Definition of life cycle assessment
Life cycle assessment (LCA) is a method to evaluate the environment and the impacts of industrial products on the environment. The assessment covered the goal and scope, inventory analysis from the early stage of the extraction of raw material, manufacturing of the wireless mouse, product use by consumers, and the impact of the product on the environment.
The function unit of the item is a wireless mouse, which compromises a receiver and AAA batteries which are designed and used by the common computer user. It communicates with the computer by receiving data and operates on power consumption of 0.067 watts. The AAA batteries hold the important component to provide supply the wireless mouse. On daily usage, the lifespan of the AAA battery cell is about 6 months or 4000hours , and the wireless mouse lifespan of 6 years or an equivalent life span of 52, 560 hours . This requires at least 52 times of AAA batteries used on the wireless mouse.
The purpose of this study, wireless desktop mouse and lithium battery are chosen as part a computer accessories life cycle. It is significantly popular for users to switch to wireless electronic applications because it is an affordable, lightweight, and simple design. However, this product becomes part of the electronic-waste at the end life cycle. The wireless desktop mouse and lithium battery are manufactured on resource material phases, process phases, production phases, consumer phase, and product end of life shown in Figure 1.
The average use of a computer desktop is about 4.2 hours per day. Computer users would pair the wireless devices to computers . Wireless mouse made up from Acrylonitrile Butadiene Styrene plastic (inject and molded), the micro switches from PVCs, printed circuit board from silicone and copper wire, Universal Serial Based (USB) from stainless steel, USB casing from Phenolics, internal wires from copper wire and AAA batteries from the composition of lithium ions, lithium oxide, manganese, zinc-nickel, cobalt silicon(anode material) , copper(anode connection), aluminum (cathode) and Polymer(insulator)which were shown in the table figure 2.
Inventory analysis of wireless mouse device and lithium battery
|No||Items material||Material||Mass (grams)||Mass component %|
|1||Wireless mouse casing||Acrylonitrile Butadiene Styrene (ABS), Polycarbonate, PE plastic||50g||50.5%|
Data Emission of all process
The study of data emission is based on the eco indicator ’99 method which reflects on the environmental impact from the production phase. As compared to various type of computer device, Wireless mouse composition has the lowest environmental impact shown in figure 1.3
Consumers of computer and electronic products would have preferred a rechargeable AAA Lithium battery compared to an alkaline battery. It has a longer life span and alternatives sources of energy. A cylindrical type AAA Lithium-Ion battery composition weight 7.6grams with 1000 mAh. Lithium-ion batteries consist of Lithium oxide, cobalt, nickel, zinc, manganese, olivines, aluminum for cathode connection, copper for anode connection, silicone as anode material, polymer electrolytes as a plastic cover insulator, and seals.
The impact analysis begins from the resource extraction and production phase. Wireless mouse was produced from polymer polycarbonate plastic (PC), ABS plastic, PE plastic, silicone, stainless steel, and lithium battery components from lithium-ion, manganese, zinc, and copper. For the purpose of the study, the product impact analysis starts from its production, transportation, consumption, and end-of-life phase. The cumulative energy demand (CED) is used to quantify the total amount of energy consumption and global warming potential (GWP) on the total greenhouse gas emission. The cumulative energy demand and global warming potential for manufacturing common electronic computer mouse at the production phase depicted in the table1.4. These various type of high density and durable properties plastic gives a carbon footprint cumulative result of 0.47 kgCO2 and total accumulated energy of 6.09MJ . Airfreight contributed the highest total energy of 73.3MJ due to the excessive amount of airplane fuel consumption between land and sea freight. Airfreight is the most favored form of transportation because high-speed transportation and high-speed transportation is a form of diversification. The total carbon footprint consumed 0.627kgCO2 and 76.75MJ at the transportation phase, this measure of greenhouse emission relates to climate change . Based on the data, the production phase of the wireless mouse contributed to the total emissions of water eutrophication of 0.0002364kgPO4 and air acidification of 0.004214kgSO4. Phosphorus is emitting on the water surfaces and sulfur deposition forms in the air. The impact results in environmental effects such as toxins in the water and acid rain.
The printed circuit board (PCB) is another major component, which was found in the wireless mouse. PCB contains silicon, lead, cadmium, and tin-antimony for soldering embedded into the wireless mouse. The amounts of material used in manufacturing PCBs are inevitably important for the processing of the wireless mouse device. As compared, Logitech company have innovated its wireless mouse device by decreasing the weight and PCB component, which was parallel to lowering carbon footprint to 40 percent.  This follows as the PCB component production emits 0.95kgCO2 and the packaging of the devices emits 0.368kgCO2. It depicts that, at the production phase of the PCB component contributed the second-highest carbon footprint. Various type of plastic engineered for both wireless mouse and battery insulator contributed to the highest consumption of energy*
At the production phase, AAA lithium battery usage has an emission of 3.6-27kg CO2-eq/kWh. [Lithium A] Lithium battery has been a substitution for nickel-cadmium and nickel hydride battery. It is known as high capacity energy and lightweight properties. cumulative energy demand? Total greenhouse gas emission? Main impact?
Water eutrophication during the production phase
Table 1.4 Environment Impact Category
|At production phase||Carbon footprint, kg CO2||Water Eutrophication,
|Total energy consumed, MJ|