The best way to go about understanding a how is to first get a good understanding of the what involved - that's one principle that I believe in and live by! Hence, before proceeding towards understanding how to make algae biofuel, let's take a closer look at what this particular variety of biofuel is all about.
As the name suggests, this type of fuel is derived from algae and the method most commonly used is breaking down the alga's carbohydrate content via fermentation. This fermentation would result into biologically produced forms of the alcohols ethanol and butanol. Although it is gaining a lot of popularity these days as a potential alternative for traditional fossil fuels, this is so merely due to the fact that the doubled-edged sword of rapid depletion of traditional resources and ever-increasing fossil fuel prices is hanging over the head of human civilization by a precariously thin thread.
Other than that, algal fuel doesn't offer us much novelty value in terms of low polluting potential. You see, burning algal biofuel releases equally large amounts of carbon dioxide into the air as burning coal or petroleum-based fuels do, as algae, being plant forms, need atmospheric carbon dioxide for photosynthesis. When you make fuel out of algae and burn it, this locked up carbon dioxide gets released into the atmosphere, undoing what algae did during its lifetime as a botanical life form. That being said, let's proceed towards finding out all about the algal biofuel extraction process.
How do You Make Algae Biofuel at Home?
Here are a few simple steps that you can easily follow to produce biofuel from algae, more or less the same way as algal biofuel companies do. So, here we go:-
- Prepare the proper growing environment for cultivating the algal variety of your choice. A conventional cultivation environment would comprise a still water body such as shallow ponds or waste water holes. You may also use plastic bottles, tubes or any other plastic container but then, the water needs to be refreshed at regular intervals. Whatever environment you choose, make sure that it is exposed to abundant sunshine and make sure that the water is slightly more saline than regular freshwater. Such an environment is known as a bioreactor.
- Decide which algal variety you'll be using to extract fuel and make preparations to cultivate the same. If you intend to optimize by using the leftover algal matter post fuel extraction for food and other purposes, the most economic choice would be Chlorella. However, if it is solely lipid extraction you're looking for and want more to do with oil extraction than anything else, you should opt for either Botryococcus or Dunaliella algal varieties.
- Depending upon the specific varieties, add appropriate nutrition to the algal cultivation environment. The most important nutrition for algal growth, irrespective of the variety, include potassium, nitrogen and phosphorus. Trace amounts of additional mineral micronutrients such as iron, silica and chloride accelerate the growth and enhance the health of the algae. In case you're wondering how to go about preparing a nutrient bath, you can easily buy pre-made algal nutrition mixtures containing botanical micronutrients from the market. You can also directly order these nutrient preparations online from small scale biofuel and related items manufacturing companies.
- Once you see the required growth of your algal crop, harvest a major chunk of it, leaving behind not more than about 10% of the total growth. Keep the harvested crop in the sun to allow them to dry.
- Pass the sun-dried algae through a conventional oil press and collect the oil. Mix the leftover algal pulp with hexane and pass this mixture through an oil filter. Hexane is an efficient chemical solvent which dissolves the remaining traces of oil from the pulp and passing this mixture through an oil filter ensures that least lipid content is lost.
- The last step is refinement of the oil for getting the desired fuel, be it biodiesel, biogasoline or biobutanol. In order to refine the extracted lipids, you need to subject the crude oil to various separation processes, depending upon the particular type of algal biofuel you need. A centrifuge is usually employed for conducting most of these separation processes.
Store the biofuel in properly secured containers and keep the containers away from heat and flames as these can catch fire as easily as conventional fossil fuel based oils. As far as the environmental impact is concerned, algal biofuel is about as polluting as conventional fossil fuels. Moreover, when burned to produce heat, their thermal output is also somewhat lower than that of conventional fossil fuels. However, being easy to grow and, therefore, infinitely renewable, algal biofuel does bring us a lot of hope in the face of eternally skyrocketing oil and gas prices.