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AbstractCalcium oxide supported on ZrO2 is a highly active catalyst for base‐catalyzed reactions such as aldol‐type reactions and transesterification reactions. The role of key parameters during preparation, that is, impregnation versus precipitation, heat treatment, and metal oxide loading on the basicity and catalytic activity were investigated for CaO supported on ZrO2. An impregnation of 10 wt % CaO on monoclinic zirconia followed by heat treatment at 600 °C resulted in high activity for the self‐condensation reaction of acetone. An evaluation of a series of CaO/ZrO2 samples with different loadings showed that the activity increased for impregnated amounts per gram catalyst of 0–10 wt % CaO, and at higher loading the activity decreased as a result of a decrease in dispersion. The number of strong base sites (calculated from CO2 desorbed at temperatures higher than 625 °C) correlated with the activity. For MgO, CaO, SrO, and BaO on zirconia the catalytic activity increased as the ionic radius of the metal cation increased, suggesting the impact of base strength on catalytic performance.

AbstractTransition to a bio‐based economy will create new demand for biomass, e.g. the increasing use of bioenergy, but the impacts on existing markets are unclear. Furthermore, there is a growing public concern on the sustainability of biomass. This study proposes a methodological framework for mapping national biomass flows based on domestic production‐consumption and cross‐border trade, and respective share of sustainably‐certified biomass. A case study was performed on the Netherlands for 2010‐2011, focusing on three categories: (i) woody biomass, (ii) oils and fats, and (iii) carbohydrates. Between 2010‐2011 few major shifts were found, besides the increasing biofuel production. The share of sustainably‐certified feedstock is growing in many categories. Woody biomass used for energy amounted to 3.45 MT, including 1.3 MT imported wood pellets ( >85% certified). About 0.6 MT of oils and fats and 1.2 MT (estimation) of carbohydrates were used for biofuel production. It is assumed that only certified materials were used for biofuel production. For non‐energy purpose, more than 50% of woody biomass used was either certified or derived from recycled streams. Certified oils has entered the Dutch food sector since 2011, accounted for 7% of total vegetable oils consumption. It is expected that carbohydrates will also be certified in the near future. Methodological challenges encountered are: inconsistency in data definitions, lack of coherent cross‐sectorial reporting systems, low reliability of bilateral trade statistics, lack of transparency in biomass supply chains, and disparity in sustainability requirements. The methodology may be expanded for future projection in different scenarios. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd

Extreme summer droughts are expected to occur more often in the future in NW Europe due to climate change. These droughts might accelerate the rate of peat oxidation in drained peat areas, with impacts on soil subsidence, GHG emission and water quality. This study aimed at providing more insight in the oxidation of deep peat layers that had not previously been exposed to air, the so-called secondary decomposition. We incubated two types of peat (eutrophic and oligotrophic), sampled from permanently anoxic peat layers from nature reserves and agricultural peat meadows. Peat samples were incubated for thirteen weeks under anoxic conditions, but were exposed to air for one to eight weeks. The production of CO2 and CH4 was quantified as a proxy for decomposition; concentrations of soluble nutrients and phenolic compounds were also measured. The results showed that oxygenation led to a steep increase in the rate of decomposition, indicated by higher carbon loss rates during and after oxygenation compared to non-oxygenated samples. Carbon loss rates increased more for eutrophic peat (agricultural area: 352%, nature reserve: 182%) than for oligotrophic peat (83% and 159% respectively). Most peat samples investigated showed higher post-oxygenation CO2 and/or CH4 production compared to the anoxic pre-oxygenation period. This indicates that oxygenation stimulates decomposition, even after anoxic conditions have returned. Contrary to the enzymic latch theory, no effects of oxygenation on the concentrations of soluble or condensed phenolic compounds were detected. Soluble nutrient concentrations did not change due to oxygenation either. Noteworthy is the occurrence of pyrite mineralization and associated acidification in eutrophic peat. Thus, low summer water levels, for example due to climate change, should be avoided in order to limit exceptionally high decomposition rates and associated problems such as increasing subsidence rates, greenhouse gas emission, sulfate release and acidification.

Organic solar cells utilize an energy-level offset to generate free charge carriers. Although a very small energy-level offset increases the open-circuit voltage, it remains unclear how exactly charge generation is affected. Here we investigate organic solar cell blends with highest occupied molecular orbital energy-level offsets (∆EHOMO) between the donor and acceptor that range from 0 to 300 meV. We demonstrate that exciton quenching at a negligible ∆EHOMO takes place on timescales that approach the exciton lifetime of the pristine materials, which drastically limits the external quantum efficiency. We quantitatively describe this finding via the Boltzmann stationary-state equilibrium between charge-transfer states and excitons and further reveal a long exciton lifetime to be decisive in maintaining an efficient charge generation at a negligible ∆EHOMO. Moreover, the Boltzmann equilibrium quantitatively describes the major reduction in non-radiative voltage losses at a very small ∆EHOMO. Ultimately, highly luminescent near-infrared emitters with very long exciton lifetimes are suggested to enable highly efficient organic solar cells. Donor–acceptor systems with low energy-level offset enable high power efficiency in organic solar cells yet it is unclear what drives charge generation. Classen et al. show that long exciton lifetimes enable efficient exciton splitting and thus generation of free charges while also suppressing voltage losses.

