Plant-Based Heat for Your Home
By: John S. Nettleton
April 16, 2007
As biofuels become a daily news topic, they entice readers with 'warm and positive feelings' about 'green' fuels. Unfortunately most coverage glosses over limits to such fuels, while ignoring clear benefits they might bring to urban settings. This brief primer may help frame the inherent constraints and the positive roles for biofuels use in green cities.
Biofuels (primarily ethanol and biodiesel) are derived from biomass or biomass by-products. In the U.S, ethanol is made from corn via a process yielding just under 3 gallons/bushel of corn and solids known as distillers dry grains, which go for animal feed. In Brazil and several Caribbean nations, ethanol is made from sugar cane at much higher efficiencies.
Biodiesel (BD) is produced either from virgin or waste vegetable oils, also yielding soybean 'crush' for use as animal feed. In the U.S., BD is made primarily from soybeans. The European Union uses rapeseed (canola) as a feedstock, although other crops (such as flax- and mustard-seed) can also be used. Rudolf Diesel's prize-winning engine at the 1900 Paris World's Fair was powered with peanut oil.
Physics and engine design make BD a much 'greener' fuel than ethanol, although both are still net carbon sources (not sinks). Corn-based ethanol reduces greenhouse gas emissions (GHG) over gasoline combustion by 12%, while BD reduces petrol diesel GHG emissions by 41%. Diesel engines can be up to 25-30% more efficient than gas-powered engines: in terms of stored energy, ethanol contains only half the energy (calories/volume) of either BD or gasoline. The current and massive conversion of U.S. cropland to corn for ethanol can therefore be viewed as a hugely subsidized method of producing 'weak beer'. Although automakers earn hybrid credits for each E85vehicle, drivers tanking up with E85 (85% ethanol: 15% gas) will see there mileage drop by 20%, requiring five gallons of gas to go the same distance as four gallons of regular. It's akin to a diner at the Carnegie Deli getting the combo sandwich and feeling good about the diet Dr. Brown's Cel-Ray soda that goes with it.
Such talk about corn and cars ignores the truly remarkable and immediate potential for biofuel use in New York that points a path toward a greener and healthier city. The real prize lies in BD use in stationery engines, especially the boilers that heat New York homes, apartments, commercial and public buildings. In the U.S., nearly 90% of all oil heat is used east of Pittsburgh and north of Washington, DC. New York is heated by steam boilers-fully half the City's dwelling units (3 million in 1996) use oil-fired or dual fuel (interruptible gas) heat. Along with exposing the City's building owners to an increasingly volatile international oil market, oil-fired heat and its remaining oil-fired power plants generate significant amounts of air pollution. The 23,500 tons of sulphur dioxide emitted in 2004 contributed to total mortality for NYC residents from diesel fine particles that was the highest in the nation, which translated into a per capita death rate behind only Beaumont, Texas and Baton Rouge, Louisiana — both major centers of petroleum refining (See Diesel Health in America: The Lingering Threat).
While enthusiasm over the increasing number of high performance 'green buildings' is welcome and warranted, there are still only 100 'green' buildings a city with 950,000 structures. To make a difference, we have to pay equal attention to demand and supply, repowering the current built environment with newer and better fuels even as we retrofit, insulate and tighten up existing structures. BD burns more cleanly, has roughly the same energy content (Btu/gallon) and the price margin between B20 (20% biodiesel) and regular #2 heating oil has narrowed over the current past heating season so that the New York State tax credit for home and coop owners can find the B20 price post-credit often below regular heating oil.
BD can be blended with existing heating oil without replacing boilers or changing over burners: this process of adopting BD for heating is already underway. A fuel dealer in Newburgh, NY has been delivering to 100+ homes for three heating seasons, and Brookhaven National Lab researchers have heated Teddy Roosevelt's Sagamore Hill National Park Service site for several seasons. Schildwachter Oil, a pioneering Bronx fuel oil dealer has been delivering B20 to all Upper Manhattan, Bronx and Westchester customers since fall 2006, and Metro Fuel Oil in Brooklyn is now providing B20 to buildings in Brooklyn and Manhattan under a demonstration project with Cornell Cooperative Extension, the Superintendents Technical Assoc. and Brookhaven. B5 to B20 is tested to an ASTM (American Society for Testing and Materials) quality standard for biodiesel as heating fuel.
