The recycling industry is in love and pain with glass bottles, which, while labeled as “infinite cycles”, today do not rise or fall in recovery rates, emphasizing the low-carbon cycle and green development. More emphasis must be placed on efficient collection and reuse in order to achieve carbon neutrality and on glass with significant carbon emissions in the production chain。
The glass industry often calls itself “a hundred per cent cycle without compromising quality or purity”, and a review in nature calls it “materials for achieving carbon neutrality”. However, glass recovery rates are low in most countries globally。
China is a big producer of glass, exporting 25 per cent of the world’s glass and glass products, and scrap glass is one of the 10 main varieties of china’s renewable resources. However, today, where other recycling resources have increased significantly, the recovery rate for scrap glass has not increased or decreased. According to department of commerce regenerative resource statistics, the amount of glass scrap generated in 2019 was approximately 2,223 million tons, an increase of 10. 9 per cent over the same period, while the volume of glass scrap recovered decreased by 5. 4 per cent (approximately 9. 84 million tons)。
The data can also be echoed by real experience. Have you ever had that experience? Carefully accumulates bottles of glass, believing that the glass can be recovered with high value, but when asked about the scrap collector, the answer is “no”. In fact, a considerable part of the bottle cans around us is unrecovered, some of them need to be mixed in building waste before they can be transported, and the fate is often buried underground。
A glass bottled with happy water. Is it really better than a plastic bottle
Summer inflammation, a bottle of ice-free and happy water filled with bubbles is the greatest comfort i have ever had after receiving solar radiation. Although happy bubble water is packed in a variety of packages, from plastic and aluminium cans to glass bottles, how many people, like me, think the same branded bubble water is the best bottled glass。
Although a brand company has made it clear that “the beverage formula is the same regardless of the packaging”, the packaging changes bubble water quietly on the shelf。
For one thing, the bubble spirit is not just a mix of sugar and taste, but also a very important bubble (co2) that becomes weak acid when entering the mouth, stimulates neurons, gives us a sense of pleasure, and the presence of bubbles makes us feel that the water we drink is colder, and adds to the joy that sugar brings。
Bubbles are affected by packaging. The plastic beverage bottle is mainly based on pet plastics (pcdd ethyl ester) as a high-molecular polymer, where the high-molecular chain is entangled like a noodle, like this:
Figure 1 high-molecule structure of plastic bottles source
The folding structure is easier to get gas through than glass and aluminium, so, over time, plastic bottled with a little less happy water bubble than glass bottles and canisters。
Second, not only is plastic used in plastic bottles, but there will also be a thin plastic coating inside the portable cans to prevent co2 and metal reactions. Don't worry, they're safe, but the presence of plastic slowly absorbs the taste of happy water. By contrast, glass can be said to be almost entirely detrimental to the filled drinks, so the water in the glass bottle is the smell closest to the initial setting of the plant。
Is it environmentally friendly to wrap it in glass
Because of the advantages of high transparency, stable chemical properties, strong corrosion resistance, etc., glass is widely used in food beverages and cosmetic packaging, and because of its ease of cleaning and stability, many countries around the globe have repeat outlets where bottles are sold. In the current wave of plastic erosion, glass bottles often replace the face of materials with environmental ones. In reality, however, the re-use and recycling rates of bottles are much lower than they were。
If the recycle is too low, is the glass still environmentally friendly
On this issue, different conclusions on the measure are not unique. We talk about the dimensions of global warming trends (which can be easily understood as carbon emissions), resource depletion, environmental impacts (ecotoxicity, human health)。
From the perspective of global warming trends, glass manufacture is a high-energy, high-emission industry globally, producing 86 million tons of greenhouse gases annually. While data on carbon emissions from the glass industry in china continue to lack uniform measures, industry estimates suggest that the manufacture of glass products per ton would result in 0. 802 to 0. 975 tons of carbon dioxide emissions, which means that in china more than 20 million tons of carbon dioxide per year would be generated by glass only。
Even so, glass is still called "the material to achieve carbon-neutrality" because such high-carbon emissions are unsolved。
The process of manufacturing glass products consists of the following components: raw materials (sands, pure alkalis, limestone, etc.) melting into liquid glass at a high temperature of 1400-1600 degrees – entering the mould formation – cooling down – transport use。
