AGC Glass Europe

 

The Kyoto Protocol expresses the world’s concern about greenhouse gas emissions and climate change, a concern that AGC Glass Europe definitely shares. The glass industry can contribute to reaching the targets of the Kyoto Protocol. There is no environmental subject that better illustrates the double focus of our environmental policy, namely:

To be at the forefront of developing new products with better environmental performance, and to manufacture these products with the best available technologies from an environmental point of view.”

In Europe, approximately 20% of the energy used for heating buildings is lost through glazing. Replacing single glazing by double glazing with the new generation of Low-E coating saves about 480 m³ of natural gas per year in an average dwelling. This means that our low emissivity coatings can limit these losses to an absolute minimum¹.

The extra CO₂ emissions and energy used for applying the coatings is negligible, amounting to only one thousandth of the savings likely to be achieved during the lifetime of the product. See also the “Products” chapter.

¹These days a double glazed window unit with Low-E coating can achieve U values of 1.1 (compared with a single glazed U value of 5.8).

Energy Efficienciency & CO₂ emissions

Fig. 6. Specific energy required to melt one tonne of glass (1880 = 100).

Fig. 7. Annual CO₂ emissions. Index 2002 = 100 on comparable basis.

Fig8. Breakdown of energy by type in all AGC Glass Europe plants.

Practically all the CO₂ emissions in AGC Glass Europe come from melting activities. Some 80% of the CO₂ emissions from the furnaces are energy-related, with the remaining 20% caused by decomposition of the raw materials. Recycling of cullet also helps to reduce CO₂ emissions by saving raw materials and energy for melting (see the “Recycling” paragraph in this chapter).

Today the amount of energy required to produce 1 tonne of flat glass is only 10% of what it was 100 years ago (See Fig. 6).

In Fig. 7 it can be seen that total CO₂ emissions for AGC Glass Europe plants have decreased. This decrease is entirely due to the economic recession negatively impacting our production volume. On a comparable basis it shows a decrease of 8% in CO₂ emissions since 2002!

The greatest part of the energy is used for the production of glass (melting the raw materials) and consists mainly of heavy fuel oil and natural gas. Electricity accounts for only a minor share of the total energy used: around 13% (See Fig. 8).

In 2005, the European Emissions Trading system was implemented. The float glass and patterned glass plants situated in the European Union (10 plants) are part of the scheme.

The first CO₂ period in the European Union is now over (2005-2007). AGC Glass Europe exceeded the quotas overall (around 69,000 tonnes out of a total of 1,797,265) because the glass market developed better than forecast during these last years, thus leading to higher glass production.

The second period extends from 2008 to 2012. Since 2008, CO2 emissions have remained below the received allocations. In 2013 phase 3 of the Kyoto Protocol comes into force (2013-2020) with more ambitious targets, a reduction of 20% in greenhouse gas emissions, or 30% if international agreement is signed. The AGC Group is currently preparing to meet this challenge.

As already mentioned, our main environmental objective is to further reduce emissions of dust, acidifying pollutants and CO₂, but tackling these in an integrated way is a complex matter. Most reduction technologies have disadvantages as well as advantages in terms of efficiency, glass quality, yield, cross-media effects etc.

Under the terms of the European IPPC directive (2008/1/EC Integrated Pollution and Prevention Control) a Glass BAT (Best Available Techniques) reference document has been published. This describes the environmental techniques applicable to the glass industry together with their advantages and disadvantages. This document can be downloaded at http://eippcb.jrc.es/reference/.

To be proactive, AGC Glass Europe started the Air Pollution Control (APC) project six years ago. The project is led by a multi-disciplinary team (covering the environment, engineering, purchasing and technical coordination) in collaboration with the plants. The goal is to draw up the air environmental strategy for each plant, and to implement the strategies with real actions.

Within this project, AGC Glass Europe also participates actively in the process of developing new techniques.

Fig. 9 SO₂ and HCl specific emissions relative to 1980.

