(152f) Lignocellulose to Biofuels: Membranes for Process Intensification

Authors: 
Wickramasinghe, S. R., University of Arkansas
Qian, X., University of Arkansas

Lignocellulose to
biofuels: membranes for process intensification

Membrane
based processes are often attractive as they can frequently lead to tremendous
levels of process intensification.  This
is particularly important in the development of sustainable manufacturing
processes.  This presentation focuses on
the conversion of lingnocellulosic biomass to biofuels and chemicals, where
development of cost efficient manufacturing processes are essential.  The figure below gives the glucose
concentration as a function of time for a both a batch and continuous process
(left hand side y-axis), as well as the rate of glucose production (right hand
side y-axis) for enzymatic hydrolysis of cellulose.  As can be seen in the continuous process the
rate of glucose production is several times higher than for the batch process but
the glucose concentration is almost10 times lower. This is due to product
inhibition of the enzyme

A
membrane reactor with an appropriate pore size could lead to continuous removal
of glucose in the permeate as it is produced. 
Thus the rate of glucose production will be maximized.  However it will be essential to concentrate
the glucose prior to further biochemical or thermochemical, processing.  Here results are presented for a submerged
membrane reactor that enables continuous enzymatic hydrolysis.  Development of such a process can lead to
more rapid hydrolysis and smaller reactor volumes. 

Finally
we have developed a unique catalytic membrane that not only enables removal of
glucose as it is produced, but also catalyzes the hydrolysis of cellulose in
one step.  As cellulase enzyme continues
to represent one of the most expensive components in the production of biofuels
and chemicals, replacement of the enzyme is highly desirable.  Using our results for the hydrolysis of
cellulose, the tremendous potential of membranes for process intensification
will be discussed.

Variation of glucose
concentration and glucose production rate as a function of time for batch and
continuous processing.