A Sustainable Chemicals Manufacturing Paradigm Using CO2 and Renewable H2

Abstract

The chemical industry must decarbonize to align with UN Sustainable Development Goals. A shift toward circular economies makes CO 2 an attractive feedstock for producing chemicals, provided renewable H 2 is available through technologies such as supercritical water (scH 2 O) gasification. Furthermore, high carbon and energy efficiency is paramount to favorable techno-economics, which poses a challenge to chemo-catalysis. This study demonstrates continuous gas fermentation of CO 2 and H 2 by the cell factory, Cupriavidus necator, to (R,R)-2,3-butanediol and isopropanol as case studies. Although a high carbon efficiency of 0.75 [(C-mol product)/(C-mol CO 2 )] is exemplified, the poor energy efficiency of biological CO 2 fixation requires 8 [(mol H 2 )/(mol CO 2 )], which is technoeconomically infeasible for producing commodity chemicals. Heat integration between exothermic gas fermentation and endothermic scH 2 O gasification overcomes this energy inefficiency. This study unlocks the promise of sustainable manufacturing using renewable feedstocks by combining the carbon efficiency of bio-catalysis with energy efficiency enforced through process engineering.

Engineering Cupriavidus necator H16 for the autotrophic production of (R)-1,3-butanediol

“…DASware® control software was used for automated control of DO, temperature, and pH. The preculture was prepared and fermentation was performed as described previously ( Bommareddy et al, 2020 ) with some modifications. Briefly, The first seed culture was grown overnight at 30 °C with 200 rpm shaking in 10 mL of LB from a single colony.…”

“…Besides the gasification of plant's waste, which allows the complete utilisation of carbon contained within the biomass, CO 2 , suitable for gas fermentation, can be captured from chemical plants and steel mills reducing its emission to limit the climate change ( Liew et al, 2016 ). Considering these advantages, C. necator H16 has been engineered to produce a wide range of commodity chemicals including methyl ketones, alcohols, terpenes, and alka(e)nes ( Bommareddy et al, 2020 ; Chakravarty and Brigham, 2018 ; Crepin et al, 2016 ; Grousseau et al, 2014 ; Krieg et al, 2018 ; Lu et al, 2012 ; Müller et al, 2013 ) demonstrating its versatility and potential as an industrial chassis.…”

Synthetic biology toolkit for engineering Cupriviadus necator H16 as a platform for CO2 valorization

“…To achieve IPA production from CO 2 , Garrigues et al designed a pressurized bioreactor to provide higher gas abundance and increase the gas transfer rate, with the IPA titer reaching as high as 3.5 g/L by gas fermentation [ 138 ]. Similarly, Bommareddy et al established a continuous autotrophic fermentation system and obtained 7.7 g/L IPA [ 139 ]. Recently, an MES system was set up by coupling C. necator strain Re2133/pEG12 and water-splitting system, resulting in the production of 216 mg/L IPA [ 25 ].…”

Production of Biopolymer Precursors Beta-Alanine And L-Lactic Acid From CO2 With Metabolically Versatile Rhodococcus Opacus DSM 43205

“…It can be considered an emerging autotrophic production platform and has been explored by several metabolic engineering studies [6,8] for the production of value-added compounds such as isopropanol [9], 2-hydroxyisobutyric acid [10], methyl ketones [11], alkanes [12], α-humulene [13], isobutanol [14] and acetoin [15]. Moreover, the recent studies demonstrated that the energy e ciency of CO 2 xation via the CBB cycle can be improved and the product titers increased by optimizing the fermentation process and bioreactor design [16,17].…”