Science Buddies: "Ask an Expert"

i want to set up a pilot plant of 50-100 liters to produce bio diesel from algae. i have heard of many harvesting and extraction process to get oil from algae. i want to know the cheapest method to get oil from algae at low scale and also at high scale.
will here electrolysis work? its urgent

Hi Prokashkumar,

This is a very worthwhile but challenging science fair project. Here are 3 biofuel projects from the Science Buddies website that should give you some design ideas. I don’t have any information on costs, but you should have some idea of the local cost of the materials. Don’t forget to include the cost of the growth media for the algae as well:

https://www.sciencebuddies.org/science- ... p032.shtml

https://www.sciencebuddies.org/science- ... p038.shtml

https://www.sciencebuddies.org/science- ... p027.shtml

Are you actually building a pilot plant, or are you doing the design work for the scale up plant?

Donna Hardy

i am first designing a pilot scale for 100-300 liters. then within two weeks will be constructing it on a large scale of more than 10 acres of land with more than $400,000 investment. but my main problem is cost of production, so i want a method to reduce the cost of harvesting of algae. i have heard of passing electricity ya ultrasonic waves. but i don'y know how it works. so can you please help me. none of the links worked much for me.
its urgent.

Hi,

Harvesting the algae is one of the more difficult steps in biodiesel production. The method used depends on the specific algae that you are using and there is not one method for all type of algae. Are you growing macroalgae or microalgae? Here is a commercial website that describes the various methods used to harvest algae.

http://www.oilgae.com/algae/har/har.html

Here is a review article from a scientific article that includes a discussion on various methods for harvesting and also includes other references that you might be able to access and read. It seems like filtration would be the simplest and lowest cost method available is you are growing microalgae. This article describes using ultrasound and microwaves to extract the algae cells after harvest, so maybe that what you have heard about.

https://wiki.umn.edu/pub/Biodiesel/WebH ... ations.pdf

Before you do your pilot scale project on a 100-300 liter scale, you need to do a lab experiment on a 1 liter scale and optimize all of the techniques you will be using. Besides the harvesting step, there are may other details required for a successful experiment. When you are successful at the 1 liter scale, then you can scale up to 10-15 liters before going on to the 100 liter scale.

Let me know more details about your project and the type of algae you are growing.

Donna Hardy

i will be using microalgae like Botryococcus braunii , Nannochloropsis ya Chlorella protothecoides. which ever easily available. my main aim is to produce bio diesel from algae on a large scale.

Hi,

Good if its microalgae, then the information in the review article that I cited in my last post will apply. This is a fairly recent review article and includes a discussion with additional references for algae cultivation, harvesting, processing, oil extraction and biodiesel production. You will see in the harvesting and biomass concentration section, the authors have noted that this is an area of research and there is not just one way to harvest algae. They suggest sedimentation, centrifugation, filtration, ultra-filtration, and flocculation. Read this section (2.2.3) carefully, and look up the other articles cited in the text to get more ideas. Once you decide which algae you will be using, check the size of the algae cells as this will affect the selection of a filter if you select this method.

Since this is a science fair project, you should try to read as much of the current scientific literature as you can on your topic. Your experiment should be based on the current literature.

This is a very worthwhile project. Good luck.

Donna Hardy