CHAPTER 5. THE CHEMICAL INDUSTRY 5.2
DEFINITION: Fractional distillation
Fractional distillation isthe separation of a mixture into its component
parts, or fractions. Sinceair is made up of a number of gases (with the
major component beingnitrogen), fractional distillation can be used to
separate it into these different parts.The syngas is then passes through a Sasol Slurry Phase Distillate (SSPD) process.
In this process, the gasis reacted at far lower temperatures than in theSAS re-
actors. Apart from hardwax and candle wax, high quality diesel can also be
produced in this process. Residual gas from theSSPD process is sold aspipeline
gas while some of the lighter hydrocarbons aretreated to produce kerosene and
paraffin. Ammonia is also produced, which canbe used to make fertilisers.FACT
Sasol is a major player in
the emerging Southern
African natural gas
industry, after investing
1.2 billion US dollars
to develop onshore
gas fields in central
Mozambique. Sasol has
been supplying natural
gas from Mozambique’s
Temane field to cus-
tomers in South Africa
since 2004.Exercise 5 - 1
Refer to the diagrams summarising the three main Sasol processes, and use these to
answer the following questions:
- Explain what is meant by each of the following terms:
(a) crude oil
(b) hydrocarbon
(c) coal gasification
(d) synthetic fuel
(e) chemical feedstock - (a) What is diesel?
(b) Describe two ways in which diesel can be produced. - Describe one way inwhich lighter chemicalproducts such as ethylene, can be
produced. - Coal and oil play animportant role in Sasol’stechnology.
(a) In the table below, summarise the similaritiesand differences betweencoal,
oil and natural gas in terms of how they are formed (’origin’), their general
chemical formula and whether they are solid, liquid or gas.
Coal Oil Natural gas
Origin
General chemical formula
Solid, liquid or gas
(b) In your own words,describe how coal is converted into liquid fuels.
(c) Explain why Sasol’s’coal to liquid fuels’ technology is so important inmeet-
ing South Africa’s fuel needs.
(d) Low grade coal is used to produce liquid fuels. What is the mainuse of
higher grade coal in South Africa?
More practice video solutions or help at http://www.everythingscience.co.za(1.) 01rf (2.) 01rg (3.) 01rh (4.) 01ri