Evaluation of the Additive Power of Ethanol Obtained from Angola Grass in Direct Distillation Gasoline Samples, Case Study: Straight Run (SR) Gasoline Produced at Luanda Refinery

Abstract

Alongside the process of blending naphtha, fuel anhydrous ethyl alcohol is an additive recurrently used to adjust commercial properties such as the octane index of gasolines during its formulation. This additive is environmentally recommended due to the promotion of decarbonization in gasolines that is evidenced in its consumption with the reduction of CO2 emissions into the atmosphere, compared to the consumption of other gasolines. There are several ways to obtain the respective additive, the research leads to obtaining it from the Angolan grass (Brachiaria purpurascens "Forsk" Stapf). Angola grass has a low fiber and protein content, thus becoming with low preference in the choice for animal feed and has a significant content of nonnitrogen extractives giving it a high energy potential to be raw material for biofuel production Through an experimental study and on a laboratory scale, alcohol was produced, then the quantities of the two components of the mixture were determined using additive calculations, and then mixed in samples of Straight run (SR) gasolines direct distillation produced in Luanda Refinery. Next, octane index tests were performed in the final mixture by the RON method following ASTM D22699 and adulteration potencies were verified in the samples. The octane index defined to be reached was 95 octane and it was proven that alcohol produced from Angola grass has the potential to promote improvements in octane index, as we found increases in the octane index of additive gasoline shows. We recorded an improvement of the rate of 91% for sample 1 namely the mixture of anhydrous alcohol of grass and light gasoline (SR) of the Luanda Refinery and finally an improvement in the order of 81% for sample 2 namely the mixture of anhydrous alcohol of heavy gasoline grass of the Luanda Refinery. However, it is demonstrating in the first instance starting methodologies for the additive of gasoline samples, and in the second instance the "effect" of a fuel anhydrous alcohol derived from a "differentiated matter" called Angola grass, when used as an additive in direct distillation gasoline, which is concluded to be positive.