Due to energy consumption growth and especially world attention to clean energy, gas process development is inevitable. One of the main objectives of these processes is the removal of hydrogen sulfide from acid gas of sweetening units in oil and gas refineries. Most of this gas is the hazardous and toxic substance hydrogen sulfide (H2S) that makes up the great harms to the environment and human and nowadays environmental regulations has become more stringent about its emission.
The use of sulfur recovery process for converting toxic hydrogen sulfide to elemental sulfur has been common since decades ago. Elemental sulfur is used in chemical, agriculture, health and military industries.
Due to environmental issues, H2S and SO2 emissions even as low values are not permitted. Therefore, in the absence of this unit operation of refineries is not possible. So, the development, design and construction of this plant in order to localize the process and avoiding the frequent purchase of foreign license is necessary.
In this plan, using of different sources of information, the design and construction of sulfur recovery pilot plant through reverse engineering is done and technological information and bottleneck of the process is found in the shortest time. Finally with know-how access, basic design of industrial units of National Iranian Gas Company (NIGC) is done.
Also, by production the required catalysts of the process and physical, chemical, mechanical and reactor testing, catalyst manufacturing know-how package is prepared and presented for manufacturing on industrial scale.
Since most of the Iranian gas reservoirs are sour, this process is widely used and there are SRU units in seven oil refineries (Abadan, Arak, Esfahan, Tabriz, Tehran, Bandar Abbas and Shiraz), Shahid Hasheminejad and Ilam Gas Refineries, Razi and Kharg Petrochemical Complexes and most of the South Pars phases.
So with the localization of this technology oil and gas refineries can use domestic license for this plant. On the other hand, the knowledge gained can be used for troubleshooting and optimization of available units.
As mentioned, the purpose of this study is the localization of sulfur recovery process know-how.
In the first phase of the study, know-how of the catalyst manufacturing is localized through formulation of different catalysts (alumina, promoted alumina,Titania and TGT catalyst) on the scale of 200 kg with properties similar to or better than foreign samples.
In the second phase, the basic design of first SRU for Bidboland gas refinery with the capacity of 160 tons per day was done and it was selected as a top project in Research and Technology Festival of Oil Ministry (2014).
In the third phase, process and equipment design of Claus and TGT (Tail Gas Treatment) Pilot Plants was done to develop the know-how. These pilots will be installed and started up in Hasheminejad Gas Refinery.
Another goal of the Localization is the manufacturing of certain equipment such as reaction furnace, condenser and reactor that is being finalized
Prevent the outflow of currency:
All current sulfur recovery units at Iran oil and gas refineries have been designed and built with foreign license and to make these units with a capacity of 100 tons per day about $30 million investment is required.
The localization of know-how of the process and equipment design will prevent the outflow of currency.
With the completion of all phases of this study ,commercialization of the technology will be done by RIPI and the supporting of NIGC in near future that can offer the following services:
SRU Know-how including Acid Gas Enrichment (AGE), Claus and TGT with sulfur recovery of %99.5
Basic design of SRU
Special equipment design and manufacturing by selected companies
Manufacturing of promoted catalysts for refineries
Troubleshooting of SRU in the refineries
Increasing recovery of existing units by TGT unit design and construction
As mentioned, the SRU license has been purchased abroad.
Furthermore, most of the costs related to its equipment have been outsourced. The localization of know-how and manufacturing of equipment within the country will have a lot of savings.
This plan is done through the support of Research & Technology Management of NIGC as the client and developed know-how is divided equally. NIGC has confirmed the design and in a common letter of RIPI director and NIGC manager to Oil Minister, RIPI's capability on SRU design was stated and suggested to deliver new units design to RIPI. Based on oil minister order, six engineering companies evaluated the capabilities of RIPI for SRU design and approved it.