Studi Penambahan Etilena Glikol dalam Menghambat Pembentukan Metana Hidrat pada Proses Pemurnian Gas Alam

https://doi.org/10.22146/jrekpros.59871

Muslikhin Hidayat(1*), Danang Tri Hartanto(2), Muhammad Mufti Azis(3), Sutijan Sutijan(4)

(1) Departemen Teknik Kimia, Fakultas Teknik, Universitas Gadjah Mada, Jl Grafika No. 2 Kampus UGM, Yogyakarta, 55281
(2) Departemen Teknik Kimia, Fakultas Teknik, Universitas Gadjah Mada, Jl Grafika No. 2 Kampus UGM, Yogyakarta, 55281
(3) Departemen Teknik Kimia, Fakultas Teknik, Universitas Gadjah Mada, Jl Grafika No. 2 Kampus UGM, Yogyakarta, 55281
(4) Departemen Teknik Kimia, Fakultas Teknik, Universitas Gadjah Mada, Jl Grafika No. 2 Kampus UGM, Yogyakarta, 55281
(*) Corresponding Author

Abstract


The gas processing facilities are designed to significantly reduce the impurities such as water vapor, heavy hydrocarbon, carbon dioxide, carbonyl sulfide (COS), benzene-toluene-xylene (BTX), mercaptane, and the sulfur compounds. A small amount of those compounds in natural gas is not preferable since they disturb the next processes.  It was proposed to decrease natural gas's operating temperature to -20 ⁰F to remove the impurities from natural gas. The decrease of the natural gas's operating temperature has some consequences to the gas mixers such as hydrate formation at high pressure and low temperature, solidification of ethylene glycol (EG) solution, and the icing of the surface due to low temperature on the surface of chiller (three constraints). The Aspen Hysys 8.8 was used to obtain the suitable flowrate and concentration of the EG solution injected into the natural gas. Peng-Robinson's model was considered the most appropriate thermodynamic property model, and thus it has been applied for this research. The calculation results showed that the EG solution injection would reduce the hydrate formation due to water vapor absorption in the natural gas by EG. The EG solution's flowrate and concentration were varied from 20,000-2,000,000 lb/hr and 80-90 wt.%. When the separation was carried out at the operating temperature of -20 ⁰F, the EG solution's concentration fulfilling the requirement was of 80-84 wt.% with the flowrate of EG solution of 900,000 lb/hr and even more. This amount is not operable. More focused investigation was done for the variation of the operating temperature. Increasing operating temperature significantly reduced the flowrate of EG solution to about 200,000 lb/hr. An alternative process was proposed by focusing on two concentration cases of 80 and 85 % of weight at the low flow rate of EG solution, respectively. These simulations were intended to predict impurities' concentration in the effluent of Dew Point Control Unit (DPCU). The concentrations of BTX, heavy hydrocarbon, mercaptane, and COS flowing out of DPCU were 428.1 ppm, 378.4 ppm, 104 ppm, and 13.3 ppm, respectively. The concentrations of BTX and heavy hydrocarbon are greater than the minimum standard required. It is needed to install an absorber to absorb BTX and heavy hydrocarbon. However, the absorber capacity will be much smaller than if the temperature of natural gas is not decreased and not injected by the EG solution.

Keywords: DPCU gas treatment; ethylene glycol solution; hydrate formation; simulation


