Before your SVO/WVO can be used as a fuel
you will need to filter it & dewater it.
It is recommended that you filter your WVO down
to at least ten microns (2 or 5 microns is better!)
& you MUST remove all the water from the veggie oil!
Filtration.
It is imperative that
the gunk & particles of food, flour, chicken parts, small rodents, insects,
snakes, etc. be
filtered out of the oil before it can be used as your fuel.
The best method to clean & dewater your WVO is by using a centrifuge. We are currently working on an affordable prototype & will be posting information on that as soon as we finish tweaking it & can bring it to market here in Belize. Normally these are extremely expensive & can cost up to $50,000+ BZ. We are estimating that when we finish testing our centrifuge prototype, we'll be able to make them available for under $5,000. BZ. If you are using a lot of WVO, you'll make this money back very quickly!
Until then, the only other choice is by running it through strainers & filters & letting it settle out.
Using big filters & passing the WVO through multiple filtering stages ensures a good, clean, useable VO. Filter the VO in stages, starting with straining through a plastic strainer or metal window screen, then several layers of cloth & finally several different size filters. Let it settle out for 12-48 hours or several days before you process it through the next stage. The more time you spend on filtering your oil will always be well worth it. & if you're not sure, pass it through several more layers of cloth sheets & see if anything gets left behind, indicating that the VO is still dirty. The fine sediment has a way of clogging your filters quickly! Clean it BEFORE you put it into the BELIZEL tank.
This is not the process to skimp on!
Your
filter (& pumps) may have a high flow rating (i,e, 20 gpm), but no matter how hot the veggie oil is, you will
never get that flow rate with VO. Keeping the oil warm or heated while filtering
will help
it flow better. A good temperature to try to reach is 120f. It is much thicker
than regular diesel & over time will clog your filters quicker. Try to do all your filtering during the middle heat of the day,
using the Sun's free heat to warm your WVO or by heating it before you run it
through the filters/prefilters.
Your filters will all eventually clog. When, & how often depends on how clean
the oil was to start with & how you process & filter it. Filtering in multiple stages
& allowing it to settle a few days or a week between the
different filtering stages will help a lot.
There are several ways to properly filter the SVO/WVO. After filtering many thousands of gallons of WVO, this is one of my preferred methods for low volumes. If you will be processing lots & lots of WVO, then I recommend using a centrifuge system (see below & links pages for more information).
For small to moderate volumes I use a gravity feed system for the first pass, & then h& pumps, with multiple drums & filters as described below.
Most times you'll be picking up the oil in the buckets the restaurant received it in, or pouring it into your own 5 gallon pigtail bucket through a strainer. Then after you bring it home, filter it with our Filtering Method as described below.
Obtain 2-4 plastic 55 gallon drums or tanks. You can buy these directly from Jabiru Bamboo Limited. You'll need at least two, though 3 or 4 is preferred. Outfit the first 2 drums with an open top that can also be sealed. Install a drain valve about 2-3" from the bottom of each. the first drum is for straining & pre0filtering the WVO. The 2nd Drum is for Filtering, plus de-watering The 2nd & 3rd Drums are the final product, that gets pumped into your BELIZEL Tank after passing through one More filter.
Make a flat area for them to sit on, & if possible, make a two-tiered area, so you can drain "Tubby" into the 5 gallon 1st Stage Filtering Bucket or a water 5 gallon container simply using gravity. If you only have a single flat surface, then you'll need to use a pump or a vacuum to pump the VO into the next tank/drum. These are best when under a zinc roof for protection from rain & the sun. They also need to be easily accessible to your vehicles for filling up the tank & dropping them off to get filtered.
Filtering Method
STEP 1-Straining The
Veggie Oil: Pour the
warm WVO through our plastic
strainer, an aluminum window screen or both. This is
usually done when collecting the oil right at the restaurant or at back of the
truck before I take it home. If it's raining, I'll wait until I get home & can
do it under a roof where the veggie oil can stay dry.
