Energy demand of biofuel production applying distillation and/or
pervaporation
E. Nagya, S. Boldyryevb
a
University of Pannonia, Research Institute of Chemical and Process, Egyetem u. 10.,
Veszprem, 8200, Hungary; e-mail: nagy@mukki.richem.hu
b
National Technical University,Frunze str. 21., Kharkiv, 61002, Ukraine; e-mail:
stasboldyryev@gmail.com
Bioenergy from renewable resources is already today a viable alternative to fossil
fuels; e.g to bioethanol or biobutanol. Bioethanol can be produced from e.g. sugars, starch and
various lignocellulosic materials such as straw, wood and waste. One of the most energy
consuming step of fuel production in these technologies is the concentration of ethanol up to
the required fuel quality obtained during fermentation. Although several separation
technologies are technically capable of removing volatile products from fermentation broths,
distillation remains the dominant technology. This is especially true for the recovery of
biofuels such as ethanol or butanol. The energy used for distillation reaches the 40 % of the
total energy demand in bioethanol production. The pervaporation is an important alternative
membrane separation process to distillation that can be applied as a hybrid process or even as
a single process to produce high quality of biofuel. To reduce this cost the distillation should
be integrated with membrane separation not only above the azeotropic concentration but
below that point. E.g. the pervaporation can be more efficient separation process than the
distillation depending on the membrane separation properties. Other alternative separation
processes are e.g. the membrane distillation and the vapor permeation. The main aim of this
lecture is to analyze the energy demand of these processes and to investigate how the
necessary energy can be reduced. Accordingly, the following processes will be analyzed
focusing their energy demand:
 distillation integrated by pervaporation,
 more stages pervaporation,
 membrane distillation,
 vapor permeation.
All these processes will be compared to the energy demand of the distillation process.
It will be shown how the membrane properties as separation factor, permeation rate affects the
energy consumed during the processes, applying one-stage or multi-stage pervaporation
process and it will be offered an efficient, alternative separation process for biofuel
production.
The National Development Agency grant TÁMOP-4.2.2.A-11/1/KONV-2012-0072 and grant
TÁMOP-4.2.2/B-10/1-2010-0025 greatly acknowledged for the financial support.