Development, Implementation and Future Frontiers for Enzyme Solutions Improving Process Economics and Product Qualities Within Oils and Fats Processing – an Overview

2021 ◽  
Author(s):  
Hans Christian Holm ◽  
Anders Madsen ◽  
Per Nielsen
Keyword(s):  
Process Economics

scholarly journals In situ measurements of oxidation–reduction potential and hydrogen peroxide concentration as tools for revealing LPMO inactivation during enzymatic saccharification of cellulose

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Adnan Kadić ◽  
Anikó Várnai ◽  
Vincent G. H. Eijsink ◽  
Svein Jarle Horn ◽  
Gunnar Lidén
Keyword(s):  
Reduction Potential ◽  
Enzymatic Saccharification ◽  
The State ◽  
Enzyme Inactivation ◽  
Ex Situ ◽  
Process Economics ◽  
Complete Inactivation ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

Abstract Background Biochemical conversion of lignocellulosic biomass to simple sugars at commercial scale is hampered by the high cost of saccharifying enzymes. Lytic polysaccharide monooxygenases (LPMOs) may hold the key to overcome economic barriers. Recent studies have shown that controlled activation of LPMOs by a continuous H2O2 supply can boost saccharification yields, while overdosing H2O2 may lead to enzyme inactivation and reduce overall sugar yields. While following LPMO action by ex situ analysis of LPMO products confirms enzyme inactivation, currently no preventive measures are available to intervene before complete inactivation. Results Here, we carried out enzymatic saccharification of the model cellulose Avicel with an LPMO-containing enzyme preparation (Cellic CTec3) and H2O2 feed at 1 L bioreactor scale and followed the oxidation–reduction potential and H2O2 concentration in situ with corresponding electrode probes. The rate of oxidation of the reductant as well as the estimation of the amount of H2O2 consumed by LPMOs indicate that, in addition to oxidative depolymerization of cellulose, LPMOs consume H2O2 in a futile non-catalytic cycle, and that inactivation of LPMOs happens gradually and starts long before the accumulation of LPMO-generated oxidative products comes to a halt. Conclusion Our results indicate that, in this model system, the collapse of the LPMO-catalyzed reaction may be predicted by the rate of oxidation of the reductant, the accumulation of H2O2 in the reactor or, indirectly, by a clear increase in the oxidation–reduction potential. Being able to monitor the state of the LPMO activity in situ may help maximizing the benefit of LPMO action during saccharification. Overcoming enzyme inactivation could allow improving overall saccharification yields beyond the state of the art while lowering LPMO and, potentially, cellulase loads, both of which would have beneficial consequences on process economics.

scholarly journals Identification of the major fermentation inhibitors of recombinant 2G yeasts in diverse lignocellulose hydrolysates

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Gert Vanmarcke ◽  
Mekonnen M. Demeke ◽  
Maria R. Foulquié-Moreno ◽  
Johan M. Thevelein
Keyword(s):  
Second Generation ◽  
Industrial Process ◽  
Superior Performance ◽  
Fermentation Inhibitors ◽  
Inhibitor Tolerance ◽  
Xylose Consumption ◽  
Process Economics ◽  
Partial Inhibition ◽  
Second Generation Bioethanol ◽  
Lignocellulose Hydrolysates

Abstract Background Presence of inhibitory chemicals in lignocellulose hydrolysates is a major hurdle for production of second-generation bioethanol. Especially cheaper pre-treatment methods that ensure an economical viable production process generate high levels of these inhibitory chemicals. The effect of several of these inhibitors has been extensively studied with non-xylose-fermenting laboratory strains, in synthetic media, and usually as single inhibitors, or with inhibitor concentrations much higher than those found in lignocellulose hydrolysates. However, the relevance of individual inhibitors in inhibitor-rich lignocellulose hydrolysates has remained unclear. Results The relative importance for inhibition of ethanol fermentation by two industrial second-generation yeast strains in five lignocellulose hydrolysates, from bagasse, corn cobs and spruce, has now been investigated by spiking higher concentrations of each compound in a concentration range relevant for industrial hydrolysates. The strongest inhibition was observed with industrially relevant concentrations of furfural causing partial inhibition of both D-glucose and D-xylose consumption. Addition of 3 or 6 g/L furfural strongly reduced the ethanol titer obtained with strain MD4 in all hydrolysates evaluated, in a range of 34 to 51% and of 77 to 86%, respectively. This was followed by 5-hydroxymethylfurfural, acetic acid and formic acid, for which in general, industrially relevant concentrations caused partial inhibition of D-xylose fermentation. On the other hand, spiking with levulinic acid, 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid or vanillin caused little inhibition compared to unspiked hydrolysate. The further evolved MD4 strain generally showed superior performance compared to the previously developed strain GSE16-T18. Conclusion The results highlight the importance of individual inhibitor evaluation in a medium containing a genuine mix of inhibitors as well as the ethanol that is produced by the fermentation. They also highlight the potential of increasing yeast inhibitor tolerance for improving industrial process economics.

