Sustainability assessment of a pneumatic monitoring and control system

Abstract

Sustainability has emerged as the central focus of many manufacturing and automation industries, particularly in compressed air systems (CAS). This is because these systems are very inefficient, as they typically have an average output energy of 10-12%. This inefficiency often results due to compressed air leakages and other pneumatic faults. In Malta, such leakages can result in a waste of 16,000 MWh/year, €2 million in costs, and 6,000 tonnes of carbon dioxide (CO2) annually. To address this, project AIR SAVE developed a Pneumatic Monitoring and Control System (PMCS) which saves 30% of the compressed air consumption during a lifetime of 10 years. Despite its benefits, such a system has its own environmental and financial impact. Therefore, a sustainability assessment was carried out through a Life Cycle Assessment (LCA) and a Life Cycle Costing (LCC) to evaluate the system’s feasibility. An LCA was conducted using SimaPro, employing a cradle-to-grave approach to analyse the environmental impact of the PMCS with a focus on the Global Warming Potential (GWP). The Life Cycle Environmental Impact Assessment (LCEIA) concluded that the PMCS had a total environmental impact of 536.42 kgCO2eq. Additionally, the use phase was determined to have the highest environmental impact with 60%, followed by the raw material production and manufacturing and disposal phase, with 39% and 1%, respectively. Moreover, through an LCC analysis, the total life cycle cost of the PMCS was determined to be €4710.25 + €8.63/year. The Environmental Payback Period (EPP) and Financial Payback Period (FPP) were calculated for the PMCS implemented in a pick and place system at the University of Malta (10 end uses) with an average flow rate of 188 NL/min. The results showed that the EPP was less than 3 months for all scenarios, signifying immediate environmental payback. Conversely, the FPP was determined to be 24 years, which is not viable given the 10-year lifespan of the electronic components. Consequently, a sensitivity analysis was conducted to vary key parameters to achieve the desired financial payback period and hence understand whether the analyses are sensitive to the assumptions taken into consideration. In summary, this dissertation concluded that PMCS is environmentally feasible, however it is not financially feasible.