Chapter 18

• Read page 296 The beginnings of an industry

• Australia is about 20th on the list of world exporters of chemicals, with annual trade worth around US$3 billioin.

• Over 40 000 Australians are employed directly in the industry.

• Overall about 1 person in 10 are employed in a job either directly or indirectly related to the chemical industry

• A range of different skills and qualifications are required by industrial chemists.– Chemical engineers – constantly supervise the

operation of the plant, solve production problems, develop modifications to the existing plant and assist in the design of new projects.

– Analytical chemists – are concerned with quality control, providing analysis of raw materials, products and emissions and problems, develop modifications to the existing plant.

– Research chemists – undertake research on new processes and new materials and develop new analytical techniques

The extent of conversion of raw materials to product is influenced by reaction conditions such as temperature, pressure and concentration.

To avoid waste and reduce costs, conditions are carefully selected to ensure that acceptable yields of product are obtained.

Chemists therefore try to ensure that: The reaction rate is fast A high proportion of reactants is converted to

products at equilibrium Turn to table 18.1 on page 299 There is often a need to compromise

between rate and equilibrium considerations.

Is one of the two main ways that reactions are controlled in industry.

It is the method used when fixed amounts of reactants are mixed, giving fixed amount of products.

It is used when there are low costs or negligible delays in starting or stopping productions, for one-off productions and small quantities of product.

Reactants are mixed continuously, providing a constant supply of product.

This technique uses smaller, less expensive equipment than batch processing.

Is the preferred method when there are high costs or long delays in starting or stopping production.

It allows greater control over reaction conditions, especially temperature, than batch processing.

Other factors that influence the final choice of reaction conditions. Catalyst – a less expensive one may be

preferred to a more efficient one Pressure – high-pressure reaction vessels are

costly to build and operate Temperature – fuel costs rise rapidly as

operating temperatures increase Choice of reactant to use in excess Safety and waste minimisation and disposal.

The safest option is not always the cheapest Energy costs

Page 301 Question 3, 4 and 7

This is the area of employee safety. Australia has laws that enforce a duty of

care by organisations that supply or use chemicals.

Penalties for negligence that results in someone’s death or serious injury can include hefty fines or imprisonment.

Dangerous goods have the potential to pose immediate danger to people, property or the environment.

Examples of dangerous goods include Petrol Pool chlorine Ammonium nitrate fertiliser.

Turn to page 302 for the HAZCHEM signs

Hazardous substances are classified on the basis of their short- and long-term effects on the health or safety of people.

Some such as a asbestos may cause illness or disease some time after exposure.

Over 2000 Australians die each year as a result of exposure to hazardous substances.

Warning signs about dangerous goods are required at any site where they are used or stored.

A risk assessment is a formal way of identifying risks and assessing potential harm from a hazardous chemical in a particular situation.

Effective risk management reduces exposure to hazardous chemicals to at least acceptable levels.

Victoria’s OH&S regulations require schools to perform a risk assessment for each activity using hazardous chemicals

Risk assessments should include Identification of hazardous chemicals

(products as well as reactants) Assessment of the risk Control of the risk (how do we minimise the

risk and disposal) documentation

Manufacturers have to supply MSDS for hazardous substances.

An MSDS needs to provide: Company name and contact details Scientific and trade names Major uses and applications Physical data (appearance, colour, boiling point,

solubility etc) Health effects Treatments Precautions Safe handling Date of publication

Page 306 Question 9

A waste is considered as an unwanted or unvalued substance that is discarded or discharged.

Wastes occur as: Contaminated soil and solids Organic liquids of low volatility Wastes containing high volatile liquids Solid and semi-soli process materials Aqueous wastes Sludges, spillages Products past their used-by date

Hazardous waste may be toxic, radioactive or contaminated by disease-causing organisms

Industrial waste treatment technologies now go beyond landfill and dumping at sea.

They include high-temperature incineration and vitrification.

Other options still under development include: Dispersion in controlled amounts in water or air Removal of pollutants from waste gases and liquid Storage in sealed drums in secure locations Catalysed dechlorination Ionic replacement of halogens in halogenated

organic compounds High-temperature steam and water treatments

Chemical industries aim to deal with wastes in the following strategic order of priority:

1. Prevention2. Elimination3. Reduction4. Recycling5. Treatment6. Disposal

Page 310 Question 12, 14 and 17

What kinds of things would you need to consider when deciding on a location for a chemistry plant???