2,484 research outputs found
COMPARATIVE FAST PYROLYSIS OF AGRICULTURAL RESIDUES FOR USE IN BIOREFINERIES
In the light of depleting fossil resources, biomass is gaining renewed interest as a source of renewable carbon, which can be used for energy and chemicals. The production of biofuels such as ethanol, palm oil and bio-diesel has come under criticism for its likely competition with food. These production systems need either huge areas of monocultures or use some parts of plant material such as the carbohydrate fraction only for fermentation to produce ethanol. Other technologies such as fast pyrolysis offer the advantage of using whole plant material for the production of so called \u27bio-oils\u27, which adheres to the condensates of the pyrolysis process.
Bio-oils are complex mixture of various molecules with different polarities. Their content of monomers, oligomers and water depend not only on the pyrolysis conditions but also on the characteristics of the feedstock. In order to broaden the palette of feedstocks to be considered, 12 agricultural waste types from annual plants were comparatively pyrolyzed in a laboratory fluidized-bed reactor against white wood from beech wood. Agricultural wastes such as wheat straw, wheat grains, whole corn plants (cobs, stems, leaves) were used untreated, whereas corn, rape, barley, oat, sorghum, whole plant silage, and winter peas were used after silage. Moreover, press cakes from hemp seeds and flax seeds were also investigated.
Pyrolysis temperature was kept constant at 475 °C. The residence time was varied and set to 1 or 2 s. Organic yields were highest with beech wood (55 wt.%) and lowest with flax seeds (13 wt.%). Detailed quantitative GC/MS analyses of the bio-oils were carried out. In total, 44 components were used for the comparison of the feedstocks. The components were grouped into distinct chemical categories such as organic acids, aldehydes, aromatics, furans, guaiacols, ketones, phenols, pyrans, anhydrosugars, and syringols. Interestingly, sorghum silage gave similar bio-oil composition compared to beech wood. Corn silage gave superior results in comparison to whole plant material. Other properties of the bio-oils such as pH and elemental composition were also determined
Ablative fast pyrolysis of biomass: A new demonstration project in California, USA
California is the fifth largest economy in the world and has about 40 million inhabitants. The California federal government has decided to stick to the Paris climate change agreement by 2030. For many years, California has been feeling the effects of global warming caused by the largest tree extinction in modern history, a five-year dry spell and resulting bark beetle plague, and severe forest fires coupled with heavy winds, heavy rains, and rising sea levels. California is therefore promoting the use of biogenic fuels in the transport sector. In spring 2017, there was a grant funding opportunity from the California Energy Commission (CEC) in the program: Research and Demonstration to Decarbonize Transportation Fuels . Funding supported innovative processes for production of bio-intermediate fuels. to be further used for the generation of sustainable low-carbon fungible biofuels in California\u27s transport sector. In order to meet the given budget, a modular pyrolysis system with an ablative reactor was proposed by the authors. The advantage over fluidized bed processes lies in the better space-time yield, i.e. the systems can be kept small and fit in standardized shipping containers, since neither a fluid heat carrier nor a cycle gas is needed. After careful consideration of the submitted project proposals, our concept was considered worthy of support so that in October 2018 the contracts could be signed. The project duration is 3.5 years. The American business partner is Biogas Energy, Richmond, CA. According to the contract, the pyrolysis plant must produce at least 50,000 gallons (about 190,000 L) of bio-oil. At the beginning of the 21st century, there were two patents on ablative fast pyrolysis reactors. On the one hand the BtO process of PYTEC GmbH, Hamburg with a disk reactor (Fig. 1a), on the other hand the drum reactor, consisting of stator and rotor, Aston University, Birmingham, UK (Figs. 1b, c). In both systems wood chips are pressed against a hot, rotating surface (about 600 ° C) of the reactor. While the disk reactor of PYTEC needs a complex, multiple feeder system which was implemented in a pilot plant with a capacity of 250 kg/h, the drum reactor comes with a conventional two-stage lock hopper system, since only in the reactor the wood chips are being pressed between the walls of the stator and the rotor using a special blade system. The latter fast pyrolysis reactor system was brought to pilot maturity in recent years by Energolesprom (ELP), Kazan, RU and is now being used after some modifications in California. The plant, with a throughput of 500 kg/h, will be built on the site of Western Place Management Authorities close to Sacramento. Expected start of operation is summer 2020. For start-up demolition wood will be the preferred feedstock. Later on biomass from forestry and agriculture will be processed.
