Effect of DTPMPA on Bamboo Kraft Pulping

2014 ◽  
Vol 1033-1034 ◽  
pp. 216-219
Author(s):  
Hong Xia Gao ◽  
Xiu Qiong Guan ◽  
Miao Xu ◽  
Xiong Zhang
Keyword(s):  
Phosphonic Acid ◽  
Kraft Pulping ◽  
Maximum Temperature ◽  
K Value ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Cooking Temperature ◽  
The Impact

As a cooking additive, the impact of Diethylene Triamine Penta Methylene Phosphonic Acid (DTPMPA) on bamboo kraft pulping was studied. The effect of DTPMPA dosage at different maximum cooking temperature was discussed. The results showed that the cooking aids DTPMPA added in bamboo kraft pulping was able to reduce K value of pulp, improve the screened stock yield and brightness and reduce the alkali charge. The optimized bamboo kraft pulping conditions are: DTPMPA dosage 0.3%, alkali charge 17%, when sulfidity was 20%, maximum cooking temperature was 160°C and time at maximum temperature was 90min. Under the conditions of cooking, the screened yield is 41.53%, the K value is 15.4 and the bamboo pulp brightness is 26.8%.

Study on DTPMPA as Cooking Additive in Bamboo Pulping

2013 ◽  
Vol 781-784 ◽  
pp. 2601-2604
Author(s):  
Hong Xia Gao ◽  
Jing Zhang
Keyword(s):  
Phosphonic Acid ◽  
Chelating Agents ◽  
Kraft Pulping ◽  
Maximum Temperature ◽  
Pulp Yield ◽  
K Value ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Cooking Temperature ◽  
Optimized Conditions

The application of chelating agents DTPMPA (Diethylene Triamine Penta Methylene Phosphonic Acid) as cooking aids in kraft pulping of bamboo was researched. The effect of DTPMPA dosage at different alkali charge was discussed. The results showed that the cooking aids DTPMPA added in bamboo kraft pulping was able to reduce K value of pulp, improve the screened stock yield and brightness and reduce the alkali charge. The optimized bamboo kraft pulping conditions are: DTPMPA dosage 0.4%, alkali charge 19%, when sulfidity was 20%, maximum cooking temperature was 165°C and time at maximum temperature was 90min. Under optimized conditions of cooking, the screened bamboo pulp yield is higher, the K value is lower and the bamboo pulp brightness is higher.

Study on Bamboo Kraft Pulping with DTPMPA

2013 ◽  
Vol 781-784 ◽  
pp. 2658-2661
Author(s):  
Hong Xia Gao ◽  
Xiu Qiong Guan ◽  
Chun Yue Ding
Keyword(s):  
Phosphonic Acid ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Maximum Temperature ◽  
Pulp Yield ◽  
Waste Liquor ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Cooking Temperature ◽  
Optimized Conditions

DTPMPA (Diethylene Triamine Penta Methylene Phosphonic Acid) was used as cooking additive in Bamboo pulping. The effect of cooking parameters such as alkali charge, maximum cooking temperature, and time at maximum temperature on bamboo kraft pulping adding additive Diethylene Triamine Penta Methylene Phosphonic Acid was studied. The results show that the optimized bamboo kraft pulping conditions are: alkali charge 17%, maximum cooking temperature 162°C, and time at maximum temperature 60min when DTPMPA dosage is 0.4%. On the optimized conditions of cooking, the highest screened bamboo pulp yield 49.52%, the kappa number of bamboo pulp is 24.68, residual alkali in kraft waste liquor 3.62g/L .

Application of Chelating Agents as Cooking Aids in Bamboo Pulping

2013 ◽  
Vol 750-752 ◽  
pp. 1520-1523
Author(s):  
Hong Xia Gao ◽  
Wen Hua He ◽  
Xiu Qiong Guan ◽  
Chun Liu ◽  
Bo Yuan
Keyword(s):  
Phosphonic Acid ◽  
Chelating Agents ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Pulp Yield ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Strength

The effect of chelating agents Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp yield was 49.52% when DTPMPA dosage is 0.4%, at the same time the Kappa number was lower. With the increasing of DTPMPA dosage in bamboo kraft pulping, the bamboo pulp strength was increased.

Application of Diethylene Triamine Penta Methylene Phosphonic Acid in Bamboo Pulping

2012 ◽  
Vol 550-553 ◽  
pp. 3331-3334
Author(s):  
Hong Xia Gao
Keyword(s):  
Phosphonic Acid ◽  
Kappa Number ◽  
Diethylene Triamine ◽  
Bamboo Pulp ◽  
Kraft Cooking ◽  
Pulp Properties

The effect of Diethylene Triamine Penta Methylene Phosphonic Acid in bamboo kraft cooking was studied. The results show that the bamboo pulp properties are optimal when DTPMPA dosage is 0.4%. The optimal properties are as follows: the kappa number is 16.4, brightness is 37.8%, and the screened yield is 41.9%.

