Homemade RO project

[Gary in NH]

Small Sap RO Project

I’m finally getting around to posting the details of my homemade RO system. I work in water treatment and have worked with RO systems for along time. I started building this RO toward the end of the season last year from different parts from other scrapped systems. I did buy new module housings and RO membranes. This is my 1st full season using the RO system.

System details:

(2) Filmtec TW30 – 2521 RO Membranes rated @ 325 GPD each @ 225 psi
Procon Stainless Steel RO High Pressure Pump
Pressure and Concentrate adjusting valves
Concentrate and Permeate flow meters
On / Off RO Control with low pressure shut-down
Sap Pump – Procon Stainless Steel – will provide 100 psi from gravity feed
10” Sap pre-filter using 1-micron disposable cartridge

This system is located in my basement. I store sap outside in sealed containers and run a ½” line in through a basement window to feed the system. I have a 35 gallon permeate tank and a couple of 5 gallon containers in the basement to collect concentrated sap. When my 35 gallon permeate tank is almost full I redirect permeate to a dry well line. I also have hot and cold running softened water available. Washing the membranes is done by mixing up a solution of RO soap in a bucket and drawing it into the system by way of the sap pump. The system is tubed with food grade polyethylene plastic tubing. The high pressure side uses tubing that is rated for 250 psi. I have utilized push-in type quick connect fittings. This makes moving tubing around for washing or maintenance easy.

The system will process 11 gallons per hour of 34 degree F sap. Production will increase if sap is warmer. I concentrate to 8.0 - 8.5% sugar content. If I start with 65 gallons of sap I will have around 15 gallons of concentrate to boil. I can boil at around 5 to 6 gallons per hour with two propane burners and stainless steel restaurant pans. One pan gets used as a pre-heater.

The system is very small compared to most RO’s. I only have 35 taps and not all are big producers so the system works good for me. The nice thing about this system is I can start it up and walk away for several hours. I also didn’t need to invest in an evaporator. Running the propane burners off a bulk propane tank is a reasonable fuel cost. I am estimating my total syrup production will be around 5 or 6 gallons this year. My kids call the system “ The SAP-erator

[MaplePancakeMan]

That looks awesome. How much did you spend total and if you added another membrane, could you up the output?

[skinny78]

Looks good Gary! Can you explain more about washing the membranes? You mentioned moving tubing around. Have you checked your permeate sugar content? Just wondering if any sugar is getting through your membranes. I hope to build a system similar to yours next year.

[Russell Lampron]

Nice looking RO Gary.

I have seen this question asked in a few threads so here goes. I wash my RO with soap after every use. I then rinse it with all of the filtrate water that I saved from that use. I use the Lapierre RO soap and mix about 2 tablespoons with 15 gallons of water. The ph of the mixture is about 11%. This is the first season that I am checking the ph and can't seem to find what I should be setting it at. If I remember right I was told that it should be in the 10.5 to 12.5 range. My RO has a valve that by-passes the high pressure pump when I am doing a wash cycle and rinse cycle. The soap works best in the 30 to 43 degrees Celcius range and my RO machine automatically shuts at 43 degrees Celcius.

Russ

[Gary R]

Nice looking RO! Thanks for sharing the details. I would think there are lots of small producers that would love something like this instead of investing in a larger rig. Good luck with the sugarin':D

[WESTVIRGINIAMAPLER]

What do you RO guys do with really cloudy and low quality sap, won't it plug the membrane fast??

[Amber Gold]

I’m working on a 2x6 this year and plan on expanding to 50 taps next year and further expanding my operation as I find trees around town. To do that I would need to either buy a larger evaporator or buy an RO system. If it wasn’t too expensive I’d rather buy an RO. I was wondering what your full materials list is, where you get those materials, the cost, an assembly diagram and/or instructions. I’ve never seen an RO before, but am mechanically inclined.

I understand that they need to be cleaned after every use, which isn’t bad, but is there any yearly maintenance? Also how often do the membranes need to be replaced and at what cost? Also do they use a lot of electricity?

Thanks for the info.

Josh

[Russell Lampron]

Brandon, I run every drop of sap that I get through my RO, cloudy, buddy or yellowish. It doesn't seem to affect the performeance of the membrane at all. I wash mine more often than the manufacturer recommends because I don't get the sap runs that would require me to run it that long.

Josh, the amount of electricity that my RO uses is much less than the cost of the fuel that I would otherwise burn in my evaporator. I burn wood that I harvest on my own land and the actual dollars spent on fuel for the tractors, chainsaws, wood splitter, wood elevator and dump truck is still a lot more.

Russ

[802maple]

Like Russell said you can't wash them to much. If you wash them religously everyday that you use them, and rinse them before they need it, they will be like the energizer bunny. The R.O."s that we had been running 22 to 24 percent sap thru are now 7 years old and all 6 membranes are still producing over 100 percent of what they are rated to do and not passing sugar. There are sugarmakers in the area that have 12 year old membranes and they are still working well,yet when I used to service them I saw guys destroy them in 2 years as they were just to busy to take care of them, so they pay the price. My theory is when you think you have washed them enough, wash them again.

[saphead]

Jerry,I'm curious as to what brand and model # you're using.Was it Filmtec nf270 that they had the problem with?
Craig

[802maple]

I won't use the 270 as they will not allow you to go to high concentration without passing sugar as I have been finding out. All I would use is the Mark 1, they are a little slower but they will take the abuse of high concentration and come back for more.

[Gary in NH]

That looks awesome. How much did you spend total and if you added another membrane, could you up the output?

