Methds to increase Performance of Activated Carbon Filters in 4 gas sweetening units in South Pars Gas Complex, Phases 2&3

One of the main problems in 4 gas sweetening units in pheses 2,3 of south pars gas complex, is contamination of amine solution by hydrocarbon. A liquid coalescer system is provided upstream the absorber column in order to avoid hydrocarbon liquid entrainment. Some of the hydrocarbon is seperated from amine solution in rich solvent flash drum ,located downstream of absorber, but Complete separation of hydrocarbon from amine solution to be carried out in Amine Filtration Package which is equipped with a charcoal filter. The Dr.Mouller filtration package is used.In this work, several samples from inlet and outlet of charcoal filter were taken and analysed during several months. Analysing demonestrated, relation between poor efficiency of charcoal filter and following problem of 4 gas sweetening units : • Increasing foam tendency in H2S absorption column which lead to high presser drop and reducing H2S removal from sour gas • Increasing Anti foam consumption • Amine lost during foaming in absorber column• Contamination of Amine solution • Unwanted flash gas flaring with high concentration of H2S • Increasing steam consumption in Amine regeneration section• Hydrocarbon carry over from regenerator top product to sulfur recovery unit and aromtic formation in burners and catalyst bed of this unit Run life of each charcoal bed has been predicted 3-6 months by vendor and our sample analysing, confirmed 4 month. Each charcoal replacement prolong 4 days(at least) and 10 days are required till normal condition of unit. during this time, amine solution is poluted by hydrocarbon and caused mentioned problem. In this work, adding one extra charcoal filter in parallel whit original one has been suggested. Bythis modification not only adsorption capacity will be twice more, but also during replacement of carbon bed, new filter will be kept in service and continuouse filteration is possible. type of activated carbon in phases 2&3 is NORIT PK 1-3 With iodine number 700 , by using of activated carbon with iodine number 1000(its available), adsorption capacity would be increased. Size and granule distribution of activated carbon is another problem.pore size distribution ,as a main factor in adsorption process, to be changed. activated carbon with broader range of pore sizes in multi- lyers arrangement is another modification requeste.

کلیدواژه ها:

activated carbon ، amine solution ، foam tendency ، adsorption ، iodine number