Refining Community Logo

Incinerator’s refractory and shell damage due to condensation in TGTU absorber overhead line

By: Alya Al Ali, Process Engineer; Muhammad Nisar, Senior Process Engineer; and Ravi Sernivas, Manager, Engineering Services, ADNOC

The following was summarized from a presentation given at a recent Sulphur + Sulphuric Acid Conference by Alya Al Ali, Muhammad Nisar, and Ravi Sernivas of ADNOC. The paper highlighted ADNOC Sour Gas SRU’s Incinerator Refractory and shell damage root causes and remedial actions taken to avoid recurrence of the problem, thereby helping other refiners and companies to avoid a similar problem in their own units.


ADNOC Sour Gas is the largest single Sulphur production plant in the whole region, producing more than 12,000 tons of liquid Sulphur every day. TGTU is to treat the Claus tail gas from the upstream SRU to meet the emission specifications. The Incinerator (0751-H-201) oxidizes the off gas streams mainly from TGTU Absorber (0751-V- 202) overhead during normal operation using fuel gas and combustion air.


The objective of this paper was to share ADNOC Sour Gas’s root cause analysis study conducted for investigation of damage in the Incinerator Refractory and Shell. Furthermore, this paper also highlighted the remedial actions taken to avoid recurrence of this incident that posed ~15 days’ production loss.


Root cause analysis study helped to analyze the whole system and consider all potential sources of water carry over to Incinerator. TGTU Absorber overhead gases composition contains 7% water vapors and operate on equilibrium. TGTU Absorber overhead line was uninsulated and is 104 meters in length before it reaches to incinerator. Thermal survey indicated drop in temperature (1~2 0C) from Absorber overhead to Incinerator inlet. This drop in temperature was causing water condensation inside the line. In case of liquid water formation/carryover from the TGTU Absorber overhead, both H2S and CO2, from different sources can be corrosive as individual compounds, but the chemical reaction between these species, with or without the participation of Sulphur, has the potential to produce both sulphurous acid (H2SO3) or carbonic acid (H2CO3). Both have the potentiality to generate weak acids that can attack the refractory at the bottom part of the inlet nozzles.

Deterioration of calcium aluminate cement (CAC) bonded refractory structures subjected to acidic water is often characterized by the leaching of calcium from hydrates as mentioned on API TR 978. This reaction affects the mechanical properties of the refractory and promotes degradation of the refractory layer enhanced by the gases/liquid fluids.

In order to enhance the lifetime of the insulating refractory materials for the inlet nozzle applications the following shall consider:

Download the full presentation below:

Leave a Reply

Your email address will not be published. Required fields are marked *

Posted by: The Refining Community

Refining Community