23 research outputs found
Induced Defects in Carbonaceous Materials for Hydrogen Storage
The induced defects in carbonaceous materials for hydrogen storage were studied. The effect of exfoliation was studied and the graphite nanofibers (GNF) diameter before and after exfoliation was quantified. Thermal decomposition of the GNF before and after sulfuric/nitric acid exfoliation indicated a clear loss of thermal stability. GNF exfoliation enhanced the hydrogen uptake by a factor of five compared to the untreated GNF. The amorphous carbon was reactive than GNF, and decomposed before the GNF. The higher pretreatment temperature was intended to preferentially remove amorphous carbon leaving a higher purity of exfoliated GNF
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Refinery Integration of By-Products from Coal-Derived Jet Fuels
This report summarizes the accomplishments toward project goals during the second six months of the third year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts and examination of carbon material, the use of a research gasoline engine to test coal-based gasoline, and modification of diesel engines for use in evaluating diesel produced in the project. At the pilot scale, the hydrotreating process was modified to separate the heavy components from the LCO and RCO fractions before hydrotreating in order to improve the performance of the catalysts in further processing. Characterization of the gasoline fuel indicates a dominance of single ring alkylcycloalkanes that have a low octane rating; however, blends containing these compounds do not have a negative effect upon gasoline when blended in refinery gasoline streams. Characterization of the diesel fuel indicates a dominance of 3-ring aromatics that have a low cetane value; however, these compounds do not have a negative effect upon diesel when blended in refinery diesel streams. Both gasoline and diesel continue to be tested for combustion performance. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Activated carbons have proven useful to remove the heavy sulfur components, and unsupported Ni/Mo and Ni/Co catalysts have been very effective for hydrodesulfurization. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Combustion and characterization of the latest fuel oil (the high temperature fraction of RCO from the latest modification) indicates that the fraction is heavier than a No. 6 fuel oil. Combustion efficiency on our research boiler is {approx}63% for the heavy RCO fraction, lower than the combustion performance for previous co-coking fuel oils and No. 6 fuel oil. An additional coal has been procured and is being processed for the next series of delayed co-coking runs. Work continues on characterization of liquids and solids from co-coking of hydrotreated decant oils; liquid yields include more saturated and hydro- aromatics, while the coke quality varies depending on the conditions used. Pitch material is being generated from the heavy fraction of co-coking. Investigation of coal extraction as a method to produce RCO continues; the reactor modifications to filter the products hot and to do multi-stage extraction improve extraction yields from {approx}50 % to {approx}70%. Carbon characterization of co-cokes for use as various carbon artifacts continues
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Refinery Integration of By-Products from Coal-Derived Jet Fuels
This report summarizes the accomplishments toward project goals during the second six months of the third year of the project to assess the properties and performance of coal based products. These products are in the gasoline, diesel and fuel oil range and result from coal based jet fuel production from an Air Force funded program. Specific areas of progress include generation of coal based material that has been fractionated into the desired refinery cuts and examination of carbon material, the use of a research gasoline engine to test coal-based gasoline, and modification of diesel engines for use in evaluating diesel produced in the project. At the pilot scale, the hydrotreating process was modified to separate the heavy components from the LCO and RCO fractions before hydrotreating in order to improve the performance of the catalysts in further processing. Characterization of the gasoline fuel indicates a dominance of single ring alkylcycloalkanes that have a low octane rating; however, blends containing these compounds do not have a negative effect upon gasoline when blended in refinery gasoline streams. Characterization of the diesel fuel indicates a dominance of 3-ring aromatics that have a low cetane value; however, these compounds do not have a negative effect upon diesel when blended in refinery diesel streams. Both gasoline and diesel continue to be tested for combustion performance. The desulfurization of sulfur containing components of coal and petroleum is being studied so that effective conversion of blended coal and petroleum streams can be efficiently converted to useful refinery products. Activated carbons have proven useful to remove the heavy sulfur components, and unsupported Ni/Mo and Ni/Co catalysts have been very effective for hydrodesulfurization. Equipment is now in place to begin fuel oil evaluations to assess the quality of coal based fuel oil. Combustion and characterization of the latest fuel oil (the high temperature fraction of RCO from the latest modification) indicates that the fraction is heavier than a No. 6 fuel oil. Combustion efficiency on our research boiler is {approx}63% for the heavy RCO fraction, lower than the combustion performance for previous co-coking fuel oils and No. 6 fuel oil. An additional coal has been procured and is being processed for the next series of delayed co-coking runs. Work continues on characterization of liquids and solids from co-coking of hydrotreated decant oils; liquid yields include more saturated and hydro- aromatics, while the coke quality varies depending on the conditions used. Pitch material is being generated from the heavy fraction of co-coking. Investigation of coal extraction as a method to produce RCO continues; the reactor modifications to filter the products hot and to do multi-stage extraction improve extraction yields from {approx}50 % to {approx}70%. Carbon characterization of co-cokes for use as various carbon artifacts continues
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial
Background:
Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936.
