9.5 Tasks | EGEE 439: Alternative fuels from biomass sources (2023)

MARK HALL: Hello. I'm Mark Hall, Renewable Energy Specialist at Auburn University. We are doing many of these things in relation to the energy choices you can make, many pieces that in each piece of the puzzle can contribute to our energy independence by making ethanol and biodiesel and becoming more energy efficient in the process. that you run your house.

Today we are going to talk about how to make biodiesel. And we have Lance Hall. Lance made biodiesel to run his car. He bought a used Volkswagen on eBay and started producing biodiesel. And he liked it so much that he bought a new diesel car. And that has been very successful for several years.

Before I bring Lance in, I want to thank my friend and colleague Walter Harris, Madison County Coordinating Agent, for filming us today. Bid, come by and show us what you have in mind. And congratulations, you succeeded.

I spoke to my father about my new job a few years ago. And he said, well, Lance has been doing this for a long time. I said that? I knew nothing about it. So Lance, show people how to make biodiesel.

LANCE HALL: Okay. Many people are familiar with biodiesel. You read the stories. You did some research. But they still don't have enough confidence in their ability to make a batch. Today I'm going to show you how to make a batch of biodiesel, just on a small scale, but it's easy.

OK. The first thing we're going to do is start with vegetable oil. Now it will be 800 milliliters. And don't get confused between milliliters and your normal units of measurement. It's a simple conversion that anyone with a calculator can do.

We have 800 milliliters here. Well, the first thing we want to do is heat it up. Don't worry about that chic outfit either. The key element here is heating in any way you can safely do.

And these things are magnetic stirrers. Do not worry. Just stir it while you heat it to even things out. And we're going to heat that up to about 130 degrees Fahrenheit.

MARK HALL: Lance, tell them where you got this gear.

LANCE HALL: All of this equipment that I have in my shop, all of my lab supplies, eBay is a wonderful place to find used lab supplies and lab glassware. These are magnetic stir plates. These are really useful if you have the means to buy them. Of course you don't have to have them. But I like using them.

And this is also an electronic scale, which comes in handy when you start weighing your catalytic converter and do whatever you want to measure an accurate weight. It's worth the money there. And that's gonna take a while, so...

MARK HALL: Lance, are there any other sites on the internet that you would recommend for people interested in making biodiesel?

LANCE HALL: There are many sites out there. One of the most informative websites on what biodiesel is and where it is used is biodiesel.org. This is the National Biodiesel Council website, there is a lot of good information there. It won't really tell you much about how to do this, but I hope this is one of the more informative sites where you can watch someone make one, make a batch.

OK. As our oil heats up, we need to mix our mixture of methanol and potassium hydroxide. Therefore, safety is paramount when using methanol or the highly caustic bleach potassium hydroxide. Methanol can cause blindness or death and can be absorbed through the skin. And potassium hydroxide will burn your skin if it comes into contact with you.

So that's what we're going to do. Let's take our methanol and pour it into a container. Face shield is good too.

We will use 175 milliliters of methanol. That is about 20% of 800 milliliters of oil. Typically you want to use about 20% of the volume of methanol compared to the volume of vegetable oil.

OK. Our next ingredient is our potassium hydroxide. This is our lie. Now we need to quickly calculate how much of this we need to mix with our methanol for the reaction to take place.

I have a nice spreadsheet that I like to use. It's Biodiesel-o-matic. You can usually find it online at various biodiesel websites. I will upload this.

OK. We want to use 7 grams of potassium hydroxide per liter of vegetable oil. So you take 7 divided by 0.8. And that's 6.4 grams.

Double-bag this material or it will absorb moisture. And it will kill your process.

So let's use our scale. Let's clean the container. And then we add 6.4 grams to it. Make sure you have your gloves with you.

OK. That's our 6.4 grams. Close them immediately. Double pack. OK. Now take your 6.4 grams of potassium hydroxide and add that to your 175 milliliters of methanol.

Again, you want to shake this up. However, it is not necessary to heat it. Just stir. And stir until at least the potassium hydroxide is completely dissolved in the methanol. You don't want to see white flakes of potassium hydroxide.

Everything's ok. Our potassium hydroxide is fully mixed with our methanol. We want to remove the stirring stick. And then we're going to slowly pour that into our oil while stirring.

Again, you don't need any fancy equipment. Just pour it in while stirring by hand. But the key is to do it slowly.

Credit:Expansion of the Universities of Alabama, A&M and Auburn

BARMAN: You should always start with a much larger container than you have for the amount of oil you will be making because you will need to add another 20% with the methanol. This is a 1000 milliliter container. So if I did 1000 milliliters it would overflow if I put another 200 milliliters of methanol in it. Okay, we've added about half of our methanol. let him stir So I add. Add a little more.

You can tell when you need to add more. Once the color changes from opaque to translucent. And when we come back, it will... we'll show you how it separates.

OK. We have completed the first batch of biodiesel. We make biodiesel from regular virgin oil. And as you watch it will eventually fall. And it will be clear. And you will have separate layers.

