Tag Archives: methane

Kroger Converts Food Waste To Energy (article)

(original article found here: http://www.wasterecyclingnews.com/article/20130516/NEWS02/130519945/kroger-converts-food-waste-to-energy?utm_campaign=corpsustain_newsletter&utm_medium=corpsustain_email&utm_source=corpsustain_20130520&utm_content=article1)

The Kroger Co. unveiled an anaerobic digestion system to convert food that can’t be sold or donated into biogas that will help power its distribution center in Compton, Calif.

The Cincinnati, Ohio-headquartered retailer expects the system will process more than 55,000 tons yearly of unsold organics and food processing effluent, roughly 150 tons per day. The energy produced will provide 20% of the energy needed by the distribution center, the company said in a news release.

“Investing in this project is a good business decision for Kroger and, most importantly, an extraordinary opportunity to benefit the environment,” Rodney McMullen, President and COO of The Kroger Co., said in a statement. “We want to thank Governor [Jerry] Brown and his team at CalRecycle and CalEPA, the City of Compton, the [South Coast Air Quality Management District], and most importantly the team at FEED [Resource Recovery] for making this renewable energy project a reality.”

Oh Kroger… they hold a special place in my heart because the last few times I was out traveling in the midwest, they were one of the few that didn’t compact their waste (resources, as I like to call them).  Their dumpster was full of food from every corner of the store- cakes, fruits and veggies, sandwiches.  Good friends of mine would live off of the spoils of that place, and I hope they still do.

Have you read their sustainability report? They seem to have a grip on the idea of what sustainability means.  Their report in addition to the article state that their composting programs are being utilized for non-donation organics, which is great.

I’m curious if the anaerobic digester that they’re feeding is strictly organic materials and not inclusive of anything toxic.  Anaerobic digestion is best when the gas collected is used for heating, but not for electricity generation, which unfortunately seems to be the focus here.  It would really bother me if it’s being considered a “renewable” energy… when you burn something, there’s no renewal- it’s gone.  Ugh, don’t get me started.

Either way, Kroger is making some good progress here, and is to my knowledge one of the more responsible grocery chains out there.  Donating their spoils and keeping the rest from the landfill via composting is a critical step that all grocery stores need to partake in- it’s too easy to set up and the benefits are too great.  While it’s not the highly preferred aerobic composting method, it’s still composting, and we need a lot more big companies thinking like this.

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

Why Compost When I Can Landfill It?

Obviously I’m joking about the title, but people often forget that one of the main benefits of composting relates to greenhouse gas reduction.  How?  You may have wondered about this before…I know I did.  Why would throwing food scraps in my backyard pile be any different than in a landfill?

It all started today when I was reading a document about waste treatment methods (my other favorite topic) and I noticed a parallel with composting.  It was comparing the global warming potential of carbon dioxide alongside methane.

When waste is incinerated, it creates carbon dioxide amongst many other toxins that are conveniently ignored, although they include lead, mercury, dioxin, furans, and hydrochloric acid amongst others.  Carbon dioxide (CO2) has a global warming potential of 1.0.

On the other hand, landfilling results in the production of methane (CH4) amongst other things, which has a global warming potential of 21.0.  More and more landfills are installing landfill gas collection systems primarily to prevent gas migration and can utilize the non-methane gas (methane is usually burned off) to create some electricity.

Where was I going with this?  Oh right.  As I was reading about these global warming potentials, I remembered the time where I was asked how composting differs from landfilling as an eco-friendly waste disposal option.

To break it down simply, it all relates to airflow.  Composting is an aerobic process that requires oxygen to work best, and as soon as it’s lacking oxygen, the anaerobes start to take over, and now your compost pile is smelling pretty gross.  A good compost pile creates carbon dioxide.

On the other hand, landfills are anaerobic, which means there’s no oxygen in the process.  There seems to be this huge assumption that landfills are magical places full of biodegradation…they aren’t!  Yes, stuff degrades, but it’s done in the slowest and lamest way possible.

Again, composting creates carbon dioxide while that same material thrown in a landfill will create methane.  I feel like this explanation is often forgotten about when speaking about the benefits of composting, but it’s very legit and worth mentioning.

I often wonder what it will take to get most people to start composting…I think that this reason alone will come to the forefront in the next few years.  For those of you that don’t compost, dig a hole and get started!