I usually make my rounds once a week to my local smaller restaurants & take with me
several 5 gallon buckets with lids. At my normal stops where they always have WVO for
me, I leave buckets so they can empty the fryer as needed. These have
the plastic strainers &/or aluminum wind screens fitted to the top so it gets the big chunks out right
away. If it's a smaller restaurant, or one that doesn't have much left over WVO,
I pour it into one of my 5 gallon buckets with the plastic strainer that I carry
with me. I also carry a 12vdc diesel fuel pump with a double strainer & a 50'
hose to suck the oil our of 55 gallon drums either I have left or the restaurant
already had for disposing the WVO.
Step 2 -Straining & Pre-Filtering the WVO: Once I get
the WVO home, I
pour or pump it through a double or triple layer of cloth sheets fitted tightly to the
top of a 55 gallon drum.
Blue Jeans can also be used by sewing the pant legs tightly shut & cutting two
holes in a drum lid & placing the blue jeans legs through them. Each leg will
hold about 5 gallons. I made a wood frame to hold 2-3 layers of cloth, supported
by chicken wire underneath. After it strains through the cloth, I put the top lid back on
& let it settle
out for at least a day, preferably 2-4+ days. Longer is always better! Then it'll be ready for for
Stage 1 Filtering. I use
"Tubby", a short drum cut from a 55 gallon drum for
this straining & pre-filtering step. It has a drain
above the 5 gallon mark on the drum for gravity pouring into the
Stage 1 Filter
bucket. After a few days of settling, I drain it into our
Stage 1 Filtering System.
I leave in the bottom 4-5 gallons where all the sediment has settled out & after a few months, I pour this carefully off into a 5 gallon bucket & through several layers of bed sheets or t-shirts. The very dirty bottom sludge with all the fine sediment & gunk I just dump. After I clean out "Tubby" & any remaining gunk in the bottom, I pour this same WVO back into "Tubby", through it's double layer of bed sheets when I start to strain another batch so I can reuse it.
Filtering Stages:
Step 3 -Stage 1 Filter: Drain the
strained VO into our
Stage 1 Filtering System, which cleans it down to about 30 microns. I use
"Tubby"
for my straining & settling in Step 2 & place our 5 gallon Stage 1 Filter
below the drain.
I then drain
"Tubby"
into the Stage 1 Filter. When that bucket
gets close to full, I pour it into the next 55 gallon drum for settling, &
dewatering.
I found it easiest to pour directly from Tubby into a 5 gallon water container & then place this upside down on the Stage 1 Filter (just like your water bubblers at home). Then I can walk away & do something else while 4-6 gallons of veggie oil gets filtered. I then pour this into a clean 55 gallon drum to settle again, & then test for water.
Step 4 - Dewater Stage: When it has settled in this next drum, I test it for water & if needed (which usually it does!) I mist wash it (as described below) to remove any traces of water left in the WVO & then let it settle for a few more days before the next step. Mist Washing also helps to removes some of the sediment & food particulates that are left that will clog your filter prematurely. Heat Settling will also help the water to separate out. Once the water is removed, then it's ready for final filtering.
Step 5 -Stage 2 Filter: After it has settled in the drum for a few days after Mist Washing, I drain off the bottom water. Then I then pump it through our Stage 2 Filtering System. This cleans it down to 10 microns. I only pump from 6" or so above the bottom of the drum & don't use the bottom oil in the drum since it can still contain sediment (& water) that will prematurely clog your vehicle's filter. You'll know when to stop filtering by the gunk line that forms on the drum insides & by the color & content of the veggie oil. When it starts to get white &/or thicker, stop!
Step 6 -Stage 3 Final Filtering: At this final stage, the WVO is pretty clean & has fully settled out. I pass it through a Stage 2 5-10 micron diesel fuel filter as it gets pumped into the BELIZEL Tank. On my h& fuel pump for this drum, I installed this Stage 2 Filter 5-10 micron diesel fuel filter, & this ensures that the VO is extremely clean when it reaches my BELIZEL Tank.
It is recommended that you use a different 5 micron spin on filter for the Stage 2 Final Filtering, but a 10 micro will work if that's all you got. I am looking for a constant source of 5 microns filters here in Belize & when I find a reliable source, I will offer them for sale. Right now, I can only find the 10 micron size.
