Because of the volatility and boiling temperatures of these streams, high pressure containers are needed to store the streams in liquid form. LP Gas is unique in that it can be stored in liquid form, but when its use is required, they will vapourize back into a gaseous state with all the benefits of the fuel gas or feedstock characteristics..
Methane (and ethane not used as a chemical feedstock) is usually never stored in a refinery but is sent directly to the fuel system as it is produced. There are some surge drums in the system which can accumulate some of the gaseous methane for short periods of time during operating changes.
Propane and butanes (and sometimes ethane) can be stored in steel storage or in underground storage. Underground storage takes one of two forms: caverns mined in rock, shale or limestone or jugs leached out of salt in underground salt domes.
A mushroom-shaped or plug-shaped diapir made of salt, commonly having an overlying cap rock. Salt domes form as a consequence of the relative buoyancy of salt when buried beneath other types of sediment. The salt flows upward to form salt domes, sheets, pillars and other structures. Hydrocarbons are commonly found around salt domes because of the abundance and variety of traps created by salt movement and the association with evaporate minerals that can provide excellent sealing capabilities.