An analysis of the energy life-cycle for production of biomass using the oil-rich microalgae Nannochloropsis sp. was performed, which included both raceway ponds, tubular and flat-plate photobioreactors for algal cultivation. The net energy ratio (NER) for each process was calculated. The results showed that the use of horizontal tubular photobioreactors (PBRs) is not economically feasible ([NER]<1) and that the estimated NERs for flat-plate PBRs and raceway ponds is >1. The NER for ponds and flat-plate PBRs could be raised to significantly higher values if the lipid content of the biomass were increased to 60% dw/cwd. Although neither system is currently competitive with petroleum, the threshold oil cost at which this would occur was also estimated.

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A survey of the most recent papers regarding the advanced control of polymerization reactors is carried out. Special attention is focused on optimal control theory, nonlinear control, adaptive control, and predictive control. A review is also performed in related areas, such as optimization and state estimation in polymerization systems. I t is shown that there is a huge gap between industry and research practices. Actual implementation of advanced control theory in the polymerization area requires the improvement of measurement and state estimation techniques.