Dairy processing heat and energy recovery: an analysis of energy usage within the dairy processing sector in Ireland

The Irish dairy processing sector is one of the largest in Europe with annual production figures in excess of five billion litres. In 2013, the revenue from the dairy sector surpassed €3 Billion for the first time with an influence on the Irish food and drink export market of almost 30%. With the abolishment of milk quotas in 2015 leading to a forecasted growth of 50% by 2020, the environmental impact of the dairy industry in conjunction with the increased water and energy requirements associated with the forecasted growth is a key limiting in the sector at a level never seen before (Dairy Water 2016). In addition to Irish production volumes increasing, change is also on the horizon for the electrical system in Ireland with the introduction of a dynamic pricing system with variable peak and off-peak prices scheduled for rollout in 2020 (EURELECTRIC 2017). As such, not only will it cost more to process milk in the future but dairy co-operatives will also be expected handle more milk than they ever have before. This thesis aims to support the dairy co-operatives in dealing with these new horizons by benchmarking the present-day energy usages of seven large scale processing co-operatives around Ireland. This is achieved via review benchmarking which involves a neutral party gathering, compiling and assessing the energy and production data for 2015 with a view to discovering common high energy consumers (hotspots) of dairy processing and culminating in a database in excess of 8.5 million data points. These hotspots have been determined as drying, evaporation, casein and cheese production which account for 85% of the total energy usage on an average site at 24%, 23%, 22% and 16% respectively. Considering the high energy processes identified, technologies such as expansion turbines and work exchangers subsequently have the greatest impact and/or value to Irish dairy processing in general and would critically support these locations in minimising future energy usage while dealing with the forecasted growth.