Comparison of bioethanol dehydration technologies

Bachelor’s thesis abstract

Author: Péter Bárány

Supervisors:

Tamás Benkő Dr,

Assistant Professor

Prof. Péter Mizsey Dr,

Head of Department

The goal of my thesis is to compare two well known ethanol dehydration technologies. For the analysis of these processes, namely the extractive and the azeotropic distillation, I build a working model in ChemCAD professional process simulator, and make a cost estimation for them. I compare the results with the cost of the membrane-separation process.

Before building the models I made an overview about the tendency of the energy consumption in the past years, the price of the energy, the number of participants in the traffic and what we can expect about these in the future.

After the short overview of the development of the fuels used in engines, I presented the alternative fuels that can replace fossil-energy carriers.

I choose bioethanol, and showed its advantages and disadvantages compared to the petrol, when using it as fuel.

I started the the presentation of its production with the list of the possible raw materials, then shortly showed their processing, mentioning the handling of the derivatives as well. Since the ethanol can be used for fuel after dehydration only, I shortly introduced and presented with pictures the dehydration technologies found in the technical literature.

Before comparing the technologies I stated which strategy I would use to make decisions. I also made restrictions about the volume and other properties of the raw material and requirements for the characteristics of the end-product.

I started building models with the extractive distillation. I specified the attributes of the extraction-chemical, and proved its suitability. Knowing the needed volume, I built the model. I did it colon by colon, first with short-cut method, then with exact calculation. On the stable working model I made significant modifications which increased its efficiency.

I built the model of the azeotropic distillation the same way as the extractive distillation. I determined the quantity of the solvent, and built the model. I significantly modified this type of model too, which yielded favorable results.

Using the properties of the stable working models, namely height, diameter and heat-demand, I estimated the operational and investment costs of the processes, so compared them this way. I presented the cost saving effect of the increased operational time.

Finally I compared the cost of a litre of ethanol produced with the most effective process above with the cost of the same amount of ethanol made with membrane-separation process.