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 Increased utilization of this renewable biofuel results in significant microeconomic benefits to both the urban and rural sectors, and the balance of trade. Several commercially available technologies exist today and the number of biodiesel/additive patents have grown extensively in the last couple of years as well, which suggests that biodiesel is now, and will stay at the top of the list of the renewable fuel industry.Technically, use of 100% biodiesel fuel (B100) does reduce the fuel economy and power of diesel engines by 10%, but it is important to note that biodiesel is not the only way to increase the percentage of biofuels in regular fuels (Figure 1).  Figure 1 Different biofuels produced from biomass with different methods. The raw material (oil seed) has a very important effect on the final product properties and at the same time its oil content determines the yield of biodiesel as well. In general, biodiesels are all kinds of vegetable oils, animal fats or their derivations, which could be applied in diesel engines, but currently defined biodiesels refers only to products made by changing the chemical structure of the above mentioned materials to form fatty acid alkyl esters, which have more similar chemical structures compared to diesel fuel molecules. Biodiesel production (producing vegetable oil/fatty acid alkyl esters) could be accomplished in two ways: batch or continuous. Depending on the applied catalysts it could be alkaline, acid, or enzyme catalyzed process, but there are many other ways to classify the great number of technologies, which are available in the market today. Out of the available processes, at the industrial scale, methanol and alkaline catalyst (NaOH / KOH) method is utilized most because of its efficiency (Figure 2), unless both the vegetable oil and alcohol feedstocks are free of water (<500ppm). If the free fatty acid content is high (depending on the source and type of vegetable oil, or presence of water ) usage of sulfuric acid is suggested. It should be also noted that biodiesel production is slightly less efficient than petroleum diesel production (2.5%). The advantages of this process are low temperature (20-80C (68-176F)), almost atmospheric pressure, flexibility in capacity, lower energy consumption, excellent product quality, feedstock quality flexibility and safe unit operation.  Figure 2 General flow chart of biodiesel production including STRATCO Biodiesel Contactor reactor.. What is STRATCO's involvement in the Biodiesel Industry?  STRATCO offers the Biodiesel Contactor™ reactor for transesterification reactions regardless of the type of catalyst or feedstock (vegetable oils, yellow grease, animal fats, waste oils, algae etc.). The Contactor reactor provides reduced operational costs due to its extremely high degree effectiveness in heat transfer, dispersion and intimate contacting of reactants. These unique characteristics in a chemical reactor application results in more complete reactions in a shorter period of time.The high dispersion mixing in the Contactor reactor is achieved using the hydraulic head assembly, in conjunction with the unique internal vessel configuration, forcing the entire contents through multiple blending cycles every minute. Intense mixing capability enhances quality of products, through homogenous mixture and temperature. The material blend is pulled down through the inside of the circulation tube via the impeller. Turbulence is established between the stationary shear vanes and the blades of the impeller, resulting in a zone of high shear and intense mixing. As the material passes through the impeller, its velocity is greatly increased. At the discharge side of the impeller, the stream is impinged against the diffuser vanes. The direction of the flow is reversed at the bottom of the hydraulic head where the vanes force an axial turbulent flow as the dispersion/emulsion passes through the annular space formed by the circulation tube and vessel wall. The liquid then flows over the top of the circulation tube and back into the impeller. Heat transfer oil is circulated in the external heating jacket. High heat transfer coefficients are achieved by the high fluid velocities across the heating surface. The STRATCO Biodiesel Contactor reactor provides increased efficiency for biodiesel manufacturers by offering: • reduced time in transesterification • intense mixing capability, enhancing quality through homogenous composition • more precise temperature control • reduced energy cost through its heat transfer effectiveness • substantially increased production capability • reduced maintenance costs • operating temperature range can go up to even 450 degrees Fahrenheit.  The STRATCO Biodiesel Contactor reactor’s inner circulation tube is removable, which provides easier cleaning for maintenance. If required, the inner tube could be heat jacketed, too. The Contactor reactor could be pressurized as well.STRATCO is equipped for industrial partnering to accomplish pilot plant scaled testing in its laboratory for specified feedstock and catalysts. For more information on STRATCO's biodiesel R&D capabilities, email at info@stratcoglobal.com |
