3 weeks microbial growth in biodiesel with some water added
Diesel is an organic fuel. When mixed with water it becomes an ideal environment for bacteria, fungi and yeasts to grow & needs…
This microbial growth was taking place before with fossil fuel (B0), however, it is exponentially faster now with B30. BioDiesel absorbs more water than B0 diesel. It also provides a better medium for accelerated microbial growth to take place.
Live microbial growth or ‘diesel bug’ is normally present in between free water layer & diesel. However, it is also present in the form of heavy sludges on the bottom of tanks. This is when the diesel bug dies and then drops to the bottom of the tank.
The live as well as dead diesel bug causes high levels of particulate contamination which is extremely problematic for engines, injectors, fuel level sensors and fuel pumps.
Diesel engine filters can be expensive to replace. High levels of diesel bug found with biodiesel fuels can exponentially increase the speed that fuel filters get blocked. Not only does this become very expensive, but also cause problems starting engines, idling and loss of power.
The downtime for fuel filter replacement is also critical as often one piece of fixed or mobile plant’s operation is interdependent on other equipment. So if you haul truck stops working, so does the digging or loading equipment losing you operational time.
Toyota Landcruiser High Incidence Failures Within 6 Months of using BioDiesel – Remote Mine, Indonesia
Toyota Landcruiser High Incidence Failures Within 6 Months of using BioDiesel – Remote Mine Site, Indonesia
The problems utilizing biodiesel are surprisingly diverse and challenge operational productivity in many ways!
Modern Common Rail Fuel Injection Systems
Modern diesel engines have injector nozzles with sizes as low as 2 – 3 microns. On average, the human eye cannot see particles less than 50 – 60 microns.
Even older specification diesel engines with larger injector nozzle sizes will also change shape over time with the diesel bug contaminate having an abrasive effect on the.
Glycerine is a by-product of biodiesel production. This glycerine can separate from the biodiesel causing solid contaminants.
The image on this page showing Glycerine solidifying out of BioDiesel causing blockages.
Colder temperatures or extended periods of time will cause Glycerine to wax out into fuel system components, pipes or tanks.
Note: Generally, sulphur retards microbial growth
As noted, water presence is what facilitates microbial growth (major contamination)
Water can come from:
Increased lubricant oxidation | Oxidation control can be affected by fuel dilution, biodiesel concentration, raw materials, severity of conditions & lubricant quality |
Wear control | High levels of fuel dilution may reduce the viscosity of the lubricant & the oil film thickness, increasing the possibility of wear |
Soft metal corrosion | Biodiesel can cause significant corrosion of bearing materials such as copper & lead |
Piston deposits | Increased piston deposits can cause ring sticking & increase fuel dilution |
Lubricant contamination | Unburnt biodiesel in the oil sump may be oxidized, promoting lubricant degradation & thickening. |