| 摘要 |
<p>A process for drying organic waste, such as sewage sludge, by contacting the organic waste with hot vapors. In the preferred embodiment, adsorption of hydrocarbons vaporized during the drying step is achieved by mixing recycled dried solids into the drying zone effluent stream. The drying zone effluent stream is then separated into vapor and solids streams, with a portion of the solid stream being recycled as the adsorbent. The unrecycled portion of dry solids is preferably extruded in a separate operation to form compacted granules having good flow characteristics and suitable for application by commercial fertilizer spreaders. In another embodiment, a vapor stream derived from the drying zone effluent stream is contacted with the dry solids downstream of the solids-vapor separation zone to effect the adsorption of hydrocarbon vapors.</p> |
