Advanced energy saving in low rank coal drying based on self-heat recuperation technology

An advanced drying system for low rank coal drying with a very low energy consumption has been developed based on self-heat recuperation technology. In self-heat recuperation technology, all the energy involved in drying is always recirculated/reutilized. This proposed advanced-drying system would like to give the best answer in low rank coal drying due to its lower energy consumption and better performance in heat exchange. Furthermore, the proposed advanced drying system was compared to the drying systems employed a conventional heat recovery and self-heat recuperation with direct compression. As a result, the proposed advanced-drying system showed a significant reduction in drying energy consumption by about 70% of that required in conventional heat recovery drying system. In addition, there is no significant difference in terms of energy saving to the formerly developed drying system with direct compression after drying. However, the proposed advanced drying system has a significant better performance in heat exchange inside the dryer due to better convective heat transfer following two-phase condensation of pure steam rather than air–steam mixture in previous developed drying system with direct compression.

► Low rank coal drying based on self-heat recuperation technology has been developed.
► All the energy involved in drying is recirculated and reutilized optimally.
► In advanced system, a non-condensable drying medium is removed from the vapor.
► Energy consumption in drying could be reduced drastically.
► Heat exchange inside the dryer improved due to condensation of pure steam.