As glass manufacture requires a high temperature environment, heating materials such as coal and natural gas are currently used. In addition, glass-made raw materials are carbon-rich (sodium carbonate, calcium carbonate), and the process of turning these materials into liquid glass releases large amounts of carbon dioxide. Thus, glass burning is one of the most energy-consuming and carbon-emitting components, with energy consumption accounting for more than 70 per cent of the entire manufacturing process, while almost half of the carbon emissions from glass combustion are from energy combustion and 36 per cent from carbon dioxide from raw material heating。
However, the use of regenerative glass during glass burning can effectively mitigate these high energy consumption and emissions. According to the european glass containers association, the glass manufacturing process can be reduced by 5 per cent for every 10 per cent recycled regenerative glass added. Now, on average, the glass container manufacturing in europe has added 52 per cent to the recovered content, which can continue to rise as long as the scrap glass is well controlled. If combined with renewable energy use, glass manufacturing is expected to reach carbon neutrality in the short term。
If all the components of raw material production - packaging production - product production - packaging - transport - waste are measured, the environmental impact of different packaging materials is compared over the life cycle, glass, plastics, portable cans, paper-based rembrands (lily packs) etc. Are used as a one-off use, and the carbon emissions of bottles are much higher than other materials。
Therefore, if the recovery rate is low, the glass bottle, as a one-off packaging, has no advantage in terms of carbon emissions, that is, not environmentally friendly material。
From the point of view of environmental impact: glass is a non-degradable material, and natural degradation takes longer in the environment than plastic, but glass does not cause soil or air pollution in the environment. “in comparison, if plastic packaging enters the environment, it affects the health of the soil and causes marine pollution, and the chemicals contained therein may also affect the health of flora and fauna and humans”, du jing, director of the institute of cycle economics of the university of toji, told the intellectuals, “of course, there are other materials, such as paper and wood, which are more degradable and less hazardous to the environment if they do not contain toxic and hazardous chemicals”。
From the point of view of resource conservation: the glass industry often says that “glasses are materials that can circulate indefinitely”, with low recovery losses, guaranteed quality and efficient reuse. According to the american glass association, it takes less than a month to repackage the glass from the recycling box to the new packaging。
Recovering a ton of scrap glass saves 720 kg of quartz sand, 250 kg of pure alkali, 60 kg of long stone powder and 400 degrees of electricity by using less than 10 tons of coal. Once a ton of glass is returned, 20,000 bottles of wine are renewable, which is 20 per cent less expensive than the production of new materials. It is therefore unreasonable from the point of view of resources to use glass only as a one-time use without recovery。
What if the packaging is not one-off
Although the market share of refilled bottled beverages is lower than before, this pattern is still rare at home and abroad. In particular, with the expansion of circular economic solutions in recent years, more and more regions and brands are re-exploring reuse patterns to reduce the generation of packaged waste, and more relevant life-cycle studies have followed。
These studies basically use the “cradle-to-grave” method, which measures all the components of raw material production - packaging production - product production - packaging - transport - waste. Comparative environmental impact indicators also cover global warming trends, resource depletion, ecosystem impacts (ozone layer depletion, acidification, ecotoxicity, etc.), human health (human toxicity)。
These studies target a particular product, such as soft drinks in brazil, beer in italy, wine in france, milk in england, etc., in several directions:
Compare the environmental impacts of packaging materials such as glass, plastics, portable cans and paper-based coverings (little packs) from different dimensions to assess the full life-cycle effects of different modes of filling, such as reuse, one-time use and use of recycled regeneratives。
Compare the increase or decrease in the proportion of repeated and one-time packagings to identify the best proportion to balance environmental and economic benefits。
Assessing how many re-uses of packaging are required and the environmental benefits are optimal。
Because each product situation varies from region to region, the comparative conclusions of the life-cycle study are not the only ones, and several key factors influencing the end result can be summarized as: re-use of packaging, self-heaviness of packaging, and recycling utilization after waste of packaging. Taken together, most studies have concluded that repeated packaging is more cost-effective than a single packaging environment。
In brazil, for example, studies have shown that 40 re-uses of bottles are more efficient than other packaging environments, while an italian study on red wine packaging suggests that 15 re-uses of bottles provide the best environmental performance。