This 6 Step Filtering Process makes sure that your filters on your vehicle go much longer between changing & clogging. I always carry extra spare filters anyways in my truck so when they do clog, I can quickly change them on the road & keep going. I usually go for more than 300o-6000 miles before having to change my filters on my truck.
Water in the Oil
Water is heavier than oil (the specific gravity of water is lower than VO, so the water sinks & the VO floats on top). After a few days of settling in a drum, the majority of the water will sink to the bottom & can be drained off. There can still be water suspended in the VO, & that will need to get dewatered before it can be used as a fuel. You want to get the water in the oil down to around 500ppm before using.
There are two types of water exist in VO:
Free water &
Suspended water
Free water exists in diesel fuel & is the reason why there is a water drain on most diesel engine's
filter. Even a teaspoon of water passing through the Injector Pump (IP) or
Injectors can severely damage them requiring replacement. Since these are
expensive, great care is
taken to prevent this free water from passing though them.
Suspended water does not exist in diesel fuel since it does not have
sufficient viscosity to keep even microscopic droplets of water suspended for
long. Both WVO & SVO does have sufficient viscosity to keep microscopic
droplets of water suspended for a long period of time & you must remove not only the visible but
also the invisible (to
the eye) suspended (micro droplets of) free water as well.
Suspended water causes damage to Injection Pumps (IP) & Injectors in a process called
cavitation. This can also cause pits to develop on the piston walls &
is very costly to fix. It can ruin an entire engine (& has!) not to mention
ruining the IP & injectors. When in doubt of the quality of WVO, dewater it!
Most of the problems people have when using SVO/WVO in their vehicles are due to one of the following:
Air leaks in the fuel line causing the engine to be starved of fuel. (Recheck & tighten all hose clamps)
Clogged filters from not properly filtering the WVO. (Filter it!)
Too much water in the SVO/WVO! (Dewater it!)
If you're not sure if you have too much water in your oil,
simply dewater it
(Remember: Air Leaks, Clogged Filter & too much water in WVO are usually the main problems!)
Testing SVO/WVO for Water
Place a drop of the SVO/WVO on a very hot comal, wok, cast iron
or heavy fry pan. It should sputter & only form small bubbles if there is no water
present. If it sputters & splatters, you have water that will need to be
removed from the SV0/WVO.
Dip your finger into the SVO/WVO & quickly run it across a cast iron or heavy duty fry pan or Wok. Heat the pan to a very on high temp (approx 350f) until the streak you made with your finger begins to produce smoke. Then pour in the some more of the SVO/WVO, so it covers about 1/4" of the bottom of the pan.
Look closely at the bottom of the pan, at the line where the oil meets the
bottom of the pan. If there are very
small bubbles forming, then this indicates some suspended water. The more
bubbles you see indicates more suspended water in the SVO/WVO.
You can accept a FEW suspended bubbles (up to 3 per sq inch maximum). If there
are lots of small bubbles, that oil is unacceptable. If crackling or popping is
heard then way too much water is present for the VO to be safely used as fuel.
It will need to be dewatered.
If water droplets are visible in your oil then no
further testing is needed. Seeing them means you got water in your oil & it
needs to be dewatered. Visible droplets of
water will spatter hot oil out of the pan & can cause burns or fire.
The visibility of bubbles is dependent on the
temp of the underlying pan & this may be regionalized depending on your heat
source.
If the cast iron pan has been washed or not used previously it must be "seasoned" to make certain there is no moisture trapped in the pores on the surface of cast iron.
False positive results (bubbles) can be obtained if the pan is WAY too hot or if solvents were previously mixed in the WVO.
False negative results (no bubbles) are possible if the suspended water has high concentrations of salt/sugar/ acids. If you are unsure, always dewater!
Removing the Water
There are several ways to dewater your SVO/WVO. One method is by Mist Washing. I use my 2nd drum & Step 4 for this process. Heat settling will also do a good job, (but the best method is by using a centrifuge).
