Chemistry 30 Lesson 4-07 Page 1© 2012 T. de Bruin

Chemistry 30 Notes – Hydrocarbon Refining

· Petrochemicals are the basic hydrocarbon raw materials, such as ethene and propene that are used tomake plastics and other synthetic materials.

· Crude oil is the unprocessed complex oil mixture that is pumped from oil wells. It consists of hundreds ofdifferent compounds that must be separated.

· Fractional distillation is the process of separating the components (called fractions) of the crude oil bydifferences in boiling points (London Force).

o The crude oil is heated to high temperatures inside a large fractionating tower and vapourizes. Asthe hot gases rise up the tower, they start to cool off, condense back into liquids at variouspoints up the tower and are collected.

· Many of the fractions are further processed into other compounds using one of two methods:o Longer chain hydrocarbons can be split (“cracked”) into smaller pieces by a process called cracking.

§ Steam cracking uses high temperature steam to break carbon-carbon bonds.§ Catalytic cracking uses lower temperatures and catalysts to break carbon-carbon bonds.§ Hydrocracking is the process of adding hydrogen gas to either steam or catalytic cracking

to produce alkanes. This prevents the formation of double bonds.o Reforming uses heat, very high pressure and catalysts to convert straight-chain alkenes into

branched-chain alkanes, cyclic alkanes and aromatics.· Complete the following problems from your textbook:

o p. 584 #6-22