July 16, 2006

Spinning “Gold” Out of Trash

With its huge population and guilt-free car culture, California is the world's largest consumer of gasoline. By state regulation, 5.67% of the fuel pumped is actually ethanol - which is used as an oxygenate for gasoline. As a result, California is also the world's biggest consumer of ethanol - closing in on 1 Billion gallons per year.

As a rich agricultural state, one would think that there would be a huge production of corn or sugar cane to produce ethanol to meet the demand. Not so. 95% of the ethanol consumed is imported from, primarily, the Midwest by truck. There is no corn farming to speak of in California, nor will we see a sudden switch in cultivation. New ethanol plants located there will be shipping the corn in from surrounding states.

Assuming that California wants to become self-sufficient in ethanol, what will the feedstock be if not corn or sugar cane? The answer is agricultural, forestry, and urban waste. Being a heavily wooded, agriculturally rich, population booming, and super-consuming state means an incredible amount of waste. Therefore, progressive thinkers in California are looking to its waste streams to provide feedstock for the next big thing - biomass conversion of waste into biofuels including cellulosic ethanol, with the co-generation of electricity.

Such a switch couldn't come at a better time. Many professionals in the waste disposal industry recognize that major urban centers like Los Angeles will be faced with a "Peak Landfill" problem way in advance of a "Peak Oil" problem. Available land is scarce in a region of burgeoning development, NIMBYism, and accelerating waste disposal growth.

Kay Martin, Ph.D is vice president of the BioEnergy Producers Association. She directed Ventura County's solid waste programs from 1987 to 2004. She has been an active proponent of waste diversion from landfills for over a decade. She has written an incisive article about the need for landfill diversion and the potential of bioenergy production using conversion technologies. Here are some excerpts from a recent article she wrote for the Ventura County Star - a neighboring county of Los Angeles:

S.V. Landfill has chance to spin gold out of trash
By Kay Martin

...the total amount of garbage disposed in the county and statewide has not changed much over the past 10 years, despite the best efforts of local governments, businesses and residents to recycle. Recent gains made by recycling have been largely eclipsed by the effects of population and economic growth, and this trend is expected to continue. The growing waste problem is real, and requires some strategic planning now to avert a future crisis.

...Complicating the picture of where waste will flow in the future is the disappearance of local landfills. About the same time that recycling laws were passed, the federal government imposed stringent new standards on disposal sites intended to abate air and groundwater pollution threats. These costly permitting standards contributed to a 63 percent decline in the number of landfills nationally since 1988. The trend is for fewer and larger facilities, more remote from urban centers.

Several landfills in our neighboring Southern California counties are slated for closure, and NIMBY factors have trumped attempts at siting new ones, save for expensive desert landfill options accessible only by rail.

Role for bioenergy

The factor that should weigh heaviest in decisions to expand the Simi Valley Landfill, however, is the emergence of new "bioenergy" industries that can convert about 80 percent of the materials currently going to landfills into environmentally beneficial products — green power, biofuels and a variety of chemicals that reduce our reliance on petroleum. Moreover, because these industries produce valuable commodities, they can be cost-competitive with landfills. Bioenergy plants are operating successfully in both Europe and Japan, and are in various stages of development in other parts of the United States. The central question is, should we be looking to simply bury our wastes in the decades to come, or should we take positive steps now to turn these wastes into resources that can help build a more sustainable society?

The county of Santa Barbara, and the city and county of Los Angeles are each actively engaged in procurement processes to site bioenergy facilities (so-called "conversion technologies") to reduce and ultimately to replace their dependence on landfills.

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Anonymous said...

I certainly applaud these sorts of efforts to close the cycle. However, we must remember that the input side is still wide open. I hope that when people are considering these sorts of projects, that they're also giving some thought to carbon offsets, since 100% recycling takes away a very significant carbon sink.

C. Scott Miller said...

My understanding is that as feedstock decomposes it releases carbon back into the atmosphere. In contrast, gasification and conversion of trash to biofuels removes carbon dioxide that traditional recycling would only return to the atmosphere. The only value of modern landfilling is that it somewhat "mummifies" the otherwise decaying material that is dumped into them. Without capture systems, landfills still reek carbon dioxide and methane (23 times more toxic a greenhouse gas than C02).

Anonymous said...

First, there is a very high fraction of landfill material that is not typically going to self-degrade. I'm thinking of things like plastics, foams, paper products. These are going to be stable for timescales on the order of centuries, possibly millenia.

The good news, from your perspective at least, is that garbage probably represents a smaller percentage of our total emissions as humans than I feared.

The Carbonfund tells me that my neighbors have a carbon footprint of 23 tons a year, but I believe others have estimated that number as being in the low teens. Other sites tell me that the average American produces 1.5 tons of garbage a year. That's not all that is carbon-based, so we're talking about less than 10% of our carbon footprint being sunk, but given how poor our carbon offsets are at present, that's an important 10%. The act of recycling itself will offset some of that, but probably not all. This is the concern that I have with closing the exit side of the cycle today.

Most landfill managers are trying very hard to ensure that their landfills are NOT biodegrading. A biologically active landfill is in danger of leaking all sorts of noxious chemicals both into the air and the water table. It's also in danger of being mechanically unstable: You wouldn't want that bulldozer on top of the fill to fall into a sinkhole, would you?

This is why modern landfills have things like liners, and clay caps: It's to keep water from migrating into and out of the fill materials. No water means less migration of material, and less biological activity. This is the prime reason that discarding 'biodegradable' packing materials is a farce: They are indeed, as you say, being mummified.

As for the methane, that is, as I understand it, an anaerobic process that starts before the material is fed into the landfill. The good news is that we have ways of capturing this directly and using it (see also: landfill gas), in part because of the way a modern landfill is constructed.

# said...

We need to figure out alternative fuel sources, ethanol is one, but we need to have solar ENERGY!#