This study reports the hydrodeoxygenation (HDO) of acetic acid. The authors have chosen a packed bed microreactor for the purpose. The reason for put forward by the authors for choosing micro reactor is its efficiency in operation under reduced hydrogen pressure of 300 psig as opposed to normal reactors (macro reactors) which need to be maintained at very high hydrogen pressure (1050 to 3000 psig) and in practicality, not feasible. The highlight of this study is the use of acetic acid to analyse and quantify the HDO products which can serve as a model for HDO of pyrolysis oil.
The Reactions of Interest:
In total, the reaction schemes involving complex reactions consisting series of reactions to form CH3CHO, CH3CH2OH, and CH3COOCH2CH3 and parallel reactions with CH3CHO, CO2, CO, and CH4 as products, within the temperature range of 200oC to 450oC have been highlighted.
- On experimental run, I found the conversion takes place in sequential reaction scheme from reaction 1 to 6 as mentioned by the authors, the conversion starts at 210oC with formation of ethyl acetate and ethanol as intermediates with detection of acetone at 430oC in a significant amount. At 450oC the formation of carbon dioxide, carbon monoxide, and methane are observed and these reaction schemes proceed with liquid phase acetic acid.
- While comparing to liquid phase reaction, the gas phase of acetic acid gives 97% conversion rate at very low pressure maintenance of 1-15 psig which is significantly safe in operation and easy in commercialization of micro reactor process.
- If the channel width is less, the conversion rate is high and reduces on increase of channel diameter. So, care must be taken in design of channel dimensions most preferred 130µm.
- The major observation is the formation of acetone which was not mentioned by previous authors and this literature outstands all by representing the acetone formation.
- In simple terms, the chosen reaction methodology is feasible with available microfluidic technology.