The invention relates to a dryer system for drying lignite coal used in a power plant. The system comprises a dryer and a closed loop heat pump circuit that is configured and arranged to provide heat energy to the dryer. The closed loop heat pump circuit includes a working fluid, a dryer heat exchanger, an expansion device fluidly connected and downstream of the dryer heat exchanger, arranged to enable heat energy transfer from the vapor of the second outlet line to the first working fluid and a compressor for compressing the working fluid.