Oil Feedstock for Biodiesel

The idea of running internal combustion engines on vegetable oil is almost exactly as old as the engine itself — Otto Diesel’s original design was for an engine to run on peanut oil. Likewise the process used to make most of the biodiesel produced today is a decades old process

The conventional process for biodiesel production imposes rigorous constraints on the quality and purity of input oil feedstock, particularly with regard to water content and Free Fatty Acid (FFA) levels. These issues can sometimes be addressed by pre-processing the inputs to bring them up to a required standard. But the capital and operational requirements to do so are significant and add to the overall cost of production and to the process complexity.

Although the standard approach to making biodiesel today is to use fresh vegetable oil feedstock, it is both expensive and supply constrained. The availability of the crops on which traditional biodiesel production is based is inadequate to service even a fraction of today’s demand. There is consequently massive industry investment now being made to harness alternative biomass sources for the production of feedstock oil. New developments are taking place in two interrelated tracks:

• Development of new biomass sources for greatly increased oil production
• Development of more appropriate processing technology that addresses the challenges posed by the new biomass opportunities

The most promising of the new biomass alternatives for the production of biodiesel is algae. Algae contain proteins, carbohydrates, fats and nucleic acids. It is the fat content that makes algae a potential source feedstock for biodiesel. And unlike with terrestrial plants, the entire biomass production of algae can be concentrated witin the active part of its cellular structure. Growing in water algae don’t need roots, trunks, leaves, or any of the other required infrastructure that terrestrial plants do. Thus some algae species have oil contents as high as 70% of their total mass. They are also able to grow at very rapid rates and therefore represent substantial yield advantages per area farmed versus traditional oilseed crops. It is clear that the potential for algal oil production is massive, and it stands to rapidly overtake land based oil fuel crops.

The two main challenges exist in producing biodiesel from algae:

• Separating the algae from the water in which they grow
• Separating the oil from the algae that contain it

Conventional biodiesel production techniques have very low tolerance for water in the feedstock (most can tolerate far less than 1% water). Therefore before algal oil can be converted into biodiesel under traditional production techniques it has to be rigorously processed to make sure all of the water is removed.

BioFuelBox’s patent pending technology provides an integrated solution to both the water removal and algal oil extraction process challenges. Specifically developed to be tolerant of an order of magnitude higher levels of feedstock contaminants such as water, it is much better suited to processing algae into biodiesel than equipment based on the traditional approach. Our capabilities allow BioFuelBox to offer three major advantages:

• The elimination of one or more of the expensive pre-processing steps required prior to biodiesel production process
• A more flexible approach to integration with a range of pre-processing solutions
• The potential for the algae producer to later modify parts or all of their pre-processing chain to exploit more efficient pre-processing technologies as they emerge.

Alcohol Use in Biodiesel Production

Alcohol is another important component of the biodiesel production process. But as with oil feedstock, traditional biodiesel production (transesterification) is intolerant of any water in the alcohol input to the process. Most traditional processes use methanol since methanol absorbs little moisture from the air and therefore stores relatively easily in its dry state. However using methanol in biodiesel production does present significant handling and storage challenges for the producer as methanol is both toxic and volatile. Although methanol can be handled with adequate plant safety design, there are costs associated with this, and operational procedures need to be carefully adhered to.

The BioFuelBox patent pending process tolerates water levels in input feedstock that are far higher than what occurs in standard methodologies with no special storage requirements.

The BioFuelBox system provides a level of flexibility that is not practically available to biodiesel producers using the conventional process. The producer using a BioFuelBox system may;

• Switch between alcohol inputs depending on availability and price at any given time
• Produce their own renewable alcohol input