Study of esterification reactions in a batch reactor

Study of Esterification Reactions in a Batch Reactor:
Modeling the Industrial Synthesis of Benzoic Acid and Biodiesel
Chida Balaji Brett Levine Shirin Poustchi
chidabalaji@gmail.com levine.brett@gmail.com spoustchi@msn.com
Abstract
This experiment examines two esterification reactions: the de-esterification of
ethyl benzoate into benzoic acid and the transesterification of palm oil intobiodiesel.
Through the de-esterification of ethyl benzoate, we mimicked the processes and
experimental designs that are involved in the production of API’s (active pharmaceutical
ingredients). The transesterification of palm oil allowed us to observe the production of
biodiesel on a small scale. In a 1L batch reactor at 40oC and 0.25 ethanol mole fraction,
the rate constant was experimentallyfound to be 0.47 M-1s-1. This value is important in
that it tells us the rate (speed) of the reaction under the given conditions and compares
favorably with the literature value of 0.51 M-1s-1 [2]. For the biodiesel reaction, we
successfully produced biodiesel in a 1L batch reactor with a percent yield of 23% at
60oC.
Introduction
The demand for pharmaceuticals
is increasing; consequently,the need for
efficient production designs is vital to
the success of the pharmaceutical
industry. By studying the synthesis of
APIs, chemical engineers are striving to
discover new ways to optimize the
efficiency of these valuable reactions.
Although API synthesis covers a
multitude of chemical reaction types, our
research focused on one specific reaction
type: esterification.
As withpharmaceuticals, the
petroleum industry is constantly
searching for new ways to increase their
productivity. Additionally, these
companies are actively pursuing viable
and renewable alternative energy sources
as a result of the decreasing fossil fuel
reserves, which include wind power,
solar power, and the focus of our second
experiment: biodiesel.
Esterification reactions involve
eitheradding (transesterification) or
removing (de-esterification) an ester
group to/from a molecule. Esters are a
type of molecule formed from an organic
acid and an alcohol and have the general
structure of R-CO-OR’. Ester molecules
exist in a variety of forms, ranging from
naturally occurring esters such as
vegetable oils to commercially prepared
products such as biodiesel.
Commercially,esters are very
prevalent and a valuable resource to
many industries, especially the
pharmaceutical industry. Many APIs, or
active pharmaceutical ingredients, are
formed in esterification reactions (ex.
Aspirin). Without these quintessential
ingredients, the medical and
pharmaceutical industry would not be
where it is today. Furthermore, it is of
great importance to continue to study
andunderstand how these esterification
reactions work so engineers and other
professionals can continue to produce
products that will further benefit
mankind.
Commercially, these reactions
take place in very large batch reactors.
These specially designed vessels are
often tailored to the reaction taking
place, and provide a closed system that
can often easily be controlled by a
computer.These reactors also have the
ability to control temperature, reactant
concentrations, and many other things
such as pressure and pH depending on
the specific reactor involved. [1]
Carefully analyzing past experiments
enables chemical engineers to make
changes to the reactor conditions that
would make the reactions more efficient
and effective.
Figure 1: The Batch Reactor
Above is apicture of the 1L batch reactor used in
both experiments. The outer layer of the reactor
is a water jacket with a dedicated temperature
probe that constantly monitors the reactor’s
temperature.
This paper analyzes two different
esterification reactions. The first, the deesterification
of ethyl benzoate into
benzoic acid, serves as a model for the
synthesis of APIs in batch reactors. The...