVO). In hot rotting, hygenisation requires a temperature of over 55°C preferably for 2 weeks  or 65°C over 1 week. The temperature should not go over 65°C over a prolonged period of time as this would cause unwelcomed charring and, at temperatures over 75°C, spontansous combustion can occurr. If temperatures dip below 15°C microoganism activity slows down and the rotting process slows down significantly.

Temperature is clearly the most important measurement parameter for the composting process. Differing mixtures of material, rotting conditions and material development after irrigation can be monitored accurately with a precise knowledge of  temperature development. Moreover, the compocheck24 provides a temperature reading as proof of hygienisation.

The compocheck24 automated measuring system works all weathers and outside temperatures and continuously monitors core temperatures of the variety of waste and compost materials. The measured temperature values are  transmitted  automatically and directly to the compoAPP  per probe via mobile network, without the need for an external power source or any components in between.

Composting problems such as an unintentional change in temperature, are detected straigh away by the measuring system and signalled immediately via the compoAPP. This enables rapid and well-informed interventions saving time and taking the stress and guesswork out of the composting process.