M8 Green Chemistry processes and practices

Question 1

What is green chemistry

Answer 1

the design, development and implementation of chemical products and processes which reduce, or eliminate, the use of hazardous substances, that could harm people or the environment

Question 2

What chemical products and processes are considered for chemical manufacturing to follow green chemistry principles (12)

Answer 2

• Prevent waste
• Atom Economy
• Less hazardous chemical synthesis
• Design safer chemicals
• Use safer auxiliaries
• Energy efficiency
• Use renewable feedstock
• reduce derivatives
• Use Catalysts
• Design products to degrade
• Real Time analysis and monitoring
• Accident prevention

Question 3

How do chemical manufacturing businesses prevent waste

Answer 3

• Instead of treating and cleaning the waste (very expensive)
• Prevent waste through atom economy

Question 4

How do chemical manufacturing businesses manage atom economy

Answer 4

By ensuring that all materials used in the process are incorporated into the final product or is used to make another product

ie anti inflammatory drug ibuprofen

• old method, 6 steps, low atom economy at 40.1%
• New method, 3 stage, high atom economy 77.4%

Question 5

How do chemical manufacturing businesses ensure Less hazardous chemical synthesis

Answer 5

By managing the use of substances and the products produced have little or no toxicity to humans and the environment, where possible

ie antifouling chemicals (prevent the growth of organic subaquatic organism on a boat)

• initaly was very toxic and persisted in the environment
• replaced with low life span toxins that exist only for a few hours, minimising the risk to marine life

Question 6

How do chemical manufacturing businesses design safer chemicals

Answer 6

• ensure a balance between efficiency and toxicity, to ensure it can still be used and has a minimised risk

Question 7

How do chemical manufacturing businesses use safer auxiliaries (2)

Answer 7

• minimise use of auxiliary substances (solvents and separation agents) due to being highly volatile and flammable, toxic and explosive
• introduction of a green solvent, should be non-toxic, inexpensive, readily available and work well

Question 8

How do chemical manufacturing businesses ensure energy efficiency (2)

Answer 8

• minimising energy requirements in order to have little impact as possible on the environment and economy
• wherever possible allow synthesis to occur at ambient temperature and pressure to prevent the use of energy

Question 9

How do chemical manufacturing businesses use renewable feedstock

Answer 9

• Ensure raw materials and fuels (feedstock) should be renewable wherever it is technically and economically practicable

ie biofuels, biodegradable polymers

Question 10

How do chemical manufacturing businesses reduce derivatives

Answer 10

• By avoiding unnecessary production of byproducts wherever possible, by decreasing the amount of steps in production (by making it more direct

ie Penicillin
- use of enzymes as biocatalyst makes a more direct production process and are biocompatible

Question 11

How do chemical manufacturing businesses use Catalysts (2)

Answer 11

• use them to speed of up production by providing a alternate pathway (lower activation energy) for breaking and making bonds
• collect clean and reuse them

Question 12

How do chemical manufacturing businesses design products to degrade

Answer 12

• design them so that they degrade after fulfilling there purpose, rather than persisting in the environment causing unintentional damage

Question 13

How do chemical manufacturing businesses use real time analysis and monitoring

Answer 13

-in order to prevent the formation of hazardous substances analytical methodologies are developed to monitor and control

Question 14

How do chemical manufacturing businesses achieve accident prevention

Answer 14

• substances and their form are used to minimise the potential for chemical accidents ie releases, explosions and fires