Financial and parametric study of biodiesel production from hemp and tobacco seed oils in modified fruit blender and prediction models of their fuel properties with diesel fuel

Abstract

Biodiesel is the most widely accepted complement fuel for diesel engines due to its characteristic properties, environmental and strategic advantages. In recent years, the high cost of biodiesel and the competition with food has been reduced by using non-edible feedstocks. However, if further cost reduction is to be achieved, new methods of production should be adopted. In this study, an attempt has been made on the cost reduction by producing biodiesels from non-edible oils (hemp seed oil and tobacco seed oil) in the laboratory using a domestic blender. Parametric studies were conducted to determine the optimal conditions such as KOH dosage (0.5–1.5 wt%), reaction duration (50–100 min) and methanol to oil molar ratio (4.0–8.0) for low fatty acid hemp seed oil methyl ester (HSOME) and tobacco seed oil methyl ester (TSOME) production and to establish density and viscosity correlation for the HSOME and TSOME with diesel blends. Regression models were adopted in predicting the basic properties of HSOME and TSOME, and their blends with diesel fuel. Optimum conditions of 0.9 wt% of KOH and 1.1 wt% of KOH and reaction time of 70 and 80 min were obtained with more than 95% conversion for both HSOME and TSOME with methanol/oil molar ratio of 6:1. The cost estimation for HSOME and TSOME was conducted and the commercial value detected as ($1.35 per litre) and TSOME ($1.36 per litre). The respective energy efficiencies for HSOME and TSOME were 0.044 × 10−3 g/J and 0.0396 × 10−3 g/J. The fuel properties correlated with a high regression coefficient with biodiesel fraction and were similar to those found in literature and complied with both ASTM D6751 and EN 1421 standards.