scholarly journals Experimental study on light volatile products from thermal decomposition of lignin monomer model compounds: effect of temperature, residence time and methoxyl group

RSC Advances ◽  
2021 ◽  
Vol 11 (59) ◽  
pp. 37067-37082
Author(s):  
Huamei Yang ◽  
Ju Jiang ◽  
Bingzhe Zhang ◽  
Panpan Xu
Keyword(s):  
Experimental Study ◽  
Thermal Decomposition ◽  
Residence Time ◽  
Methoxyl Group ◽  
Effect Of Temperature ◽  
Model Compounds ◽  
Volatile Products ◽  
Effects Of Temperature ◽  
Elimination Reactions

Effects of temperature, residence time and methoxyl on the decomposition of phenol, guaiacol and syringol, were investigated. Thermal decomposition pathways of the three model compounds were discussed based on ring reduction/CO elimination reactions.

Effect of temperature during the synthesis process of CdSe nanoparticles using the colloidal technique

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta
Keyword(s):  
Scanning Tunneling Microscope ◽  
Electron Cloud ◽  
Cdse Nanoparticles ◽  
Effect Of Temperature ◽  
Synthesis Process ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
First Results ◽  
Effects Of Temperature ◽  
Scanning Electron

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.

The effects of reaction parameters on the non-enzymatic browning reaction between l-ascorbic acid and glycine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Yan Yang ◽  
Ya Li ◽  
Liang Feng ◽  
Ai-Nong Yu ◽  
Bao-Guo Sun ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Reaction Pathway ◽  
Enzymatic Browning ◽  
Reaction Parameters ◽  
Remarkable Effect ◽  
Ph Values ◽  
Browning Reaction ◽  
Zero Order Kinetics ◽  
Volatile Products ◽  
Effects Of Temperature

AbstractThe non-enzymatic browning (NEB) reaction between l-ascorbic acid (ASA) and glycine (Gly), including the effects of temperature (110–150 °C), time (10–150 min) and pH (4.5, 6.8, 8.0 and 9.5) on the formation of un-colored intermediate products (UIPs), browning products (BPs) and volatile products (VPs), were investigated. The results showed that pH had a remarkable effect on the reaction. The characteristics of zero-order kinetics for the formation of UIPs and BPs were discussed, and the corresponding activation energy (Ea) was also calculated. When the pH was 4.5, the Ea for the formation of UIPs was approximate 53.76 kJ/mol and less than that at other pH values; while the Ea for BPs formation was approximate 94.06 kJ/mol and much higher than that at other pH values. The results suggested that an acidic environment facilitated the generation of UIPs, but did not remarkably promote the formation of BPs. The possible reaction pathway between ASA and Gly was proposed according to the experimental results.

scholarly journals Torrefaction of Napier Grass and Oil Palm Petiole Waste Using Drop-type Pyrolysis Reactor

2021 ◽  
Author(s):  
Syazmi Zul Arif Hakimi Saadon ◽  
Noridah Osman ◽  
Moviin Damodaran ◽  
Shan En Liew
Keyword(s):  
Residence Time ◽  
Oil Palm ◽  
Waste Product ◽  
Calorific Value ◽  
Napier Grass ◽  
Effect Of Temperature ◽  
Energy Yield ◽  
Pyrolysis Reactor ◽  
Parameter Ranges ◽  
Two Parameters

Abstract Interest in torrefaction has improved along the recent years and it has been studied extensively as a mean of preparing solid fuels. Biomass to be considered as a renewable source of energy must endeavor improvement continuously and where it is more sustainable going forward in which can come from waste product, wild and cultivated plant. The aim of this study is to investigate the effect of temperature and residence time of wild Napier grass and Oil palm petiole from waste. The torrefied samples were derived by pyrolysis reactor mimicking torrefaction procedure. The temperature parameter ranges between 220 and 300 ℃ while residence time parameter is from 10 minutes to 50 minutes of reaction. It was found that as temperature and time increasing, moisture content and amount of O and H atoms decreases as well as both mass and energy yield, but calorific value and the energy density increase along with both two parameters. Between the two parameters, the temperature variation shows more significant changes to the torrefied samples as compared time. The optimized temperature and time are found to be 260 ℃ and 30 minutes, respectively. Remarkably, the usage of pyrolyzer as torrefaction reaction has proved to be a good option since they share similar characteristics while can also produce product with similar properties reflecting torrefaction process.

scholarly journals Efektifitas Biofiltrasi Dengan Media Arang Tempurung Kelapa Dan Batu Apung Terhadap Penurunan Kadar COD, Nitrat Dan Amoniak Dalam Air Limbah Domestik

2020 ◽  
Vol 5 (1) ◽  
pp. 27-35
Author(s):  
Fivi Elvira Sirajuddin ◽  
Muhammad Fadly Saleh
Keyword(s):  
Experimental Study ◽  
Wastewater Treatment ◽  
Residence Time ◽  
Nitrate Removal ◽  
Domestic Wastewater ◽  
Ammonia Removal ◽  
Sampling Time ◽  
Media Composition ◽  
Filter Media ◽  
Domestic Wastewater Treatment