A B S T R A K

Unit pengolahan gas dirancang untuk mengurangi sebagian besar senyawa pengotor seperti uap air, hidrokarbon berat, karbon dioksida, karbonil sulfida (COS), benzena-toluena-xilena (BTX), merkaptan, dan senyawa sulfur lainnya. Keberadaan senyawa tersebut dalam gas alam berbahaya karena mengganggu proses selanjutnya walaupun dalam jumlah sedikit. Untuk membersihkan gas alam dari senyawa pengotor, maka suhu operasi gas diturunkan menjadi -20 °F. Penurunan suhu operasi gas dapat menyebabkan pembentukan hidrat pada tekanan tinggi dan suhu rendah, pembekuan larutan etilena glikol (EG), dan pembentukan lapisan es pada permukaan chiller. Aspen Hysys 8.8 digunakan untuk memperkirakan berapa kecepatan alir dan konsentrasi larutan EG yang diinjeksikan ke gas alam. Model Peng-Robinson adalah model termodinamika yang diterapkan untuk penelitian ini. Hasil simulasi menunjukkan bahwa injeksi larutan EG dapat mengurangi pembentukan hidrat karena larutan EG menyerap uap air dalam gas alam. Kecepatan alir dan konsentrasi larutan EG divariasikan dari 20.000-2.000.000 lb/jam dan 80-90 % (%b/b). Saat pemisahan dilakukan pada suhu operasi -20 °F, konsentrasi larutan EG yang memenuhi syarat adalah 80-84 % (%b/b) dengan kecepatan alir larutan EG 900.000 lb/jam atau lebih. Jumlah ini sangat banyak dan kurang layak untuk dioperasikan. Penelitian difokuskan pada variasi suhu operasi. Peningkatan suhu operasi diikuti dengan pengurangan kecepatan aliran larutan EG secara signifikan yaitu menjadi sekitar 200.000 lb/jam. Alternatif proses diusulkan dengan berfokus pada penggunaan kecepatan alir larutan EG yang rendah dengan konsentrasi larutan EG sebesar 80 dan 85 % (%b/b). Simulasi dapat memprediksi konsentrasi pengotor yang keluar dari Dew Point Control Unit (DPCU). Konsentrasi BTX, hidrokarbon berat, merkaptan, dan COS yang mengalir keluar dari DPCU berturut-turut adalah 428,1 ppm, 378,4 ppm, 104 ppm, dan 13,3 ppm. Konsentrasi BTX dan hidrokarbon berat tersebut lebih besar dari standar minimum yang disyaratkan. Oleh karena itu, diperlukan pemasangan absorber untuk menyerap BTX dan hidrokarbon berat. Namun, kapasitas absorber akan jauh lebih kecil apabila dibandingkan dengan kondisi tanpa menurunkan suhu dan menginjeksikan oleh larutan EG.

Kata kunci: DPCU; larutan etilena glikol; pembentukan hidrat; simulasi


 


Keywords


DPCU gas treatment; ethylene glycol solution; hydrate formation; simulation

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References

Alvarez, V. H., and Saldaña, M. D. A., 2012., Thermodynamic prediction of vapor–liquid equilibrium of supercritical CO2 or CHF3+ ionic liquids, J. of Supercritical Fluids, 66, 29-35.

Aspen Hysys Documentations, 2006, Aspen HYSYS property packages: overview and best practices for optimum simulation.

Bhattacharjeea, G., Choudarya, N., Barmechab, V., Kuswahaa, O. S., Panded, N. K., Chugd, P., Royc, S., and Kumara, R., 2019, Methane recovery from marine gas hydrates: a bench scale study in presence of low dosage benign additives, Applied Energy, 253, 113566.

Costa, G. M. N., Cardoso, S. G., Soares, R. O., Santana, G. L., and de Melo, S. A. B. V., 2014, Modeling high pressure vapor–liquid equilibrium of ternary systems containing supercritical CO2 and mixed organic solvents using Peng–Robinson equation of state, J. of Supercritical Fluids, 93, 82-90.

Farhadian, A., Varfolomeev, M. A., Kudbanov, A., and Gallyamova, S. R., 2019, A new class of promising biodegradable kinetic/anti-agglomerant methane hydrate inhibitors based on castor oil, Chem. Eng. Sci., 206, 507-517.

Filarsky, F., Schmuck, C., and Schultz, H. J., 2019, Development of a gas hydrate absorption for energy storage and gas separation – proof of concept based on natural gas, Energy Procedia, 158, 5367-5373.

