Concept in Definition ABC

Candela Rocío Barbisan | Sea. 2022
Chemical engineer

Parts that make up a bioreactor

Typically, a bioreactor is made up of different modules that allow its adequate functioning. In the first place, a casing or envelope that constitutes the container container, is often known as dorna and adapts the sterility conditions required, therefore, in general, the constituent materials are usually stainless steel and glass, according to the working conditions and volumes required.

Secondly, there is the controller module, the one that allows setting the parameters so that the work atmosphere is adequate; Like any control loop, this module allows you to take a census of different variables and manipulate others in order to avoid disturbances and activate tools that allow controlling the reactions that are carried out inwardly. Likewise, this control system requires auxiliary control and measurement instruments and even equipment added to the bioreactor.

For the control of the temperature, the bioreactor has a thermostatic bath that allows this variable to be maintained at a desired value, so that the temperature is homogeneous throughout the entire reactor.

Finally, like any industrial system, it may require additional instruments and equipment for auxiliary services such as compression systems air and flowmeters, in order to dose the air and gases that are necessary for the development of the microorganisms.

How do they work?

To understand it better we can use an example. The case of a bioreactor in the control of quality of water. In this case, the container is filled with wood chips through which the water drains. Thus, the soil microorganisms dragged by the water prior to entering the reactor colonize the chips and feed on their carbon. In addition, in their vital processes they inhale nitrates from the water and exhale nitrogen into the atmosphere, so that the water is finally avid for nitrates.

Depending on the type of treatment desired, the bioreactor changes its composition. Widely, its use is widespread in the treatment of effluents and wastewater, which are known as anaerobic and aerobic reactors, depending on the type of microorganisms (commonly bacteria). Based on them, the assimilation capacities of organic matter and dissolved nutrients are determined, which allows the removal of these components from the water. Organic matter, as stated above, is the source of feeding of these microorganisms and, in addition, a source of nitrogen and phosphorus must be provided for the inhalation process, which allows the growth of the microorganism. The biomass generated is separated by density difference and, thus, the final water is clean of organic matter and nitrogen and phosphorus compounds. Of course, this application has the limitation that the effluent to be treated does not contain biocides.

Operation mode

Although this is developed here for bioreactors, it can be said that they are the typical operation modes of any reactor in the industry.

In the case of operating the bioreactor in batch, the volume remains fixed throughout the period of operation and the microorganisms consume reagents (nutrients) and generate the products stipulated. On the contrary, if the operation is continuous, through an inlet stream the reactor is fed continuously and, simultaneously, a certain flow of product is extracted.

An operation that combines both modes can also occur, where it operates in batches, and after certain time intervals a feed current is injected.

Other application examples

The different utilities that have been given to bioreactors in recent years place them at a point of development. From the generation of plant cells and fertilizers for the agricultural industry to the hydrocarbon industry for remediation tasks environment and the treatment of effluents and the renewable energy industry, such is the case of the production of biogas and biodiesel.

Likewise, they have managed to enter the food industry, for the generation of probiotics that are in fashion today and even in the manufacture of beer.

Of course, in the cosmetic and pharmaceutical industries they are also widely used, in the manufacture of creams, acetone, antibiotics and even vaccines.