18 Nov 2014

Paper Recycling

paper-recycling-k

Paper recycling process

The process of paper recycling involves mixing used paper with water and chemicals to break it down. It is then chopped up and heated, which breaks it down further into strands of cellulose, a type of organic plant material; this resulting mixture is called pulp, or slurry. It is strained through screens, which remove any glue or plastic that may still be in the mixture then cleaned, de-inked, bleached, and mixed with water. Then it can be made into new recycled paper.

The share of ink in a wastepaper stock is up to about 2% of the total weight.

Rationale for recycling

Industrialized paper making has an effect on the environment both upstream (where raw materials are acquired and processed) and downstream (waste-disposal impacts).

Today, 90% of paper pulp is created from wood (in most modern mills only 9-16% of pulp is made from pulp logs; the rest comes from waste wood that was traditionally burnt). Paper production accounts for about 35% of felled trees,and represents 1.2% of the world’s total economic output. Recycling one ton of newsprint saves about 1 ton of wood while recycling 1 ton of printing or copier paper saves slightly more than 2 tons of wood. This is because kraft pulping requires twice as much wood since it removes lignin to produce higher quality fibres than mechanical pulping processes. Relating tons of paper recycled to the number of trees not cut is meaningless, since tree size varies tremendously and is the major factor in how much paper can be made from how many trees. Trees raised specifically for pulp production account for 16% of world pulp production, old growth forests 9% and second- and third- and more generation forests account for the balance. Most pulp mill operators practice reforestation to ensure a continuing supply of trees. The Programme for the Endorsement of Forest Certification (PEFC) and the Forest Stewardship Council (FSC) certify paper made from trees harvested according to guidelines meant to ensure good forestry practices.It has been estimated that recycling half the world’s paper would avoid the harvesting of 20 million acres (81,000 km²) of forestland.

Recycling facts and figures

In the mid-19th century, there was an increased demand for books and writing material. Up to that time, paper manufacturers had used discarded linen rags for paper, but supply could not keep up with the increased demand. Books were bought at auctions for the purpose of recycling fiber content into new paper, at least in the United Kingdom, by the beginning of the 19th century.

Internationally, about half of all recovered paper comes from converting losses (pre-consumer recycling), such as shavings and unsold periodicals; approximately one third comes from household or post-consumer waste.

Some statistics on paper consumption:

  • It is estimated that 95% of business information is still stored on paper.
  • Recycling 1 short ton (0.91 t) of paper saves 17 mature trees, 7 thousand US gallons (26 m3) of water, 3 cubic yards (2.3 m3) of landfill space, 2 barrels of oil (84 US gal or 320 l), and 4,100 kilowatt-hours (15 GJ) of electricity – enough energy to power the average American home for six months.
  • Although paper is traditionally identified with reading and writing, communications has now been replaced by packaging as the single largest category of paper use at 41% of all paper used.
  • 115 billion sheets of paper are used annually for personal computers. The average web user prints 16 pages daily.
  • Most corrugated fiberboard boxes have over 25% recycled fibers. Some are 100% recycled fiber.
  • Recycling one ton of paper saves roughly 17 trees.
  • In 1997, 299,044 metric tons of paper was produced (including paperboard).
  • In the United States, the average consumption of paper per person in 1999 was approximately 354 kilograms. This would be the same consumption for 6 people in Asia or 30 people in Africa.
  • In 2006-2007, Australia 5.5 million tonnes of paper and cardboard was used with 2.5 million tonnes of this recycled.
  • Newspaper manufactured in Australia has 40% recycled content

Source:Wikipedia