Various adsorbents to improve the filterability of biodiesel

Abstract

Cold flow properties are the primary drawback to the common usage of biodiesel as an alternative fuel to diesel. Biodiesel's cold flow behaviour is discovered for the main reasons of presence of precipitant or crystal initiate by minor components such as monoglycerides and steryl glycosides. The ASTM test for this precipitant is ‘The Standard Test Method for Determination of Fuel Filter Blocking Potential of Biodiesel (B100) Blend Stock by Cold Soak Filtration Test (CSFT)’. Therefore, in this study, the performance of commercial activated carbon, silica and beach sand as adsorbent is studied in improving the filterability of two different level of refined biodiesel. The adsorbents were used to treat the biodiesel by removing the impurities present in the biodiesel such as the monoglycerides and steryl glycosides compound from biodiesel using adsorption technique. The efficiency of the adsorbent is determined by performing the cold soak filtration test. Based on the cold soak filtration test, precipitate is not visible and the CSTF is within the 360 s limit for the both refined level of biodiesel. However, treatment of these biodiesel with commercial activated carbon, silica and beach sand resulted in further reduce in CSFT. Commercial activated carbon found to be the most effective adsorbent, followed by silica. This is because both adsorbents possessed high surface area of 657.0420 m2/g and 320.2724 m2/g respectively and high pore volume of 0.379097 cm3/g and 0.952320 cm3/g respectively which further enhance its potential as an excellent adsorbent to improve the filterability of biodiesel compared to beach sand which possessed lowest surface area and lowest pore volume of only 1.2630 m2/g and 0.001751 cm3/g respectively.