Estimation of fuel properties and characterization of hemp biodiesel using spectrometric techniques

Abstract

ABSTRACT Reducing fossil fuel reliance is considered a great challenge for several progressive emerging economies. The development of alternative renewable fuels tends to improve energy security as well as diminish fuel supply vulnerability. This paper details an enhanced protocol intended for the manufacture of hemp biodiesel over two-stage base catalyzed transesterification from crude hemp oil (CHO). The estimation of fuel properties, along with the various spectrometric techniques like Gas Chromatography and Mass Spectrometry (GC-MS), Fourier Transform Infra-Red Spectrometry (FTIR), and Thermo Gravimetry-Differential Scanning Calorimetry/Derivative Thermogravimetry (TG-DSC/DTG) methodologies were used to properly assess the quality and quantity of hemp (Cannabis Sativa L.) biodiesel (HB). The density, kinematic viscosity, and cetane number of HB were found to be 876 kg/m3, 3.91 cSt, and 50, respectively. Since the estimated fuel properties fall well within the range of American Society for Testing and Materials (ASTM) standards, HB could be considered as a sustainable fuel alternative to conventional diesel. GC-MS results demonstrate that the HB contains unsaturated long-chain fatty acids like 9,15-Octadecadienoic acid methyl ester as dominant in the mixture. The FTIR spectrum of crude hemp oil and the synthesized biodiesel confirm the conversion of triglycerides in the CHO into methyl esters in the HB. The findings obtained from TG-DSC/DTG are in near agreement with the results of GC-MS and FTIR. It is therefore proven the hemp oil has abundant potential to be used as an inedible source for the manufacture of bio-diesel.