(599h) Reformulation of Gasoline to Replace Aromatics By Biomass-Derived Oxygenates

Reformulation of Gasoline To Replace
Aromatics by Biomass-Derived Oxygenates

Gourav
Shrivastav¹, Tuhin S. Khan¹,
Manish Agarwal², and M. Ali Haider^1,*

¹Renewable Energy and Chemicals Laboratory,
Department of Chemical Engineering, Indian Institute of Technology Delhi, New
Delhi, India

²Computer Services Centre, Indian Institute of Technology
Delhi, India

Abstract: Gasoline, a complex hybrid of various
hydrocarbon families, is an economical, efficient, and ubiquitous fuel. Despite
such properties, the major problem with gasoline is its adverse effects on the
environment at both local and global scales. This is primarily due to the
presence of aromatic components which are added to maintain the octane rating
of the gasoline fuel. These compounds are well-known to exhibit toxic and
carcinogenic behavior. For decades, methyl tertiary butyl ether (MTBE), an
oxygenated additive, has been widely used to improve octane ratings of gasoline.
However, now it is proven to be carcinogenic and a major contaminant of
groundwater, owing to its high aqueous miscibility. Hence, an environmentally
benign oxygenated additive is required for the reformulation of gasoline. In
the search for a “green gasoline”, a new reformulation strategy, having no or
reduced amount of aromatics, is proposed. Biomass-derived alkyl levulinates are
prospected as oxygenated additives as well as blending components to circumvent
the use of aromatics and MTBE in gasoline. By utilizing molecular dynamics simulations,
the thermophysical and dynamical behavior of gasoline blends with four alkyl
levulinates, viz. methyl levulinate, ethyl levulinate, propyl levulinate and butyl
levulinate was scrutinized and compared with those of MTBE−gasoline
mixtures. It is shown that, at 300 K and 1 atm, ALs in conventional gasoline can
be used for reformulation with amounts up to 18 mol% while maintaining the
density, viscosity, and compressibility within the recommended limits. However,
this amount can be further increased to 35 mol% by modification of aromatic
content. Among the studied oxygenates, BL was observed to have the lowest
miscibility in water as compared to other ALs studied. The methodology may be
applied to study similar biomass-derived oxygenates for their applicability as
a fuel additive or blend. In addition, a wide variety of oxygenates, such as
alcohol, ketones, esters, diesters, and cyclic ethers, were also scrutinized. The
preliminary results for these oxygenates suggest that they can maintain
thermophysical and dynamic properties of reformulated fuel but will reduce the
energy density.