Findings:
Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79).
Interpretation:
In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial
Background:
In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation.
Methods:
This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936).
Findings:
Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001).
Interpretation:
In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids.
Funding:
UK Research and Innovation (Medical Research Council) and National Institute of Health Research
Exfoliated Graphite Nanofibers for Hydrogen Storage
Exfoliation of graphite nanofibers (GNF) expands the interplanar spacing of the GNF, which leads to increased hydrogen storage. Hydrogen uptake measurements at 20 bar indicated that the overall hydrogen uptake and operative adsorption temperature are sensitive to the structural variations and graphitic spacing. The increased surface area of the EGNF-1000 led to a 1.2% hydrogen uptake at 77 K and 20 bar, a three-fold increase in hydrogen physisorption of the starting material. These results suggested that selective exfoliation of a nanofiber is a means by which to control the relative binding energy of the hydrogen interaction with the carbon structure and thus vary the operative adsorption temperature. This is an abstract of a paper presented at the ACS Fuel Chemistry Meeting (Washington, DC Fall 2005)
Investigating Reactive Ball Milling of Anthracite Coal
Development of alternative energy technologies is the key to address future energy concerns of depleting fossil fuel reserves and the hydrogen economy is one of the forerunners amongst the various options being considered. A combined hydrogen production and storage process using coal as a precursor and ball milling it in the presence of a hydrogen donating solvent is investigated here. Tests of our current hypotheses that ball milling induces cross links in the coal structure facilitated by the evolution of hydrogen will be presented. The effect of mineral matter present in the coals has been investigated as well and will be presented along with the possible commercial applications
Subcritical Water Reactions of a Hardwood Derived Organosolv Lignin with Nitrogen, Hydrogen, Carbon Monoxide, and Carbon Dioxide Gases
Subcritical H<sub>2</sub>O at 365 °C is considered
for lignin
conversion, because H<sub>2</sub>O exhibits unusual properties at
higher temperatures (i.e., decreased ion product and static dielectric
constant), such that there is a high solubility for organic compounds.
This high solubility for organic compounds is expected to apply to
lignin for its conversion into high value transportation fuels, which
may prove the effectiveness of integrated biorefineries. Experiments
were conducted with hardwood derived Organosolv lignin, subcritical
H<sub>2</sub>O (defined here as H<sub>2</sub>O at 365 °C and
autogenous pressure), and various industrial gases (N<sub>2</sub>,
H<sub>2</sub>, CO, and CO<sub>2</sub> at a cold pressure of 500 psi)
for 30 min to determine both lignin’s potential to generate
value-added products (e.g., monomer compounds and methanol) without
the need for a catalyst and the roles (if any) of the H<sub>2</sub>O and the gases in the reactions. The behavior of H<sub>2</sub>O
at temperature (365 °C) and pressure within this research is
expected to be similar to the behavior of supercritical H<sub>2</sub>O (374 °C and 3205 psi), without the need to maintain supercritical
conditions. Different characterization techniques were used for the
products collected including primarily gas chromatography with flame
ionization detection and thermal conductivity detection (GC/FID-TCD)
of the evolved gases, GC/MS analysis of the organic liquids, solid
phase microextraction analysis of the recovered H<sub>2</sub>O, and
solid state <sup>13</sup>C NMR analysis of the solid residues. The
reactor pressure at temperature was shown to influence the outcome
of products, and the highest conversions (≈54–62%) were
obtained when adding gas. The collected solids from the N<sub>2</sub>, H<sub>2</sub>, and CO reactions appeared to be the most reacted
(i.e., the most changed from the unreacted lignin) according to solid
state <sup>13</sup>C NMR analysis, and the widest variety of products
(methoxy-substituted phenolic compounds) were also obtained when using
CO, according to GC/MS analysis
Combined Hydrogen Production and Storage via Reactive Ball Milling: Investigation of Carbon Structure for Hydrogen Capture
A combined hydrogen production and storage process was developed in which hydrogen was trapped within a coal-based structure, chemically modified via reactive ball milling. Low-temperature hydrogen evolution via TGA with mass spectroscopy (TG-MS), coupled with unusual Raman spectra, suggested both trapped molecular hydrogen and low-temperature dehydrogenation. The results of an investigation of the precursor coal structure in the resulting hydrogen evolution profiles were presented. This is an abstract of a paper presented at the 2006 AIChE National Meeting (San Francisco, CA 11/12-17/2006)