29 research outputs found
Utilizing grass for the biological production of polyhydroxyalkanoates (PHAs) via green biorefining: Material and energy flows
The meat and dairy industry across Europe is dependent on the production of grass. However, faced with competing pressures to reduce the environmental impact of agriculture, a potential future reduction of meat and dairy consumption in western diets, and pressure to minimize food production costs, grass could be used to produce alternative products. The biological production of polyhydroxyalkanoates (PHA) by using grass as the primary carbon source in a novel mixed culture process has been studied. A total of 30,000 t of fresh grass would yield approximately 403.65 t of dried biopolymer granules. On the basis of this early stage, non-optimized process, the cumulative energy demand (CED) of PHA produced from waste grass and cultivated grass was found to be 248.4 MJ/kg and 271.8 MJ/kg, respectively, which is the same order of magnitude as fossil-carbon-based polymers. Improvements in volatile fatty acid yields, reduction in chemical and water inputs, and using residues to make other products will reduce the CED. Given the future requirement to produce polymers with little or no fossil-carbon feedstock, an optimized version of the process could provide a viable future production option that also contributes to the long-term sustainability of agricultural communities
Anaerobic Biodegradation, Activity and Inhibition (ABAI) Task Group Meeting 9th to 10th October 2006, in Prague
Instrumentation and control of anaerobic digestion processes: a review and some research challenges
The final publication is available at Springer via http://dx.doi.org/10.1007/s11157-015-9382-6[EN] To enhance energy production from methane or resource recovery from digestate, anaerobic digestion processes require advanced instrumentation and control tools. Over the years, research on these topics has evolved and followed the main fields of application of anaerobic digestion processes: from municipal sewage sludge to liquid mainly industrial then municipal organic fraction of solid waste and agricultural residues. Time constants of the processes have also changed with respect to the treated waste from minutes or hours to weeks or months. Since fast closed loop control is needed for short time constant
processes, human operator is now included in the loop when taking decisions to optimize anaerobic digestion plants dealing with complex solid waste over a long retention time. Control objectives have also moved from the regulation of key variables measured online to the prediction of overall process perfor-
mance based on global off-line measurements to optimize the feeding of the processes. Additionally, the
need for more accurate prediction of methane production and organic matter biodegradation has
impacted the complexity of instrumentation and should include a more detailed characterization of the waste (e.g., biochemical fractions like proteins, lipids and carbohydrates)andtheirbioaccessibility andbiodegradability characteristics. However, even if in the literature several methodologies have been developed to determine biodegradability based on organic matter characterization, only a few papers deal with bioaccessibility assessment. In this review, we emphasize the high potential of some promising techniques, such as spectral analysis, and we discuss issues that could appear in the near future concerning control of AD processes.The authors acknowledge the financial support of INRA (the French National Institute for Agricultural Research), the French National Research Agency (ANR) for the "Phycover" project (project ANR-14-CE04-0011) and ADEME for Inter-laboratory assay financial support.Jimenez, J.; Latrille, E.; Harmand, J.; Robles MartĂnez, Ă.; Ferrer Polo, J.; Gaida, D.; Wolf, C.... (2015). Instrumentation and control of anaerobic digestion processes: a review and some research challenges. Reviews in Environmental Science and Biotechnology. 14(4):615-648. doi:10.1007/s11157-015-9382-6S615648144Aceves-Lara CA, Latrille E, Steyer JP (2010) Optimal control of hydrogen production in a continuous anaerobic fermentation bioreactor. 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Genotoxic effect induced by hydrogen peroxide in human hepatoma cells using comet assay
Background: Hydrogen peroxide is a common reactive oxygen intermediate generated by variousforms of oxidative stress. Aims: The aim of this study was to investigate the DNA damage capacity ofH2O2 in HepG2 cells. Methods: Cells were treated with H2O2 at concentrations of 25 ÎŒM or 50 ÎŒM for5 min, 30 min, 40 min, 1 h or 24 h in parallel. The extent of DNA damage was assessed by the cometassay. Results: Compared to the control, DNA damage by 25 ÎŒM and 50 ÎŒM H2O2 increasedsignificantly with increasing incubation time up to 1 h, but it was not increased at 24 h. Conclusions:Our Findings confirm that H2O2 is a typical DNA damage inducing agent and thus is a good modelsystem to study the effects of oxidative stress. DNA damage in HepG2 cells increased significantlywith H2O2 concentration and time of incubation but later decreased likely due to DNA repairmechanisms and antioxidant enzyme
A techno-economic case for volatile fatty acid production for increased sustainability in the wastewater treatment industry
European Association for the Development of Renewable Energies, Environment and Power Quality (EA4EPQ) International Conference on Renewable Energies and Power Quality (ICREPQ'12) Santiago de Compostela ( Development of Energy Saving Mechanism for Renewab
Abstract: This paper describes the development of energy saving mechanisms for renewable hydrogen vehicles, thereby providing extended range and improved efficiency. Simulation studies of configuration setup and analysis for better energy management strategies are carried out using simulation tools developed by the University of Glamorgan (UoG), Faculty of Advanced Technology (FAT). The simulation tools are used to analyze the effect of operating conditions and energy demand of a hybrid vehicle. A dynamic model of onboard hydrogen production employing electrolysis energized by electricity recovered from the vehicle's suspension sub-system, is implemented in MATLAB/Simulinkâą and integrated with a fuel cell vehicle model. The entire system model is then parameterized to represent a renewable hydrogen fuel cell vehicle for simulation analyses. Simulation results show that by using recovered energy normally lost in damping, appreciable benefits might be accrued from hydrogen production on-board
Stopping hydrogen migration in its tracks: the first successful synthesis of group ten scorpionate complexes based on Azaindole scaffolds
The first successful synthesis and characterization of group ten complexes featuring flexible scorpionate ligands based on 7-azaindole heterocycles are reported herein. Addition of two equivalents of either K[HB(azaindolyl)3] or Li[HB(Me)(azaindolyl)2] to [M(ÎŒ-Cl)(η1,η2-COEOMe)]2 leads to the formation of two equivalents of the complexes [M{Îș3-N,N,H-HB(azaindolyl)3}(η1,η2-COEOMe)] and [M{Îș3-N,N,H-HB(Me)(azaindolyl)2}(η1,η2-COEOMe)] (where M = Pt, Pd; COEOMe = 8-methoxycyclooct-4-en-1-ide), respectively. In these reactions, the borohydride group is directed towards the metal center forming square based pyramidal complexes. In contrast to analogous complexes featuring other flexible scorpionate ligands, no hydrogen migration from boron is observed in the complexes studied. The fortuitous linewidths observed in some of the 11B NMR spectra allow for a closer inspection of the BâHâąâąâąmetal unit in scorpionate complexes than has previously been possible
Defining the biomethane potential (BMP) of solid organic wastes and energy crops: a proposed protocol for batch assays
The application of anaerobic digestion technology is growing worldwide because of its economic and environmental benefits. As a consequence, a number of studies and research activities dealing with the determination of the biogas potential of solid organic substrates have been carrying out in the recent years. Therefore, it is of particular importance to define a protocol for the determination of the ultimate methane potential for a given solid substrates. In fact, this parameter determines, to a certain extent, both design and economic details of a biogas plant. Furthermore, the definition of common units to be used in anaerobic assays is increasingly requested from the scientific and engineering community. This paper presents some guidelines for biomethane potential assays prepared by the Task Group for the Anaerobic Biodegradation, Activity and Inhibition Assays of the Anaerobic Digestion Specialist Group of the International Water Association. This is the first step for the definition of a standard protocol.<br/