Physicochemical properties of Indonesian lignite continuously modified in a tunnel-type microwave oven for slurribility improvement》.pdfVIP

Fuel 150 (2015) 493–500 Contents lists available at ScienceDirect Fuel journal homepage: www.else /l ocate/fuel Physicochemical properties of Indonesian lignite continuously modified in a tunnel-type microwave oven for slurribility improvement Jun Cheng ⇑, Fan Zhou, Xin Wang, Jianzhong Liu, Junhu Zhou, Kefa Cen State Key Lab of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China a r t i c l e i n f o a b s t r a c t Article history: Indonesian lignite was continuously modified in a tunnel-type microwave oven to improve its slurribility. Received 7 October 2014 The maximum solid concentration of coal–water slurry (CWS) prepared from modified lignite increased Received in revised form 11 February 2015 from 41.6 wt.% to 54.0 wt.% with an enhanced rheological behaviour. The contact angle, oxygen function- Accepted 12 February 2015 al groups, molar ratio of methylene to methyl, paramagnetic centres of modified lignite were analysed on Available online 23 February 2015 contact angle analyzer, Fourier transform-infrared spectroscopy, X-ray photoelectron spectroscopy, elec- tron paramagnetic resonance spectroscopy to clarify the modification mechanisms. The molar ratio of the Keywords: methyl group to the methylene group of the modified lignite decreased, resulting in shortened aliphatic Lignite Modification chains and condensed aromatic rings. The unpaired electrons concen