In communicating with environmental groups over the past weeks, I’ve discovered that there is a good deal of confusion over the terms biomass, biofuels, and biogas.
Although the technical use of the term biomass covers any kind of plant material whether still living or dead: wood, wood chips, forest or yard detritus, garbage, etc.––as used in current discourse it usually refers to its use as fuel via direct incineration. In other words, when an article refers to biomass as a fuel it’s referring to something that gives off energy by being burnt, as we warm ourselves and our homes by burning wood in a wood stove or fireplace.
While biofuels is another general term, this time covering all fuels derived from plant matter, in current use it generally means gasoline substitutes, fuels that power cars and other vehicles. Fuels like bio-diesel, obtained from reprocessing used vegetable oils, are being developed as a less polluting replacement for petroleum-based diesel. The term biofuels also covers automotive fuels derived from plants normally grown to feed humans and other animals, such as corn and sugar cane.
In general usage, biogas refers to the combination of gases produced by the natural process of decomposition of plant materials as they break down in the absence of oxygen. Previously used for the smelly aura rising from overheated swamps and wetlands, biogas has become the preferred term for gas produced through monitored human engineering of the decomposition of agricultural, animal and human waste, a fuel intended primarily for the same uses as the “natural gas” we’ve been using for years for cooking and heating homes and office buildings, the one the drillers are touting all over the media as the energy solution of the future.
The differences between these must be understood and emphasized so we can have a useful discussion over how to approach a future without fossil fuels. Because it produces heat through direct burning, biomass as fuel is a major contributor to the greenhouse gases that are causing global warming, so, despite the claims made for it online, it should be obvious that burning biomass is not the way to go. As for biofuels, they may be less damaging to the environment than the diesel and gasoline they are meant to replace, and useful where they remove used vegetable oils from the waste stream, but they too have their drawbacks. Unlike biogas, ethanol made from corn and sugar cane does nothing to reduce the waste stream; it requires an elaborate and expensive system of controlled fermentation; and it cuts deeply into much needed human and animal food resources while driving up the price of corn and sugar products.
By contrast, biogas has most of the advantages of the other two plus some of its own and none of the problems. It is the most naturally and therefore most cheaply produced of all the fuels, being simply an extension, in a controlled environment, of a process that takes place wherever anaerobic digestion breaks down agricultural, animal and human waste into gases, liquids and solids. Leave garbage in a closed black plastic bag on the porch in the sun, and soon you’ll have a bag of biogas and (mostly liquid) fertilizer. The only difference between biogas and the so-called “natural gas” currently being drilled at such disastrous expense to the environment from deep within the earth is that biogas doesn’t need to be “cleaned” of the petroleum byproducts that “natural gas” brings with it from its proximity to underground oil deposits and certain deadly elements best left untouched. Although biogas does produce carbon dioxide when burnt for heat, it’s nowhere near the amount produced by petro-gas or burning biomass.
This EPA site explains how capturing the methane that’s produced naturally by garbage dumps, landfills, and dairy farms––methane that, next to carbon dioxide, is the most potent element in causing global warming––can be processed into fuel. Even more sensibly, if these gases are captured after a more exacting separation of degradable materials before they reach the landfill, they can be purified and distributed to households directly through the present system that provides us with basically the same gas that we’ve been using for years.
Actually not quite the same, for there are poisonous elements in the gas from underground, elements that the industry can’t eliminate, that are never a factor with the methane that comes from above-ground waste. Also, when you consider that in some heavily populated areas (such as where I live in a New York suburb), tons of unrecyclable waste is routinely transported hundreds of miles to distant landfills in trucks run on petro-fuels that add their own considerable share to the pollution of our air and water, it seems there is simply no choice between continuing as we’re going or switching to the biogas that can provide, not only cheap gas for cooking and heating homes, but vehicle fuel, electricity and fertilizer, both solid and liquid.
Point being: by making use of the waste that at present is befouling our air and water, not only do we have a better and cheaper gas ready to hand, we also have a system for distributing it, that is, if the oil and gas industry could be persuaded to pull their heads out of the sand (they own the distribution networks).
In seeking a biogas company near where I live I’ve come up with dozens of companies in the business of creating such facilities, most of them in other parts of the world. Germany is the great leader, China is second, but there are small scale operations in Africa and Asia bent on making small farms and even individual households energy independent through units that transform each farm or household’s own waste into cooking fuel. There’s an entire town in Sweden that’s energy independent through processing its waste into biogas. Other towns are running their buses and taxis on it. Due chiefly to the political strength of the international oil and gas industry based in the US, we lag way behind the rest of the world. There are biofuels companies here, but most are located on the west coast. When a municipality wants to convert its waste to methane fuel, they generally get a German or Scandinavian company to design it.
The combination of ease of manufacture and distribution of biogas with the fact that it eliminates the waste that is another of our biggest problems makes it the necessary future of a planet supporting so many humans and animals. The big question for us now becomes: Can we get there before the petroleum industry befouls our landscapes and water resources beyond redemption?
There is a great deal more to be said in favor of biogas, which you can read about in the links provided here under SOLUTIONS (scroll down to the right), or simply by googling biogas.