Energy and economic assessment of anaeroic digesters and biofuels for rural waste management

Book · Sun Jan 01 04:00:00 EST 1978

OSTI ID:5925511

Abeles, T P; Freedman, D F; DeBaere, L A; Ellsworth, D A

A technological and socioeconomic assessment of anaerobic digester feasibility for small- to mid-size livestock operations was undertaken. Materials handling presented the greatest obstacle to satisfactory operation of the full-scale systems. Conversion of the biogas to electricity via standard engine-generator sets is capital- and maintenance-intensive. Electrical conversion requires engine-generator sets that can add 30% to the cost of the system, and that have conversion efficiencies of only 10 to 25%. The system becomes more economical if the biogas can be used on site for direct thermal loads, suggesting that the economic feasibility of anaeroic digesters is site specific and should be closely integrated with the total farming operation. If excess engine heat can be recovered from electrical-conversion equipment, and if provisins can be made on the farm to level electrical loads and conserve energy, then the economics are enhanced. Analysis was performed for farms with 100 animal units. Laboratory studies using a 2:1 mixture of dairy manure to Municipal Solid Waste showed that the biogas production per pound of volatile solids added is nearly the same as for straight manure. Addition of the organic portion of MSW to small farm digesters could make marginal systems economically attractive. Preliminary refeed studies indicated that the digested manure may not have the same nutritional value as raw manure, and that the cost of dehydrating the effluennt for refeed to the same animals could be cost prohibitive for the small to mid-size farming operation.

• OSTI ID: 5925511
• Report Number(s): NP-23969
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
090122 -- Hydrocarbon Fuels-- Preparation from Wastes or Biomass-- (1976-1989)
29 ENERGY PLANNING, POLICY, AND ECONOMY
299003* -- Energy Planning & Policy-- Unconventional Sources & Power Generation-- Other-- (-1989)
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320305 -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Industrial Waste Management
AGRICULTURAL WASTES
ALGAE
ANAEROBIC DIGESTION
BIOCONVERSION
BIOGAS PROCESS
COMPARATIVE EVALUATIONS
CONSTRUCTION
DATA FORMS
DESIGN
DIAGRAMS
DIGESTION
ECONOMIC ANALYSIS
ECONOMICS
ENERGY ANALYSIS
GRAPHS
HYDROGEN PRODUCTION
INSTITUTIONAL FACTORS
MANAGEMENT
MANURES
MUNICIPAL WASTES
PLANTS
PROCESSING
RURAL AREAS
SOCIO-ECONOMIC FACTORS
SOLID WASTES
TABLES
TECHNOLOGY ASSESSMENT
WASTE HEAT UTILIZATION
WASTE MANAGEMENT
WASTE PROCESSING
WASTE PRODUCT UTILIZATION
WASTES