Cost Analysis of Microalgae Biomass Systems. Final Report. Design Assumptions and Engineering Plans for 100-Square Mile System

摘要

A conceptual design and detailed cost estimate for a 100 mi exp 2 microalgal biomass production system is presented. The individual growth ponds are 100 acres in size, divided by 18-in. high baffles into six 200 ft-wide channels and surrounded by two-ft-high earthworks. Harvesting is accomplished in eight-ft deep settling ponds which are operated in a three-day cycle (two days for settling), with three settling ponds per two growth ponds. The ponds are arranged in a modular design of 20 growth ponds per module and 32 modules per 100 mi exp 2 system. A central corridor in the modules contains space for secondary and tertiary harvesting ponds, biomass conversion systems, nutrient mixing stations, etc. To allow low-cost biomass production, favorable assumptions about pond construction and operations must be made, e.g., cost-effective control of percolation and erosion, almost complete nutrient recycling, high biomass productivities (20 tons/acre/yr), etc. A capital cost of $222 million and yearly operations costs of $18 million was calculated for the 100 mi exp 2 system. This is equivalent to biomass costs about $40/ton (assuming no land costs, taxes, etc.). The preferable option is to produce petrochemical feed stocks from the algal biomass. Higher value products, e.g., animal feeds, could be produced from algal biomass in the short range. (ERA citation 03:047097)