The ecological impact of membrane-based extraction of phenolic compounds – a life cycle assessment study

2010 ◽  
Vol 62 (4) ◽  
pp. 915-919 ◽  
Author(s):  
C. Bayer ◽  
M. Follmann ◽  
T. Melin ◽  
T. Wintgens ◽  
K. Larsson ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Phenolic Compounds ◽  
Ecological Impact ◽  
Porous Membrane ◽  
Aqueous Fluid ◽  
Reactive Extraction ◽  
Molecular Weights ◽  
Process Economics ◽  
Process Implementation

Many phenolic compounds show high boiling points, low molecular weights, moderate polarities or high toxicities. Therefore, conventional wastewater treatment is limited or expensive. Recycling of the separated compounds is often not possible. But, if liquid-liquid reactive extraction is linked to a non-porous membrane, some or all of the above mentioned limitations may be overcome. The key element is a composite membrane with a dense, hydrophobic top layer which avoids the mixing of the two aqueous fluid streams. The dilute phenol stream is one of them, the other is caustic soda as stripping solvent. Since the basics of this technology have been discussed before, the scope of this study is to facilitate process implementation and integration. To this end, a life cycle assessment framework is used to identify the optimal equipment size for the treatment of wastewater that may, for example, originate from the production of polycarbonate. Limiting for this application is not the environmental performance though, but most likely process economics.

scholarly journals Value-Added Products from Urea Glycerolysis Using a Heterogeneous Biosolids-Based Catalyst

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 373 ◽  
Author(s):  
Mattia Bartoli ◽  
Chengyong Zhu ◽  
Michael Chae ◽  
David Bressler
Keyword(s):  
Weight Ratio ◽  
Value Added ◽  
Economic Feasibility ◽  
Biodiesel Production ◽  
Wastewater Management ◽  
Thermal Hydrolysis ◽  
Process Economics ◽  
Air Stream ◽  
Increasing Temperature ◽  
Value Added Products

Although thermal hydrolysis of digested biosolids is an extremely promising strategy for wastewater management, the process economics are prohibitive. Here, a biosolids-based material generated through thermal hydrolysis was used as a catalyst for urea glycerolysis performed under several conditions. The catalytic system showed remarkable activity, reaching conversion values of up to 70.8 ± 0.9% after six hours, at 140 °C using a catalyst/glycerol weight ratio of 9% and an air stream to remove NH3 formed during the process. Temperature played the most substantial role among reaction parameters; increasing temperature from 100 °C to 140 °C improved conversion by 35% and glycidol selectivity by 22%. Furthermore, the catalyst retained good activity even after the fourth catalytic run (conversion rate of 56.4 ± 1.3%) with only a slight decrease in glycidol selectivity. Thus, the use of a biosolids-based catalyst may facilitate conversion of various glycerol sources (i.e., byproduct streams from biodiesel production) into value-added products such as glycidol, and may also improve the economic feasibility of using thermal hydrolysis for treatment of biosolids.

scholarly journals Biomass Gasification for Gas Turbine Based Power Generation

1997 ◽  
Author(s):  
Mark A. Paisley ◽  
Donald Anson
Keyword(s):  
Power Generation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
Department Of Energy ◽  
Renewable Biomass ◽  
Process Economics ◽  
Gasification Process ◽  
The Us ◽  
Power Generation Systems

The Biomass Power Program of the US Department of Energy (DOE) has as a major goal the development of cost-competitive technologies for the production of power from renewable biomass crops. The gasification of biomass provides the potential to meet his goal by efficiently and economically producing a renewable source of a clean gaseous fuel suitable for use in high efficiency gas turbines. This paper discusses the development and first commercial demonstration of the Battelle high-throughput gasification process for power generation systems. Projected process economics are presented along with a description of current experimental operations coupling a gas turbine power generation system to the research scale gasifier and the process scaleup activities in Burlington, Vermont.

scholarly journals Influence of phenolic acid content on the antioxidant capacity of hemicellulose from sorghum plant fractions

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7933-7953
Author(s):  
Ryan J. Stoklosa ◽  
Renee J. Latona ◽  
Michael J. Powell ◽  
Madhav P. Yadav
Keyword(s):  
Free Radical ◽  
Antioxidant Capacity ◽  
Radical Scavenging ◽  
Free Radical Scavengers ◽  
Process Economics ◽  
Scavenging Effect ◽  
Sorghum Bran ◽  
Sorghum Bagasse ◽  
Sorghum Plant ◽  
Methoxy Content

Recovered hemicellulose fractions from biorefineries have the potential to improve overall process economics during the production of biofuels or other high value chemicals. A common hemicellulose found in many agricultural feedstocks is arabinoxylan (AX). This work investigated the influence of ferulic and p-coumaric acids on the antioxidant capability of AX hemicellulose recovered from sorghum bran, biomass, and bagasse. Sorghum bagasse and sorghum biomass AX contained the largest quantities of bound ferulic and p-coumaric acids at 13.1 mg/100 g and 6.3 mg/100 g, respectively. Antioxidant performance showed that sorghum bagasse AX hemicellulose produced the best reducing capability, while sorghum biomass and sorghum bran AX hemicellulose performed better as free radical scavengers. A reduction in free radical scavenging, as determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, occurred for sorghum bagasse and sorghum biomass AX hemicellulose at higher polysaccharide concentrations, which was either caused by the solution properties of the AX hemicelluloses or DPPH reaction reversibility in the presence of phenolic compounds with methoxy content. Alternatively, H2O2 scavenging by the AX hemicellulose revealed a dose-dependent response. Although scavenging effect was reduced at higher concentrations, sorghum bagasse AX hemicellulose functioned as having the best antioxidant capacity with respect to total reducing capability.

scholarly journals The Role of H2:N2 Ratio on the NH3 Synthesis Rate and on Process Economics over the Co3Mo3N Catalyst

2020 ◽  
Author(s):  
Mustafa Yasin Aslan ◽  
Justin Hargreaves ◽  
Deniz Uner
Keyword(s):  
Atmospheric Pressure ◽  
Ammonia Synthesis ◽  
Synthesis Rate ◽  
Process Economics

In this study, the process economics of ammonia synthesis over Co3Mo3N was investigated by searching an optimum feed stoichiometry. By ammonia synthesis rate measurements at atmospheric pressure and 400 oC...

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