Tag archive for 'metal'

Recycle Guru: Carbon Savings Achieved by Recycling

Posted On

Recycle Guru is an online platform helping citizens recycle their waste by enabling the informal recycling sector. It promotes the more sustainable use of resources to make communities healthier and cleaner and seeks to instill greater dignity in the recycling profession as well as into the perception of citizens who rely upon their services. Recycle Guru initiates the recycling process by collecting paper, plastic, metal, and glass wastes from households in Bangalore.

 

The motive of this project was to create a tool to estimate the Energy and GHG Emissions (or Carbon Footprint) conservation benefits of recycling versus the business-as-usual option for municipal waste management in India: landfilling. Achieved Energy saving is contextualized in terms of equivalent hour of usage of CFLs (compact fluorescent lamps), ceiling fans, laptop, washing machine, LCD TV, and the equivalent carbon sequestration capacity of trees.

Paper

Paper waste is categorized into following categories: paper sheets, newspaper inserts, newsprint, cardboard, and magazines. The Recycle Guru team observed the percentile contribution of each waste type as the following:

Paper sheets – 95%

Newspaper Inserts – 5%

Cardboard – 60%

Magazines – 40%

Life cycle emission (implies manufacturing from Virgin material, 0% recycled material) of each subcategory mentioned above is as follows:

Life cycle emission of Virgin and Recycled Paper

Using the first order decay method, the emissions from disposal is estimated to be 1.725 kg CO2e/kg of waste. The total emissions saved from recycling is calculated by subtracting the life cycle emissions of the recycled material from the life cycle emissions of the virgin material and then adding the landfilling emissions. The results are displayed in the following table:

Paper: Total Avoided Emission (Per Kg of paper)

Plastic

Plastic waste consists of the following three categories: high value plastic (high density polyethylene), PET bottles (polyethylene terephthalate), low value plastic (low density polyethylene). The life cycle emissions from manufacturing for each subcategory are displayed in the table below.

Life cycle emission of virgin and recycled plastic

Since Degradable Organic Carbon in plastic is almost negligible, methane generation from its disposal in landfills is considered to be Zero. To calculate the avoided emissions from recycling, the same formula as that for paper was used. The results are displayed in the following table:

Plastic: total avoided emission (per kg of plastic)

 

Metal

Metal waste only contains one category comprising both aluminum and steel. As per the pattern observed so far, percentile contribution of aluminum and steel in metal waste is found to be 75% and 25%, respectively. The life cycle emissions (implies manufacturing from Virgin material, 0% recycled material) of each subcategory mentioned above is as follows:

Life cycle emission of virgin and recycled metal

 

Since degradable organic carbon in metal is almost negligible, methane generation from its disposal in landfills is considered to be zero. Emission savings for each category is estimated using the same equation as paper and plastic with the results displayed below.

Metal: total avoided emission (per kg of metal)

 

Glass

Glass waste is categorized into the following categories: beer bottles (brand: Kingfisher), container glass, and generic glass. As observed so far by Recycle Guru team, there were many instances when beer bottles were counted in pieces instead of kilogram. Hence, carbon saving from beer bottles is estimated based on number of pieces taken for recycling. Kingfisher beer bottles (made up of glass) mostly come in 650ml and 330ml. These two
major categories are considered in modeling the carbon saving from piece of each type. Life cycle emission (implies manufacturing from virgin material, 0% recycled material) of each subcategory mentioned above is as follows:

Life cycle emission of Virgin Glass, Life cycle emission of Virgin Beer Bottle Glass

Since degradable organic carbon in metal is almost negligible, methane generation from its disposal in landfills is considered to be zero. Emission savings for each category is estimated using the same equation as paper, plastic, and metal and the results are displayed in the following two tables.

Glass: Total avoided emission (per kg of Glass), Beer Bottle: Total avoided emission (per piece of beer bottle)

As discussed above, the energy saving achieved is expressed in terms of following contexts: CFLs (compact fluorescent lamps), ceiling fans, laptop, washing machine, LCD TV, and the equivalent carbon sequestration capacity of trees. Electricity emission factor (including AT&T Loss) for Bengaluru city is 1.27 kgCO2e/kwh generated. The following table displays the results:

Energy consumption of contexts (appliances)

To find about the assumptions taken and the equations used, the original report can be read here.