Living in Southern California and going to the beach, it seems impossible to consider a world with a shortage of algae, but when it comes to biofuels… patrolling the beach and bagging up that washed up algae is just not good enough. When it comes to looking for sources for sustaining the need for algae in energy production, perhaps we can learn more from waste…water that is!
The use of algae to generate biofuels seems good in theory, but skeptics say it is just too costly because propagation of algae requires nitrogen and phosphorus. Nitrogen and phosphorous are costly macronutrients that are crucial for algae growth. Luckily, these costs can be mitigated.
By incorporating algae remediation to wastewater treatment – in other words, using water that is already contaminated with high levels of phosphorous and nitrogen from eutrophication.
Eutrophication is the addition of artificial or natural substances through fertilizer or sewage to an aquatic system.
The diagram above is just one example of a microalgae water treatment process. This process treats wastewater (a cost effective feedstock) to efficiently produce algae to meet a customers energy demands.
Traditional wastewater treatment of sewage cannot be used directly to feed algae, since this will hinder growth or actually kill the desired algae strain. An Anaerobic Digestor is a key process by bacteria, which creates the proper environment for growing algae.
Genetically engineering strains for growth optimization in reduced levels of nitrogen and phosphorous can also be beneficial. Making limiting factors like low nitrogen and phosphorous concentrations a thing of the past through opportunities in metabolic engineering.
Because sustainability and economics are both equally important a cost-effective design intimately links priorities and metrics. Properly utilizing available technology would also allow major algae producers the opportunity to use treated freshwater with added nitrogen and phosphorous, a process not used at all today.
Ideally, a closed-loop system which recycles all of its nitrogen and phosphorous leftovers would be the most effective and best practice to reduce release into the environment as runoff.
Sapphire Energy, Inc. is an example of a company that is conscious of its leftover nutrients and is working towards this closed-loop system.
If engineers can develop a way to efficiently recycle nutrient-rich water from agricultural and municipal waste, effectively reducing costs of algal fuel production, treat wastewater, and mitigate carbon dioxide levels – it creates a path towards a more sustainable, energy-efficient country.
With so many opportunities to create a sustainable energy supply… The power of Biofuels is where our energy can grow!