Biogenic ammonia for CO2 capturing and electrochemical conversion into bicarbonate and formate

• A new biological route for CO2 capturing process has been established by producing ammonia from synthetic urine.
• Synthetic urine was used as anolyte for conversion of CO2 into ammonium bicarbonate.
• Ammonium bicarbonate and formate were produced in catholyte while passing CO2 in catholyte.
• It can be understood that biogenic ammonia is a very good capturing agent for CO2 conversion process.

Capturing and conversion of CO2 into useful chemicals will render greater impact in reducing the concentration of CO2 in the atmosphere. In the present study, a novel system viz. “Bio-assisted Electrochemical System” was employed for carbon dioxide conversion. Biogenic ammonia was used as CO2 capturing agent, which was produced from synthetic urine by ureolytic bacteria. The ureolytic bacteria (Serratia ureilytica and Serratia marcescens) were isolated from railway track fecal contaminant. These bacteria were identified by biochemical and molecular techniques. Titanium Substrate Insoluble Anode (TSIA) was used as anode; lead coated SS316 wire mesh was used as cathode in electrochemical system for CO2 conversion. The Nafion 961 membrane was used for the transport of cations. The electrochemical experiments were carried out at current density of 100 mA/cm2. The final products of ammonium bicarbonate and formate were collected from the electrochemical cell and were analyzed by UV–visible spectrophotometry, Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonance spectroscopy (NMR) techniques.

Figure optionsDownload as PowerPoint slide