I spent around 450.00 total. The membrane housings were 95.00 each with end plugs and the membranes were 103.00 each. I could easily add another membrane to the exsiting two and increase output by 1/3. I don't think I would go to four membranes. I would need to go with a higher output RO pump. I would re-design the system and go to larger membranes. I don't have the sap to justify expanding it though. A note to those who may try this at home. I tried running this system with one membrane and recirculation of sap to the feed side of the RO pump. I couldn't get more than 4.0 to 4.5% sugar concentration. The system runs at 225 psi so I think you would need to get to the 500 psi range to get to 8.0% with one membrane. The plastic tubing and fittings aren't rated for higher pressure like that.

[Gary in NH]

Looks good Gary! Can you explain more about washing the membranes? You mentioned moving tubing around. Have you checked your permeate sugar content? Just wondering if any sugar is getting through your membranes. I hope to build a system similar to yours next year.

Permeate sugar content is non-detectable with my sap hydrometer. I am using tap water RO membranes and they let less through the membrane than a nanofilter membrane. When I clean I draw RO soap out of a 5 gallon pail and it recircs back to the pail for while. I can bypass the inlet solenoid assembly on the RO and circulate the RO soap by way of the sap pump. I can clean the membranes in series or parallel and adjust pressure and flow by the throttling valves. I usually just do it in series. I am only processing 60 to 80 gallons of sap at a time.

[Gary in NH]

Nice looking RO Gary.

I have seen this question asked in a few threads so here goes. I wash my RO with soap after every use. I then rinse it with all of the filtrate water that I saved from that use. I use the Lapierre RO soap and mix about 2 tablespoons with 15 gallons of water. The ph of the mixture is about 11%. This is the first season that I am checking the ph and can't seem to find what I should be setting it at. If I remember right I was told that it should be in the 10.5 to 12.5 range. My RO has a valve that by-passes the high pressure pump when I am doing a wash cycle and rinse cycle. The soap works best in the 30 to 43 degrees Celcius range and my RO machine automatically shuts at 43 degrees Celcius.

Russ

Russ,

Thanks for the info. Is yours a Filmtec membrane? I use the Airablo RO soap and bring the solution pH up to 11.0. I can mix with warm water since my system is in the basement of my house. Filmtec's website has info on maximum pH range and contact time for all their membranes. I could go to a pH of 13 for up to 30 minutes. I have also done a couple of citric acid washes after flushing out the RO soap. The citric acid only goes down to around a pH of 4.0. Hydrochloric acid would go lower and the membrane will take a pH of 1.0 for 30 mins. With the limited amount of sap I process I haven't had any membrane problems. My kids still talk about how nice your Mother was to them last year during Maple weekend. They really liked the sugar on snow.

[Gary in NH]

[quote=Amber Gold;44985]I’m working on a 2x6 this year and plan on expanding to 50 taps next year and further expanding my operation as I find trees around town. To do that I would need to either buy a larger evaporator or buy an RO system. If it wasn’t too expensive I’d rather buy an RO. I was wondering what your full materials list is, where you get those materials, the cost, an assembly diagram and/or instructions. I’ve never seen an RO before, but am mechanically inclined.

I understand that they need to be cleaned after every use, which isn’t bad, but is there any yearly maintenance? Also how often do the membranes need to be replaced and at what cost? Also do they use a lot of electricity?

Thanks for the info.


I started my system from a frame and components from other systems that I had available to me and I was able to buy components at cost. I don't think you could start from scratch and build one cheaper than you could find a used one somewhere. You could also look on the internet for other tap water RO systems. Try Crane Environmental http://www.cranenv.com/

[Amber Gold]

Thanks for the info.

[Russell Lampron]

Gary I have a Filmtech NF90-4040 membrane in my RO. What brand type are you using. I had a chance to check out Dows web site and see that the XLE membrane is ok to use as a replacement for the NF90 and NF270 membranes. Unfortunately they don't make a 4" Mark 1 membrane. I also found that 12 is the ph number that they recommend for a caustic cleaner.

[Gary in NH]

Gary I have a Filmtech NF90-4040 membrane in my RO. What brand type are you using. I had a chance to check out Dows web site and see that the XLE membrane is ok to use as a replacement for the NF90 and NF270 membranes. Unfortunately they don't make a 4" Mark 1 membrane. I also found that 12 is the ph number that they recommend for a caustic cleaner.

I am using Filmtec TW30-2521's. They are tap water membranes. The operational spec per Filmtec for this membrane is pH 2-11. Short term cleaning up to 1/2 hour is pH 1-13. If you ever want to try an XLE 4" x 40" let me know. I have several on hand. The XLE designation means a low energy (low pressure) membrane. They typically run at 120 to 150 psi.

[Russell Lampron]

Gary,

I would very much like to try one. I have been reading the specs for the XLE and it will produce 1000 gallons more permeate per day than my NF90 which does 1500 gallons per day. The spec sheet also says that the XLE can be operated up to 600 psi but doesn't say what the optimum pressure should be. It looks like less sugar will pass through it too. Send me a pm and we can discuss the details of this further.

[mapleman3]

802.... 22% sap??? isnt that kinda harsh, I thought I heard from many out there that you shouldnt go more than 12% for taste... less boiling less flavoring by the natural carmalization by the heat??? I'm just learning so I'm just asking.

[802maple]

I have said on here before that 22 percent sap does have a lighter flavor then 12 percent but not a bad flavor. When the packers buy it they like it as they blend most of there syrup into Dark amber anyway. They can get away with using the crappy late season syrup when they can blend with the lighter flavored high concentrate. Also I think that some off flavors that come from so called high concentrate comes from sugarmakers concentrating to far ahead and letting it set until they feel they have enough to boil. When I high concentrate I feed the sap almost directly to the evaporator, and at 22% or more I can make 130 gallons of syrup per hour, and burning 22 gallons a hour of oil, it is a no brainer. 6 gallons of syrup to a gallon oil