(DE19503669-A1)      A sec. fuel comprises a mainly organic material, rich in crude fibre, biologically inert and low in pollutants, obtd. from waste contg. organic material by (a) feeding the waste, without pre-fermentation, into a single or multi-chamber rotting device, (b) subjecting the material for not more than 100 h to intensive aerobic rotting under the usual conditions, (c) subjecting the material for not more than 350 h to closed aerobic post-rotting, under the usual conditions, and (d) stopping further rolling by lowering the moisture in the rotting device or during the post-rotting to below 40%, thus drying the mainly organic compsn. to a dry matter content of at least 60%.    USE -   Use of the organic compsn. as a sec. fuel is claimed,e.g. in vortex or grate firing or in the cement industry.    ADVANTAGE -   The sec. fuel has a valuable heating value, can be stored for long periods, is cheap to produce, is bio-inert, and is flexible w.r.t. starting materials. No drainage water is formed.    (DE19680036-T)      A sec. fuel comprises a mainly organic material, rich in crude fibre, biologically inert and low in pollutants, obtd. from waste contg. organic material by (a) feeding the waste, without pre-fermentation, into a single or multi-chamber rotting device, (b) subjecting the material for not more than 100 h to intensive aerobic rotting under the usual conditions, (c) subjecting the material for not more than 350 h to closed aerobic post-rotting, under the usual conditions, and (d) stopping further rolling by lowering the moisture in the rotting device or during the post-rotting to below 40%, thus drying the mainly organic compsn. to a dry matter content of at least 60%.    USE -   Use of the organic compsn. as a sec. fuel is claimed,e.g. in vortex or grate firing or in the cement industry.    ADVANTAGE -   The sec. fuel has a valuable heating value, can be stored for long periods, is cheap to produce, is bio-inert, and is flexible w.r.t. starting materials. No drainage water is formed.