5.7: Green chemistry in industry

Green chemistry is an uprising form of chemistry, with an objective to have minimal negative environmental impact

Green chemistry practices include:

-selecting renewable, non-toxic,or recycled materials

-considering the end of the product's life

-The 5 principles of green chemistry can be applied to manufacturing processes to make them 'greener'

-Primary idea behind green chemist is: why generate pollution if there is a greener (less polluting) alternative?

-A green manufacturing process includes each step being designed to have minimal environmental impact

->Process known as 'benign by design'

There is always a way that a manufacturing process can improve. The plastic industry is considering some improved materials as starting materials.

-Adipic acid is a key ingredient in the making of plastic

-It is produced globally in millions of tonnes

-Adipic acid production starts with the making of Benzene

-Problem: Benzene comes from oil (non-renewable), and is a carcinogen

-Solution: Chemists came up with an alternative for Benzene, which is glucose

-Glucose comes from starch-rich foods, and is renewable

-The catalyst that allows for this alternative is modified E.Coli bacteria

The manufacturing process often includes a step that harms the environment.

The polystyrene industry searched for a better option.

-Polystyrene is used to manufacture foam packaging products

-Process;

->inject liquid polystyrene into mold

->A gas (expanding agent) injected to expand polystyrene, to fit mold accordingly

-CFCs used to be used as 'gas' but since they harmed the ozone layer, chemists developed a process that CO2 can be used

-CO2 is cheaper, and non-polluting, but adds to greenhouse gasses so is not completely benign

A catalyst makes a chemical reaction faster, without being consumed in it

Speeding up the production of sulfuric acid

->Process is called the 'contact process'

->Pure sulfur is transformed into product after 3 steps

1) " " is burned

2) " " is oxidized, and is in contact with Vanadium pentoxide (catalyst)

3) " " is bubbled into concentrated sulfuric acid

->Normally the reaction is slow, but catalyst helps speed up the process

The excess use of energy affects industries financially, and environmentally. Therefore, they are looking into ways of being more resourceful

-Updating old equipment helps reduce energy costs

-Furnace upgrades can also result in a reduction of air pollutants, and greenhouse gasses

-Although a new blast furnace may cost millions of dollars, it is cheaper in the long run when you increase productivity, and have decreased costs.

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5.7: Green chemistry in industry

Principle 4: use less energy

Principle 3: Use catalysts to increase reaction efficiency

Principle 2: use chemicals that have less environmental impact

Principle 1-Use renewable resources as starting materials

How it applies to industries

What is green chemistry?