It’s amazing some of the sources of biofuel researchers have found in recent years.  Sources range from corn stalks, to used tires, manure, and even human fat.  Among the various selections, the following five sources of biofuel have shown promising potential.

Whey (cheese waste)
An interesting source of biofuel is cheese waste product – whey. DuBay Ingredients LLC, a Wisconsin company, has developed a twenty-six step process that converts whey permeate into ethanol. The process requires approximately one hundred gallons of whey (the residue remaining from milk in the cheese making process) to generate ten gallons of ethanol fuel. By using whey as a source of biofuel, dairy companies can greatly reduce their disposal costs of cheese waste. Waste is generally either shipped overseas for disposal, or disposed on location, which poses an environmental risk. DuBay, thus, can greatly reduce the costs and environmental hazard of whey management.

New Cyanobacteria
Professor R. Malcolm Brown Jr. and Dr. David Nobles Jr. at the University of Texas, Austin, have created a new cyanobacteria that uses sunlight to secrete cellulose, glucose, and sucrose.  These sugars are the primary sources used to produce ethanol.  And, unlike other sources such as corn and algae, these sugars can be directly and repeatedly harvested from the cyanobacteria without any harm to the organism.  Corn and algae require destroying the organism and using enzymes to break down and extract these sugars, which is a costly process.  As with many new sources of biofuel, another benefit is the reduced need for arable land to grow biofuel sources (unlike corn).  Brown and Nobles estimate that the cyanobacteria can produce ethanol using half the area needed for corn-based ethanol.  For more info read Professor Browns and Dr. Nobles research abstract. (pictured at left is fluorescence microscopy of the cyanobacterium (chlorophyll in red) and blue cellulose material stained with a fluorescent brightener)

Switchgrass
Switchgrass, a perennial crop, has been reported to be very energy-efficient.  Researchers at the University of Nebraska-Lincoln documented switchgrass to produce over five hundred times more energy than needed to harvest and convert it into ethanol.  The joint USDA-ARS and Institute of Agriculture and Natural Resources study also reported that emissions from switchgrass-based ethanol were ninety-four percent lower than from gasoline production.  It has also demonstrated a higher yield rate than corn, up to one hundred gallons of ethanol per ton.  And, because it requires minimal pesticide use and low production costs, switchgrass presents favorable economic production.  source: sciencedaily.com

Lesquerella
Lesquerella, a member of the mustard family, has received increasing attention as a potential source of biofuel.  The plant’s seeds hold a unique and valuable characteristic – a vegetable oil loaded with hydroxy fatty acids.  Currently, castor oil is the primary source of hydroxy fatty acids, but contains toxic chemical, ricin.  Researchers, therefore, are now favoring the prospect of lesquerella.  And, because lesquerella contains estolides (unique molecules that promote flow under various conditions), it can flow with greater ease at colder temperatures than petroleum.
source: usda.gov newsroom

Citrus Waste
Citrus peels consist mostly of sugars, making it an ideal source of ethanol.  Citrus Energy LLC, a Florida-based company, is building a four million gallon per year ethanol bio-refinery.  Because Florida lacks the suitable climate for corn production, it must look for alternative sources of biofuel.  Considering Florida’s large production of citrus, citrus peel makes a favorable candidate.  It has the advantage of eliminating feedstock and transportation costs, and does not produce any toxins in ethanol production, as other cellulosic feedstocks may.

Related – previously on altCon:

camelina – a better source of biofuel

green crude production: algae