Tag Archives: anaerobic digestion

Compost king: Paul Sellew at TEDxBoston

While TED talks mostly make me cringe, this one explains composting pretty well.

To be clear, he owns an anaerobic digester and that puts his presentation in a light I don’t fully agree with, but if you put that aside it’s worth watching.

The initial pitch is spot on up until about 6 minutes when he goes pro-burn while taking a dig at solar and wind…super lame.

It’s best to view composting as avoiding the landfill, cutting emission, and replenishing soil- the energy talk is nice, but it’s not the job for anaerobic digestion.

That being said, the reality is that this model is expanding, and I’m not opposed to it entirely- outdoor aerobic piles can be difficult to manage when their daily allowance is several hundred tons per day and the inputs aren’t being screened properly.

Our efforts must focus on everyone composting at home for the best results- no trucks, no burning, and immediate use of the finished compost at home and in the community.

Don’t get me wrong- whatever it takes to get organics out of the landfill is great…but I encourage everyone to learn how to compost at home and leave anaerobic digestion facilities for the large quantity generators.

Anaerobic Composting – Is It Worth It?

Anaerobic Composting – Is It Worth It?

Anaerobic composting is a simple and fun alternative to the usual ways of composting, which include using a compost bin, a tumbler, or worms. While it may be the easiest method, it takes a really long time to finish and it has different environmental consequences…more on that in a moment.

A popular method I’ve read about is to use two thick black garbage bags, a bucket to measure out the contents and some water. Add equal parts shredded food scraps (no meat/dairy/seafood), soil+some finished compost, and “brown” materials (shredded leaves, shredded paper). Add some water to get the material damp, but not completely soaked. Tie off the bag, then put it inside the other garbage bag and tie that off, too. All done!

This process is often said to finish within 6-8 weeks, but based on my findings, I’m willing to bet that’s unusually fast. I gave it another six months to sit…how does it look? The results are really nice! Was it worth it? Yes and no.

If you’re composting, that means you’re avoiding throwing away perfectly good material to the landfill, which is always a good thing. Speaking of landfills, they spew out one third of our methane output (along with nearly 100 non-methane organic compounds that are severely toxic such as dioxins and furans), which has a global warming potential 23 times greater than carbon dioxide (results from aerobic composting).

While only a small amount is emitted when opening the bag, every little bit counts and aerobic home composting is the best method.

Maybe I’m being a bit over the top…your home composting effort is obviously not composed of the same materials as a landfill and therefore has drastically different emissions. Regardless, I want you to think about it… compost as much as you can!

The easily avoidable negative aspect is that I’m creating garbage bag waste, so this will be the last time I try anaerobic composting using this method. At least I can hold onto this garbage bag and fill it up over time with my non-compostable/non-recyclables, which is a pretty small amount of our waste if you think about it.

A commenter on my previous anaerobic composting video stated that I should try using a 5 gallon bucket with lid so I avoid the plastic bag waste. While the standard lid wouldn’t be airtight enough, there are definitely airtight lids out there such as the Gamma Lid brand that has locking lids.

So there you have it- not the best possible method, and I always suggest aerobic composting over anaerobic, but if this method works better for you (try buckets!) and keeps you from sending stuff to the landfill, go for it.

If you’d like to learn more about landfill gas and their emissions, check here: http://www.energyjustice.net/lfg#2

Anaerobic Composting Update

Ahhhh, the weather broke… kind of.  I went out on the balcony for the first time since the Fall and checked out the garbage bag, it was stuck to the deck a little bit.

Back in November, I opened this bag the first time around and the material was definitely breaking down in there, but it wasn’t finished.  I wanted to give it another six months and take a peek, so when May comes around we’ll see how it went through the winter months, and if the cold had a serious effect on the process.

An aside: I was collecting the last of the leaves off my street yesterday to use for my next compost pile, and I decided to try a biodegradable garbage bag since I had some different ones lying around.  What a disaster!  I was only able to fill it halfway before the bottom fell out.  While I would love to support using bioplastics in some applications, they don’t make sense if you’re performing a heavy duty task…like filling a bag halfway with dry leaves.  Maybe the bag was really old.

Anyway, garbage bag opening ceremony in another 6 weeks…

Anaerobic Composting – How Does It Work?

Anaerobic Composting – How Does It Work?

Anaerobic composting is a simple and fun alternative to the usual composting methods, such as using a compost bin, a tumbler, or worms.  While it may be the easiest way to do it, it takes a really long time to finish.

All you need is two thick black garbage bags, a bucket to measure out the contents and some water.  Add equal parts shredded food scraps (no meat/dairy/seafood), soil+some finished compost, and “brown” materials (shredded leaves, shredded paper).  Add some water to get the material damp, but not completely soaked.  Tie off the bag, then put it inside the other garbage bag and tie that off, too.  All done!

This process is often said to finish within 6-8 weeks, but based on my findings here, I’m willing to bet that’s unusually fast.  Perhaps if the process is done during the warmer months it would be quicker, but it’s gotten to near freezing here for the last week or two and my batch isn’t finished.

However, the end results thus far are impressive: almost everything is unrecognizable, and the finished compost inside smells just like the earthy stuff you buy from the garden center.

While this experiment was mostly a success, I’m going to bag it up and give it another six months…I’ve read that some crazy composters will give it at least a year to be completely finished.  To be continued!