BD use at the 20% level for heating fuel significantly cuts particulates, carbon dioxide and sulphur dioxide, and even higher blends are possible. New work is underway to assess BD blended with #6 heating oil, an inexpensive, 'dirtier' fuel oil compared with #2. 'Big small users' such as major universities and hospitals typically use large amounts of #2, #4 or #6 heating oil, often in dual fuel (oil and gas) systems, switching back and forth by price and/or season: for example, St. John's University alone burns 2 million gallons of heating oil each year. Over 80% of the 170,000 NYC Housing Authority units use oil heat, with many developments located in City Health Districts (South Bronx, Morrisania, East Harlem and Bushwick, etc.) that show extremely high residential asthma rates, especially for children and the elderly. Immediate conversion of those developments to BD20 is an environmental and a public health imperative. Wide adoption of BD for bus fleets would further benefit residents in those communities of color where MTA bus depots are invariably sited. Cincinnati runs its buses on B30, and all school buses in Denver use B20.
"If biofuel use is such a good idea, why doesn't everyone?" Adoption of new fuel and technologies is rarely simple or direct, and barriers-both physical and psychological-need to be overcome to build an industry sustainable and supportive for user and producer alike. At present, there's one refinery (as distinct from blending plant) using virgin oil operating in the New York region, Fuel-Bio, Inc. in Elizabeth, NJ. Others are in development, in Brooklyn by Metro Fuel (Newtown Creek), near Rochester (Northern Biodiesel), and near Fulton (Homeland Energy). A plant using waste vegetable oil (WVO) feedstock is being built in Red Hook, Brooklyn by Tri-State Biodiesel. Research by Cornell (2005) showed that 1.6 to over 1.8 million gallons of WVO is generated by retail food businesses just in Brooklyn, one indication of the potential biofuel resources generated within NYC.
Currently, renderers collect almost all WVO, which makes them potential future BD sources. If there were widespread adoption of B20 as a heating fuel for all apartments yields, overall NYC demand for B20 would take up 1/5 of all projected BD produced in the U.S. this in 2007! BD presently arrives either by rail (from the Midwest) or by barge (from Mid-Atlantic states). Suppliers need an economy of scale and delivery for their customers, as fuel trucks can't readily switch fuels, and NY building owners.
A well-insulated and efficient building using B20 will reduce demand for oil by the same amount (20%), especially if the BD is refined as close as possible to the user (think local food), making fuel choice sustainable only if the scale and the life cycle costs are closely balanced. Such life-cycle standards should promote development of regional feedstocks and WVO use wherever possible, as cost-driven industry decisions are generating investment decisions and fuel source choices that are neither sustainable nor self-reliance. For example, as soybean prices rise in step with corn prices and the related shift to grow corn instead of soybeans, BD refiners are seeking out imported soya oil (from Brazil) and palm oil (from Indonesia) grown on cleared forestland and sensitive habitat. When lowland habitats are burned for use as palm oil plantations, that process releases 3 times more carbon than one 'saves' by using palm oil as BD: the climate effect is not positive.
European writers and environmentalists are clamoring for a 'time out' in biofuel production to assess long-range BD goals in light of these troubling global trends. In the U.S. Midwest, rising natural gas prices have even led some plants to power their ethanol refineries with coal, and the run up in corn production is increasing U.S. imports of fertilizer from Saudi Arabia and Venezuela while environmental costs of fuel production are often indirect and far away, we have to be mindful of the origin and nature of the fuels and the overall impact of crops grown to satisfy increasing international demand. A gatha or prayer, written over ten centuries ago and still recited by Zen Buddhist practitioners says, "Light and darkness are a pair, like the foot before and the food behind in walking". Supply and demand are just like that, and must be addressed in equal measure if a growing green fuel industry is to provide real and sustainable environmental and public health benefits.
John S. Nettleton, Sr. is an Associate at the Cornell Co-operative Extension in NYC