Preliminary assessment for global warming potential of leading contributory gases from a 40-in. LCD flat-screen television

Abstract

Purpose As liquid crystal display (LCD) flat-screen televisions increase in popularity, their potential contribution to global warming has received wide attention. This study presents global warming impacts resulting from the life cycle assessment (LCA) of LCD flat-screen televisions for key global warming contributors from the "cradle-to-gate" and use stages of the product's life cycle. The emissions from nitrogen trifluoride (NF 3 ), a greenhouse gas with a global warming potential (GWP) 17,000 times more potent than carbon dioxide (CO 2 ), are not monitored in the Kyoto Protocol. Emissions in the cradle-to-gate and use stages were modeled in this study according to their GWP (kg CO 2 equivalent), focusing and analyzing the most significant source of NF 3 emissions. Materials and methods NF 3 is used during the manufacturing process of LCDs to clean the vacuum chambers. In this study, a system diagram of the cradle-to-gate stage and use stage of a 40-in. LCD television was proposed using the software package Gabi®, particularly investigating NF 3 to determine its possible effects on global warming based on a typical LCA. Results and discussion The energy inputs in the use stage of the LCD flat-screen television resulted in major global warming impacts, while the contribution of GWP resulting from NF 3 was trivial. However, as energy efficiency continuously improves over time, the GWP resulting from NF 3 may become significant. Findings in this study allow industry to focus on those critical stages of the production life cycle that most directly affect global warming while permitting government agencies to enact proper regulations to help decrease CO 2 equivalent emissions. Conclusions The preliminary assessment of our LCA also offers manufacturers the ability to determine the largest sources of greenhouse gases and their connection in the life cycle analysis of a product. This extension may help guide legislation and industrial management in the future. For further decision making, an in-depth sensitivity analysis may be needed to strengthen the results.

Life cycle environmental evaluation of kettles: Recommendations for the development of eco-design regulations in the European Union

“…Electrical appliances and electronic products generate environmental impacts in all stages of their life cycle (Andrae, 2016), from extraction and production of raw materials, to manufacture and use, to end-of-life waste management. This has been demonstrated by many authors who have analysed different devices such as: televisions (Thomas et al, 2012), refrigerators (Monfared et al, 2014), laptops (Deng et al, 2011), mobile phones (Yu et al, 2010), digital cameras (Park et al, 2007), vacuum cleaners (Gallego-Schmid et al, 2016) and microwaves (Gallego-Schmid et al, 2018). Several life cycle assessment (LCA) studies have also been carried out for kettles, considering electricity and water consumption associated with their use when analysing environmental impacts of hot drinks.…”

Climate change and industrial F-gases: A critical and systematic review of developments, sociotechnical systems and policy options for reducing synthetic greenhouse gas emissions

“…Source: 117 Within this process, the F-gases account for up to 30% of the lifecycle emissions of LDC products, with the bulk of these (80%) coming from etching processes and 20% from CVD processes or the cleaning of vacuum chambers. 118 Unfortunately, after SF6 is used to provide fluorine radicals for the purposes of etching polycrystalline silicon layers, the gas is frequently released into the atmosphere with one assessment suggesting that up to 30% of SF6 is commonly vented in this manner at LCD manufacturing facilities.…”

“…One study estimated that roughly 2,560 metric tons of NF3 are produced for the LCD industry each year, and that up to 5.4% or 138 tons escape into the atmosphere. 117…”

Earth’s Climate System

“…The primary atmo- 31 At one time SF 6 was used to cushion sports shoes, but this use ceased a decade ago and is not considered to be atmospherically important. 32 Atmospheric abundance of SF 5 CF 3 was 0.00015 ppb in 2012 (Sturges et al 2012 spheric release of NF 3 seems to be due to the manufacture of large, liquid crystal display screens (Thomas et al 2012). The present RF of climate due to NF 3 is small, ~2.4 × 10 −4 W m −2 .…”