Environmental Assessment of Co-location Alternatives for a Microalgae Cultivation Plant: A Case Study in the City of Kingston (Canada)

AbstractIn recent years there has been growing interest in the use of microalgae as a feedstock for biofuels, particularly for biodiesel. The production process of biodiesel from microalgae generally consists of five different phases: cultivation, harvesting, drying, lipid extraction and transesterification. While existing technologies are available to undertake each of these phases, the process would benefit from enhanced sustainability achieved by reducing environmental impact and costs. One process innovation currently under consideration is the use of waste products as inputs to the process, including CO2 captured from industrial flue gas, or nutrients from wastewater. These could be employed in algae cultivation. The co-location of an algae cultivation plant with other industrial facilities, such as a cement plant or a wastewater treatment facility, could result in significantly reduced atmospheric emissions and improve wastewater effluent discharges. A comparative life cycle assessment approach is used to examine two different, realistic alternatives for the co-location of an algae cultivation plant with an existing cement plant or wastewater treatment facility near Kingston, Ontario, Canada. The study seeks to identify a preferred siting option from the perspective of minimizing environmental impacts. The first alternative involves the co-location with the Lafarge Cement plant, on the north shore of Lake Ontario, near Bath Ontario. The second alternative consists in the co-location with the Ravensview wastewater treatment facility east of the city of Kingston on the St. Lawrence River. The algae production plant is based on an open pond technology and is assumed to have a production capacity of about 120 tons of dry microalgal biomass per year