... the growth to product yield (Y(x/CH4)) of a biological methane production (BMP) process performed with Methanothermobacter marburgensis, AIMS.
Modular methods for development of gas converting bioprocesses illustrated by the development of Krajete® biomethanation technologies Sébastien Bernacchi & Arne Seifert, Alexander Krajete Krajete GmbH – Scharitzerstraße 30, A-4020 Linz.
What is Krajete® biomethanation? A highly efficient biological process converting hydrogen (H2) and carbon dioxide (CO2) to methane (CH4) and water using archaea microorganisms
Process advantages?
Process declinations: • Waste to value • Power to Gas (P2G) • Green mobility • Intermittent methanation
Mild conditions i.e. low pressure (p) and low temperature (T), intermittency, impurity tolerance, stable selectivity over time, defined mineral media, knowledge based process optimization leading to customized & scalable feed strategies for a controllable process at highest possible efficiencies
Assessment of process efficiency In Silico?
Use of real substrates in bioprocess development?
The first module consists of a simulation platform to calculate the overall efficiency of the integrated process by using experimentally obtained kinetic models
The second module presents a method for assessing the impact of real industrial gaseous substrates on biomethanation process productivity Type of Gas Synthetic H2 enriched waste gas Impure biogas Combustion gas
Convertable component H2 CO2 CO2
Synthetic H2-enriched waste gas Experiment Nr° 1 Experiment type Real gas Reference Total flow rate [vvm] 0.54 Flow rate H2 [NL/min] 0 1.527 Flow rate CO2 [NL/min] 0.3 0.348 Flow rate real gas/N2 [NL/min] 2.424 0.848 Real gas content [Vol.-%] 89 Reactor volume [L] 5 Reactor pressure [barg] 0 MERReal / MERRef
Bernacchi et al. (2014) Process efficiency simulation for key process parameters in biological methanogenesis. AIMS bioengineering 1: 53–71
1.07 ± 0.076
Concentration [Vol.-%] ~60 ~50 ~10
Other components CO,CO2, short-chain alkanes CH4, unknown mainly N2, O2
Impure biogas 2 Real gas Reference 0.501 1.625 1.625 0 0.4048 0.88 0.4752 35.1 5 1.5
Combustion gas 3 Real gas Reference 0.625 0.2224 0.2224 0.0276 0.0556 0.25 0.222 50 0.8 0
0.98 ± 0.05
1.07 ± 0.12
Seifert et al (2013) : Method for assessing the impact of emission gasses on physiology and productivity in biological methanogenesis, Bioresour Technol 136: 747–751
Quantification of mineral “biologic broths” ?
Determining variability of biocatalytic activity?
This module focuses on media quantification for developing a rational and scalable feeding strategy based on the real physiologic requirements
Growth to product yield Y(X/CH4) (selectivity for carbon transformation) in Krajete® process was quantified for multiple process parameters variation using multivariate data analysis and modelling strategies
Mineral elements such as: Fe, K, Mg, Na, P, S, can be quantified at ppm level
DoE
Trace elements such as Ca, Co, Cu, Mn, Mo, Ni, Zn quantification goes up to ppb level
Nischkauer et al. (2014): Radial line-scans as representative sampling strategy in dried-droplet laser ablation of liquid samples deposited on pre-cut filter paper disks; SpectrochimicaActa Part B Atomic Spectroscopy 11/2014
Optimisation
constant p = 10 barg
Variables: T Agitation S, N and D rate, pH, Gin, H2/CO2 CNH4+
Responses: CH4 Productivity, Biomass Y(X/CH4)
Multivariate data analysis 1) 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
Control & Automation
Take home message: The interdisciplinary approach applied to Krajete® process development allowed: • Identification of suitable real gaseous substrate(s) • Techno-economic analysis • Establishing a scalable control strategy and optimize biocatalytic performance • Stability in continuous and intermittent operations over >2500 hours
Bioreactor from 1 to 400 L scale rCH4 ≈ 3 Ln,CH4
-1 L
-1 h
Bernacchi et al 2016
Bernacchi et al 2016
at 95 vol. % up to 22.4 Ln,CH4
-1 L
-1 h
