Capacity and Efficiency in Small- to Medium-Sized Biodiesel Production Systems.

Summary This article applies principles of industrial ecology to small- and medium-sized biodiesel production facilities. A large potential for gains in efficiency and profit are realized through technology retrofits and the novel application and reuse of process materials. Our basic criteria for sustainability of farm-scale biodiesel production systems are measured by the following questions: Are all of the resources, mass, and energy flows in the system rational and harmonized? Is the feedstock produced without adverse effects on natural resources or the food chain? We answer these questions by presenting and applying the latest chemical engineering and technology research to support the harmonized and rationalized use of resources and energy within the system boundaries of a farm economy. The feedstock must include refuse and secondary oil sources with low impact on the food chain. Emissions must be reduced to a minimum for a smaller carbon footprint and positive emissions balance from seed to exhaust. Discharges should be avoided; wastes must be turned into primary and intermediary products or energy resources. Proper techniques and routines should serve environmental and human health and safety targets. Reuse of existing assets is considered for improving unit capacity and efficiency, thus lowering costs of conversion. Significant benefits in profitability and production capacity, combined with improved environmental performance, are the main outcomes of the recommended restructuring of production at farm-scale. [ABSTRACT FROM AUTHOR]