While we wait for that to be resolved, most people who want to make biodiesel want to make it from recycled vegetable oil from restaurants, cafes, whatever. There are a few things we need to do before we can start with this. The most important thing you need when using recycled vegetable oil is the titration solution. That will determine... that will help us determine how much additional catalyst we need to neutralize the free fatty acids contained in the vegetable oil that is produced during the cooking process.

Let's start our balance here with a glass of at least one liter. I will reset that. We need a gram of our potassium hydroxide. Now let's add 1000 grams of water, which is very close to a liter or 1000 milliliters. So let's add it to our current jar. Oh, maybe okay, there's our liter of titrant solution. OK.

So we made our solution. We reheat our 800 milliliters because, as before, we're only using 1000 milliliters at 140 degrees. I'll wait while it gets warmer. Biodiesel is bad. Prepare to have all kinds of paper towels and soap and anything else ready for cleanup. Okay, while this is heating up, let's do the titration to determine how much we need to add.

So let's use that. This is a titrating burette. They can be found on eBay at very reasonable prices and they are really accurate. So I recommend taking at least that much. Okay, let's take a small container. So let's measure out 10 milliliters of isopropyl alcohol. Also known as ISO HEET. The regular version of HEET is not isopropyl. Let's take 10 milliliters. We have milliliters of our isopropyl alcohol. Now we need a milliliter of the oil that we want to convert into biodiesel.

And that means... You can find them anywhere. These are the grocery store turkey flavor injectors. Do not use them as turkey injectors after making biodiesel with them. take the air And these are graduated to 1 milliliter, so let's go from row to row. OK. Replace the rest. We have 10 milliliters of isopropyl alcohol and 1 milliliter of our vegetable oil. Now we need an indicator solution to determine when the pH has changed to the correct level. So let's add about four drops of a phenolic saline solution. This can be purchased on eBay. A few small bottles go a long way.

And like everything else, I have a stir stick for this. It's an insect. So we let the oil dissolve in isopropyl alcohol. OK. Now let's use this. These are graduated in 0.1 milliliter increments. So it's very accurate. So I'm going to pour in some distilled water just to wash out the impurities. And then we pour in our titrant, our 0.1 potassium hydroxide titrant. And we want to do this multiple times to make sure the remaining water doesn't affect our readings.

OK. We wash our Duray titration with our titration solution. Now we're going to slowly add the titration solution to our isopropyl alcohol and vegetable oil mixture down here. The indicator solution that we put in the phenolic salt solution will turn light pink when we reach a certain pH level that we want. Once it turns pink and stays pink, we'll stop.

Credit:Expansion of the Universities of Alabama, A&M and Auburn

LANCE HALL: OK, you can see it's still pink now. This gives us about 4 milliliters of our solution to change from dull yellow to pink.

So let's record that in our worksheet.

I use spreadsheet. You could also create a spreadsheet just by writing your numbers. And you use a standard pocket calculator.

Just like before, we will use the same glass. This time we're going to put in 9 grams of our potassium hydroxide.

OK, let's get our 9 grams out. Now we add 175 milliliters of methanol.

OK, let's shake it again.

Alright, so we have our mixture of methanol and potassium hydroxide. And then we do the same thing, just slowly add it to our used vegetable oil, recycled vegetable oil, whatever you want to say. And you can tell when you need to add more by the color change.

I don't know if the camera can see it or not, but if you look through the top you can tell when it becomes translucent. And look how it glows. It's not that clear.

Okay, I can see how it's lit there and add it a bit. This will become darker translucent as it blends. OK, let's let this mixture sit for a few minutes. And when we come back, we'll show you how it broke.

Just for demo, this is a batch I made, a larger batch I made a few weeks ago. And you can see how clear it becomes after a little stabilization time. This is almost if not as clear and the same color as virgin vegetable oil. So once you get your process under control, you should be able to do just as high quality things with used vegetable oil as you can with virgin oil.

Ok, once you're comfortable with your biodiesel production technique, it's time to move on to a reactor. I have five tanks in my system. This is an oil processing tank. When I first get my used vegetable oil, I run it through a large screen to catch any large chunks of french fries, french fries, chicken nuggets and anything else.

And I'm getting hot So I can put it in my storage tank. I have to heat it up because there is another filter in this tank to filter out even the smallest parts. And it has to get hot to go through that filter. Then when we're done with storage and ready to make a batch, it's all about this 60 gallon full drain inducer tank.

It has a large lid. So I put my vegetable oil in here. This tank is the methanol caustic mixing tank. In this tank there is only methanol and lye. Once I figure out how much caustic and methanol I need for my batch of oil, I'll mix it up here. And then it is mixed in the pump and also heated. And react in this tank.

And once I'm done with the reaction, I'm going to dump the glycerin off the bottom with this set of valves. And then I'll do whatever it takes to get the methanol and other nasties out. And when it's done, and I'm happy about that, it goes into this storage tank. And once it's in the storage tank, I can put it in my tractor, my car, whatever.

MARK HALL: Walter, Lance, thank you for showing us how biodiesel is made today. Wherever you live, you can make a difference in our country's energy crisis. Watch and do what you can to reduce our dependence on foreign oil. Visit our website and you will see more ways to save renewable energy. For the Alabama Cooperative Extension system, this is Mark Hall.

Credit:Expansion of the Universities of Alabama, A&M and Auburn