Each year a large amount of plant material, cellulose, is deposited on the surface of Planet Earth. What are the natural processes this cellulose undergoes before yielding carbon dioxide, water and other end products?

Cellulose is being considered the most abundant organic compound on the earth. The chemical formula of cellulose as a chain is (C6H10O5)n. Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes. Some species of bacteria secrete it to form biofilms.

Properties of Cellulose

    • Complex carbohydrate that consists of oxygen, carbon, and hydrogen.
  • A chiral, tasteless compound without any odour.
  • Biodegradable, insoluble in water and most organic solvents.

Natural Processes of Cellulose

Biosynthesis

    • In plants, cellulose is synthesized at the plasma membrane by Rosette Terminal Complexes (RTCs).
  • The RTCs contain the cellulose synthase enzymes that synthesis the individual cellulose chains.

Breakdown (Cellulolysis)

    • Cellulolysis is the process of breaking down cellulose into smaller polysaccharides called cellodextrins or completely into glucose units.
  • The breakdown products are then used by the bacteria for proliferation.
  • The bacterial mass is later digested by the ruminant in its digestive system (stomach and small intestine).

Breakdown (thermolysis)

    • At temperatures above 350 °C, cellulose undergoes thermolysis (pyrolysis).
  • It decomposes into solid char, vapors, aerosols, and gases such as carbon dioxide.
  • The semi-crystalline cellulose polymers react at pyrolysis temperatures (350–600 °C) in a few seconds.
      • This transformation has been shown to occur via a solid-to-liquid-to-vapor transition.
  • Maximum yield of vapors which condense to a liquid called bio-oil is obtained at 500 °C.

Generally, cellulose is mainly used to produce paperboard and paper. But its conversion from energy crops to biofuels such as cellulosic ethanol is under development as a renewable fuel source. The biofuel production from cellulose would be a revolutionary technology as it can fulfil India’s target in Paris Climate Agreement.



POSTED ON 08-06-2023 BY ADMIN
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