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More Update Post: 06_05_2008; 03_04_2009;
03_21_2009
The design or development
of fermentation process often views the project as a monolithic
task. However, the design of such processes consists of two tasks:
the design of the process for the production of the substrates, or
reactants, for the catabolic reactions and then, of course, the
design of the process for the fermentative utilization of the
substrates by the microbes. A much more efficacious approach
therefore is the performing of the technology design as two separate
process designs tasks.
Several advantages attend the separation of the
substrate processes from the Fermentation Process.
The fact is that such approach enables a more focused design and
analysis of each component of the overall project. Moreover such
component-wise perspective is more likely to enable global view to
the selection of resources from which to produce the substrates,
given that quite possibly a particular substrate could be produced
from a diversity of raw materials. The production of glucose as a
substrate for ethanol fermentation presents a classic case of such
design consideration.
Glucose substrate for use
in fermentation reactors is
currently produced from
three or four raw materials: Grain, Cellulosic [Grass] Source,
Sugar-cane and Palm Sap. These, of course, are used most
commonly and so constitute the primary sources, from amongst the
sources sampled in course of the development a myriad of feed source
have been experimented with for the sugar-feed for the fermentation
reactor, as a result of huge global interest that currently exists
in the development of ethanol production process. However, the
sourcing of the newer substrate-sources has invariably been
responsible in eliciting the need for the process partition of
fermentation processes: Fermentation Substrate Processes for
producing the substrate, and Fermentation Processes in which
the fermentative microbial utilization of the substrate is effected.
Notably though, the
separating of the various empirical methods of production of ethanol
was the factor that enabled the focus on empirical development
spanning several years evolved as sets of process steps and
consequentially the mapping of the different production steps into the Fermentation
Substrate Process Engineering basic design and correspondingly
engineering
process equipment set for the processing of the feed into the
substrate. In general, the direct translation of the process steps
into corresponding engineering process can be optimized such that a
better process design can be developed.
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Evidently, because the
Substrate Production Process may be entirely developed as chemical engineering
process and therefore only tangentially biotechnological, the
engineering the process design more from a chemical engineering perspective may
result in a better optimized design than if the Substrate Process
design were lumped with the Biochemical Fermentation Process which
is more a biotechnological.
The adoption of the
perspective of chemical engineering for the design of the substrate
process, also opens up the task to actually consider other chemical
process for producing the same substrate, because even a given raw
material can be converted by more than one process into the same
substrate.
The production from
starch of glucose-substrate as raw material for ethanol
fermentation presents an example of option to choose from among
multiple process chemistry for the process engineering of a
production design. In general, glucose is produced from starch by
acid hydrolysis. By this method, starch is mixed with hydrochloric
acid, and then heated to a temperature than can be anywhere from
about 55oC to 160oC for a period than can
range from 20 secs to 5 hours depending on the pressure which can be
as high as 160psig, and then neutralized with either Sodium
hydroxide, Sodium Carbonate. obviously these near continuous spans
of variables of temperature, pressure and neutralizing agents
provides a range of choices from which to perform a process
engineering design for the production of glucose.
Clearly from a process
design perspective this enable the support of Glucose
Substrate Process under several varied conditions endemic of
operating circumstances. Effectively several Process Chemistry can
be defined and each one is bound to lead to different process design
for the same fermentation process operation. Clearly this should
available the substrate process design task with flexibility for
optimization against various cost-functions.
Further relative to the
biochemical reaction, the substrate production process if designed
as a chemical engineering process offers the opportunity to support
much higher production volume demand. of course, in such cases the
fermentation becomes a bottle neck in the overall process.
Eliminating a potential source of process bottleneck has advantages
as production improvement efforts can now be focused on the
intrinsically slow biochemical reactions, and therefore provide a
better return.
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Moreover, the focused
development of a process substrate production should also enable the
potential support of other biochemical fermentation processes.
Glucose substrate-feed processes clearly be found use as raw
material sources for the industrial production operations of other
fermentation processes such as
butanol bioprocess, or any other such biotechnology process that
depends on the specific substrate
In any event, quite evidently, the design of
Fermentation Substrate[-Feed] Processes must not only address the issue of the processing of
the feed-source into substrates but rather must also factor into the
design project the development of a
process-specific
Mash Feeder. Such device or equipment is crucial to
effectively introducing the mash into a fermentation reactor.
Based on the advantages
elicited so far, the design of the fermentation Substrate process
being separated from the whole project should be the approach for
invariably designing an efficacious substrate process.
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