Frenergy / Puxin 2 65m3 Biodigester Assembly

Unpacking and assembly of the Puxin 2.65 m3 domestic biodigester. This product is now available for sale in New Zealand from Solabode Ltd (Trading as: Frenergy; Free Energy from Waste). Contact: [e-mail] or www.frenergy.co.nz for prices.

[@alanwong3989]

Hi mate. Thank you for sharing this video. I live in Christchurch. How is your Puxin biogas digester performing? I’m curious to know.

[@Solaboder]

Hi Alan, pardon the late reply, I didn't seem to get a prompt so only just realised you commented. The Puxin digester has been going great guns since it activated in the early spring last year (2023) in fact i can't keep up with the amount of gas it makes even though i hardly feed it any 'food'. One day i came back from a weekend away and the gas bag was completely deflated, I was like "Oh shit, it burst the bag!" but no there was no hole and after a day or so i figured out the issue and this was confirmed by my Puxin agent; so if the gas level builds up to drum like inflation in the gas dome, it pushes the liquid below it down and out of the outlet pipe, which i had noticed had filled up the 20L flagon I had under it and then some. So if the increase in gas keeps pushing down the liquid level, it can get to just below the inlet pipe invert level and at that point releases all the gas from the dome - I wish I had seen that happen, it might have been dramatic..! So now I keep checking the inlet pipe water level and just top it up with 10 - 20 L of expelled digestate that I keep in 20L flagons. Thus it gets re-fed with cow manure water and it keeps the liquid level topped up. I am down to just me living at home after my son's family moved out so not doing much cooking, though try to use it to boil the kettle for cuppas even though it takes a bit longer than the electric jug. I feed it food waste, about 5 litres with water about once every 2 weeks, with this warm weather and my dome greenhouse being very hot inside, the gas dome is always full or nearly full when the temperature drops as the gas seems to expand when the air around it is very warm.

[@patriot1560]

How is it holding up? Are you getting a lot of cook time? Would you say it's worth the investment?

[@Solaboder]

Hi there, thanks for asking! - i have just replied to alanwong above with a report on how the Puxin digester is working, please read that for an answer to your question. As for the 1000L IBC digester I sold to a local person some months back; that has still not activated even after adding more cow manure. I imported some probiotic tablets from Homebiogas in Israel, (second time they came through, first time MPI seized them...) my customer is in the process of adding 2 tablets every second day for 20 days so hopefully that will activate the digester. My lesson from this is that the bacteria are very sensitive to any contaminants in the tanks before adding cow manure. This one has fertiliser residue which I cleaned out thoroughly but I am thinking that that is the problem. So lesson learned; only use a clean food grade IBC tank when building a biodigester, which cost more but the extra cost is worth it so you get success... Worth the investment..? well I invested in a hot water solar panel 25 years ago, that gives me 100% free hot water... 4 years ago i invested less than $6K on PV panels (2.2kW) and now with a couple of biodigesters going my power bills over the last 3 months have been: $20.48 , $1.08 , and just recently $13.20c -and that all includes the line charge and GST. So yes I do think it's a good investment and cooking on energy created by ones own waste food is very satisfying indeed. I have noticed that the larger the digester, the more efficient it is. The Puxin 2.65m3 has a 2000L liquid capacity while the IBC tank is just 1000L and the Homebiogas2 (which i also have) is 1200L. The Puxin unit can go a long time between feeding and still produce ample gas, perhaps because of the larger colony of bacteria in the tank. You do need to keep them warm though so a tunnel house or geodome greenhouse is the thing.

[@rahulbumra]

Price

[@Solaboder]

In New Zealand I sell these complete units, together with the stove and all the components for NZ$1699 including GST. Freight around the country varies but is around NZ$120