Natural gas is a mixture of various hydrocarbon and inorganic gas compounds that have been produced over thousands of years by the de-composition of carboniferous material trapped in underground formations. Natural gas is a combustible mixture of hydrocarbon gases formed primarily of methane (70-90%) but it can also include ethane, propane, butane and pentane. It is colorless, shapeless and odorless in its natural form and is a much cleaner source of fossil fuel. Natural gas is the portion of petroleum that exists either in the gaseous phase or is in solution in crude oil in natural underground reservoirs and which is gaseous at atmospheric conditions of pressure and temperature. Natural gas may include amounts of non hydrocarbons. In order In order to be able to transmit and use this natural gas, it must be processed to remove any undesirable components and render it safe for transmission and consumption. The first process to be carried out is the removal of bulk liquids from the gas stream, utilizing a separation process that removes both hydrocarbon liquids and water, using a simple heat exchange mechanism. Depending on the gas composition, it may then be clean enough to compress and transport to a remote processing plant or may require further processing to remove contaminants such as the inorganic gases and heavy hydrocarbons prior to compression and transportation. Wherever the processing occurs, the objective is always the same – to produce a gas suitable for high-pressure transportation and with the appropriate chemical and physical characteristics to render it suitable for sale and for combustion. The determining parameters in terms of the gas quality are many and varied, but essentially are based around two main criteria – safety and value. In terms of safety, the gas must not be overly corrosive or introduce risk of pipeline, plant or domestic appliance failure. In practice this means that corrosive components such as hydrogen sulphide and carbon dioxide must be removed and that excess water and condensable hydrocarbon content must be reduced to a level that will prevent condensation anywhere in the downstream pipeline system. Removal of water and heavy hydrocarbons is particularly important as an excess of these components, leading to condensation in adverse conditions, can cause hydrate formation within the pipeline leading to excessive pressure drop and potential blocking of the pipe. In terms of value, the equation is simple: the gas is processed to give it the best balance of value (measured by it’s calorific value) against processing cost. Removal of water and heavy hydrocarbons costs money, but both processes improve the value of the gas at fiscal transfer. So control of the water dew-point and hydrocarbon dew-point reduction processes will produce an optimal gas composition that meets the fiscal requirements of seller and buyer and minimizes the safety risks involved in transporting the gas at high pressure.