Chapter 18

Read page 296 The beginnings of an industry Australia is about 20 th on the list of world exporters of chemicals, with annual trade worth around US$3 billioin. Over 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. Prevention 2. Elimination 3. Reduction 4. Recycling 5. Treatment 6. 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???