A dryer system for drying lignite coal for use in a power plant, the system comprising: a dryer, adapted to dry lignite coal, having: an inlet line for direction lignite coal into the dryer; a first outlet line for removing dried lignite coal from the dryer; and a second outlet line for removing vapour from the dryer, a closed loop heat pump circuit, configured and arranged to provide heat energy to the dryer, comprising: a first working fluid; a dryer heat exchanger in the dryer; an expansion device fluidly connected and downstream of the dryer heat exchanger; an evaporator heat exchanger fluidly connected to and downstream of the expansion device and further connected to the second outline line so as to enable heat energy transfer from the vapour of the second outlet line to the first working fluid; and a compressor, fluidly connected to and downstream of the evaporator heat exchanger and at an upstream end of the dryer heat exchanger, for compressing the first working fluid; characterised in that the dryer comprises a pre-heater connected to the inlet line so as to enable preheating of the lignite coal before entry into the dryer, wherein the pre-heater is connected to the second outlet line downstream of the evaporator heat exchanger so as to enable the use of a remaining heat of the vapour and /or vapour condensate exiting the evaporator heat exchanger thereby preheating of the lignite coal before entry into the dryer. a dryer, adapted to dry lignite coal, having: an inlet line for direction lignite coal into the dryer; a first outlet line for removing dried lignite coal from the dryer; and a second outlet line for removing vapour from the dryer, an inlet line for direction lignite coal into the dryer; a first outlet line for removing dried lignite coal from the dryer; and a second outlet line for removing vapour from the dryer, a closed loop heat pump circuit, configured and arranged to provide heat energy to the dryer, comprising: a first working fluid; a dryer heat exchanger in the dryer; an expansion device fluidly connected and downstream of the dryer heat exchanger; an evaporator heat exchanger fluidly connected to and downstream of the expansion device and further connected to the second outline line so as to enable heat energy transfer from the vapour of the second outlet line to the first working fluid; and a compressor, fluidly connected to and downstream of the evaporator heat exchanger and at an upstream end of the dryer heat exchanger, for compressing the first working fluid; a first working fluid; a dryer heat exchanger in the dryer; an expansion device fluidly connected and downstream of the dryer heat exchanger; an evaporator heat exchanger fluidly connected to and downstream of the expansion device and further connected to the second outline line so as to enable heat energy transfer from the vapour of the second outlet line to the first working fluid; and a compressor, fluidly connected to and downstream of the evaporator heat exchanger and at an upstream end of the dryer heat exchanger, for compressing the first working fluid; characterised in that the dryer comprises a pre-heater connected to the inlet line so as to enable preheating of the lignite coal before entry into the dryer, wherein the pre-heater is connected to the second outlet line downstream of the evaporator heat exchanger so as to enable the use of a remaining heat of the vapour and /or vapour condensate exiting the evaporator heat exchanger thereby preheating of the lignite coal before entry into the dryer.