Agriculture, Food Processing and Biofuel Manufacturing: Producing Electric Power from Biogas

Biogas, a byproduct of many agriculture, food processing, and ethanol or biodiesel manufacturing operations, is used today as a fuel source for engine generators. Cat^® generator sets designed to run on biogas can yield significant long-term savings and:

• Reduce carbon emissions through the destruction of naturally occurring methane
• Reclaim valuable land space normally utilized for purifying organic wastewater
• Eliminate odor and pest issues caused by the decomposition of organic material

 
How It Works

Consisting primarily of methane and carbon dioxide, biogas is produced through the anaerobic decomposition of organic waste. Instead of allowing the organic waste to decompose in an uncontrolled setting, the waste and resulting gases are contained in an oxygen-deprived environment such as a covered lagoon or above ground steel tank. From there, methane is extracted and burned to generate electricity or heat.

Because of the impurities and inconsistencies in biogas, pretreatment is generally required. However, using a gas engine specifically designed to operate on biogas can reduce the amount of investment in pretreatment. Cat low-energy fuel generator sets are engineered to handle fuel with variations in methane content, which is typical of biogas. Cat biogas engine features include:

• Crankcase ventilation pump to eject potentially acidic blow-by gases
• Specially designed aftercooler cores, cylinder heads, main bearings and connecting rod bearings that are hardened against corrosive elements
• Differentiated cooling systems to operate at elevated jacket water temperatures to prevent condensation of contaminants

Cat Switchgear with PLC-based controls is supplied to parallel the generator to the local electrical grid to export renewable power at a premium to the local electric utility. For more remote installations, the power produced can be used by the facilities on site.