%0 Journal Article %T The vortex layer apparatus as a source of low-grade heat in the process of pretreatment of the substrate before anaerobic digestion %A Kovalev, Andrey A %A Kovalev, Dmitriy A %A Grigoriev, Victor S %A Litti, Yuriy V %J IOP Conference Series: Earth and Environmental Science %V 938 %N 1 %P 9 %@ 1755-1307 %D 2021-12-01 %I IOP Publishing %~ DeepDyve