Invited for this month′s cover is the group of Tao Zhang at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences. The image shows that Au promoter can simultaneously improve the ...glycerol conversion and 1,3‐propanediol selectivity under relatively mild conditions, by enlarging the analogue of “Frustrated Lewis Pairs” with the assistance of H2. The Communication itself is available at 10.1002/cssc.201601503.
“The Au promoter serves as “the magic bean”, little but powerful…” This and more about the story behind the research that inspired the Cover image is presented in the Cover Profile. Read the full text of the corresponding research at 10.1002/cssc.201601503. View the Front Cover here: 10.1002/cssc.201700326.
In this work, limestone, aluminum nitrate hydrate, and glycerol water solution by combustion synthesis method were proposed to prepare a synthetic CaO/Ca.sub.3Al.sub.2O.sub.6 sorbent for CO.sub.2 ...capture in calcium looping cycles. The effects of the mass ratio of CaO to Al.sub.2O.sub.3, cycle number, carbonation conditions, and calcination conditions on the CO.sub.2 uptake by the obtained synthetic sorbent in the repeated carbonation/calcination cycles were studied in a dual fixed-bed reactor and a thermogravimetric analyzer. The optimum mass ratio of CaO to Al.sub.2O.sub.3 was 90:10 in the preparation process of the synthetic sorbent, which exhibited a 0.43 g g.sup.-1 of CO.sub.2 uptake after 50 cycles. The main compositions of the synthetic sorbent contained the mass ratio of CaO:Al.sub.2O.sub.3 = 90:10 were CaO and Ca.sub.3Al.sub.2O.sub.6, and the mass ratio of CaO to Ca.sub.3Al.sub.2O.sub.6 was 74:26. The CO.sub.2 uptake by CaO/Ca.sub.3Al.sub.2O.sub.6 increases rapidly with the carbonation time in previous 5 min and then rises slowly after 5 min. The carbonation time to reach the maximum CO.sub.2 uptake rate of CaO/Ca.sub.3Al.sub.2O.sub.6 was much sooner than that of CaO derived from limestone in each cycle. The optimum carbonation temperature window of CaO/Ca.sub.3Al.sub.2O.sub.6 was 650-700 °C. CaO/Ca.sub.3Al.sub.2O.sub.6 sorbent possessed obviously higher sintering resistance than CaO under the more severe calcination conditions in the cycles. The high CO.sub.2 uptake capacity of CaO/Ca.sub.3Al.sub.2O.sub.6 was attributed to its stable porous structure in the multiple carbonation/calcination cycles.
It is of importance to convert glycerol, the primary by-product from biodiesel manufacturing, to various valuable C3 chemicals, such as acrolein via dehydration, lactic acid, 1,3-dihydroxyacetone via ...oxidation, and 1,3-propanediol, allyl alcohol via hydrogenolysis. As compared to petroleum-based resources, C3 chemicals from glycerol provide a benign, sustainable and atomically economic feature. Extensive heterogeneous catalysts have been designed, prepared and tested for these transformations. In recent five years, great progress, including high yields to target products over appropriate catalysts, insight into reaction mechanism and network, has been achieved. The present review systematically covers recent research progress on sustainable C3 chemical production from catalytic glycerol transformations. We hope that it will benefit future research on transformations of glycerol as well as other polyols.
ABSTRACT The present work is related to the preparation and characterization of biodegradable flexible films from macáçar bean starch, plasticized with glycerol and the glycerol and glacial acetic ...acid (HAc) mixture. The films were obtained by casting using macáçar bean starch (3 g/100 g of film-forming solution) and different concentrations of the glycerol plasticizing agent (20 g and 30 g/100 g of starch) and the glycerol and glacial acetic acid mixture, in the proportions 20 g and 10 g/100 g of film-forming solution, respectively. Water and glycerol as plasticizers affect mechanical and water vapor barrier properties of an edible wheat gluten film. Edible composite filme of wheat gluten and lipids water vapor permeability and other physical properties.
Solid frustrated-Lewis-pair catalysts, based on Zn-Al composite oxide modified loaded with Au (Aux/ZnAl-CHT), were prepared by calcination of hydrotalcite precursors and tested for the direct ...synthesis of glycerol carbonate using CO2 as the carbon source. An Au5/ZnAl-CHT catalyst shows the highest catalytic performance with the glycerol carbonate yield of 19.5 % and the selectivity of 50.5 % at 170 °C and 4.0 MPa CO2, while maintaining good thermal stability and excellent regeneration ability. A series of characterization results and density functional theory (DFT) calculations indicated the introduction of Au leads to more frustrated-Lewis-pairs in Zn-Al composite oxide (ZnAl-CHT), which improve the adsorption and activation of CO2. Meanwhile, FTIR analysis indicates that glycerol is activated by Zn2+ for the formation of zinc glycerolate intermediates. The above dual synergistic activation processes effectively enhance the catalytic performance. And the reaction pathway is proposed for the synthesis of glycerol carbonate from CO2 and glycerol.
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●Au5/ZnAl-CHT exhibited excellent catalytic performance with the yield of 19.5 %.●Au played a potential “bridge” promoting the formation of FLPs.●Characterization results and DFT calculations indicated that Au led to more FLPs.●The reaction mechanism for direct synthesis of glycerol carbonate was proposed.
Understanding the glycerol market Ciriminna, Rosaria; Pina, Cristina Della; Rossi, Michele ...
