The　integration　of　flue　gas　fan　mill　dryer　with　an　open　pulverizing　system　significantly　improves　the　plant　thermal　efficiency　of　the　Flue　Gas　Pre-dried　Lignite-fired　Power　Systems　(FPLPS).　The　aim　of　this　article　is　to　simulate　the　flue　gas　drying　process　applied　for　high　moisture　lignite　and　to　find　an　optimal　operation　mode　for　various　lignite　compositions.　A　previously　validated　GSE　simulation　model　of　the　FPLPS　is　used　in　the　present　work.　Two　types　of　lignite　from　China　and　Greece　have　been　investigated　as　the　feeding　coal.　The　plant　thermal　efficiency　of　a　600　MW　supercritical　unit　increases　by　1.46　%　at　design　case　when　the　moisture　content　of　lignite　is　being　reduced　from　39.50　%　to　12　%.　The　improvement　value　reduces　from　1.46　%　to　1.19　%　in　water-cooled　units　and　1.39　%　to　1.13　%　in　air-cooled　units　when　the　moisture　content　of　Chinese　raw　lignite　decreases　from　39.50　%　to　29.95　%.　When　Greek　lignite　is　supplied,　with　moisture　content　varying　from　53.20　%　to　60　%,　and　lower　heating　value　from　5.44　MJ·kg-1　to　6.31　MJ·kg-1,　the　plant　thermal　efficiency　drops　by　a　maximum　value　of　0.53　%,　without　considering　the　limited　drying　capacity　of　the　pulverizing　system.　Moreover,　two　operational　modes　are　compared　in　order　to　address　the　issues　of　fuel　type　variation,　including　the　adjustment　of　the　drying　degree　to　maintain　the　boiler　load,　as　well　as　the　reduction　of　the　boiler　steam　output.　Case　studies　are　presented　to　highlight　the　importance　of　the　match　between　lignite　pre-drying　system　and　the　boiler　thermal　system.　Both　the　energy-saving　potential　and　the　flexibility　to　fuel　type　variations　are　concluded　as　the　benefits　of　lignite　flue　gas　pre-drying.　©　2016　University　of　Ljubljana.