PEC12-25 CAPEC-PROCESS Industrial Consortium ... - DTU Orbit

A key reaction characteristic of the immobilized lipase-catalyzed transesterification is that
it is multi-phasic system. The by-product glycerol can potentially impose inhibitory effects
on immobilized lipases and likewise the un-dissolved ethanol can inhibit the lipase. The
options for addressing these issues can be used as the basis for selecting the biocatalyst and
the reactor (e.g. a hydrophobic carrier for the immobilized lipase and the capabilities to
provide sufficient mixing as well as stepwise/continuous feeding of ethanol to the reactor).
An STR is efficient for batch operation while a PBR is efficient for a continuous
production.
An STR can more easily provide sufficient external mass transfer for a reaction, but will
lead to more mechanical damage of the biocatalyst particles, than a PBR. A reactor
combination of CSTR with PBR can couple the advantages of both, delivering an efficient
continuous process.
The second case study (esterification) shares some similar process characteristics to the first
case (e.g. the multi-phasic nature). However, instead of glycerol, water shows a great
impact on the extent of reaction. The removal of water should therefore be feasible during
the operation of the reactor, either intermittently or preferably in situ. Highly anhydrous
reaction conditions and the smaller substrates for this reaction place particular requirements
on the lipase.
In order to validate the established processes at a larger scale, both lipase-catalyzed
transesterification and esterification developed in the lab-scale STRs have been carried out
in pilot-scale STRs. Results in both scale STRs correlate well with respect to the biocatalyst
performance and mechanical stability.
Once the technical and scientific challenges of the process have been addressed, it is of
course important to evaluate its economic and environmental feasibility. To that end,
process evaluation has been performed for six processes composed of transesterification
and product purification for making ‘in-spec’ biodiesel and the conventional chemical
process is taken as a bench mark for comparison. The optimal process is a process
composed of lipase-catalyzed transesterification with ‘in-spec’ biodiesel product as output
with less feedstock input and waste production and much saved energy from the absence of
product purification.
5.2 Publications Record
The last 12-months have seen a big increase for CAPEC in the number of peer-reviewed
journal publications. 72 published paper from 2011 to present (plus 38 “in press” or
“submitted”) have been published in major chemical engineering journals (see Appendix
7.3). There have been 14 plenary or keynote lectures international conferences and 104
presentations have been made in important international conferences. This has given
CAPEC greater visibility and attracted more attention to the research results published by
CAPEC coworkers. CAPEC continues to have an open policy with respect to the
publication of model parameters (especially, the CAPEC developed property models). The
new version of ICAS 15.0 has all the latest property models and updated property model
parameters.
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