European journal of lipid science and technology,
October 2014, Volume:
116, Issue:
10
Journal Article
Peer reviewed
As a result of the booming biodiesel and oleochemicals manufacturing taking place worldwide since more than a decade, 2 million tonnes of glycerol consistently reach the market every year, even ...though after a decade of growth the total glycerol supply is expected to slightly decrease in 2014. Today the supply of glycerol is entirely independent of its demand, as there is as much glycerol as the amount of vegetable oils and animal fats are hydrolyzed to make oleochemicals, or transesterified to produce biodiesel. This unique situation has led to consistently low glycerol prices, which initiated both the market penetration of glycerol in countries where it was not used due to traditional high price, as well as new uses of glycerol as raw material for the production of value added chemicals. This article sheds light on the market of this uniquely versatile chemical whose number of applications is unique amid all existing chemicals. About 2 million tonnes of glycerol consistently reach the market every year, even though after a decade of growth the total glycerol supply is expected to slightly decrease in 2014. Today the supply of glycerol is entirely independent of its demand, as there is as much glycerol as the amount of vegetable oils and animal fats are hydrolyzed to make oleochemicals, or transesterified to produce biodiesel. This article sheds light on the market of this uniquely versatile chemical whose number of applications is unique amid all existing chemicals.
The increase in global biodiesel production is originating a glycerol surplus, which has no defined destination. An alternative to overcome this problem is its use as energy source in animal feeding. ...In Brazil, Pacu (Piaractus mesopotamicus) is one of the most farmed native fish species, whereas Silver catfish (Rhamdia quelen) is suitable for production in subtropical region. Considering little knowledge about crude glycerol utilization in feeds for Neotropical fish species, it was evaluated the apparent digestibility coefficients (ADCs) for energy of crude glycerol for P. mesopotamicus and R. quelen. The digestibility and digestible energy content of crude glycerol can be considered excellent even when compared to energy of common ingredients such as maize and wheat, presenting 0.97 and 0.89 of energy ADCs, and 15.2 and 13.95MJ kg.sup.-1 of digestible energy for Pacu and Silver catfish, respectively. In conclusion, crude glycerol is an energetic ingredient with good potential in Brazilian native fish diets. Key words: byproduct, glycerin, non-protein energy, nutrition. O aumento na producao mundial de biodiesel esta gerando um excesso de glicerol, sem destinacao definida. Uma alternativa para superar este problema e seu uso como fonte de energia na alimentacao animal. No Brasil, o pacu (Piaractus mesopotamicus) e uma das especies de peixes nativas mais cultivadas, enquanto que o jundia (Rhamdia quelen) e apropriado para a producao na regiao subtropical. Considerando a falta de conhecimento sobre a utilizacao do glicerol bruto em racoes para especies de peixes Neotropicais, determinaram-se os coeficientes de digestibilidade aparente (CDAs) para a energia do glicerol bruto em P mesopotamicus e R. quelen. A digestibilidade e o conteudo de energia digestivel do glicerol bruto podem ser considerados excelentes, mesmo quando comparados a energia de ingredientes comuns, como o milho e o trigo, apresentando para energia CDA de 0,97 e 0,89, e 15,2 e 13,95MJ kg.sup.-1 de energia digestivel para o pacu e o jundia, respectivamente. Por fim, o glicerol bruto e um ingrediente energetico com bom potencial para dietas de peixes nativos do Brasil. Palavras-chave: subproduto, glicerina, energia nao-proteica, nutricao.
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) are a novel proxy for mean annual air temperature (MAAT) and have the potential to be broadly applicable to climate reconstruction using ...lacustrine sediments. Several calibrations have been put forth relating brGDGT distributions to MAAT using a variety of linear regressions, including the methylation (MBT) and cyclization (CBT) indices of brGDGTs, the relative abundances of the major, non-cyclized brGDGTs (MbrGDGTs), and best subsets regression (BSR) of the fractional abundances of the nine most common brGDGTs. However, these calibrations have rarely been applied to lake sediment cores to reconstruct temperatures and test the applicability of this proxy as a paleothermometer.
We present an expanded East African lakes surface sediment brGDGT dataset based upon 111 lakes and examine three methods of calibrating brGDGTs to MAAT. These methods include recalculations of the East African lake MBT/CBT calibration and MbrGDGTs calibrations, as well as a new stepwise forward selection (SFS) calibration that uses the four combined brGDGTs that explain the most variance in temperature in our calibration set. We apply these new calibrations as well as five previously published lacustrine brGDGT calibrations to the brGDGT distributions of our surface sediment dataset and a 48kyr sediment core from Sacred Lake, Mt. Kenya, producing the first brGDGT temperature reconstruction available from a small tropical lake. We compare the reconstructed temperatures to previously published paleotemperature records from East Africa to help us assess the performance of the brGDGT calibrations. We find that the SFS calibration has a consistently low root mean squared error of prediction (RMSEP) over the entire range of MAAT, while the MBT/CBT and MbrGDGT calibrations have relatively large RMSEPs, particularly between lakes with similar temperatures but variable pH. This suggests that these techniques do not properly deconvolve the temperature and pH signals recorded in the distributions of the brGDGTs. We further find that only the SFS calibration produces a credible reconstructed temperature history from Sacred Lake when compared to other last glacial maximum paleotemperature estimates from East Africa. Thus, we advocate for the use of the SFS calibration when reconstructing paleotemperatures from brGDGTs in East Africa.
► We examine branched GDGTs in surface sediments in 70 lakes and a single lake core. ► We create three new lacustrine branched GDGT temperature calibrations. ► We compare new and previously published calibrations. ► Only our new calibration deconvolves the pH influence from the temperature signal. ► We present the first branched GDGT temperature record from a small tropical lake.
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