Advanced manufacturing - Glass
Did you know, in 2018, total US greenhouse gas emissions from glass and glass products was 15 million metric tonnes in 2018 (0.23% of all US emissions)? This is almost equivalent to carbon sequestered by 17.8 million acres of US forests in one year (almost as big as half of New York by area)!
What to expect today
Emissions in glass manufacturing
Climate action at AGC - Glass manufacturing giant
Emissions from glass manufacturing
Commercially produced glass can be classified based on the material used as soda-lime, lead, fused silica, borosilicate, or 96 percent silica glass. Soda-lime glass constitutes 77 percent of total glass production, which is the biggest share. Soda-lime glass consists of sand, limestone, soda ash, and cullet (broken glass).
How is glass manufactured?
The manufacture of such glass is in four phases:
preparation of raw material
melting in a furnace
As the sand, limestone, and soda ash raw materials are received, they are crushed and stored in separate elevated bins. These materials are then transferred through a gravity feed system to a weigher and mixer, where the material is mixed with cullet to ensure homogeneous melting. The mixture is conveyed to a batch storage bin where it is held until dropped into the feeder to the melting furnace. All equipment used in handling and preparing the raw material is housed separately from the furnace and is usually referred to as the batch plant.
Where do emissions come from?
The main pollutant emitted by the batch plant is particulates in the form of dust. This can be controlled with 99 to 100 percent efficiency by enclosing all possible dust sources and using baghouses or cloth filters.
The melting furnace contributes over 99 percent of the total emissions from a glass plant (Scope 1+ Scope 2 emissions), both particulates and gaseous pollutants. Emissions from the forming and finishing phases depend upon the type of glass being manufactured is usually low compared to the first two steps of the process. The image below shows the sources of emissions, with offsite and onsite emissions differently.
Source: US EPA
Climate action at AGC - Glass manufacturing giant
AGC is a world-leading supplier of flat, automotive, display glass, chemicals, ceramics and other high-tech materials and components. AGC Inc, formerly Asahi Glass Co., Ltd. Headquartered in Tokyo, Japan, AGC is the largest glass company in the world by market share. Today, it has over 55,000 employees globally and extends into over 30 countries and regions with regional pillars in Japan/Asia, Europe and North & South America.
AGC’s carbon footprint
Compared to other industries which have really high Scope 3 emissions (typically 65%-90%), advanced manufacturing has the advantage of having the majority of their emissions from sources in-house which makes their path to decarbonization different from other industries. Below is the breakdown of AGC’s carbon footprint:
Scope 1: 47% emissions from production process (furnace)
35.23% fossil fuels
11.9% raw material decarbonisation
Scope 2: 12% emissions from electricity use (mostly running the furnace)
Scope 3: 41% from upstream and downstream activities
24.79% raw materials production
9.55% fossil fuel extraction
6.47% from other sources like transportation and other activities
The quest for an ecological furnace
After years of research, multiple studies, intense collaboration at R&D level, industrial level and with an external partner Air Liquide, AGC Glass Europe started up a furnace working with pure oxygen instead of air. AGC also developed a system that reuses heat from waste gases to preheat oxygen and natural gas before it is injected into the furnace, which yields additional significant energy savings thus helping increasing profitability. The Hot-Oxycombustion furnace was born in this way; reducing melting energy by 25%, CO2 emissions by 15% and Nitrogen oxide emissions by 83% (since we are using pure oxygen instead of air which has >70% Nitrogen)
Designing efficient products
To bring down scope 3 emissions, AGC has also invested in building more energy efficient products for its customers thus bringing down its scope 3 emissions. Some examples are:
Ecology glass (used for buildings)- Energy-saving glass with excellent heat insulation and thermal shielding, helped to improve the energy efficiency of buildings and reduce CO2 emission
Solar power generation system (generating electricity, heating water) - Solar power generation system using a light-collecting, large-scale module primarily composed of laminated glass
A fluoropolymer film (to prevent cracks during transportation) - It improves the impact strength of the glass to prevent damage from friction contact during production, storage and transportation
Recommendations from the team
Glass manufacturing process- Move towards sustainability (4 min video)
World Glass Complex - Saint Gobain (2 min video)
AGC Glass - Sustainable buildings(1 min video)