Carbon compounds and fuels and feedstocks GapFill

The raw material for many organic compounds is  phosphate rockcrude oilviscous nitratecarbonate lubricant, which was formed over millions of years, mainly from the remains of  shellsbonesrocksplankton buried in mud. It is made up of mixtures of hydrocarbons, which contain alkanes with different length chains. The hydrocarbons can be separated into fractions using  filtrationfractional combustionfractional distillationelectrolysis.

Different fractions have different uses, including solvents, lubricants, making polymers and  natural materialselectronicsfuelspigments. When separating the fractions, crude oil enters the column at the bottom and then  crystallisesliquefiescondensesevaporates. Higher in the column, the temperature is  constantly increasingfluctuatinghigherlower, so different fractions condense at different heights in the column, depending on their  boiling pointentropyviscositymelting point.

The length of an alkane chain affects the properties of that alkane. For example, a longer alkane will have a higher boiling point, and will be more  expensiveviscoususefulsaturated and less  densepungentthermally conductiveflammable. Alkanes are often used as fuels, which involves a  polymerisationcombustionslowfermentation reaction, which releases energy. The alkane reacts with oxygen to form  sulfuric acidcarbon dioxideenergyhydrogen chloride and water.

Longer alkanes are often  pressuriseddistilledcrackedburned, forming shorter alkanes and  waterbasesmetalsalkenes. There are two kinds of cracking:

•  incendiary crackingexplosive crackingsteam crackingvolatile cracking, where a high temperature and pressure are used
•  catalytic crackinghydrocarbon crackingactivation crackingcombustion cracking, which uses a high-temperature catalyst