Adsorptive Selectivity and Mechanism of Three Different Adsorbents for Nitrogenous Compounds Removal from Microalgae Bio-Oil

Abstract

Microalgae bio-oil is of interest as a potential alternative to traditional fossil-fuel-based transportation fuels. However, the presence of nitrogenous compounds in the bio-oil can lead to the release of NO x (a polluting gas) during combustion, and is detrimental to the environment. Thus, it is necessary to selectively remove these compounds from the bio-oil prior to the bio-oil being used as a transportation fuel. This study investigates the adsorptive capacity, selectivity, and mechanism of three adsorbents, Cu-zeolite Y, silica gel, and activated carbon, for the removal of nitrogen-containing compounds from bio-oils derived from pyrolysis of the microalga Tetraselmis suecica. Since Cu cations preferentially adsorb nitrogen over oxygen, the affinity of Cu-zeolite Y for nitrogen could allow denitrogenation of microalgae bio-oils. Moreover, when Cu-zeolite Y was used for selective denitrogenation, the presence of the compounds containing aromatic rings such as benzocyclobutene and phenol would not substitute indole or hexadecanamide. The adsorptive selectivity of the silica gel depends on the acid–base interaction. Hydrogen bond interaction and acid–base interaction play an important role in adsorptive denitrogenation over the activated carbon. This study found that activated carbon is a promising adsorbent for the removal of nitrogenous compounds from microalgae bio-oil.

Co-transesterification of waste cooking oil, algal oil and dimethyl carbonate over sustainable nanoparticle catalysts

“…Moreover, the reaction rate was affected by the concentration of TGs in the bio-oil transesterification process which followed a zero or first order kinetic model. The higher performance for co-transesterification may be due to the change in internal pressure, molecular interaction, bond affinity, and surface collision [22] , [23] . The higher TG conversion and FAMEs content can be attributed to certain synergistic effects during the co-transesterification of WCO and AO.…”

Adsorption of Major Nitrogen-Containing Components in Microalgal Bio-Oil by Activated Carbon: Equilibrium, Kinetics, and Ideal Adsorbed Solution Theory (IAST) Model

“…The analysis was conducted in situ by the infrared microscopy beamline. The method for FTIR analysis is based on our previous work …”

“…The method for GC-MS analysis is based on our previous work. 6 Both the quantitative and qualitative analyses (MassHunter Workstation Software) of the bio-oil were performed using a 5977A GC-MS (Agilent Technologies Inc.) equipped with HP-5 capillary column (30m × 0.25 mm × 0.25 mm). Helium was used in this part as the carrier gas.…”

“…It is clear that the use of the pyrolysis process to convert microalgae to bio-oil is increasingly important in the application of biomass resources. Tetraselmis suecica can be used for the generation of biofuels, particularly as a renewable microalgal source of pyrolysis conversion. − The bio-oil produced from Tetraselmis suecica has high calorific value and a low concentration of oxygenous compounds . However, the microalgal bio-oil has high nitrogen-containing functional groups which can cause the emission of nitrogen-containing gas during combustion.…”

Physisorption of bio oil nitrogen compounds onto montmorillonite

“…Presently, there are only a few targeted studies of nitrogen compound adsorption from algae oils, the most recent of these using phyllosilicate clays, e.g. montmorillonite 15,16 , activated carbon 11,12 , Cu-zeolites 11 , silica gels 11 , and aminated metalorganic frameworks 17 . Computational approaches to surfactants in apolar environments have mostly focused on bulk assemblies, see e.g.…”