H2 Prescence in a Column

alhameli · Apr 18, 2025

We are having a 24m by 2.6"m structural column where we would like to have some refurbishment activities (including cutting/welding etc...) on the column, however we have found a presence of hydrocarbons (H2 and H2S) and we are not certain of the concentrations.

We would like to displace/remove the hydrogen, using Nitrogen is not possible due to the volume required and with only four 10mm holes drilled is not feasible. Adding water from the top might introduce static electricity which might lead to a reaction with hydrogen. Are there any other possibilities to inert the column other than N2 or filling with water?

shvet · Apr 18, 2025

Displacing a hazardous gas with an inert foam, often called nitrogen foam inerting.

GD2 · Apr 21, 2025

OP,
Both H2 and H2S are highly flammable and explosive gases. In addition H2S is highly toxic. You need to be extremely careful to take the refurbishment work.

LEL/LFL for both H2S and H2 is 4% in air at room temp.

Limiting Oxygen Concentration (LOC) for H2 is also 4%. H2S has no LOC.

Inerting is a very effective and common method of explosion prevention.
It relies on reducing the concentration of the oxidizer (commonly oxygen in air). Inerting is recommended for mixtures having a very low minimum ignition energy (MIE) such as H2.

Usually, a greater volume of N2 is required than CO2 to reduce the oxygen content.

Your concern for water mixing is genuine. In addition to giving rise to static electricity, you will need to take extra effort to dry the column to prevent corrosion.

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

H2 Prescence in a Column

alhameli

Mechanical

Recommended for you

shvet

Petroleum

Attachments

GD2

Mechanical

Similar threads

Part and Inventory Search

Sponsor