HTC-15 - Abstract

Abstract Title: Fingerprint characterization of bio-oil from the pyrolysis of African palm and its esterification product
Abstract Type: Seminar
Session Choice: Energy & the Environment
Presenter Name: Mrs Diana Palacio
Co-authors:Mrs Claudia Ramirez
Mr Josear Sarmiento Chaparro
Dr Enrique Mejia-Ospino
Dr Mark Barrow
Company/Organisation: University of Warwick
Country: United Kingdom

Abstract Information :

Bio-oils are produced from renewable sources, such as biomass. The chemical composition of the bio-oil is an important feature for the optimization of the feedstock transformation processes. Pyrolysis of the biomass (thermal decomposition in the absence of oxygen) produces solid materials (chars), liquid (pyrolysis oil or bio-oil) and gas. The high oxygen content, poor volatility, high viscosity and corrosiveness of the resulting bio-oil obtained from pyrolysis limit its use as a fuel. For bio-oil to be refined into usable transportation fuel, post-production upgrading is required. Esterification is an important upgrading technique where and acid-catalysed reaction with excess of alcohol is used to reduce the acid content of the bio-oils. Bio-oils contain chemical compounds with varying volatility and polarity. Gas chromatography-mass spectrometry (GC-MS) is a useful technique that allows to identify lightweight compounds in bio-oil with high volatility and low polarity. Thus, polar organic compounds are difficult to analyse with GC-MS. To overcome this, highly polar compounds can be characterised by electrospray coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). This ultrahigh resolution mass spectrometry technique, affords the characterization of the samples including heteroatomic speciation (compounds with S, N, O, Ni, V and others), aromaticity and carbon number. FT-ICR MS offers the highest performance and it is the method of choice for fingerprint typification of crude oils. Thereby, the same technology and analytical approaches can be applied to the study of bio-oils.

For a comprehensive characterization of the pyrolysis of African palm bio-oil and its esterified product, GC-MS and FT-ICR MS techniques were employed. This allows to characterize high and low volatile compounds of the samples. The unique elemental composition obtained by ultrahigh resolution mass spectrometry allows the ability to assign around two thousands of compounds, which are dominated by Ox species. Higher Ox containing species (O5-O14) were identified by FT-ICR MS but could not be observed using GC-MS. Esterified bio-oil compounds contain lower Ox containing species than the crude bio-oil, showing the effectiveness of the esterification used as upgrading technique of this bio-oil. Thus, the relative abundance of compounds containing more than eight oxygen atoms was significantly reduced after esterification.