Recycling glass burns fossil fuels. Are refills greener?

Fossil gas powers the large furnaces in Auckland that melt used glass containers and transfer them to new furnaces.

In addition, the chemical reaction to form the glass releases more carbon dioxide, which covers the atmosphere.

To avoid these emissions, a group of sustainable companies want the government to introduce a container reuse system, where bottles and jars are washed and refilled.

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On the South Island, glass containers are ‘recycled’ in road materials. Crushed glass can replace the required aggregate and sand for asphalt.

Glass containers in North Island recycling bins are sent to Auckland. Australian recycling company Visy operates a glass-making plant in Penrose, the largest in the country.

To create recycled glass, kilns must reach About 1500°C – In Auckland, it is fueled by fossil gas. Some additional equipment is electric.

This combustion creates the bulk of the Auckland plant’s carbon footprint. But there is another source: chemical reactions in the furnace itself.

Used glass is combined with chemicals Including soda ash, limestone and dolomite. Each of these substances contains some stored carbon dioxide.

This greenhouse gas is released during the reaction, enters the atmosphere and causes its temperature to rise. From this process alone, Auckland Glass Factory produced 11,700 tons of CO2 in 2020 – equivalent to more than 1,650 return flights to London.

Glass factories can reduce these emissions by using a higher percentage of used glass. This also allows the oven to operate at low temperaturesaving fuel.

In 2019, the Auckland factory produced 10 million bottles of 90% of recycled materials. But day by day, Physi Objectives For 70% recycled content. The recycled quota may be limited by the supply of used glass or the quality requirements of customers.

By choosing amber glass, companies can usually increase the share of recycled content in the bottle.


By choosing amber glass, companies can usually increase the share of recycled content in the bottle.

Amber or green glass mostly They contain a higher percentage of recycled content than clear containers.

The glass-making process also creates Toxic air pollutants that can contribute to Asthma and bronchitis. Air quality systems can remove some of these pollutants from the air before they leave the chimneys. These emissions significantly decreased In the last years.

Visy’s head office in Australia was contacted several times, and asked about any plans to replace fossil fuels or reduce operations emissions. The press office did not respond.

Low Emission Bottles

Last month, a French glassmaker made the world’s first factory Carbon free recycled glass: Using 100% used glass – and therefore no carbon-releasing compounds – with biogas furnaces. But the modified oven he ran For one week only.

This type of glass can depend on the company and consumer acceptance: Bottles with higher recycled content may own Slight tint.

Here, the government plans to pay people to return beverage containers made of glass, plastic and aluminum. Expected to start in 2025, you’ll receive about 20 cents per container of cash to drop into a dedicated machine.

Each year, kiwis purchase 2.3 billion single-use beverage containers. The government hopes that the cashback system will achieve much higher collection rates. But as currently proposed, the containers will be sent for recycling – glass (and aluminum) to an emissions-intensive furnace.

Sustainable business leaders are calling on the government to build a reuse option into this system. Standard glass and plastic bottles and jars can be converted into washing, label removal and sterilization facilities. Food companies can then purchase the reusable containers.

They say the system could be a low-carbon showcase: using zero-emission trucks, solar power, and wastewater recovery.

Currently, the ABC Swappa Crate Beer System is the largest reusable container scheme in the country, with 30 million bottles.

Florence Van Dyck, co-founder of the beverage company Chia Sisters, has written an open letter to the government, calling for a reuse option for the broader beverage industry.

She added that promoting recycling is very important. But in a circular economy, reuse must be the priority. “The proposed re-container scheme presents a real opportunity, because no small business can do it alone.”

The letter was signed by a number of other food companies — such as Fix & Fogg, Phoenix Organic, Six Barrel Soda and Wai Manuka — and climate experts, including Climate Change Commissioner James Renwick.

Van Dyck said rigid plastic packaging can be washed and reused 10 to 20 times, and glass up to 50 times. “It will have a lot of other climate and environmental benefits.”

Refilled bottles can look drab, compared to their single-use counterparts. Van Dyck said this signals to shoppers that the company prioritizes the planet over aesthetics. “Consumers, and especially our tribe, understand and expect that reused items are not 100% perfect.”

Transportation costs may be higher. The used glass sent to the furnace can be transported in the form of shards. Reusable bottles take up more space, and require more trucks.

Van Dyck said consumers – through taxes and prices – pay for recycling, landfills, and associated emissions, rather than companies choosing packaging. “When we absorb all of those costs, it’s much cheaper to reuse them.”

She hoped that the reuse system would reduce waste shipped to developing countries. This is sold as recycling, but I found the reports Lots are thrown or burned illegally. “It is not right to rely on other countries to deal with our waste.”


New Zealand’s recycling practices are under scrutiny amid revelations that hundreds of tons of plastic are still being sent to countries such as Malaysia and Thailand.

Recycle vs Reuse

Life cycle studies – which add up all emissions sources over the life of a product – find that reusing glass is better than recycling glass.

Barbara Nebel, CEO of Thinkstep-ANZ, a life-cycle consultancy, said reusable bottles are usually a bit heavier than the single-use options. That weight, she added, could mean more fossil fuels are burned while the product is being transported.

But even taking into account the extra weight, reusable bottles are produced Much lower emissionsOne study found – provided each was used up to 6 times and had a small breakout or loss.

according to a report Based on 32 life cycle analyzes, a reused glass container results in less than one-sixth of the carbon emissions of a recycled container.

The report stated that if the containers have traveled less than 100 kilometres, recycled glass is the option with the lowest emissions.

In the past, drinks – such as beer and soft drinks – were mostly made or bottled local factories. Under these regulations, refillable glass containers make economic and environmental sense. But manufacturing was simplified, many kiwi drink companies produced products for the whole country from one plant.

For companies using glass containers, the packaging is probably It is conducted in Auckland near the glass facility.

When drinks travel more than 100 kilometers from the factory to customers, single-use cartons – which are mostly made of carbon-absorbent paper, weigh less and It can now be transformed In building materials – she The greenest choice.

Nibel Company also found Cardboard and recycled PET are good low-carbon packaging options. “It’s all about the weight…the weight is very important.”

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