AbstractPhenolic compounds cause significant problems both in drinking water and wastewater due to their toxicity, high oxygen requirements, and low biodegradability. They are listed as primary pollutants by the United States Environmental Protection Agency and the European Union. In this study, the adsorption efficiency of 2,4‐dichlorophenol (2,4‐DCP) on activated carbon, which is commonly used in treatment plants, was investigated under different experimental conditions including adsorbent dose, initial phenol concentration, initial pH, and contact time. As a result of experimental studies, it was determined that the adsorption isotherm and kinetics could be perfectly fitted to Langmuir and the assumption of pseudo‐second order model, respectively. Then, the adaptive neuro‐fuzzy inference system (ANFIS) model was developed, which was the primary purpose of this study. The correlation between training and testing data and the ANFIS output was over 0.999. The generalization ability of the model was found to be 0.999. The input variables such as adsorbent dosage (14.2%), initial concentration (14.6%), initial pH (13.9%), and the contact time (57.2%) showed a higher effect on 2,4‐DCP removal efficiency in the sensitivity analysis. To summarize, modeling studies that are frequently preferred in treatment plants for the removal of different pollutants will reduce the number of experiments harmful to human health and save time, labor, and economy.

Seaweed fibre is usually discarded as biomass waste after extraction of useful ingredients from seaweed. However this seaweed fibre, a natural abundant cellulose material with uniform dimensions 10 times smaller than other plant-based fibre can be utilized as electrode material for energy storage. In this work, we converted seaweed fibre into conductive carbon electrodes by a thermal carbonisation method. The morphology, chemical composition and conductivity are highly influenced by the carbonisation temperature. In comparison to other biomass sources such as cotton pulp, seaweed fibre is finer, smoother and more conductive at low carbonisation temperature. These carbonized seaweeds were then used as a supercapacitor, giving a high supercapacitance (226.3 Fg−1) at the carbonisation temperature of 900°C, and good stability within 2400 cycles. This specific capacitance is significantly higher than values obtained from filter paper or cotton pulp.

The aim of this study was to analyze whether, and if so, in what way risks would influence the design,costs and routing of CO2pipelines. This article assesses locational and societal risks of CO2pipelinetransport and analyses whether rerouting or implementing additional risk mitigation measures is themost cost-effective option. The models EFFECTS and RISKCURVES are used to estimate the dispersion andrisk, respectively. The pipeline routes are optimized by using the least cost path function in ArcGIS.This article evaluates three case studies in the Netherlands. The results show that pipelines transportingdense phase CO2(8–17 MPa) with a minimal amount of risk mitigation measures already meet the 10−6locational risk required in the Netherlands. 10−6locational risks of 135 m are calculated for intermediatepumping stations, handling 450 kg CO2/s (about 14 Mt CO2/year). In all the cases, pumping stations couldbe located along the pipeline route without any problem.For the cases studied transporting gaseous CO2(1.5–3 MPa) leads to larger 10−6locational risk distancesthan transporting dense phase CO2. This is caused by the large momentum behind a dense phase CO2release, leading to smaller but higher jet and to a higher mixing rate with the surrounding air than for agaseous CO2release.Based on our analysis, it can be concluded that dense phase CO2transport is safe if it is well organized.The risks are manageable and widely accepted under current legislation. In addition, risk mitigationmeasures, like marker tape and increased surveillance, are available which reduce the risk significantlyand increase the costs only slightly. Pipeline routing for gaseous CO2transport appears more challengingin densely populated areas, because larger safety zones are attached to it.

Abstract This study determined the lipolytic activity of Streptomyces isolates and then purified and characterized the lipase obtained from Streptomyces sp. OC 119-7, the isolate demonstrated to have the high lipolytic activity. Ammonium sulfate precipitation and gel filtration chromatography were used to purify the extracellular alkaline lipase obtained from Streptomyces sp. OC 119-7, and resulted in 5.52-fold purification with 68.055 U/mg specific activity. The enzyme showed optimal activity at pH 8.0 and 50 °C, with stability in a temperature range of 40–60 °C and at pHs of ≥7. Enzyme activity was enhanced by the presence of Ca 2+ and Mg 2+ and inhibited by the presence of Mn 2+ , Co 2+ , Cu 2+ , Zn 2+ , K + , Na + and PMSF. OC 119-7 lipase displayed stability against surfactants and organic solvents. LipOC 119-7 catalyzed transesterification of olive oil with methanol, suggesting that this lipase may be a potential enzymatic catalyst for biodiesel production.