Research on Kraft Pulping Delignification of Bamboo (Neosinocalamus)

2011 ◽  
Vol 418-420 ◽  
pp. 2241-2244
Author(s):  
Pei Yi Li ◽  
Mei Yun Zhang ◽  
Xin Xing Xia ◽  
Chun Tao Lin
Keyword(s):  
Fiber Material ◽  
Wide Distribution ◽  
Kraft Pulping ◽  
Kappa Number ◽  
Raw Material ◽  
Maximum Temperature ◽  
Pulp Yield ◽  
Oxygen Delignification ◽  
Local Conditions ◽  
Bamboo Pulp

Bamboo, as a kind of non-wood raw material, has a long, thin fiber with wide distribution and rich abundance in China. Its pulping properties are between softwood and hardwood. Adapting to the Chinese situation, developing bamboo pulp industrialization, according to the local conditions, is an available way to solve the shortage of fiber material for paper-making. Delignification of bamboo (Neosinocalamus) was carried out by conventional kraft and soda pulping under varying conditions to determine the relationships between selected cooking parameters (EA 14~20%, sulfidity 0~40%, maximum temperature 160 and 165°C, and time at maximum temperature 60~110 min) and pulp properties (kappa number and yield). Results indicated that in order to obtain relatively low kappa numbers(17~27), high sulfidity(20~40%) at lower EA(14~16%) increased pulp yield compared to the case of low sulfidity(0~10%) at higher EA(16~18%). Pulp with lower kappa numbers (13~15) and acceptable yield can be obtained at a sulfidity level of 20~30% with 18% EA or at a sulfidity level of 10~30% with 20% EA. Meanwhile, bamboo pulp in this condition not only helps to decrease kappa number in the subsequent oxygen delignification process, but also reduces the cost of chemicals in the bleaching process.

Characterization of dissolved material during the initial phase of softwood kraft pulping

TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN
Keyword(s):  
Mass Transfer ◽  
Molecular Mass ◽  
Initial Phase ◽  
Degradation Products ◽  
Kraft Pulping ◽  
Reaction Products ◽  
Cooking Temperature ◽  
Molecular Masses ◽  
Aliphatic Carboxylic Acids

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.

scholarly journals Social media reveal ecoregional variation in how weather influences visitor behavior in U.S. National Park Service units

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily J. Wilkins ◽  
Peter D. Howe ◽  
Jordan W. Smith
Keyword(s):  
National Park ◽  
National Park Service ◽  
Spatial Behavior ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Daily Maximum ◽  
Daily Weather ◽  
Visitor Behavior ◽  
Park Service ◽  
The Impact

AbstractDaily weather affects total visitation to parks and protected areas, as well as visitors’ experiences. However, it is unknown if and how visitors change their spatial behavior within a park due to daily weather conditions. We investigated the impact of daily maximum temperature and precipitation on summer visitation patterns within 110 U.S. National Park Service units. We connected 489,061 geotagged Flickr photos to daily weather, as well as visitors’ elevation and distance to amenities (i.e., roads, waterbodies, parking areas, and buildings). We compared visitor behavior on cold, average, and hot days, and on days with precipitation compared to days without precipitation, across fourteen ecoregions within the continental U.S. Our results suggest daily weather impacts where visitors go within parks, and the effect of weather differs substantially by ecoregion. In most ecoregions, visitors stayed closer to infrastructure on rainy days. Temperature also affects visitors’ spatial behavior within parks, but there was not a consistent trend across ecoregions. Importantly, parks in some ecoregions contain more microclimates than others, which may allow visitors to adapt to unfavorable conditions. These findings suggest visitors’ spatial behavior in parks may change in the future due to the increasing frequency of hot summer days.

scholarly journals The impact of climate change in wheat and barley yields in the Iberian Peninsula

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Virgílio A. Bento ◽  
Andreia F. S. Ribeiro ◽  
Ana Russo ◽  
Célia M. Gouveia ◽  
Rita M. Cardoso ◽  
...  
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Climate Model ◽  
Global Climate Models ◽  
Maximum Temperature ◽  
Historical Period ◽  
Early Winter ◽  
Impact Of Climate Change ◽  
The Impact ◽  
Spring Maximum

