Pyrolyzer design alternatives and economic factors for pyrolyzing sewage sludge in multiple-hearth furnaces

Conference · Sun Jan 01 04:00:00 EST 1978 · ACS Symp. Ser.; (United States)

OSTI ID:5151332

Von Dreusche, C; Negra, J S

This paper considers the pyrolysis of sewage sludge in multiple hearth furnaces. This required the use of modern dewatering equipment, which now has become commercially available. Heat recovery in the range of 2000 to 3000 Btu per pound of dry sludge solids seems easily feasible. Energy recovery in the form of increased use of digesters to generate methane, while still avoiding a fuel cost to thermally destroy the organics in the resulting energy depleted sludge may in some cases be a preferred use. Energy recovery as a char ash mixture to be treated for the elimination of heavy metals, converted to active carbon, or used as a fuel at other locations than the sewage treatment plant, may also develop as the preferred form. It is believed that much work remains to be done in finding valuable uses, preferably in-plant, for the carbon ash mixture that can be produced from sewage sludge and for the heat available from the gases exhausting from the afterburner. Steady improvement in dewatering equipment and in thermal destruction energy efficiency will increase the availability of these products and thus bring about increasing efforts to utilize them. The pyrolysis of sludge alone in conjunction with better dewatering practices, will eliminate all fuel cost; and generate enough steam from the exhaust gas to run the exhaust gas fan (the only major power consumer on the pyrolysis unit) and aeration blowers for the waste activated sludge process, by steam turbine. It will at the same time provide for the production of char, thus laying a base for eventual heavy metals recovery. This should make it much more cost effective than heretofore to carryout the essential function of converting offensive and dangerous sludge organics to safe and inoffensive inorganics.

• Research Organization: Nichols Engineering and Research Corp., Belle Mead, NJ
• OSTI ID: 5151332
• Report Number(s): CONF-780305-P8
• Conference Information: Journal Name: ACS Symp. Ser.; (United States) Journal Volume: 76
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320604* -- Energy Conservation
Consumption
& Utilization-- Municipalities & Community Systems-- Municipal Waste Management-- (1980-)
ALKANES
CHARS
CHEMICAL REACTIONS
COST
DECOMPOSITION
DESIGN
ECONOMIC ANALYSIS
ECONOMICS
ENERGY RECOVERY
FEASIBILITY STUDIES
FURNACES
HEAT RECOVERY
HYDROCARBONS
MANAGEMENT
METHANE
ORGANIC COMPOUNDS
PROCESSING
PYROLYSIS
PYROLYSIS PRODUCTS
RECOVERY
REMOVAL
SEWAGE
SEWAGE SLUDGE
SLUDGES
STEAM
THERMOCHEMICAL PROCESSES
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
WATER REMOVAL