Biocatalytic production of methanol from biogas

Transcription

1 Biocatalytic production of methanol from biogas Dipl.-Ing. Matthias Stier Nobelstraße 12, Stuttgart Tel Fax

2 Motivation Biogas in Germany: 8000 biogas plants 4 GWel. Cogeneration (5.6 %) Methanol production by reforming From naturel gas 2004 ( /t): From biogas ( /t): % 62 % Composition of biogas 1 methane % CO % H 2 O 2-7 % CO 2 remains entirely unused The technological added value of biogas could be significantly higher! 25 % Electrical efficiency of CHP η = % 2 Bandi und Specht (2004): Expertise des Zentrums für Sonnenenergieund Wasserstoffforschung Baden Württemberg 1 Kaltschmitt, Martin, Hans Hartmann, und Hermann Hofbauer. Energie aus Biomasse: Grundlagen, Techniken und Verfahren. Springer Science & Business Media,

3 oxidation cascade of methane methane formaldehyde formic acid carbon dioxide methanol 2 Nguyen, L., Loridant, S., Launay, H., Pigamo, A., Dubois, J., Millet, J., Study of new catalysts based on vanadium oxide supported on mesoporous silica for the partial oxidation of methane to formaldehyde: Catalytic properties and reaction mechanism. Journal of Catalysis 237, doi: /j.jcat

4 Formaldehyde Dismutase RECHARGEABLE formaldehyde methanol NADH+H + NAD + water formic acid formaldehyde 4

5 Combination of chemo- and bio- catalysis If the produced formic acid is recycled to the catalytic process, in the whole process three moles of methane and one mole of carbon dioxide are converted to four moles methanol. There is no loss in the balance of energy. 3 CH 4 methane 1 CO 2 carbon dioxide chemical reaction in a membrane - reactor 8 CH 2 O formaldehyde 4 H 2 O water enzymereactor separation 4 CH 3 OH methanol 4 HCOOH formic acid 2 H 2 O 5

6 Real-time process mass spectrometer Simultaneous measurement of the composition of a gas phase and all volatile component of a liquid. Measures up to 30 components simultaneously in the lower ppb range. membrane inlet liquid MS vacuum pump high vacuum pump 6

7 Results 7

8 Results Horst Chmiel, Bioprozesstechnik: Einführung in die Bioverfahrenstechnik. Springer. 8

9 methanol concentration [g/l] Results Michaelis-Menten-Equation v = v max c FA c FA + K m c FA = 1.5 g/l v max = ± mmol/min K m = ± mm time [min] 9

10 Results 10

11 methanol concentration [g/l] Ergebnisse Michaelis-Menten-Equation Non-competitive inhibition v = v max c FA c FA + K m K i [I] + K i c FA = 1.5 g/l v max = ± mmol/min K m = ± mm K i = ± mm time [min] 11

12 Ergebnisse k 1 k k i 2 FDM NAD(H) + FA FDM NAD(H) FA FDM NAD(H) + P FDM NAD H k 1 k i [P] v = c FA + K m v max c FA 1 + c MeOH K i 12

13 methanol concentration [g/l] Results Michaelis-Menten-Equation competitive inhibition v max c FA v = c FA + K m 1 + c MeOH K i c FA = 1.5 g/l v max = ± mmol/min K m = ± mm K i = ± mm time [min] 13

14 methanol concentration [g/l] Results Michaelis-Menten-Equation competitive inhibition v max c FA v = c FA + K m 1 + c MeOH K i c FA = 15 g/l v max = ± mmol/min K m = ± mm K i = ± mm time [min] 14

15 Results v = v max c FA K m 1 + c MeOH K i 1 + β c MeOH ak i + c FA K m 1 + c MeOH αk i a b Type of inhibition 0 < α < β = 1 competitive 0 < α < 1 0 < β < 1, α = β Non-competitive 1 α < 0 < β < 1 mixed 15

16 methanol concentration [g/l] Results Hyperbolic equation v = v max c FA K m 1 + c MeOH K i 1 + β c MeOH ak i + c FA K m 1 + c MeOH αk i c FA = 15 g/l v max = ± mmol/min K m = ± mm K i = ± mm α = ± β = ± Matthias Stier, Biokatalytische Herstellung von Methanol aus Biogas, < α < 1 0 < β < 1, α = β Non-competitive time [min] 16

17 Results process Carrier particle with immobilized enzymes The carrier particles showed after 440 days 40 % of the primary catalytic activity. 17

18 Results process methanol formic acid reaction 200 ml fixed bed reactor 10 ml/min flow 15 g/l formaldehyde conc. 91 % yield formaldehyde 18

19 Results process reaction separation anion exchanger pervaporationmembrane 19

20 Conclusions The greatest activity of the formaldehyde dismutase is at ph 6 to ph 8 and 37 C. Several were recorded by real-time mass spectrometry and mapped by a. The enzymes were bound to carrier particles and showed 40 % of the primary catalytic activity after 440 days. In a 200 ml fixed-bed reactor, a 15 g/l formaldehyde solution was reacted continuously with a flow rate of 10 ml/min and a turnover of 91 %. The of adsorption of formic acid to an anion exchanger was recorded with a real-time mass spectrometer. Based on these data a mixed bed filter was designed. A 40 % methanol solution was obtained by three-stage Pervaporation. 20

21 Thanks to the German Environmental Foundation for the PhD scholarship. my supervisor Prof. Dr. Thomas Hirth and Prof. Dr. Dieter Bryniok for the opportunity to carry out my PhD thesis. my colleagues at the Fraunhofer IGB for the support. the Federal Ministry of Education and Research for funding the project. the project partners Prof. Pietzsch et al. (Martin Luther University of Halle-Wittenberg) and the Leibniz Institute for Catalysis for their excellent cooperation. 21

22 Thank you for your attention! 22