초록 ▼

Municipal sludge is converted from an environmental problem into soil amendment and electricity. Methane, produced in an anaerobic digester (2), is used partially to generate electricity and partially to dry the concentrated sludge in a rotary dryer (7). Excess heat from the dryer is used to maintai

Municipal sludge is converted from an environmental problem into soil amendment and electricity. Methane, produced in an anaerobic digester (2), is used partially to generate electricity and partially to dry the concentrated sludge in a rotary dryer (7). Excess heat from the dryer is used to maintain the temperature in the digester at approximately 105°to 130°F. Heavy metals are removed so that the dried sludge can be safely used as a soil amendment.

대표청구항 ▼

A process for converting sludge into soil amendment, comprising digesting sludge anaerobically to produce methane, a concentrated sludge, and supernatant, mixing additional sludge with supernatant and introducing the resultant mixture to the digestion system, transferring methane that is produced to

A process for converting sludge into soil amendment, comprising digesting sludge anaerobically to produce methane, a concentrated sludge, and supernatant, mixing additional sludge with supernatant and introducing the resultant mixture to the digestion system, transferring methane that is produced to a storage area, using methane to heat a rotary dryer into which concentrated sludge has been transferred from the digestion system, drying concentrated sludge to a solid product useful as a soil amendment, and using waste heat from the dryer to maintain the digestion system at a temperature of approximately 105°to 130°F.