Solid Bed H2S Scavenger Unit is designed to remove hydrogen sulfide effectively and safely from natural gas stream in oilfield facilities.  Solid Bed H2S Scavengers are ideal solution for gas processors to lower H2S amount and export trough pipelines protecting personnel and downstream equipment from hazardous and highly corrosive hydrogen sulfide.

Unlike liquid H2S scavengers, solid scavengers are applied in batch mode.  Sour gas (H2S-contaning gas) usually flows from well site 2-phase or 3-phase separator and enters Solid Bed Scavenger Units, which consists of inlet separator (vertical gas-liquid separator), one or two process columns, which contains adsorbent beds, dry gas filters, instruments, sampling ports and sampling kit, operator platform and other system components specified in either in HC’s technical proposal or client’s requirements. As shown in given charts by HC Petroleum Equipment, all free liquids shall be removed from feed sour gas, as iron sponges require dry gas for quality H2S-removal performance. Liquid droplets present in the gas blocks porous structure of iron sponge slowing down its performance. For this reason, gas-liquid inlet separator is required. 

After gas-liquid separation, sour gas enters process columns from the top nozzle, and flows downwards. In process column, when sour gas flows downwards, hydrogen sulfide reacts with iron sponge, forming iron sulfide and water. As H2S trapped in the sponge bed, sweet gas (H2S-free gas) flows out from the sponge bed. At downstream, dry gas filters may be used to filter small participles and dust of iron sponge. HC offers solid bed scavengers both with dry gas filer and without, based on the client’s requirements. Water, which is produced after H2S reacting with iron sponge is accumulated at the bottom of the process columns, and drained. Gas sweetening system by iron sponge process also consists of flowline valves, relief valves, process gauges, sampling ports and sampling system (optional) and other auxiliary parts required by the project.

Level of control and automation depends on the client’s operational characteristics and budget. Equipment can be designed with manually operated valves, instruments with indication functions, while fully automated system is also available. In fully automated system, several transmitters, control valves, valves with actuators, electrical and signal devices can be included, which can increase total cost price. Being flexible and experienced company, HC Petroleum Equipment can offer both manual and automatic type of control for the gas sweetening system.

Two tower process

Usually iron sponge gas desulfurization units are supplied with two towers, A and B. In practice, tower A is active and removes H2S, while tower B is standby or under regeneration process. Another operational option offered by HC Petroleum Equipment is applying two towers work simultaneously. Two towers are used simultaneously in case of high ppm content of H2S or high flowrates. 

Single Tower Process

Iron sponge gas desulfurization units sometimes supplied with single column, based on the requirements of the client. HC Petroleum Equipment offers both options with single tower and dual tower. 

Sponge Bed Regeneration

Iron sponge can be regenerated achieving around 50%. Regeneration is conducted by directing air upwards from the column bottom to the top nozzle. Additional nozzle for regeneration can be added to the configuration of the column or relief valves’ nozzle can be used with proper design. HC will provide PFD and P&IDs showing the flowlines and configuration of the system.

In practice, most companies usually replace spent sponge bed with new iron sponge, safely disposing spent beds. Replacement of spent iron sponge is simple but still very meticulous process, which requires to be handled by professionals with experience and qualifications. HC Petroleum Equipment will provide necessary documentation and manuals to handle spent sponge bend properly.

Size and configuration of the gas sweetening units by iron sponge process depends on several factors, such as flowrate, operating pressure, amount of H2S, etc. Please send your requirements and oilfield conditions to HC Petroleum Equipment to get the best suitable and cost-effective solution for oilfield gas sweetening. Another option is sending a request to HC, we will provide our data sheets for you to fill.

HC Petroleum Equipment designs and fabricates Iron Sponge Gas Sweetening System in own workshop located in Dongtai city, China. Our specialized production and assembly facility ensure fabrication, test, and inspection of the vessel as per ASME, PED and GB standards. Flowline parts will be ANSI rated and tested as per codes and standards. Construction of process flowline equipment shall be appliable in H2S-containing environments. HC Petroleum Equipment will comply with NACE MR0175 / ISO 15156 standards.