Industrial Chemistry (General Principles) and Industrial Visits

4.1 Introduction

It is recommended that students taking option 1A should visit a local chemical industry. The industrial visit should involve consideration of each of the following, as far as they are relevant to the industrial process concerned:

  • feedstock
  • rate
  • product yield
  • co-products
  • waste disposal and effluent control
  • quality control
  • safety
  • costs
  • site location
  • suitable materials for the construction of a chemical plant
  • type of process
  • uses of products
  • skills and expertise of work force
  1. FEEDSTOCK
    The reactants in an industrial process are called the feedstock. Feedstock is produced from the raw materials. In the industry visited, the raw materials should be identified, and the purification or chemical treatment of the raw materials should be studied.
  2. RATE
    The temperature, pressure and catalyst for the process should be noted, and the way in which each of these contributes to a satisfactory rate should be understood.
  3. YIELD
    The conditions chosen must be such as to result in a satisfactory yield. How the temperature, pressure and catalyst for the process each contribute to a satisfactory yield should be understood. If the reaction is reversible and the required reaction is exothermic, the conditions that give rise to a high yield may greatly reduce the rate, and vice versa. This leads to a compromise in choosing the reaction conditions.
  4. CO-PRODUCTS
    Any co-products formed in the process should be noted, and the separation of these from the main product, and their disposal (or sale), should be studied.
  5. WASTE DISPOSAL AND EFFLUENT TREATMENT
    The methods used to dispose of any solid and gaseous waste produced in the process should be studied, as well as the methods of effluent treatment.
  6. QUALITY CONTROL
    The methods of quality control used should be studied only to the extent that they relate to the instrumentation referred to elsewhere in the syllabus (see data on instrumentation in section 3).
  7. SAFETY
    The site and layout of the plant should be studied with regard to safety considerations. Safety features incorporated in the plant, on-site training of the staff and the monitoring of hazards should also be noted.
  8. COSTS
    Fixed costs are those that have to be paid regardless of the rate of production. These include labour costs, plant depreciation, land rental and repayments on loans. Variable costs are those that depend directly on the level of plant output. These include the cost of heat, electricity and the raw materials.
    The fixed costs and variable costs pertaining to the process studied should be noted (qualitatively), as well as the costs of waste disposal. Methods that are used to reduce costs should also be studied. These include some or all of the following: use of heat exchangers, use of catalysts, recycling of feedstock and selling of useful co-products.
  9. SITE LOCATION
    Chemical industries are often established near the source of the raw materials or near a market for the product. The local availability of water can also be important. The availability of a suitable work force, and of transport for raw materials and products, are also important considerations. For the process being studied, the reasons for the location of the plant at that particular site should be determined.
  10. SUITABLE MATERIALS FOR THE CONSTRUCTION OF A CHEMICAL PLANT
    Plant construction materials must not react with the feedstocks, solvents, catalysts or products involved in the process. The construction materials should therefore be unreactive and resistant to corrosion by the chemicals with which they come in contact. The materials used in the construction of the plant for the process being studied should be noted, and in particular the materials used to construct the reaction vessels.
  11. TYPE OF PROCESS
    Students should note whether a batch process, a semicontinuous process or a continuous process is involved.
  12. USES OF PRODUCTS
    The uses of the products should be noted.
  13. SKILLS AND EXPERTISE OF WORKFORCE
    Employees who are directly responsible for the operation of a chemical plant, such as chemical engineers, chemists and process operators, need to be well qualified and well trained. Students should find out what educational qualifications are needed by different types of employees in the plant and why they are needed. Other types of employees may include accountants, clerical workers, computer programmers, mechanical engineers, biochemists, biologists, physicists, fitters, cleaners, caterers, laboratory technicians, construction workers, transport workers and others.

4.2 Industrial Visits

It is not necessary that the industry visited be one of the syllabus case study industries. Whatever industry is visited, however, the factors discussed above should be kept in mind to the extent that they are relevant to the process concerned.

An industrial visit

  1. gives students an opportunity to experience industrial chemistry at first hand
  2. illustrates parts of the syllabus (especially option 1A.1)
  3. helps students to see the relevance of chemistry.

4.2.1 Preparation for the Visit

To find a suitable chemical plant to visit, and the appropriate contact person, consult The Chemical Industryin Ireland: A Directory for Teachers, published by the Schools Information Centre on the Irish Chemical Industry. If the school is in an area where there is no chemical plant, certain other processes that involve some of the factors to be studied could be considered. These include foodprocessing plants, breweries, dairies, bakeries and water treatment works.

Contact with the firm involved should be made well in advance of the proposed visit. The firm will need to agree and have an understanding of

  • when the visit will take place
  • how long it will take (a maximum of two hours is recommended)
  • how many students are involved
  • how old the students are
  • the level of the students' background knowledge
  • the context of the visit in relation to the syllabus.

Unless the teacher has previously visited the plant, it is recommended that a preliminary visit be made by him or her. In any case, the teacher needs to know in outline what goes on at the plant, in order to prepare the students for the visit. Students should have studied option 1A.1 in advance of the visit and should be given a brief description of the process. They should be encouraged to ask questions during the visit. They could be given a list of suggested questions, such as those in section 4.3. Individual students or pairs of students could be allocated particular questions to ensure that all the information is obtained.

4.2.2 During and after the Visit

For the tour around the plant, the students may have to be split into groups. They should be encouraged to ask questions not only of the guides but of other personnel in the plant. The visit should be followed up at school. Students could write reports, and should certainly complete answers to a list of questions.

4.3 Visiting a Chemical Plant

Possible questions

  1. FEEDSTOC
    • What are the main raw materials used in the plant?
    • Why are these particular raw materials used?
    • How are the raw materials converted into suitable feedstock?
  2. RATE
    • What conditions of temperature and pressure are used in the reaction or reactions?
    • What catalyst, if any, is used?
  3. PRODUCT YIELD
    • Does the choice of reaction conditions represent a compromise between rate and yield?
  4. CO-PRODUCT
    • What are the main co-products?
    • How are they separated?
    • What happens to these co-products?
  5. WASTE DISPOSAL AND EFFLUENT CONTROL
    • What environmental problems are associated with the process?
    • What emission control procedures are used?
  6. QUALITY CONTROL
    • What quality control procedures are used?
  7. SAFETY
    • Are any hazards involved in operating the process?
    • How are they monitored?
    • What safety features and on-site training are used?
  8. COSTS
    • What are the main fixed costs?
    • What are the main variable costs?
  9. RECYCLING OF MATERIALS AND ENERGY
    • Is any material recycled?
    • If so, how?
    • Is any heat energy recycled?
    • If so, how?
  10. SITE LOCATION
    • Why is the plant located at this site?
  11. PLANT CONSTRUCTION MATERIALS
    • What chemical factors affect the choice of materials used in the construction of the plant?
  12. TYPE OF PROCESS
    • Is the type of process used a continuous, semicontinuous or batch process?
  13. USES OF PRODUCTS
    • What are the products?
    • What are they used for?
  14. SKILLS AND EXPERTISE OF WORKFORCE
    • Name four types of employee in the plant.
    • In each case, suggest why they are needed.
    • In each case, state what educational qualifications they need.
 
NCCA, 24 Merrion Square, Dublin 2, Telephone: +353 1 661 7177, Fax: +353 1 661 7180, E-mail: info@ncca.ie