Simulation and optimization of large open algae ponds

This work presents a model that simulates the behavior of open algae ponds. The model can be used to evaluate the performance of raceway-type open algae ponds at different locations and periods. The model is fully dynamic and considers environmental effects as well as the dynamic behavior of the pond. The algae growth rate and carbon fixation efficiency of ponds at three different locations in the USA between April and September are evaluated. This is done by simulating their transient behavior over a typical day of the respective month. The best performing pond was then selected as a reference case. Multiple operating conditions are varied and their effect on the productivity of the pond is evaluated. The simulations show that there are optimum values for the operating conditions and that harvest rate, water depth and the pH-value have a big impact on the productivity of the pond. Furthermore, it is possible to feed the pond continuously over day and night with a constant CO2 rate if the alkalinity of the growth medium in the pond is high enough. The highest algae growth rate is achieved for the pond in Las Cruces in June at a constant supply of CO2.