Compostable plastics in landfill

If the trend continues, in the use of Petroleum fossil fuel plastics, by 2050 there will be 12 billion metric tons of plastic in landfills around the world.

Gasses from organic matter 

The two main ‘bulk’ gaseous emissions from landfill, that are having an effect on global warming are methane (63% average) and carbon dioxide (33% average).

Location location location

Once a landfill site is full, it is covered with a couple of meters of soil. Gas outlet pipes our placed in the site to allow methane and carbon dioxide to escape. The location of the site will affect whether the site is hot, cold, wet or dry. This will influence whether the site is suitable for biodegradable or inorganic waste.

About 60% of landfill sites in the UK are for biodegradable materials, such as newspaper, card packaging, textiles, nappies etc.

Compostable plastics in landfill - it's all about perspective

Most current UK waste management streams do not allow for natural plastics that are made from compostable plant starch called PLA (which is what we manufacture). Ideally compostable plastics should be recycled, as they have a very high recycling waste value in terms of economics and environmental benefit. If PLA cannot be recycled, the next best alternative is to incinerate the waste in a waste to energy incineration plant. Compostable plastics are classed as clean energy when combusted.

Compostable plastics can also be composted industrially in industrial anaerobic digestion plants (currently there are 48 in UK). Depending on the thickness it can also be composted at home.

Holy Cow - a perspective

If in a landfill site with 65% humidity, the amount of methane generated by 1 tonne of compostable plastics in a year is about .094kg which has a global warming potential over 100 years 28 times the impact of carbon dioxide. So 2.632kg CO2e per year 

If we took all of the possible global capacity for our bio plastic material and put it into a landfill site today, it would emit the same amount of methane/CO2 as 2523 cows a year. If we deducted our material from the production of fossil fuel plastics, the petroleum plastics would be the equivalent of 98 million cows a year.

Landfill gas to electricity extraction sites

There are 414 sites in the UK turning landfill bio gas into electricity, with a total capacity of 900MW producing about 3.04TWh of green electricity in the last year (2018). This is enough to power Leeds for a year.

Municipal solid waste from the landfill gas can generate 56 kWh per tonne of waste.

As a company sku-driver, inset (not offset) 3p per kg of our material produced to dairy farmers (the equivalent of 39p a litre of milk production).

We pay the farmer to avoid calving a new milk cow, we pay them enough for what they would bill for 7,959 litres of milk (capacity for a cow to produce in a year). We avoid 100kg of methane (2800kg of CO2e) by doing this.

The farmer keeps 50% for his overheads and profits, the remaining 50% of the money goes to helping to lower the farmers energy use, reducing amps of equipment, solar panels etc.

 

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