what is the difference between fractional distillation and destructive distillation?
Fractional distillation is a method used for separating two miscible liquids. Separating funnel on the other hand is a lab apparatus which is used to separate a mixture of two immiscible liquids.
In fractional distillation a mixture containing two or more liquid, which do not differ much in their boiling points are separated, by heating them. The liquids change into vapours at different temperatures and are passed through a fractionating column, where the vapours of constituent liquid condense to form the liquid at different temperatures. Vapours of a liquid mixture are passed through a fractionating column (fitted over the mouth of the round bottom flask) before condensation. As liquids have different boiling points, they will vapourise and hence condense at different temperature.
destructive distillation-the process of separation which is based on heating process 2.this process is mainly applied to solid components for example from destructive distillation of coal we mainly get coal gas,coal tar and coak .
Destructive distillation is the chemical process involving the decomposition of feedstock by heating to a high temperature; the term generally applies to processing of organic material in the absence of air or in the presence of limited amounts of oxygen or other reagents, catalysts, or solvents, such as steam or phenols, it is an application of pyrolysis. The process breaks up or'cracks' large molecules. Coke, coal gas, gas carbon, coal tar and ammonia liquor are examples of commercial products of the destructive distillation of coal.
Fractional distillation is used when the boiling points of chemicals in a mixture are close to each-other, usually within 77°F (25°C). In this method, heat is added to the mixture until it begins to boil. The gas, usually purer than the mixture but still containing all of the chemicals, then travels up into a fractionating column. The fractionating column blocks the gas from directly rising by putting a large amount of surface area in its way, either by using a series of trays or plates, or by filling the entire column with packing material. The rising gas then condenses on the trays or other materials and becomes a liquid. The rising gases from below, however, heat this liquid again, causing it to distill again, and an even purer gas travels up to the next level of the column. Eventually, the gas makes it out of the fractionating column, is cooled to liquid, and empties into a receiving vessel.