The present application discloses a waste argon separation system capable of reducing emission of cryogenic waste argon. The waste argon separation system capable of reducing emission of cryogenic waste argon includes a valve bank, at least two adsorption towers, sewage discharge channels having at least the same number as the adsorption towers, a gas inlet component, and at least one argon reflux component. The valve bank includes a gas inlet valve, an analytic control valve, and at least two sewage discharge valves. The top of each of the adsorption towers is provided with an argon-rich gas outlet, and the argon-rich gas outlet at the top of each of the adsorption towers is connected to each other to form a regeneration channel. The argon-rich gas outlet at the top of each of the adsorption towers is further connected to an argon-rich gas outlet channel.

An apparatus and process for argon recovery can be configured so that an argon-enriched stream including oxygen therein can be recycled to a column for air separation and subsequent argon separation to provide improved argon recovery with reduced power. The recycling of this argon-enriched stream can be provided such that there is sufficient nitrogen within the column to facilitate separation of argon from oxygen within the column so additional argon that can be provided via the recycling can be separated and purified instead of being output as a waste stream or otherwise lost.

A system and method of ultra-high purity (UHP) oxygen production from an argon and oxygen producing cryogenic air separation unit incorporating a dedicated methane rejection column or column section having a liquid to vapor (L/V) ratio lower than the L/V ratio in the associated argon rectifier is provided.

An air separation apparatus comprises: a first rectification column, a first condensing portion, a second rectification column, a third rectification column, a second condensing portion, a fourth rectification column, a third condensing portion, and a recycling pipe for recycling a gas drawn from the third condensing portion to the second rectification column. The air separation apparatus furthermore comprises: a branch pipe branching from the recycling pipe; and a control unit for controlling opening/closing of a valve so that a gas drawn from the third condensing portion is fed to the branch pipe for a predetermined period from the start of driving of the third condensing portion, and for controlling opening/closing of the valve so that the gas drawn from the third condensing portion is fed to the recycling pipe after the predetermined period has elapsed.