The first objective of this project is to pre-treat the crude bio-oil to reduce the amount of free fatty acids and avoid saponification. Presently, studies are developed in the laboratory concerning the chemical characteristics and physical properties of acorn oil, peanut oil, canola oil, corn oil, and soybean oil as sources from which to produce biodiesel. By titrating the crude bio-oil will determine the amount free fatty acids by weight, which will be used in calculating the amount of acid needed to pre-treat the bio-oil. Once the free fatty acids are reduced to an acceptable level the normal base catalyst method will be applied. By esterifying the free fatty acids first we will also increase the yield of biodiesel of non-food source crude bio-oil.
The second objective of this project will be to study five neat methyl esters (methyl palmitate, methyl stearate, methyl oleate, methyl linoleate, and methyl linolenate) and the pure fatty acids, which are the building blocks for most bio-oils such as (soybean oil, poultry fat, corn oil, peanut oil, and rapeseed oil) to further our understanding of their individual characteristics and to fine tune the testing methods by comparing the results to known values from reference literature. In this stage of the project, characteristics such as cloud point, pour point, and viscosity will be analyzed. This will provide a basis for crude bio-oil and biodiesel analysis while simultaneously allow us to know which components should be further investigated for a sustainable environment.
The third objective of the project will be in biodiesel production waste management. The preliminary glycerol separation trials yielded promising results. Acid neutralization of the glycerol was conducted in the Renewable Energy Laboratory at GSU and trials were conducted with 6% acid based on volume of glycerol using two types of acid, phosphoric and hydrochloric. Various temperatures and stirring times were investigated to determine the most efficient combination. The crude glycerol separated into three distinct layers; free fatty acids, crude glycerin, and the precipitated catalyst. All layers were separated for analysis. The aim of this research will be conducted through glycerin refining and recycling waste products into usable biofuels. Here the amount of free fatty acids will be verified and glycerin in the top and middle separated layers, which are derived from the glycerol produced from biodiesel production. Titration will be used to determine the exact amount of acid needed to neutralize the glycerin and to convert the soap back into free fatty acids. Gas chromatography-mass spectrometry will be used to confirm the amount of free and total glycerin in the top and middle layers. The titration process will act as an indicator as to the effectiveness of the acid and to quantify the amount of acid needed to esterify the free fatty acids. Verifying the amount of free and total glycerin in the top and middle layers will indicate the purity of the top and middle layers.
The fourth objective of the research will be to convert the precipitated catalyst, formed during the neutralization of the glycerin, back into a usable form. Electrolysis will be used to recycle the precipitate back into sodium hydroxide using an apparatus that will be developed in order to achieve this process. Recycling the sodium hydroxide will help to reduce the overall cost.