Economic and Systems Assessment of the Concept of a Water Hyacinth Wastewater Treatment/Methane Production System

摘要

Production of pipeline-quality gas from anaerobic digestion of hyacinth-sludge blends is possible with current technology. The cost varies from $2.54 per thousand cubic feet, associated with primary and hyacinth treatment of 50 million gallons per day of raw waste, to $75.30 per thousand cubic feet associated with hyacinth polishing of one million gallons per day of secondary effluent. The $2.54 cost includes a large credit for wastewater treatment of $28.20. These costs correspond to a municipal system with U.S. Environmental Protection Agency participation in treatment works' capital cost. If the ownership shifts to industrial financing, the cost increases to $6.74 for the 50 million gallon per day system. The major cost element common to all systems evaluated is harvesting of hyacinths. Maximum energy production potential is less than 0.002 quads for an area which includes all wastewater treatment plants (projected to the year 2000) for the nation's southern tier states with a flow of more than five million gallons per day. Addition of other material to the anaerobic digestion feedstock could increase the quad impact.