Glycerol and biodiesel

Question 2

What are the physical properties of glycerol?

Answer 2

• very soluble
  
  • readily forms H-bonds
  • three O-H groups

Question 3

How is glycerol used in medical products and cosmetics?

Answer 3

• used in pharmaceutical and cosmetic perparations
  
  • attracts water
  • prevents ointments and creams from drying out
• used a solvent in many medicine, also present in tooth paste

Question 4

How is glycerol used in industry?

Answer 4

• solvent in food industry, e.g. food colourings
• plasticise various materials like sheets and gaskets, cellophane and special quality paper

Question 5

What are plasticisers?

Answer 5

• introduced between the molecules of the polymers which make up the material
  
  • allows molecules to slip over each other
• material becomes flexible and smooth
• PVC may contain 50% plasticiser, such as exters of hexandioic acid
• over time it leaks away, leaving the plastic brittle and inflexible

Question 6

What is biodiesel?

Answer 6

• renewable fuel
• made from oils derived from crops, such as rape seed
• rape seed oil is a triglyceride ester

Question 7

How is biodiesel made?

Answer 7

• oil is reacted with methanol
  
  • with a strong alkali as a catalyst
• forms a mixture of methyl esters
  
  • can be used as a fuel in diesel vehicles with little or no modification

Question 8

How is biodiesel used?

Answer 8

• being introduced commerically
• due to simple chemistry, people are making their own biodiesel at home starting with used chip-shop oil
• germany has thousands of filling stations supplying biodiesel, it is cheaper there than ordinary fuel
• all fossil diesel fuel sold in france contains between 2% and 5% biodiesel

Question 9

Draw the equation for production of biodiesel

Answer 9