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<Preliminary>Components and Anti-fungal Efficiency of Wood-vinegar-liquor Prepared under Different Carbonization Conditions
この論文は国立情報学研究所の学術雑誌公開支援事業により電子化されました
Komplexe proximale Humerusfraktur beim alten Menschen: Winkelstabile Plattenosteosynthese vs. Hemiarthroplastik
Zusammenfassung: Hintergrund: Ziel der vorliegenden Untersuchung ist ein direkter Vergleich der Schulterhemiarthroplastik (SHA) mit der winkelstabilen Plattenosteosynthese (WSPOS) beim alten Patienten mit komplexer proximaler Humerusfraktur. Patienten und Methoden: Zwischen 2003 und 2005 wurden alle Patienten (n=52, Alter ≥70Jahre) mit 3- und 4-Segment-Frakturen des proximalen Humerus, welche mit einer WSPOS (PHILOS®) versorgt wurden, prospektiv erfasst und nach einem Jahr mittels Constant-Score (CS), Oxford Shoulder Score (OSS) und radiologisch nachkontrolliert. Verglichen wurde die WSPOS mit einem historischen Kollektiv mit identischen Einschlusskriterien, welches zwischen 1995 und 1997 an der gleichen Institution mittels SHA versorgt wurde (n=59). Ergebnisse: Beide Patientenkollektive zeigten keine Unterschiede bezüglich Alter, Geschlechterverteilung und Frakturtypen. Der CS war signifikant besser für die WSPOS (median 71 vs. 41). Bezüglich Schmerzen zeigte sich im OSS kein Unterschied zwischen den Gruppen. In der WSPOS-Gruppe mussten signifikant mehr Revisionseingriffe durchgeführt werden (25% vs. 2%). Schlussfolgerung: Die WSPOS liefert beim alten Patienten, bei komplexen proximalen Humerusfrakturen deutlich bessere funktionelle Resultate, ist jedoch mit mehr Rezidiveingriffen behaftet. Die Selbständigkeit der Patienten kann bei beiden Operationsmethoden bei guter Schmerzfreiheit meist erhalten werde
Primary Hemiarthroplasty for Proximal Humeral Fractures in the Elderly: Long-Term Functional Outcome and Social Implications
Background:: Primary shoulder hemiarthroplasty is an established treatment modality for complex fractures of the proximal humerus. Long-term functional outcome is often disappointing. However, little is known about social implications particularly in the elderly. Methods:: A single-institution case series of consecutive geriatric patients (age > 70 years) treated with shoulder hemiarthroplasty for complex fractures of the proximal humerus between 1994 and 1997 was analysed. Postoperative morbidity, long-term function, radiological outcome and social implications were evaluated. Results:: Seventy-seven patients fulfilled the study criteria. Median age at the time of operation was 80 years (range 70-93 years). Systemic and local postoperative complications were observed in 8% including 2 patients (3%) with revision surgery. Postoperative mortality was 1%. Forty-eight patients (62%) were available for follow-up (median 49 months, range 25-80 months), 22 (29%) died from causes unrelated to hemiarthroplasty before follow-up and 7 patients (9%) did not attend follow-up examination. Median Constant-Murley score was 41 points (range 17-77 points). Long-term results concerning pain were satisfying. The Oxford shoulder score ranged from 14 to 40 (median 30). Forty-one patients (85%) still lived in their original environment and managed their daily life independently despite poor shoulder function. Four patients (8%) lived in a retirement home and 3 (6%) in a nursery home. Eighty percent of our patients were still able to use public transportation, do the daily shopping and wash their whole body by themselves. Conclusion:: Most patients managed their daily life independently despite poor shoulder functio
Micro-pyrolysis of technical lignins in a new modular rig and product analysis by GC-MS/FID and GC x GC-TOFMS/FID
Soluble versions of outer membrane cytochromes function as exporters for heterologously produced cargo proteins
This study reveals that it is possible to secrete truncated versions of outer membrane cytochromes into the culture supernatant and that these proteins can provide a basis for the export of heterologously produced proteins. Different soluble and truncated versions of the outer membrane cytochrome MtrF were analyzed for their suitability to be secreted. A protein version with a very short truncation of the N-terminus to remove the recognition sequence for the addition of a lipid anchor is secreted efficiently to the culture supernatant, and moreover this protein could be further truncated by a deletion of 160 amino acid and still is detectable in the supernatant. By coupling a cellulase to this soluble outer membrane cytochrome, the export efficiency was measured by means of relative cellulase activity. We conclude that outer membrane cytochromes of S. oneidensis can be applied as transporters for the export of target proteins into the medium using the type II secretion pathway
AtPTR4 and AtPTR6 are differentially expressed, tonoplast-localized members of the peptide transporter/nitrate transporter 1 (PTR/NRT1) family
Members of the peptide transporter/nitrate transporter 1 (PTR/NRT1) family in plants transport a variety of substrates like nitrate, di- and tripepetides, auxin and carboxylates. We isolated two members of this family from Arabidopsis, AtPTR4 and AtPTR6, which are highly homologous to the characterized di- and tripeptide transporters AtPTR1, AtPTR2 and AtPTR5. All known substrates of members of the PTR/NRT1 family were tested using heterologous expression in Saccharomyces cerevisiae mutants and oocytes of Xenopus laevis, but none could be identified as substrate of AtPTR4 or AtPTR6. AtPTR4 and AtPTR6 show distinct expression patterns, while AtPTR4 is expressed in the vasculature of the plants, AtPTR6 is highly expressed in pollen and during senescence. Phylogenetic analyses revealed that AtPTR2, 4 and 6 belong to one clade of subgoup II, whereas AtPTR1 and 5 are found in a second clade. Like AtPTR2, AtPTR4-GFP and AtPTR6-GFP fusion proteins are localized at the tonoplast. Vacuolar localization was corroborated by co-localization of AtPTR2-YFP with the tonoplast marker protein GFP-AtTIP2;1 and AtTIP1;1-GFP. This indicates that the two clades reflect different intracellular localization at the tonoplast (AtPTR2, 4, 6) and plasma membrane (AtPTR1, 5), respectivel
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