1 Biodiesel Fuel
The concept of converting organic matter into fuel has come of age in the past decade or two. The idea of converting biomass into biofuels is motivated by the worthy goal of lessening our dependence on fossil fuels, as well as a potentially cost-effective way to dispose of waste. The variety of sources that make up the raw material for biofuel production are mainly waste products. These include agricultural residues such as the leaves and stalks of corn, wheat, or sugar cane after the harvest, food waste such as waste cooking oil, logging residues from the forest industry, animal byproducts, including manure, and wastewater treatment sludge. Figure 1 shows the recent and projected growth in global biofuel production. Figure 2 breaks down consumption of biofuels by country. Far and away, the United States dominates the global market, with European countries and Brazil also weighing in.
New England and New York State have been leaders in the biodiesel industry. New York City runs 11,000 city buses in part on biodiesel fuel. Biodiesel is mixed with regular diesel fuel in the gas tank, making up as much as 30% of the total fuel. Biodiesel is not the only fuel that is produced from biomass. Ethanol, normally derived from corn or sugar cane, is now a common additive to gasoline, particularly in the United States. There is also a biofuel specific for use in airplanes (aviation biofuel), and another one that can be mixed in with home heating oil. Biogas is becoming increasingly popular as a substitute for fossil gas captured from underground sources, and it has many uses as a natural gas. It is produced from biomass by anaerobic microbes in facilities called anaerobic digesters. These anaerobic digesters have been exploited recently by the cruise ship industry to dispose of onboard food waste, and by the meat processing industry. Both of these industries have been beset by COVID-19 disasters.
One common feature of nearly all the sources for biofuels is likely contamination with glyphosate. Glyphosate is the most used herbicide on the planet, and the United States uses more per capita than any other nation. Glyphosate is very popular in part because it was widely believed to be practically nontoxic to humans, despite the fact that it indiscriminately kills all plants except those that have been engineered to resist it. However, this belief is eroding since the World Health Organization's International Agency for Research on Cancer (IARC) declared glyphosate a probable carcinogen in March, 2015. This later led to several successful high profile lawsuits against Monsanto, associating glyphosate with non-Hodgkin's lymphoma.
Commonly used crops for biofuel production are corn, canola, barley, sugar cane, and wheat. Most of the corn and canola are genetically engineered to resist glyphosate, which is used to control weeds. Barley and wheat are frequently sprayed with glyphosate as a desiccant just before harvest.
A “no till” approach for biogas production involves harvesting just after spraying the crop with glyphosate [5]. Added manure provides methanogenic microbes that metabolize the crops anaerobically to produce methane. The manure is also contaminated with glyphosate, because the animals are typically fed corn and soy feed laden with glyphosate. Debris from the logging industry is also likely to be contaminated. The forest industry has long used glyphosate to kill off the hardwood trees, so the area can be replanted with fast-growing conifers that yield more useful wood for paper products.
It appears that glyphosate is synergistically toxic with diesel fuel. A remarkable case study involved a mechanic who tried to clean a clogged glyphosate-based herbicide applicator using a bucket of diesel fuel as a solvent [6].