The Environmental Debate
Unlike the other issues addressed on this site, the environmental debate is not an internecine dispute. The vast majority of bio-oil enthusiasts will argue that this alternative fuel is safe and environmentally friendly. Potenial opposition due to environmental and health concerns is more likely to originate outside the field, from regulatory organizations and the public. Three problems on this front are outlined below.
Bio-Toxicity
The fact that bio-oil is a “renewable” resource does not necessarily guarantee its safety, both to humans and the environment. As pyrolysis technology improved over the past ten years, the emergence of larger tests and production facilities called for a serious investigation into the potential of bio-oil leaks, spills, and human/environmental exposure in general. In light of these issues, a group of scientists at Aston University (UK), the German Institute for Wood Chemistry, and CIRAD France initiated the BioTox project. Sponsored by the European Commission, research lasted from 2003-2005. The aims of the BioTox project were to identify the ideal operating conditions whereby reactors will avoid or minimize the formation of toxic products, to produce a standardized Material Safety Data Sheet outlining toxicity prevention procedures, and to explore the potential toxicity of bio-oil products in order to minimize their formation in the future.
Conclusions Regarding Bio-Oil Toxicty, Reached in European Commission BioTox Study:
- Not Explosive
- Non-toxic (tested on rats) when orally ingested
- Low Polycyclic Aromatic Hydrocarbon (PAHs are known carcinogens) concentration - below 10 parts per million
- Small fertilizing effects on water
- Eutrophication limited, however, due to low nitrogen concentration
- Negligible toxicity for small aquatic animals
- Biodegradability better than most mineral oil products
- Similar toxicities for different biomass sources, reactor types
- Mutagenic (!) - Ames test positive
Analysis
In their published conclusion to this study, the leaders of the BioTox project put a positive spin on their findings, pointing out that bio-oil is less toxic and biodegrades faster than traditional petroleum fuels. While this may be true, public fears over adapting to an unknown fuel source may prove irrationally strong due to the negative details uncovered in this study. Most problematic is the discovery of bio-oil’s role as a mutagen. Mutagens alter the DNA of organisms, and are most commonly discussed in respect to their role as carcinogenic agents. Bio-oil’s mutagenicity may be due to the presence of suspected carcinogens formaldehyde and acetaldehyde, in addition to a small concentration of PAHs. Regardless of the degree of actual risk, any carcinogen has the potential to cause a public uproar. As Peter Sandman explains in his theory of risk communication, public anger is often overlooked by company and government executives who are convinced that education about their product will erase all doubt. If bio-oil advocates can listen to public fears and calm outrage that may result from this knowledge - regardless of data on the actual hazards - they may be able to avert this potential roadblock in the development and implementation of bio-oil.
Transportation of Bio-Oil and U.N. Regulations: Hazardous Materials?
As demand for bio-oil grows, it is increasingly likely that methods for massive transport of bio-oil from production facilities to market will be necessary. Not surprisingly, growing alongside bio-oil demand are worries about the potential implications of a large-scale spill in transport. One need only recall the Exxon Valdez incident of 1989 to appreciate how accidents such as this can affect public perception. If a bio-oil spill resulted in widespread environmental damage or threats to human health, decades of progress in this alternative fuel sector would be lost. With these threats in mind, an independent consulting firm was hired by the BioTox group to address the economic and political issues facing bio-oil transportation demand. Their report was submitted in the summer of 2006, and contained some bad news.
Unfortunately for the advocates of biomass pyrolysis liquids worldwide, the report determined that bio-oil will most likely need to be classified as a “hazardous material.” Based on their 2005 study, the BioTox group could argue that bio-oil is actually safer than traditional fuels, which may exempt them from the same regulations regarding transportation of petroleum products. Regardless of the truth behind this statement, one crucial point remains about bio-oil: It is an extremely variable fuel source. As discussed in the “processing” section of this site, not all bio-oil is created equal. Depending on the feedstock and reactor type, a number of different compounds in varying concentrations are possible. Though some types of bio-oil feedstock may create a non-flammable, stable liquid, the existence of other more volatile liquids classified as bio-oils would be cause for a “hazardous” designation. This variability is what prompted BioTox’s consulting firm to warn the bio-oil advocates of this issue.
The likely classification of bio-oil as a “hazardous” liquid is a setback to the commercial implementation of this renewable energy source. Restrictive international transportation codes - such as those adopted by the United Nations - will undoubtedly increase capital costs across the board. In order to prevent this problem in the future, bio-oil advocates need to establish an international standard for bio-oil composition and enforce some means of quality control. Only then will regulatory agencies be willing to give bio-oil a chance.
Emissions
Proponents of biomass pyrolysis liquids point to the fact that bio-oil can be burned with zero net carbon dioxide and sulfoxide emissions. Ideally, a bio-oil-powered world would eliminate the harmful effects of global warming produced by carbon dioxide accumulation in the atmosphere and stamp out the acid rain and lung problems associated with sulfoxides. Unfortunately, combustion of bio oil also has its drawbacks.
Chief among bio-oil combustion issues is the common problem of high particulate content, especially when burning low quality fuel with a high solid content. Older, less homogenous bio-oil will also cause incomplete combustion and more contaminants to be released into the atmosphere.
Standardization of bio-oil quality would be an obvious way to address this issue. Additionally, there is a short-term method by which improve the quality of bio-oil fuels: adding methanol. Wood alcohol helps to homogenize poor quality bio-oil, thus markedly improving combustion.
Bio-Oil Topic Navigation
Sources
BioTox Project. “An Assesment of Bio Oil Toxicity for Safe Handling and Transportation.” CIRAD, France, 2005, pp. 5-7.
Conversion and Resource Evaluation Ltd. “Transport, Storage and Handling of Biomass Derived Fast Pyrolysis Liquids: Report to CIRAD-Foret.” 14 June, 2006, p. 6.
Global Pyrolysis Network. “Bio-toxicity.” www.pyne.co.uk
Personal Injury FYI. “Toxic Tort Law.” www.personalinjuryfyi.com/toxic_material.html. 2004.
Sandman, Peter. “Risk Communication.” Chemistry 333. Princeton University. Princeton, 12/12/06.
Spiro, Thomas G. and William M. Stigliani. Chemistry of the Environment. Upper Saddle River, NJ: Prentice Hall, 2003, pp. 220-221.
University of North Carolina Environmental, Health and Safety. “Safety Labels - Chemical Storage.” ehs.unc.edu/labels/chem.shtml. Last Modified 27 June 2006.
Weinhol, Bob. “Fuel for the Long Haul.” Environmental Health Perspectives. Vol. 110, August 2002, p. 458-464.