In conclusion, if glass bottles are used only as one-off, because of the weight and high energy consumption of the production process, they are not comparable to other materials in the eia and are packaging materials with significant environmental impacts. But it can be a good option for reuse。
In the case of milk packaging, for example, if milk bottles are reused and washed in water-saving mode, the single-time plastic bottles are better compared to multiple environmental indicators:
Previously, a british study on the packaging of beverages with carbonate showed that if bottles were used again once, the reduction benefit would be 40 per cent; more than eight times, with a contribution of 65 per cent. A full life cycle study of beer packaging in portugal shows that the proportion of re-use in packaging is not necessarily as large as possible, and that if 20-50 per cent of glass packagings sold in the area are reused (the remaining one-time packaging is still used), the environmental impact of a beer bottle being reused is less than that of a one-time packaging; if the proportion of re-use is increased to 60 per cent, a better environmental benefit can be found if repeated use takes 3-4 times; and when the proportion of re-use is increased to 85 per cent, repeated use is actually more environmental than a one-time packaging。
How's it going
Currently, the average collection rate for glass containers in the eu is 78 per cent, and the eu glass industry association has set the target of 90 per cent collection of glass containers after consumption by 2030. Some eu countries also have excellent numbers for repeat use and refilling of glass containers. In germany, for example, a mature deposit return system has been developed to effectively collect bottles, which can now be filled 50 times。
The deposit return system is the familiar way in which a deposit is paid for a bottle of “bottles of soda, take five and drink four” and a deposit is paid for packaging when the drink is purchased, and the amount returned after the bottle has been repaid. In some european countries, deposit return systems have developed more maturely, with branders working with large supermarkets, among others, to expand the scope of bottle return。
The deposit return system is a recovery policy that works well in both europe and the united states. According to the american glass containers association, the rate in the united states is around 31 per cent (3. 1 million tons). In states with deposit return systems, the recovery rate for glass containers can reach 63 per cent; in states without deposit return, the average recovery rate is only 24 per cent。
In china, the recycling rate of daily glass is about 30 per cent, the volume of recycling has declined in recent years and the market price of scrap glass is low。
The founder of chengdu's environmental technology company ltd. Has long focused on recycling, and its founder wang sword told the intellectuals that “the recovery price per ton of scrap glass is $200-500, which is less and less, and sometimes even less, than the recovery of `absorbed-up ' , when compared to paper boards of more than 1,500 tons, and the plastic bottle of 1800-2,500 dollars, which is low and heavy
Glass is defined as recyclable in municipal waste classification, but traditional recycling channels are reluctant to take it because of little profit from glass recycling, and even the majority of recycled glass is not able to return to the glass bottle manufacturing industry, and most of it goes to the construction industry as a building material for paving and building. Against the backdrop of the overall recession in the domestic construction industry, there are also regenerative industry operators who sell scrap glass to places such as africa。
Currently, the main force for glass recycling is located in enterprises that build channels for waste resourceization, as is the case with the oki environment. However, the limited number of integrated resource-use enterprises for waste sorting and recycling and the dispersion of used glass containers in cities also mean that large quantities of waste glass have no access to them and no stable supply of waste glass has increased the cost and difficulty of recycling enterprises。
Essentially, the low recovery rate for glass is due to the fragmentation of users, low recovery channels and low cost benefits, resulting in the non-receipt of scrap glass; high cost of recycled glass colours, which require sorting, cleaning, shredding, etc.; insufficient back-end market demand, fewer glass-processing plants and low recovery prices。
“a beer bottle could have cost 30 cents a decade ago because it would have been cleaned and reused. But now, it is long overdue, because many enterprises are no longer refilled, and the diversification of packaging has made reuse more difficult, and, together with the high cost of re-engineering the glass, which is more expensive than the raw material, has led directly to the lack of market for the recycle of the bottle。
Similar recovery difficulties exist for glass containers in other countries, such as malaysia, where some recycling centres have announced that they will no longer receive scrap glass because of low demand for recycled glass, lack of profit recovery and lack of treatment plants for recycling。
