摘要:The proposed technology is a new concept that aims at energy-efficient drying and cleanup for general purposes by the use of liquefied DME (dimethyl ether) gas. Large amounts of energy are required for the cleanup of the ground since the water contained in the soil hinders the extraction processes that use hydrophobic organic solvents. Therefore, we focus on the use of liquiefied DME, which is eco-friendly, as an extractant. The saturated pressure of DME is moderate—0.51 MPa at 20°C and 0.68 MPa at 30°C. Liquefied DME resolves high volume organic contaminants and water. Moreover, water can be easily separated from DME by flash distillation. This technology reduces the energy required for water-removal to half the latent heat of water. We almost completely removed water and other oily materials by using DME. DME was completely recycled and none of it remained in these materials. The world's first prototype of a DME deoiling/dewatering process is shown. The capacity of this system is 10 L. Because of the low normal boiling point (-25°C) of DME, it does not remain in the soil and it can thus be reused as an extractant. In this presentation, we show the general purpose deoiling and dewatering processes for several materials.