Dataset related to the determination of the volumetric mass transfer coefficient (kLa) of CO₂ from a 24% CO₂ gas mixture, preparation of the co-immobilized bifunctional biocatalyst, multi-enzymatic CO₂ reduction under varying volumetric flow rates, CO₂ balance in capture and conversion processes, process performance metrics and environmetal impact assessment.

METHODOLOGICAL INFORMATION

1. Description of the methods used to collect and generate the data:

The enzymatic activity of the enzymes was measured spectrophotometrically at 340 nm using a phosphate buffer, NAD+ at 1.67 and 5 mM, 100 mM sodium formate, 100 mM glycerol, and a variable amount of soluble enzyme. The protein concentration was quantified spectrophotometrically at 595 nm using the Bradford method. The concentration of soluble CO2 in the medium was measured using a CO₂ sensor (InPro5000i/12/220, Mettler Toledo S.A.E). Formate, DHA and glycerol quantification were performed in the liquid chromatograph using an ion exchange method with the IC-Sep COREGEL 87H3 column and sulfuric acid (H2SO4) 0.5 mM: Acetonitrile (65:35) as mobile phase. A flow rate of 0.6 mL·min-1, injection volume of 20 µL, column temperature of 30 °C, UV/Visible detector at 210 nm and RID detector at 30 °C. The co-immobilization of the enzymes was carried out in 100 mM phosphate buffer + 100 mM NaCl at pH 7.5, at a temperature of 4 °C, with a glutaraldehyde coating for GlyDH at 0.05% v/v for 150 minutes. The determination of the kLa (CO₂) was carried out in a stirred tank reactor using 100 mM phosphate buffer (pH 7.5) as the reaction medium, a 24% CO₂ gas mixture and pure CO₂, and the immobilization supports Ni2+-ReliZyme and Ni2+-Agarose. *The multi-enzymatic CO₂ Reduction reaction was carried out in a stirred-tank reactor using 100 mM phosphate buffer at pH 7.5, 100 mM glycerol, 1 mM NADH, with CO₂ continuously bubbled at 1 VVM, and 20 grams of biocatalyst in a final volume of 200 mL. The reaction was stirred at 300 rpm, maintained at 30 °C, and run for 85 hours.

1. Data processing methods: All data was processed using Excel.

2. Software or instruments needed to interpret the data: Excel

3. Information about instruments, calibration and standards: Varian Cary 50 Bio UV-visible Spectrophotometer (Agilent) SPECTROstar Nano (BMG LABTECH) Spectrophotometer Liquid chromatograph Agilent 1220 Infinity II Multi Therm Heat Block system (Benchmark Scientific Inc.). SpinChem reactor (SpinChem, Sweden) Digital in-line CO2 sensor InPro5000i/12/220 (Mettler Toledo S.A.E., Barcelona, Spain) Analytical Transmitter M400 Type 3 (Metter Toledo S.A.E., Barcelona, Spain). Mass flow controller EL-FLOW (Bronkhorst, Netherlands). BCP-CO2 gas analyzers (BlueSens GmbH, Germany). 916 Ti-Touch titrator (METROHM HISPANIA, S.L.U, Spain)

4. Environmental or experimental conditions: All experiments were carried out in a fume hood at 30°C and within a pH range of 7.0 to 8.5.