As dairies scramble to meet sustainability targets ahead of the first year of reporting for the EU CSR Directive, the significant losses in push-out processes have been identified as low hanging fruit by many companies.
However, inaccurate measuring technologies frequently prevent operators from addressing this issue in an effective way, as it can be difficult to correctly identify the product that moves through the pipeline. But with appropriate measuring technology, the end of one batch and the beginning of the next can be accurately located. If it is not, the small losses at each push-out point, of which there can be hundreds, accumulate and become significant by the end of the process.
Pipeline contents are commonly measured by one of the three technologies – flow meter, turbidity sensor or conductivity sensor. Flow meters estimate the arrival of the product at the push-out point based on the system flow rate; turbidity sensors monitor the interaction between a light beam and the liquid; and conductivity sensors operate by measuring the electrical conductivity of the liquid.
A fourth method is based on monitoring the dielectricity of the liquid, i.e. its ability to hold electric charge. This is achieved by using a sensor that accurately identifies the substance moving through the pipeline as a radiofrequency electromagnetic field is induced into the liquid. Different liquids have different dielectricity, making them distinguishable from each other, giving each liquid a unique fingerprint.
Collo sensors were recently installed in four locations in the raw milk reception of a dairy plant processing 243 million liters of raw milk per year. The plant previously used flow meters for controlling the push-outs. However, due to their low accuracy, what appeared to be optimal timing actually resulted in losses amounting to 600,000 liters per year. With the far higher accuracy of the dielectric sensor, 108 times better than the flow meter, losses were reduced to just 5,000 liters per year – a reduction by more than 99%.
Large dairy and other food producers are currently increasing their efforts to reduce their environmental impact ahead of environmental targets that loom in the near future, mainly in 2025 and 2030. Most of the greenhouse gas emissions caused by dairy operations originate at the farm. For instance, Nestlé, in its sustainability report, outlines how just 5% of its greenhouse gas emissions comes from its own operations, whereas 95% is made up of emissions in the supply chain. Raw milk production is the largest single source of emissions in dairy production, which any waste of milk-based raw material needs to be prevented and, preferably, eliminated.
