Commercial Composting: Waste Not, Want Not. What to Do?

This might surprise you:

Do you realize that food and paper waste accounts for nearly half of our landfill space? Yep, almost 50%.

“So what?” one might ask. “After all, that’s biodegradable, right?” Well, it turns out that’s not quite right after all.

You see, in a municipal solid waste scenario biodegradable waste gets mixed in with all sorts of other trash and water. Oxygenation can’t occur in the densely packed layers, so an embalming process occurs, trapping our garbage for centuries.

Yuck.

(Digression #1: land use is a major issue, but it’s not my main focus here. It is important to note though, that unless there’s a proposal to locate a refuse center in town, most people don’t loose too much sleep over where our stuff ends up. It just goes into trucks and gets hauled away. Yet toxic chemicals are being leached into the air and water supplies somewhere, right? For the best (and most, dare I say, ‘entertaining’?) perspective on this watch the phenomenal documentary “The Story of Stuff.” And show it to your kids (if you have any).

Back to the issue at hand, let’s think about our waste from a slightly different perspective, examining some things that should concern you about this scenario:

1.    Methane, worst of the greenhouse gasses is given off in massive quantities by landfills.
2.    Heat is also wasted.
3.    There is something we can do about it; existing technologies take us almost all the way there! We just need to tweak them to fit into economies of scale.

The key is (drum roll please…) composting, with a twist. Yes, your hippie grandmother was actually on to something, so be sure to give her some props (but finish reading this article first!).

Small Scale:

Composting is the best way to reduce the amount of organic waste in landfills. It starts at home, where residential consumers can fairly easily turn table scraps into nutrient-rich garden soil. That said, there are some drawbacks to traditional composting. Specifically, it can get pretty ripe (think ‘clothespin-on-your-nose’), tends to attract lots of bugs (teensy little swarming flies) and doesn’t work well in cold weather climates.

Fortunately, there is a very cool solution to these inconveniences. Introducing the NatureMill Indoor Composter.  Made to fit inside a standard kitchen cabinet, this unit greatly accelerates standard composting times. In fact, the manufacturer claims that it ‘processes up to 120 lbs of food waste per month.’

(Digression #2: how many over-ripe apples, brown bananas, wilted heads of lettuce or past-prime heads of broccoli do you throw away every year? In our family of six, my answer used to be “too many.” We now solve that problem by using Green bags, which are available in most supermarkets and really work!).

Back to the issue at hand, here’s what NatureMill says about their product:

“A NatureMill composter recycles its weight in waste every 10 days, diverting over two tons of waste from landfills over its life. This reduces emissions of methane, a harmful greenhouse gas produced when organic matter decomposes in oxygen-starved landfills. NatureMill is made from recycled and recyclable materials. Energy use is just 5 kwh / month, or about $0.50/month – less than a garbage truck would burn in diesel fuel to haul the same waste.”

Let’s review:

Less waste? Check.

Fewer toxic emissions? Check.

Economical? Check.

Let’s hope this becomes a standard appliance in our homes of the future. In the meantime, how about we look at the other end of the spectrum and consider composting from an industrial perspective too? As a Boston guy, I felt a lot of pride for hometown ingenuity when I heard the interview “Boston Wants To Harness Composting Energy” on NPR, March 25, 2008.

Big Scale:

New England charm includes the annual turning of the leaves. But when you stop to think about it, there are lots of those things falling to the ground.  Lots and lots. Enough to power 1,500 homes, to be exact.

Boston currently uses a rural open-air facility to compost. This is common practice in most cities and towns, where the negative by-products, as discussed above, always include heat and methane. But something is about to change:

“A proposed multimillion-dollar indoor urban composting facility would capture methane gas that rotting leaves give off and burn it to generate electricity for 1,500 homes, as well as to run on-site, year-round greenhouses. In addition to yard trimmings, the new indoor composting facility would take food scraps from restaurants and hospitals.”

This plan includes multiple economic and environmental benefits. “It will also require some savvy engineering. The technologies to do this have been around for years, but no U.S. city has ever put it all together on a large scale” states NPR’s Curt Nickish.  Apparently, “the economics for such an indoor operation are finally coming together to make the investment pay off.”

This is a good thing.

When we look at NatureMill and the City of Boston we see innovation at the smallest and largest scales.  But what’s happening in between, in the commercial space? In the case of the Metro Boston program, food producers and consumers (such as restaurants and hospitals) gain valuable access to a new system. A main factor that needs to be considered though, is that transporting urban waste isn’t cost prohibitive because the system is being created as a local service.  This video about a restaurant in Portland, Oregon illustrates the benefit.

Everything in-between:

But how can this model scale to the suburbs?  Trucking the waste over greater distances only adds to our fossil fuel and carbon pollution issues. That’s not a sustainable solution.

We’re back to square one, with a new wrinkle: business owners don’t like paying transportation fees. This is important: the solutions we find in this space will likely be driven by unique economic challenges (and rewards).

Here’s how Planetnatural.com describes the scenario:

In-vessel systems

“For years, hotels, schools, food processing plants, prisons, and other large institutions have used industrial composting machines [in-vessel systems] to reduce waste hauling fees.  The machines are essentially big tanks with lots of heavy duty mixing and pumping equipment.  The compost is fully contained, such that fluid drippings, flies, and odors are eliminated or otherwise disposed of.  High temperatures can be reached quickly and reliably to render meat, fish, and dairy products safe for handling.

But there is a downside.  The investment is typically tens of thousands of dollars, and requires a great deal of space with special sewer and electrical hookups.  A dedicated, trained, and experienced staff must operate and maintain the equipment.  Depending on location, odors can be a problem.”

We’re not quite there yet, and herein lies my main point: there are no commercially suitable composting options on the market today. To be marketable, such a system would need to be affordable, manageable and efficient. The best idea I can think of would essentially be NatureMill-on-steroids.

But would restaurants really install a device that would be large enough to deal with their organic waste? Let’s consider the economic benefits of doing so:

1.    Significantly reduced waste management costs (they would no longer be trucking away organic refuse).
2.    Free power: NatureMill uses very little electricity at the residential level.  Boston is producing electricity at the industrial level. Could a commercial system prove to be profitable too? Could it be plugged into their energy grid, and reverse metered?
3.    Compost sales to local greenhouses and garden supply centers would produce an adjunct revenue stream.
4.    Opportunity for carbon credits from methane capture. Some estimates project this to be a multi-trillion dollar market. Indeed, there are equipment manufacturers in the agricultural space who are giving away their equipment in order to buy up opportunities for carbon credits usage rights. That’s a different market (generally speaking, they aren’t making any more farms, and dairies in particular are huge methane producers so they are being aggressively targeted) but the far-sighted will see this is an emerging opportunity nonetheless.

Inventors, environmentalists and entrepreneurs, are you listening?