Showing papers by "David P.B.T.B. Strik published in 2017"

Production of Caproic Acid from Mixed Organic Waste: An Environmental Life Cycle Perspective

Abstract: Caproic acid is an emerging platform chemical with diverse applications Recently, a novel biorefinery process, that is, chain elongation, was developed to convert mixed organic waste and ethanol into renewable caproic acids In the coming years, this process may become commercialized, and continuing to improve on the basis of numerous ongoing technological and microbiological studies This study aims to analyze the environmental performance of caproic acid production from mixed organic waste via chain elongation at this current, early stage of technological development To this end, a life cycle assessment (LCA) was performed to evaluate the environmental impact of producing 1 kg caproic acid from organic waste via chain elongation, in both a lab-scale and a pilot-scale system Two mixed organic waste were used as substrates: the organic fraction of municipal solid waste (OFMSW) and supermarket food waste (SFW) Ethanol use was found to be the dominant cause of environmental impact over the life cycle E

Bioelectrochemical conversion of CO2 to chemicals: CO2 as a next generation feedstock for electricity-driven bioproduction in batch and continuous modes

Abstract: The recent concept of microbial electrosynthesis (MES) has evolved as an electricity-driven production technology for chemicals from low-value carbon dioxide (CO2) using micro-organisms as biocatalysts. MES from CO2 comprises bioelectrochemical reduction of CO2 to multi-carbon organic compounds using the reducing equivalents produced at the electrically-polarized cathode. The use of CO2 as a feedstock for chemicals is gaining much attention, since CO2 is abundantly available and its use is independent of the food supply chain. MES based on CO2 reduction produces acetate as a primary product. In order to elucidate the performance of the bioelectrochemical CO2 reduction process using different operation modes (batch vs. continuous), an investigation was carried out using a MES system with a flow-through biocathode supplied with 20 : 80 (v/v) or 80 : 20 (v/v) CO2 : N2 gas. The highest acetate production rate of 149 mg L−1 d−1 was observed with a 3.1 V applied cell-voltage under batch mode. While running in continuous mode, high acetate production was achieved with a maximum rate of 100 mg L−1 d−1. In the continuous mode, the acetate production was not sustained over long-term operation, likely due to insufficient microbial biocatalyst retention within the biocathode compartment (i.e. suspended micro-organisms were washed out of the system). Restarting batch mode operations resulted in a renewed production of acetate. This showed an apparent domination of suspended biocatalysts over the attached (biofilm forming) biocatalysts. Long term CO2 reduction at the biocathode resulted in the accumulation of acetate, and more reduced compounds like ethanol and butyrate were also formed. Improvements in the production rate and different biomass retention strategies (e.g. selecting for biofilm forming micro-organisms) should be investigated to enable continuous biochemical production from CO2 using MES. Certainly, other process optimizations will be required to establish MES as an innovative sustainable technology for manufacturing biochemicals from CO2 as a next generation feedstock.

Continuous Long‐Term Bioelectrochemical Chain Elongation to Butyrate

Abstract: We demonstrate here the long-term continuous bioelectrochemical chain elongation from CO2 and acetate by using a mixed microbial culture. The role of applied current (3.1 vs. 9.3 A m−2) on the performance was investigated. The main product was n-butyrate which was continuously produced over time. Trace amounts of propionate and n-caproate were also produced, but no alcohols were detected during the whole course of the experiment (163 days). Microbial electrosynthesis (MES) systems controlled with more current (9.3 Am−2) showed a butyrate concentration that was 4.5 times higher (maximum 0.59 g L−1) and increased volumetric production rates (0.54 g L−1 day−1) compared to the low-current reactors (0.12 g L−1 day−1), at 58.9 and 71.6 % electron recovery, respectively. Biocatalytic activity of the microbial consortia was demonstrated. This study revealed that the solid-state electrode does control the chain elongation reaction as an essential electron donor and determines the performance of MES systems. This study highlights MES as a promising alternative for acetate upgrading

Isobutyrate biosynthesis via methanol chain elongation: converting organic wastes to platform chemicals

Abstract: BACKGROUND Isobutyrate is a platform chemical that is currently produced from a non-renewable fossil-based feedstock. This study aimed at developing a renewable isobutyrate production process by using methanol chain elongation, a novel bioprocess that uses organic waste as primary feedstocks and an undefined reactor microbiome as the catalyst. RESULTS A continuous anaerobic bioreactor experiment was first performed using a synthetic medium containing acetate, butyrate and methanol, all of which are common derivatives from organic residues. Continuous isobutyrate (2.0 g L−1 day−1) and caproate formation (0.2 g L−1 day−1) from methanol, acetate and butyrate were demonstrated. A batch test to synthesise isobutyrate from a real organic waste, i.e. acidified supermarket waste (ASW), was performed. Up to 6.2 g L−1 isobutyrate was formed which accounted for 63% of all identified products. CONCLUSION In this study, a proof-of-principle for isobutyrate production from organic waste via methanol chain elongation was demonstrated. The continuous accumulation or supply of butyrate, the suppression of methanogenic activity and methanol addition were shown to be of use to provide conditions for isobutyrate formation. © 2016 Society of Chemical Industry

Mixed Culture Chain Elongation (MCCE)—A Novel Biotechnology for Renewable Biochemical Production from Organic Residual Streams

Abstract: MCCE is a novel biotechnology that has potential to produce biochemicals from organic residual streams in a clean, renewable and economically viable way. A pilot plant has been established by ChainCraft in Amsterdam, Netherlands to process supermarket waste into value added biochemicals. Ongoing and future researches will aim to optimise the technological and environmental performances through Life Cycle Assessments (LCA) and alternative substrates to ethanol.