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P2 for maple syrup processors
Are there any markets for the water produced by separating it from maple tree sap using a reverse osmosis process? Also is there any P2 guidance info for maple syrup processors?
Answers to this question came from members of the P2Tech e-mail list:
Response 1: Assuming the RO system is maintained well and no membrane leaks are allowed, the water generated is permeate - essentially deionized water. By its properties it should be drinkable, although given that it does not come from a potable source, it is unlikely a health department would allow it to be labeled or used as potable without testing.
In terms of markets, there should be nothing present in the water that makes it more valuable than plain water. It can be used for irrigation, for cleaning, for toilets etc. It will not have a high value, so it is not the type of material that could be trucked very far to another user. A similar stream is condensate of whey (COW water) from cheese processing. It was originally a bi-product from multiple effect evaporators and now also comes as the permeate stream from RO processing of dilute whey. In cheese dairies it is commonly used for equipment cleaning, and vacuum pump seals.
Another similar stream is RO reject water from further purifying potable water. It is city water with doubled or tripled dissolved salt content. It is fairly common that it is discharged directly to surface waters under an NPDES permit, with no treatment other than assuring that there is no residual chlorine present. This could be a last resort for maple syrup permeate, but it would be an unfortunate and wasteful disposition for very clean water.
Response 2: Without an analysis of the water I am shooting in the dark.
The RO water should be useful for wash water or make up water for boilers if low conductivity. It may need UV treatment for wash water to keep the health inspectors happy. It all depends also on the sugar content for wash water. It would also be a potential wash water for the RO system prior to maintenance.
The process condensate from evaporation processes would likely be suitable for making low pressure steam with little additional chemical treatment. It should be soft and low conductivity to start with.
The water and wash water from your process and floors would have sugars that could be beneficial to compost producers. The value would likely approach the trucking cost if the composter is nearby provided the sugar content was 2%. You may collect first hot rinse to help the sugar content.
Maybe you could make a natural drink. Check out the nutrient content..."Bottled Maple Nutrient Drink."
Response 3: That's a sticky problem you've got there....
I cannot recall the name of the firm but a few years back I spoke at a P2 workshop for food processors, conducted by SC Edison in ag regions of southern california. One of the other speakers was from a company that bought and processed all sorts of sugar-bearing aqueous waste streams, which they would then process into fermentable feedstocks and use to produce ethanol and/or citric acid.
I apologize for not remembering the name of the firm -- I do recall that they were located in Orange County, CA -- but I mention it because it leads me to believe that the business model has probably been replicated in other regions. I tried a quick Google search to find similar firms but came up empty, but a call to your local cider mill or juice plant, inquiring about what they do with their off-spec product, might provide good leads.
Hmmmm...what else? Maple syrup wine? Could be the next big thing...the world needs a good breakfast wine that goes with waffles.
As far as other p2 strategies, you might want to review the ChemAlliance virtual plant tour (http://www.chemalliance.org/Handbook/plant/index.asp) and review the case studies related to the terms "viscous" and/or "heat exchange" (to name a few). While the case studies deal almost exclusively with chemical processing, the unit operations are quite similar and you may find some inspiration from how others have dealt with the problems inherent in heating highly viscous liquids (reducing delta T driving force; improving mixing at the boundary layer, e.g. by scraped surface heat exchange; reducing adherence of materials by surface modification e.g., teflon or similar coatings).
Response 4: Here is one company that takes various products and converts them to ethanol:
They have several locations across the country.
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