Fig. 11. Dust emissions. Index 1998 = 100 on comparable basis

Generally, in order to comply with the IPPC Directive and the local legislation derived from it, the main solution chosen is to install air pollution control (APC) units, together with a set of primary measures. These units are made up of a de-SO_x system to abate the dust and acid components, and/or a de-NO_x system to reduce the NO_x depending on the level of reduction required.

At present, AGC Glass Europe has already installed eleven APCs, and the goal is to install five more in the next few years. The cost of one complete APC installation can be as much as € 5,000,000.

Fig. 9 shows the reduction in specific emissions of sulphur oxides and chlorides since 1980. This clear reduction has been achieved thanks to the early installation of de-SO_x systems in our group, together with improvements in technology and more careful selection of our raw materials.

NO_x, SO_x, HCl and HF emissions cause acid rain; they are calculated as hydrogen ion [H+] equivalents or acid equivalents . Fig. 10 shows the total amount of acid equivalent emitted in the last few years. When we take into account the large growth in the Group’s production capacity over these years, this corresponds to a reduction of 40% in specific emissions since 1998!
 

The specific dust emissions are shown in Fig. 11. The decrease in production volumes mainly due to the economic crisis has a significant impact on specific dust. But these emissions have been reduced by more than 50% since 1998!

The de-SO_x part of an APC not only reduces air emissions but also produces large quantities of by-products, mainly sulphates, resulting from desulphurisation of the flue gas. To avoid simply transferring the pollution from the air to landfill, AGC Glass Europe favours recycling these sulphates wherever possible as raw material for the production of glass.

In 2010, more than 2,180 tonnes of sulphates have been recycled as raw material, and nearly 15,000 tonnes since the start in 1999. (see Fig 12)

The de-NO_x part is based on the Selective Catalytic Reduction (SCR) system. Ammonia is injected into the flue gases and in contact with the catalyst it reacts with the NO_x to give N₂ and H₂O, both naturally present in air.

The aim of AGC Glass Europe was again to be proactive in this area, and so the Group has already installed six catalyst-based de-NO_x systems; the first of these was the second catalyst de-NO_x installed in Europe, and the second was the first catalyst de-NO_x in the world to be installed on an oil-fired furnace.
These de-NO_x systems help to prevent more than 3,500 tonnes of NO_x emissions each year within AGC glass Europe.

¹Hydrogen is used as the reference substance for potential acid deposition onto the soil and in water. The acid equivalent of a compound is calculated from the H+ ion equivalent of the acid form of NO_x, SO_x, HCl and HF emitted. The acidification potential equivalence factors are: sulphur oxides 0.031, nitrogen oxides 0.022, hydrogen fluoride 0.050 and hydrogen chloride 0.027.

Air pollution control and waste recycling

The Air Pollution Control units at AGC Glass Europe’s plants provide an example of an integrated approach to the environment. These units remove acids and particulates from furnace flues. They are based on a two step treatment. The first step is a gas scrubber where the acids in the flue gases react with a neutralising reagent injected into the reactor. The second step is an electrostatic precipitator that captures the dust from the flue gases as well as the products of the scrubbing reactions.

Fig. 12. Filter dust recycled. Up to now, around 15,000 tonnes of filter dust have been recycled.

The process is specific to glass production, as the acid scrubbing reagent in the scrubber is sodium carbonate (Na₂CO₃), which is a raw material used in glass production. This material was chosen because the reaction of the carbonate with the sulphur oxides in the flue gases produces sodium sulphate (Na₂SO₄), which is also a raw material for glass.

Na₂CO₃ + SO₂ + ½ O₂ = Na₂SO₄ + CO₂

Thus, the scrubbing system uses a raw material as a reagent and produces another raw material as result of the flue gas desulphurisation. So instead of being disposed of in a landfill, this raw material goes back to the furnace to be reused for glass production.

In other words we have a zero waste system, avoiding transfer of pollution from one medium (air) to another (ground).

AGC Glass Europe has received a Belgian environmental award for this system.

Moustier Line 2 Air Pollution Control unit.

The desulphurisation products are returned to the batch house as new raw material.