This experimental study aims to determine the most optimal biofiltration media composition for domestic wastewater treatment using 4 upflow biofilter reactors with a combining pumice and coconut shell charcoal as an media filter. ,The combination ratio of media filter is UAF 1 = 1: 0, UAF 2 = 2: 1, UAF 3 = 1: 2, and UAF 4 = 1 : 1 with an overall filter media thickness of 60 cm. Sampling time is done every 2 days for 16 day were taken at the four experimental reactors to be tested for each parameter of pH, COD, nitrate and ammonia. The method of analysis carried out after obtaining data from testing in the laboratory, that is descriptively related to variations in filter media, and the residence time of wastewater in the reactor. The results showed that the reactor with the best processing in normalizing pH was UAF 1. While the best filter media composition in COD and nitrate removal was UAF 3 reactor with 77.78% and 87.17% removal results. Ammonia removal occurred throughout the experimental reactor with a result <-0.05 mg / l was considered quite good and indicated the decomposition process was successful. Penelitian ini dilakukan untuk menentukan komposisi media biofiltrasi yang paling optimal untuk pengolahan air limbah domestik dengan menggunakan 4 reaktor upflow biofilter dengan mengkombinasikan batu apung dan arang tempurung kelapa sebagai media filter. Rasio dari kombinasi media filter tersebut adalah UAF 1 = 1:0, UAF 2 = 2:1, UAF 3=1:2, dan UAF 4=1:1 dengan ketebalan media filter secara keseluruhan 60 cm. Waktu pengambilan sampel dilakukan setiap 2 hari selama 16 hari. Pengambilan sampel dilakukan pada keempat reaktor percobaan untuk diujikan masing-masing parameter pH, COD, nitrat dan amoniak. Metode analisa yang dilakukan setelah mendapatkan data dari pengujian di laboratorium, yaitu secara deskriptif terkait dengan variasi media filter, dan waktu tinggal air limbah dalam reaktor. Hasil penelitian menunjukkan reaktor yang paling baik pengolahannya dalam menormalkan pH adalah UAF 1. Sementara komposisi media filter yang paling baik dalam penyisihan COD dan nitrat adalah reaktor UAF 3 dengan hasil penyisihan sebesar 77,78% dam 87,17%. Penyisihan amoniak terjadi di seluruh reaktor percobaan dengan hasil <-0,05 mg/l dinilai cukup baik dan mengindikasikan proses penguraian polutan berjalan dengan baik.

scholarly journals Iron reduction from concentrates of hydrometallurgical dressing

2021 ◽  
Vol 64 (10) ◽  
pp. 728-735
Author(s):  
I. A. Rybenko ◽  
O. I. Nokhrina ◽  
I. D. Rozhikhina ◽  
M. A. Golodova ◽  
I. E. Khodosov
Keyword(s):  
Experimental Study ◽  
Thermal Decomposition ◽  
Thermodynamic Modeling ◽  
Iron Reduction ◽  
Solid Phase ◽  
Experimental Studies ◽  
Statistical Processing ◽  
Reducing Agent ◽  
Volatile Components ◽  
Software Complex

The article presents results of theoretical and experimental studies of the processes of iron solid-phase reduction from an iron-containing concentrate obtained as a result of hydrometallurgical dressing of ferromanganese and polymetallic manganese-containing ores with coals of grades D (long-flame) and 2B (brown). The method of thermodynamic modeling using TERRA software complex was used to study the reducing properties of hydrocarbons by calculating equilibrium compositions in the temperature range of 373 - 1873 K. The authors obtained the dependences of compositions and volume of the gas phase formed as a result of the release of volatile components during heating on the temperature for the coals of the grades under consideration. As a result of thermodynamic modeling, the optimal temperatures and consumption are determined, which ensure the complete iron reduction from an iron-containing concentrate. The results of experimental studies were obtained by modern research methods using laboratory and analytical equipment, as well as methods of statistical processing. Results of the coals analysis carried out using the Setaram LabSys Evo thermal analyzer showed that the process of thermal decomposition of coals of the studied grades proceeds according to general laws. The process of thermal decomposition of long-flame coal proceeds less intensively than of brown coal. The results of an experimental study of the processes of thermal decomposition of reducing agents have shown that volumes of the gas phases, formed when coals are heated to a temperature of 1173 K in an argon atmosphere, practically coincide with the calculated values. As a result of thermodynamic modeling and experimental study, the optimal consumption of D and 2B grades of coal is determined at a temperature of 1473 K. The best reducing agent with a minimum specific consumption is long-flame coal of D grade. When determining the optimal amount of reducing agent in charge mixtures during the study of metallization processes, it was found that with an excess of reducing agent, it is possible to achieve almost complete extraction (98 - 99 %) of iron from the concentrate.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

Enhanced thermoelectric performance of layered SnS crystals: the synergetic effect of temperature and carrier concentration

RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 56382-56390 ◽  
Author(s):  
Bao-Zhen Sun ◽  
Zuju Ma ◽  
Chao He ◽  
Kechen Wu
Keyword(s):  
Carrier Concentration ◽  
Synergetic Effect ◽  
Thermoelectric Performance ◽  
Effect Of Temperature ◽  
Effects Of Temperature

The synergistic deployment of the effects of temperature and carrier concentration raises the ZT of SnS to a high value (1.61 ± 0.02).

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