Technology description. The BMP process is centred on a bioreactor where methanogenic archaea stirred in the liquid phase are put in contact with H2 and CO2 ...
2nd International Conference on Renewable Energy Gas Technology
Barcelona, Spain 2015
Application of a modular and interdisciplinary approach to the development of a biological methane production (BMP) process Sebastien Bernacchi1andChristoph Herwig1 1Institute
of Chemical Engineering, Research Area Biochemical Engineering, Vienna University of Technology, Gumpendorferstraße 1a, 1060 Vienna, Austria
1. Introduction BMP process is a very promising 4th generation biofuel process for upgrading industrial waste gasses containing hydrogen (H2) and carbon dioxide (CO2) to methane (CH4) and water (H2O) [1]. However, BMP process is a tendentiously gas limited bioprocess. Therefore,new approachesare needed inbioprocessdevelopment. 2. Technology description The BMP process is centred on a bioreactor where methanogenic archaea stirred in the liquid phase are put in contact with H2 and CO2. The bioprocess is performed in continuous operational mode with a constant feed of nutrients and harvest of the reaction broth. Temperatures and pressuresbelong to the range of mild operating conditions. Methane Evolution Rates (MER) up to 950 mmolCH4*L-1*h-1 were achieved [2]. 3. Modular approach for a BMP process development Our BMP setupsarewell described in literature [2, 3, 4, 6,] with online balancing and control strategies. 3.1 Evaluating BMP process efficiency The first module proposed isthe technical analysis of the process. Overall process efficiency was simulatedin ASPEN to estimate the influence of key process parameters such as the dilution of
reactant gasses compression.
or
the
energy
of
Figure 1:Process efficiencysimulation [3]. 3.2 Evaluatingthe use of real industrial gasses The next module consists of methods mantaining gas transfer rate and reactive gas fraction constant in order to evaluate the use of real industrial gasses such as raw biogas or syngas as feeds [4]. 3.3Developing rational media A feeding strategy was developed by rational media design based on physiologic requirements. An ICP-OES method with radial line-scans was developed for thefull quantification of media components.
Figure 3:Sampling method for media quantification by ICP-OES [5]. 3.4Varying growth to product yield The last module consists of multivariate DoE, univariate and dynamic experimental methods for screening multiple parameters influencing the growth to product yield.
A modular and interdisciplinary approach for developing gas fermentative bioprocesses was presented. This approach was applied for the establishment of the process conditions to apply for two different applications of a BMP process. CH4was produced in the BMP process with a single bioreactor step at a MER of 132 mmolCH4*L-1*h-1 with a CH4 purity > 92 [Vol.%] both using raw biogas or underintermittent process conditions. 6. References(
Figure 4: Variation of the growth to product yield as function of CNH4+ [6]. 4. Modular approach application The proposed approach was applied for definingprocess conditions to apply for two different applications of aBMP process:
Figure 5: Application of a BMP process in a power to gasintermittent scenario.
Figure 6: Application of a BMP process for upgrading raw biogas. 5. Conclusions
[1] Martinez Porqueras, E, Rittmann S, Herwig C (2012) Biofuels and CO2 neutrality: an opportunity. Biofuels 3(4): 413-426. [2] Seifert AH, Rittmann S, Herwig C (2014) Analysis of process related factors to increase volumetric productivity and quality of biomethane with Methanothermobacter marburgensis ApplEnerg 132: 155–162. [3] Bernacchi et al. (2014) Process efficiency simulation for key process parameters in biological methanogenesis. AIMS bioengineering 1: 53–71. [4] Seifert AH, Rittmann S, Bernacchi S, et al. (2013): Method for assessing the impact of emission gasses on physiology and productivity in biological methanogenesis Bioresour Technol 136: 747–751. [5] Winfried Nischkauer, Sébastien Bernacchi et al (2014): Radial line-scans as representative sampling strategy in drieddroplet laser ablation of liquid samples deposited on pre-cut filter paper disks; SpectrochimicaActa Part B Atomic Spectroscopy 11/2014 [6] Bernacchi et al (2014): Experimental methods for screening parameters influencing the growth to product yield (Y(x/CH4)) of a biological methane production (BMP) process performed with Methanothermobacter marburgensis, AIMS bioengineering Volume 1, Issue 2,Pages: 72 - 86,2014
