Operation scheduling of batch autothermal thermophilic aerobic digestion processes

摘要

The autothermal thermophilic aerobic digestion (ATAD) is an exothermic batchwisernoperated sludge treatment process, in which sludge undergoes heating andrnpasteurization as temperature attains values about 50-60 ℃. Based on detailed processrnmodels, different approaches have been suggested (Rojas and Zhelev, 2009) tornminimize the specific energy requirement of existing ATAD designs by altering thernoperating conditions, but less attention has been paid to process optimization by meansrnof operation planning and timing. This work aims at minimizing the specific energyrnrequirement of existing ATAD processes considering simultaneously operationalrnconditions, planning and timing. Hence, a scheduling formulation including processrnmodel variables and a flexible recipe is proposed. Energy savings are reported for a casernstudy of a simplified treatment plant. The proposed approach results in energyrnconsumption reduction by optimizing batch sizes and operating conditions.