What impact does an espresso machine have on the environment? And how can an espresso machine reduce its environmental footprint? For years, Simonelli Group engineers and researchers from the Università Politecnica delle Marche have asked themselves these two questions to try to create machines that not only perform well, but that are increasingly environmentally sustainable.
Respect for the environment was rarely a consideration by food-service operators until a few years ago. It is slowly gaining ever greater importance, both because the consumer is more and more sensitive to environmental issues and because we have become aware that without a more sustainable economy, we are likely to irreparably compromise the conditions of life on our delicate planet. Let’s find out how the environmental impact of an espresso machine is evaluated and then learn about the solutions that Simonelli Group designers have put in place to reduce the impact as much as possible. One of the most common ways of measuring environmental damage caused by an object is expressed in Kg of CO2 equivalent. This calculation expresses the imprint the product makes on the environment, taking into account its manufacture, its use and its disposal. The calculation of this metric is particularly complex since, for each material that contributes to producing an object, it takes into account the energy necessary for extraction, transformation, processing and transport. There are many variables in the calculation. Materials such as aluminum or steel can have different Kg Co2 (Kg / Co2eq) indices depending on whether they are extracted and processed in a country with a coal-based energy system or in a country where electricity is produced through predominantly renewable resources. The calculation also takes into consideration the type of machining process used to get the material in the format required for assembly in the product. Moulding, for example, will have a different impact than mechanical processing.
Above are values for materials normally used in making coffee machines, expressed per unit of mass (1 Kg).
Comparing the environmental performance in KgCo2eq emitted per kg of material, aluminum has the greatest impact, with an index of 20. This is mainly due to the huge amount of energy needed during the process of extracting the material from the minerals in which it is found, such as bauxite.
Among the other materials, brass (with a coefficient of 5.52), copper (5.47), and stainless steel (4.43) have three times the impact of carbon steel which has a coefficient of 1.85. The impact of polymeric materials varies considerably, from about 8 kg of Co2eq for the thermoplastics PA66 and PC to only 2 kg for PP. This depends on both the production process and the chemical elements in the polymer formulation. The materials with the lowest environmental impact are glass, which has a coefficient of 1.03, and wood, with 0.09. In designing a machine, engineers also have to consider the specific weight and physical-mechanical characteristics of the various materials. Making the same component in stainless steel, aluminum, or polymeric material means considerably changing the mass of the end product. The specific weight of metallic materials (8.9 kg per cubic decimeter of copper / brass, or 7.8 kg per cubic decimeter of carbon or stainless steel) is higher than aluminum (2.7 kg per cubic decimeter) and much more than polymeric materials (around 1 kg per cubic decimeter). This means that a component made of plastic will be considerably lighter than one made of stainless steel or brass. By comparing the impacts of the various materials on the volume unit (see chart in the previous page), the graph changes. The heaviest materials (copper, brass, steel) almost equal the impacts of aluminum, while polymeric materials have lower impacts due to their low density.
But in addition to the different amount of material used and therefore the different weight, the physical- mechanical performance also changes. So, where the same performance is needed, such as resistance to a given pressure (for example 9 bar of hot water), the component must be dimensioned differently depending on the material. Copper, for example, has less mechanical strength than stainless steel, so to guarantee the same sealing properties copper must be much thicker. For each component the design must also take into account the other physical properties of each material. So for an insulating component, a different material must have the same conductivity. Another aspect makes the work of engineers even more complex. Depending on the component function, its health and safety aspect must also be taken into account. For example, using glass is not recommended due to its high fragility and the consequent danger if it breaks, while using wood is not recommended because it may lead to hygiene problems and consequent bacterial proliferation.
These aspects are important in designing coffee machines as they are tools for producing beverages that are consumed by people and therefore must guarantee maximum food safety and hygiene. An additional factor to consider is the possibility of recovering materials at the end of the product life cycle. Some materials can be recycled, while others are hardly recoverable, especially if they are combined with other materials to make alloys or compounds that are difficult to parse out with current technologies. Moreover, even if there are no such technical difficulties, not all materials are recovered anyway, so only a part of what is potentially recoverable is then actually recycled. Sometimes at the end of its life the product ends up in a landfill so there is no recovery, sometimes traceability of the product itself is lost, sometimes the costs of recovery are higher than the commercial value of the material itself, etc. Many factors can hinder complete recovery of the materials in a coffee machine and these can vary from country to country.
This means that the same machine ending its life cycle in the U.S. for example, will have a different amount of recovered material than one in China, Russia, Europe, Iraq or Japan.
To take recovery of materials into account, engineers use statistics based on historical data, which highlight the average recovery percentage of each type of material in various countries.
According to these statistics in Italy, for example, 70% of copper and ferrous materials are recovered, a slightly lower percentage for aluminium (around 50%) and an even lower portion for brass (25%), while the recovery of polymeric materials is completely insignificant. The overall impact of each material will therefore be the sum of the KgCO2 used for its production and its recoverable parts at the end of its life. To evaluate the impact of a coffee machine, it is necessary to apply these weighted values to the mass of each material in the product.
Making the work of the engineers even more complex Is the energy efficiency of the machine when in operation. A machine that uses less energy but has the same performance as a less efficient machine is the ultimate goal from an environmental point of view. Any choice of material impacts the performance and efficiency of the machine. Engineers have to reduce the environmental impact of the product while also guaranteeing the same performance as a machine of the same level. At least that is, for the engineers of Simonelli Group.