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•   Name 3 compounds released during combustion of fossil fuels which are harmful to environment and health

   fine dust, nitrogen oxides, ozone (heavy metals and volatile organic compounds)

•   Name 5 alternative forms of energy which are considered as renewable alternatives to fossil fuels, and indicate why these are more sustainable

  solar energy, wind energy, water energy (hydropower), hydrogen gas, biomass.
  nuclear energy is MORE sustainable than fossil fuels, but less than the others

•   Explain the difference (give three reasons) between the 1st and 2nd generation of biofuels, and give an example for each

  1. 1st generation biofuels are made of food products, while 2nd generation biofuels are made of waste biomass (that which remains after a crop is harvested)
  2. 2nd generation biofuels are much better for the environment (reduction potential of CO2 is up to 90% vs 50% of the 1st generation)
  3. 2nd generation biofuels  take less land to produce
  4. most governments now only subsidize the 2nd generation and not the first.

  
  example of 1st generation: rape seed, corn, Sugar cane, soy beans palm oil
  example of 2nd generation: woody non edible parts of plants, grasses and trees

•  Explain in the context of renewable energies the usefulness of the Fischer-Tropsch technique, and indicate which two compounds are needed for the production of what?

  CO+H2-> Liquid hydrocarbons. this is useful because it produces biofuel out of usually useless compounds

•   Name 6 renewable materials currently in use in the construction industry, and give an example of its application or function

  1.  timber->beams
  2. flax->decking material
  3. cellulose->fibers, increasing tensile stress in construction
  4. hemp->hempcrete (insulation)
  5. wool->insulation
  6. straw_>used as roofing material
  7. coconut->used as wood(timber)
  8. fiber and wool->used for insulation
  9. reed->used as roofing material

•  The construction industry uses raw materials and energy, and produces greenhouse gasses thus affecting the environment. For what percentage does the construction industry account worldwide for 1) raw material resource consumption, 2) energy consumption, 3) greenhouse gasses emission? Is that 10, 20, 30, 40, 50, 60%? Choose a value for each category

  1) 50%               2) 40%                3) 20%

•  Which two raw materials are required in bulk for the production of ordinary Portland cement? What are the two main products formed after the reaction of cement with water?

  • limestone and clay
  • C-S-H & C-H

•  Which ingredient of a concrete mixture is by far the least sustainable compound?

  cement

•  Name 2 natural and 2 (industrial) ‘waste’ or by-products that can be used to partially replace cement in concrete. What is the chemical compound that makes these products particularly suitable to replace cement in concrete? What is a requirement for these compounds to act as binder in concrete?

  natural: meta kaolin, volcanic ashes, rice husk ash
  Industrial: blast furnace slag, silica fume, fly ash
  
   an extra alkaline activator such as calcium hydroxide is needed to make the system work.

•  What is the main difference between a Geopolymer system and ordinary concrete?

  in a geopolymer system all OPC is is replaced by and Industrial by-product such as fly ash.