Guo, P., Shen, X., Du, J., and Wang, Z., 2013, Hydrate formation conditions of natural gas with different content of carbon dioxide and inhibitors screening studies, Advance Materials Research, 781-784, 141-146

Hartanto, D., dan Triwibowo, B., 2014, Review model dan parameter interaksi pada korelasi kesetimbangan uap-cair dan cair-cair sistem etanol (1) + air (2) + ionic liquids (3) dalam pemurnian bioetanol, Jurnal Rekayasa Proses, 8 (1), 1-11.

Hemmingsen, P., V., Burgass, R., Pedersen, K., S., Kinnari, K., and Sørensen, H., 2011, Hydrate temperature depression of MEG solutions at concentrations up to 60 wt%, Experimental data and simulation results, Fluid Phase Equilib., 307, 175-179

Kelland, M., A., 2006, History of the development of low dosage hydrate inhibitors, Energy Fuels 20, 825-847.

Kim, H., Kim, J., and Seo, Y., 2020, Economic benefit of methane hydrate reformation management in transport pipeline by reducing thermodynamic hydrate inhibitor injection, J. Pet. Sci. Eng., 184, 106498.

Koh, C., A., 2002, Towards a fundamental understanding of natural gas hydrates, Chem. Soc. Rev., 31, 157-167

Lee, H., Lee, J., W., Kim, D., Y., Park, J., Seo, Y., T., Zeng, H., Moudrakovski, I., L., Ratcliffe, C., I., and Ripmeester, J., A., 2005, Tuning clathrate hydrates for hydrogen storage, Nature, 434, 743-746.

Long, S., Zhou, X., He, Y., Li, D., dan Liang, D., 2018, Performance of mixture of ethylene glycol and glycine in inhibiting methane hydrate formation, J. Nat. Gas Sci. Eng., 56, 1934-140.

Menezes, D. E. S., Filho, P. A. P., and Fuentes, M. D. R., 2020, Use of 1-butyl-3-methylimidazolium-based ionic liquids as methane hydrate inhibitors at high pressure conditions, Chem. Eng. Sci., 212, 115323.

Moshfeghian, M., 2012, Sour Gas Hydrate Formation Phase Behavior, on http://www.jmcampbell.com/tip-of-the-month/2012/12/sour-gas-hydrate-formation-phase-behavior/ (retrieved on Nov 26th, 2016).

Mutiara, T., Budhijanto, Bendiyasa, I M., dan Prasetya, I., 2016, A thermodynamic study of methane hydrates formation in glass beads, ASEAN Journal of Chemical Engineering, 16 (1), 15-20.

Nandari, Wibiana W., Praseto, I., dan Fahrurrozi, M., 2016, Thermodynamic analysis on methane hydrate formation in porous carbon, ASEAN Journal of Chemical Engineering, 16 (2), 08-20.

Nasir, Q., Suleman H., dan Elsheikh, Y. A., 2020, A review on the role and impact of various additives as promoters/ inhibitors for gas hydrate formation, J. Nat. Gas Sci. Eng., 76, 103211.

Sloan, E., D., 2003, Fundamental principles and applications of natural gas hydrates, Nature, 426, 353-363.

Sloan, E., D., and Koh, C., A., 2008, Clathrate hydrates of natural gases, 3rd edition, GRC Press, New York,

Sun, C., Li, W., Yang, X., Li, F., Yuan, Q., Mu, L., Chen, J., Liu, B., and Chen, G., 2011, Progress in research of gas hydrate, Chin. J. Chem. Eng., 19, 151-162.

Sun, T., Zhong, J., Chen, G., dan Sun, C., 2019, Enhanced depressurization for methane recovery from hydrate-bearing sediments by ethylene glycol pre-injection, Energy Procedia, 158, 5207-5212.

Tian, L., dan Wu, G., 2020, Cyclodextrins as promoter or inhibitor for methane hydrate formation, Fuel, 264, 116828.

Zenga, Y., Chena, J., Yua, X., Wanga, T., Denga, B., Zenga, F., dan Lia, J., 2020, Suppression of methane hydrate dissociation from sds-dry solution hydrate formation system by a covering liquid method, Fuel, 277, 118222.



DOI: https://doi.org/10.22146/jrekpros.59871

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