AbstractThe impact of climate change on wheat and barley yields in two regions of the Iberian Peninsula is here examined. Regression models are developed by using EURO-CORDEX regional climate model (RCM) simulations, forced by ERA-Interim, with monthly maximum and minimum air temperatures and monthly accumulated precipitation as predictors. Additionally, RCM simulations forced by different global climate models for the historical period (1972–2000) and mid-of-century (2042–2070; under the two emission scenarios RCP4.5 and RCP8.5) are analysed. Results point to different regional responses of wheat and barley. In the southernmost regions, results indicate that the main yield driver is spring maximum temperature, while further north a larger dependence on spring precipitation and early winter maximum temperature is observed. Climate change seems to induce severe yield losses in the southern region, mainly due to an increase in spring maximum temperature. On the contrary, a yield increase is projected in the northern regions, with the main driver being early winter warming that stimulates earlier growth. These results warn on the need to implement sustainable agriculture policies, and on the necessity of regional adaptation strategies.

scholarly journals Analysis of the Accelerator-Driven System Fuel Assembly during the Steam Generator Tube Rupture Accident

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1818
Author(s):  
Di-Si Wang ◽  
Bo Liu ◽  
Sheng Yang ◽  
Bin Xi ◽  
Long Gu ◽  
...  
Keyword(s):  
Fuel Assembly ◽  
Steam Generator ◽  
Metal Flow ◽  
Maximum Temperature ◽  
Steam Generator Tube ◽  
Driven System ◽  
Fuel Assemblies ◽  
Accelerator Driven System ◽  
The Impact ◽  
Steam Bubble

China is developing an ADS (Accelerator-Driven System) research device named the China initiative accelerator-driven system (CiADS). When performing a safety analysis of this new proposed design, the core behavior during the steam generator tube rupture (SGTR) accident has to be investigated. The purpose of our research in this paper is to investigate the impact from different heating conditions and inlet steam contents on steam bubble and coolant temperature distributions in ADS fuel assemblies during a postulated SGTR accident by performing necessary computational fluid dynamics (CFD) simulations. In this research, the open source CFD calculation software OpenFOAM, together with the two-phase VOF (Volume of Fluid) model were used to simulate the steam bubble behavior in heavy liquid metal flow. The model was validated with experimental results published in the open literature. Based on our simulation results, it can be noticed that steam bubbles will accumulate at the periphery region of fuel assemblies, and the maximum temperature in fuel assembly will not overwhelm its working limit during the postulated SGTR accident when the steam content at assembly inlet is less than 15%.

scholarly journals Seasonal Variations of Daytime Land Surface Temperature and Their Underlying Drivers over Wuhan, China

2021 ◽  
Vol 13 (2) ◽  
pp. 323
Author(s):  
Liang Chen ◽  
Xuelei Wang ◽  
Xiaobin Cai ◽  
Chao Yang ◽  
Xiaorong Lu
Keyword(s):  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Maximum Temperature ◽  
Maximum Temperature Difference ◽  
Rapid Urbanization ◽  
The Impact ◽  
The City

Rapid urbanization greatly alters land surface vegetation cover and heat distribution, leading to the development of the urban heat island (UHI) effect and seriously affecting the healthy development of cities and the comfort of living. As an indicator of urban health and livability, monitoring the distribution of land surface temperature (LST) and discovering its main impacting factors are receiving increasing attention in the effort to develop cities more sustainably. In this study, we analyzed the spatial distribution patterns of LST of the city of Wuhan, China, from 2013 to 2019. We detected hot and cold poles in four seasons through clustering and outlier analysis (based on Anselin local Moran’s I) of LST. Furthermore, we introduced the geographical detector model to quantify the impact of six physical and socio-economic factors, including the digital elevation model (DEM), index-based built-up index (IBI), modified normalized difference water index (MNDWI), normalized difference vegetation index (NDVI), population, and Gross Domestic Product (GDP) on the LST distribution of Wuhan. Finally, to identify the influence of land cover on temperature, the LST of croplands, woodlands, grasslands, and built-up areas was analyzed. The results showed that low temperatures are mainly distributed over water and woodland areas, followed by grasslands; high temperatures are mainly concentrated over built-up areas. The maximum temperature difference between land covers occurs in spring and summer, while this difference can be ignored in winter. MNDWI, IBI, and NDVI are the key driving factors of the thermal values change in Wuhan, especially of their interaction. We found that the temperature of water area and urban green space (woodlands and grasslands) tends to be 5.4 °C and 2.6 °C lower than that of built-up areas. Our research results can contribute to the urban planning and urban greening of Wuhan and promote the healthy and sustainable development of the city.

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