US 6,547,861 B2 · Method and materials for purifying reactive gases using preconditioned ultra-low emission carbon material

Abstract

Trace impurities such as organic compounds and carbon monoxide in reactive fluids such as ammonia, hydrogen chloride, hydrogen bromide, and chlorine are reduced to sub-ppb levels using gas purifying systems that contain a preconditioned ultra-low emission (P-ULE) carbon. P-ULE is capable of removing impurities from a reactive fluid down to parts-per-billion (ppb) and sub-ppb levels without concurrently emitting other impurities such as moisture or carbon dioxide into the purified reactive fluid. The P-ULE carbon is prepared by heating a carbon material to temperatures from 300° to about 800° C. in an ultra-dry, inert gas stream, to produce an ultra-low emission (ULE) carbon material, subjecting the ULE carbon to a second activation process under a reactive gas atmosphere to produce a P-ULE carbon and storing the P-ULE carbon in an environment that minimizes contamination of the P-ULE prior to its use in a gas purifier system.

Claims23

Dependent claims

A preconditioned ultra-low emission carbon material capable of removing contaats from a reactive fluid to produce a purified reactive fluid without concurrently emitting moisture into said reactive fluid being purified such that the concentrations of said contaminants in said ultra-pure reactive fluid are less than 100 parts-per-billion, and wherein said preconditioned ultra-low emission carbon material is store in a substantially non-contaminating environment until contacted with said contaminated reactive fluid.

A preconditioned ultra-low emission carbon material for removing contaminants from a reactive fluid, said carbon material produced according to the method comprising:

a) placing a carbon material containing trace amounts of water in a reactor having a gas inlet and a gas outlet;
b) heating said carbon material in said reactor for at least twenty four hours at a temperature between about 300° C. and 800° C. under a flow of ultra-dry inert gas;
c) measuring the concentration of water in said inert gas exiting said reactor;
d) terminating said heating when the concentration of water in said inert gas exiting said reactor is below about ten parts-per-million, whereby an ultra-low emission carbon material is produced;
e) purging the ultra-low emission carbon material with an ultra-purified reactive gas at room temperature for a specific period of time;
f) heating the ultra-low emission carbon material under the ultra-purified reactive gas purge at a temperature range of about 500 to 400° C. for between a few hours and a few days, thereby producing a preconditioned ultra-low emission carbon material;
and
g) maintaining said preconditioned ultra-low emission carbon material in a substantially non-contaminating environment.

5 more elements

Dependencies are inferred from the claim text.

Method and materials for purifying reactive gases using preconditioned ultra-low emission carbon material

Life of this patent

Method and materials for purifying reactive gases using preconditioned ultra-low emission carbon material

Life of this patent

Abstract

Claims23