Boiling the water out of the VO:
Some people boil the WVO/SVO, but there is still debate whether it removes the suspended water sufficiently. If you do boil it, settle it out for a few days before boiling it. Drain off the bottom few inches & then boil it in a steel drum for some time, watching the steam being released. Eventually, the steam will decrease & then you'll have gotten most out. Use the above test, & if needed, repeat the boiling until it passes the tests described above. Let it settle for a few days afterwards & drain the bottom off which will contain some of the remaining free water & some sediment.
Note: Be extremely careful that it doesn't boil over & catch on fire! People have burned down their houses when this happens. Oil fires are very difficult to contain & put out.
De-Watering your WVO through Mist Washing:
When your drum is about 1/2 to 3/4 full of WVO that has passed through the Stage 1 Filtering, you're ready for Mist Washing. You'll need a very fine plant misting nozzle. If you are just mist washing a 5 gallon bucket of WVO, then you can use a spray bottle with a rotating nozzle that offers several different spray patterns & use the finest mist nozzle it has. If you are doing large quantities, like a 55 gallon drum, you'll need lots of water, so getting the proper misting nozzle for a garden hose is preferred.
I wait until it's a very hot day, above 90F, & then spray the mist over the surface of the VO, being extremely careful not to break the surface tension of the VO (the meniscus). The water will sink to the bottom & the VO will float on top of it.
Keep spraying the surface, but not too fast nor with too much water. You don't want the water to pour in, just lightly mist the surface. The water droplets will quickly sink picking up any water soluble contaminates & particulates.
The first round of washing will produce very dirty water, & needs to be drained off the bottom of the drum thru the bottom drain. Pour the water out of the bottom drain on the drum until it looks like regular VO with no water remaining that you can see & repeat the mist washing until no more particulate can be see in the water as it drains out. It should look clear & clean. This may take a few gallons of mist washing or up to 25+ gallons of water depending on how dirty the oil was to begin with. After you drain the water off & it's clean, let it sit for at least 12 hours for any remaining water to settle. When it cools down below 90f, pump it through a 10 micron filter into the next drum & let it settle some more.
You can then finish dewatering it by heat settling & heating it up & letting it settle out, using a centrifuge spinning dewater filter or vacuum dewatering techniques or with Bubble Washing.
Heating Settling the VO:
After mist washing, & letting it settle for a few days, drain off the bottom. Then in a steel drum, bring it to a warm heat, about 120f, but not boiling. Hold it there for some time (about an hour or two) & then turn off the heat & let it settle out for 12-24 hours. This will help to separate the remaining water from the VO. After settling, drain this off & finish the filtering stages. This will help it to settle out much faster than just cold settling.
There is also a good heat method using an electric water heater tank, which you can add the oil, plug it in & it'll heat it & let it settle out with very little effort on your part. We'll make these available shortly.
Centrifuge:
This is the best way to do, but requires a special Centrifuge flywheel
filter. Not only does it filter out the gunk & fine particles, it removes the
water through centrifical force. There are some commercially made ones available
in the states or a good machinist can build you one. I'll have more information
here soon, but for now, check out my links page for links to systems others have
done & what's available in the States. I am looking into getting some made up
down here & have a working prototype that I'm tweaking to make it more
efficient & cost effective. I'll post the information on this Web page when
ready!
The filtered & dewatered oil should be placed in a container with minimal air space in it & sealed. Oil to be stored for some time should be kept as cold as possible & protected from sunlight. If bacterial growth is present commercial biocides designed for diesel fuel should be used. If stored oil develops a smell like paint &/or has lightened in color (indicating a raise in peroxides) it is highly oxidized & should be discarded.
When the oil is to be used, pump it from the final storage container, through another filter & into the BELIZEL tank.
Remember, this VO CAN NOT BE POURED DIRECTLY INTO YOUR diesel tank! It needs our specially designed BELIZEL tank to run properly in your vehicle.
Always leave a small amount of WVO in the bottom of the drum & never draw from the bottom. This oil can be poured into the next batch of oil being prepared, run through the straining & filtering stages again & reused.
All storage vessels should be thoroughly cleaned after filling & stored in a secure area to prevent the attraction of varmints & the possible rupture of the storage containers by pests. The smell of VO will attract insects, rodents & large carnivores like Foxes, Dogs or Jaguar. Keeping these storage oil containers & area around them clean is essential.