INSIGHT: Ethanol faces environmental scrutiny

15 February 2007 15:52  [Source: ICIS news]

New opponents of biomass ethanolBy Joe Kamalick


WASHINGTON (ICIS news)--Often hailed as the “green” transport fuel, ethanol is coming under increasing fire from environmentalists, and soon it will face environmental scrutiny by one of its biggest supporters, the US Department of Agriculture.


Ethanol proponents have long touted its environmental advantages as an automotive fuel.  Unlike gasoline, bio-based ethanol is non-toxic and biodegradable. 


According to US ethanol advocates at the Renewable Fuels Association, ethanol reduces tailpipe carbon monoxide emissions by as much as 30%, toxics content by 13% and tailpipe emissions of fine particulate matter (PM) by 50%.


Ethanol’s backers also note that the corn-based fuel indirectly helps reduce greenhouse gases in the atmosphere because corn crops grown as ethanol feedstock absorb carbon dioxide (CO2).


These and other environmental pluses are said to more than compensate for ethanol’s lower energy profile - about 30% less energy than an equivalent volume of gasoline - and taxpayer-funded incentives that encourage its use as a US motor fuel supplement.


However, as ethanol begins to emerge as a growing element of US federal energy policy, some policymakers are beginning to wonder about the possible environmental impact of a major US drive for wide scale ethanol production.


President George Bush has recently set a goal for US production of 35bn gallons of biomass ethanol by 2017. Current US output of ethanol, entirely corn-based, is nearing 6bn gallons annually. 


It is generally accepted that, even with improved yields and other advances, corn production can at best reach output of some 15bn gallons per year.


To get to 35bn gal/year in ten years, we will have to rely on fairly rapid development and deployment of cellulosic ethanol production, based on feedstocks such as switch grass, corn stover, wheat chaff, wood chips and other inedible plants.


Whether it is produced from corn or switch grass, a nearly five-fold increase in US ethanol production is going to require a great deal of land surface to grow the feedstock.


This is beginning to worry people at the US Department of Agriculture (USDA).


Marca Weinberg, chief of the resources and environmental policy branch of the USDA’s Economic Research Service, told a recent Washington audience that accelerated US ethanol production is already bringing about land use changes - not all of them positive.


She said that growing feedstock for ethanol production probably is having air and water quality impact, if only because of a consequent increase in use of fertilizers and water irrigation.


Increasing acreage for corn as ethanol feedstock also raises concerns for wildlife habitat, she told an agricultural and environmental meeting sponsored by Resources for the Future (RFF).


She noted, for example, that demand for corn for ethanol production apparently is causing some US farmers to take land out of the federal land bank programme. 


Under a variety of US agricultural plans meant to restore such habitat as wetlands and to generally encourage environmentally friendly practices, farmers are paid to keep certain lands out of agricultural production.


However, more farmers are coming to the conclusion that they can make more money by putting land bank acreage into corn crops.


As the nation develops the technology to produce cost-effective ethanol from switch grass and other non-food crops, she said, the tens of thousands of additional acreage needed cannot help but have environmental impact.


“The environmental implications of ethanol market dynamics are not well understood,” Weinberg said, “but research is under way.” 


At least that research is planned; Weinberg said USDA as yet is not sure what questions need to be asked or how the research should be directed.


Indeed, Weinberg suggested that anticipated USDA research on this issue could take years, and might not be completed before a nation-wide rush to cellulosic ethanol production and its attending agricultural feedstock growth are both well under way.


One problem with switch grass as a crop is that acres of grass make a perfect home for rabbits, squirrels, foxes, ground-nesting birds and other smaller wildlife. 


Harvesting that feedstock invariably will destroy some of those creatures or at the least lay waste to broad reaches of their habitat - and almost certainly raise the ire of wildlife environmentalists.

By: Joe Kamalick
+1 713 525 2653

AddThis Social Bookmark Button



Printer Friendly

Get access to breaking chemical news as it happens.
ICIS Global Petrochemical Index (IPEX)