Korean Journal of Chemical Engineering, Vol.33, No.12, 3401-3406, December, 2016
Efficient in situ drying of low rank coal in a pressurized down-flow flash dryer
E-mail:
Flash drying of low rank coal with synthesis gas was addressed by using a pressurized down-flow dryer. The proposed method is a potential approach to secure gaseous water that is required in coal processing by utilizing moisture in the low rank coal. The drying process was promoted by increasing the initial temperature of the synthesis gas as a drying medium and decreasing the particle size of the coal. The moisture removal rate of the coal using synthesis gas at 9 bars and 500 ℃ reached up to 97% within ten seconds. Although it is a higher temperature than that of fixed bed or moving bed dryer, outlet moisture laden synthesis gas had the low level of tar enough to be a feedstock of downstream catalytic process due to the short residence time in the dryer. The chemical composition changes of the coal during the drying resulted in reducing oxygen content to the atomic ratio of oxygen to carbon as 0.1 and enhancing its calorific value. Disappearance of hydroxyl functional group from the surface and physical reduction of the surface area of the coal decreased the moisture re-adsorption capacity, which could prevent the spontaneous combustion of the low rank coal.
Keywords:Low Rank Coal;Flash Drying;Down-flow;Synthesis Gas;Moisture Re-adsorption;Physico-chemical Properties
- Burnard K, Bhattacharya S, Power Generation from Coal: Ongoing Developments and Outlook, International Energy Agency (IEA), Paris, France, http://www.iea.org/papers/2011/power_generation_from_coal.pdf (2011).
- Osman H, Jangam SV, Mujumdar S, Dry. Technol., 29, 1763 (2011)
- Li X, Rathnam RK, Yu J, Wang Q, Wall T, Meesri C, Energy Fuels, 24, 160 (2010)
- Willson WG, Walsh D, Irwin BW, Int. J. Coal Preparation Utilization, 18, 1 (1997)
- Nikolopoulos N, Violidakis I, Karampinis E, Agraniotis M, Bergins C, Grammelis P, Kakaras E, Fuel, 155, 86 (2015)
- Katalambula H, Gupta R, Energy Fuels, 23(7), 3392 (2009)
- Li X, Song H, Wang Q, Meesri C, Wall T, Yu J, J. Environ. Sci. Suppl., 127 (2009)
- Pan LY, Liu P, Ma LW, Li Z, Energy Policy, 48, 93 (2012)
- Wilver PJ, Brumbaugh CA, Proceedings of the 13th Biennial-Lignite Symposium, Bismarck, ND, May 21-23 (1985).
- Kim SD, Lee SH, Rhim YJ, Choi HK, Lim JH, Chun DH, Yoo JH, Korean Chem. Eng. Res., 50(1), 106 (2012)
- Zhang K, You C, Li Y, Korean J. Chem. Eng., 29(4), 540 (2012)
- Jamaleddine TJ, Ray MB, Ind. Eng. Chem. Res., 49(12), 5900 (2010)
- Kim YJ, Bang JH, Kim SD, Can. J. Chem. Eng., 77(2), 207 (1999)
- Anisa S, Zainal ZA, Renew. Sust. Energ. Rev., 15, 2355 (2011)
- Ko GH, Sanchez DM, Peters WA, Howard JB, Twenty-Second Symposium (International) on Combustion/The Combustion Institute, 115 (1988).
- Jin LJ, Li Y, Lin L, Zou L, Hu HQ, Fuel, 152, 80 (2015)
- Okolo GN, Everson RC, Neomagus HWJP, Roberts MJ, Sakurovs R, Fuel, 141, 293 (2015)
- Tahmasebi A, Yu JL, Han YN, Yin FK, Bhattacharya S, Stokie D, Energy Fuels, 26(6), 3651 (2012)
- Vorres KS, Energy Fuels, 8(2), 320 (1994)
- Ko GH, Peters WA, Howard JB, Fuel, 66, 1118 (1987)
- Suuberg EM, PhD Thesis, MIT (1977).
- Yu JL, Tahmasebi A, Han YN, Yin FK, Li XC, Fuel Process. Technol., 106, 9 (2013)
- Zeng C, Favas G, Wu HW, Chaffee AL, Hayashi J, Li CZ, Energy Fuels, 20(1), 281 (2006)
- van Krevelen DW, Coal, Typology, Physics, Chemistry, Constitution, 3rd Ed., Elsevier, Amsterdam, 673 (1993).
- Mahidin, Ogaki Y, Nakata Y, Usui H, J. Chem. Eng. Jpn., 36(7), 769 (2003)
- Sato Y, Kushiyama S, Tatsumoto K, Yamaguchi H, Fuel Process. Technol., 85(14), 1551 (2004)
- Couch GR, Report of IEA Coal Research, IEACR/23, London (1990).
- Nugroho YS, McIntosh AC, Gibbs BM, Fuel, 79, 1951 (2000)
- Salmas CE, Tsetsekou AH, Hatzilyberis KS, Androutsopoulos GP, Dry. Technol., 19, 35 (2001)
- Li X, Song H, Wang Q, Meesri C, Wall T, Yu J, J. Environ. Sci., (Supplement), 127 (2009)
- Miura K, Mae K, Li W, Kusakawa T, Morozumi F, Kumano A, Energy Fuels, 15(3), 599 (2001)