We all deal with sulfur (or sour gas) in our refineries and gas plants. We are striving to meet the maximum sulfur recovery to stay above the government recovery requirements or emission limits. We’re called on to do even more by 2020 with the looming IMO regulations capping sulfur in fuel oil used on board ships at 0.50% m/m.
How do we get there and stay there? While there are dozens of issues we face, there are several problems that most of us have in common.
- Plugging issue (Liquid Sulfur Line) – Inadequate heating is obviously the main reason. Sulfur solidifies below 120°C and turns into a honey-like substance above 160°C, so the best temperature to handle liquid sulfur is between 130°C to 150°C. A 50 psi steam which converts to 147°C is recommended for this service. Steam Trap plays a major role in maintaining the proper amount of heat to the liquid sulfur line.
- Catalyst Deactivation – There are different types of deactivation mechanisms. The most common are Benzene, Toluene, Ethyl Benzene, Xylenes (BTEX). Tthese compounds need to be destroyed. If the reaction furnace is not operating above 1250°C (2282°F), there might be a risk of contaminants breaking through the process, therefore poisoning the catalyst beds.
- Tube Sheet Damage – Usually due to crack refractory which is caused by rapid cooling during the shutdown and rapid heating during startup. If the temperature rate is not controlled, the refractory will experience thermal shock which will result in cracking. Tube Sheet damage will lead to tube leak.
Let’s put together a list of the top ten sulfur recovery issues. I started by listing three. What are the problems you face? Add to the list by posting a comment below or visit us on Facebook, LinkedIn, or Twitter to add your comments there.