High temperature ammonia modification of rice husk char to enhance CO2 adsorption: influence of pre-deashing

RSC Advances ◽  
2015 ◽  
Vol 5 (128) ◽  
pp. 106280-106288 ◽  
Author(s):  
Xiong Zhang ◽  
Shihong Zhang ◽  
Haiping Yang ◽  
Jingai Shao ◽  
Yingquan Chen ◽  
...  

To enhance the CO2 adsorption capacity of rice husk char, pre-deashing of raw materials and high temperature ammonia treatment were combined to prepare the nitrogen-enriched char in this work.

2004 ◽  
Vol 225 (1-4) ◽  
pp. 235-242 ◽  
Author(s):  
J Przepiórski ◽  
M Skrodzewicz ◽  
A.W Morawski

2017 ◽  
Vol 55 (4) ◽  
pp. 494 ◽  
Author(s):  
Hoa Thai Ma ◽  
Hung Cam Ly ◽  
Van Thi Thanh Ho ◽  
Nguyen Bao Pham ◽  
Dat Chi Nguyen ◽  
...  

In this study, rice husk was used as a precursor to prepare activated carbon using steam as a physical activation agent. Steam for activation can be used to activate almost all raw materials. A variety of methods have been developed but all of these share the same basic principle of initial carbonization followed by an activation step with steam. The study also investigates the effects of preparation parameters on the surface characteristics of the carbon. These parameters include the range of temperature and time in the carbonization and activation. The initial carbonization, done at temperatures up to 500°C in 60 min, is a highly exothermic process where the temperature is strictly controlled. The creation of the internal surface is done during the activation step with steam at temperatures 800°C in 30 min., for which the BET surface area is up to 710.8m2/g. Besides, the iodine and methylene blue adsorption capacity of rice-husk carbon are the best that reach 865.98±6.5 and 217.86±1.0 (mg/g), respectively. The entire synthetic procedure was simple, environmental-friendly and economical-effectively. The application prospect of the activated carbon prepared in this work was much more promising due to its high adsorptive capacity.


Author(s):  
А.В. Вураско ◽  
Е.И. Симонова ◽  
А.Р. Минакова

Целлюлоза из плодовых оболочек злаковых культур обладает высокой сорбционной емкостью. Однако относительно короткие волокна затрудняют получение прочного бумажного материала. В то же время целлюлоза из соломы, наоборот, обладает относительно большой длиной волокна и приемлемыми сорбционными свойствами. Для разработки эффективных целлюлозосодержащих сорбентов интерес представляет композиционный материал из целлюлозы шелухи и целлюлозы соломы. Цель исследования – получение сорбционного материала на основе технической целлюлозы из соломы и шелухи риса. Техническая целлюлоза из соломы и шелухи риса получена окислительно-органосольвентным способом с предварительной щелочной обработкой растительного сырья (зольность ее 0,05 % от абсолютно сухой целлюлозы). При этом целлюлозу из соломы риса применяли в качестве целлюлозы-основы, а целлюлозу из шелухи риса – как целлюлозу- адсорбент. При постоянном содержании целлюлозы-основы в композиции независимо от степени ее помола капиллярная впитываемость изменяется в пределах погрешности измерений. При постоянном содержании целлюлозы- основы в композиции и добавлении к ней целлюлозы-адсорбента с возрастающей степенью помола капиллярная впитываемость снижается незначительно (на 1…2,5 мм). Сорбционная способность по йоду зависит от степени помола как целлюлозы-адсорбента, так и целлюлозы-основы. С увеличением степени помола сорбционная способность по йоду возрастает. Адсорбционная способность по метиленовому голубому при постоянном содержании 50% целлюлозы-основы в композиции и добавлении к ней целлюлозы-адсорбента с увеличивающейся степенью помола (35, 39, 43,5, 47,5 оШР) возрастает. Установлено, что количественная оценка эффективности композиции подтвердила наличие эффекта синергизма, который характерен для адсорбционной способности по метиленовому голубому и возрастает с увеличением степени помола целлюлозы- адсорбента с 1,07 до 1,12 с учетом погрешности эксперимента. Cellulose from the fruit shells of cereals has a high sorption capacity. However, relatively short fibers make it difficult to obtain durable paper material. At the same time, straw cellulose, on the contrary, has a relatively long fiber length and acceptable sorption properties. For the development of effective cellulose sorbents of interest is a composite material of cellulose husks and cellulose straw. The aim of the work is to obtain sorption materials on the basis of technical cellulose from straw and rice husks obtained by oxidation-organosolvent method with pre-alkaline treatment of vegetable raw materials. In the course of work, technical cellulose from straw and rice husks with ash content of 0.05% of completely dry cellulose was obtained. Upon receipt of the sorption material, cellulose from rice straw is used as a base cellulose, and cellulose from rice husk as cellulose is an adsorbent. With a constant content of cellulose base in the composition, regardless of its degree of grinding, capillary absorbency varies within the measurement error. With a constant content of cellulose-base in the composition and the addition of cellulose-adsorbent with an increasing degree of grinding capillary absorbency decreases slightly (1...2,5 mm). The sorption capacity of iodine depends on the degree of grinding, as cellulose-adsorbent, and the degree of grinding of cellulose-base. With increasing degree of grinding sorption capacity of iodine increases. Adsorption capacity of methylene blue at a constant content of cellulose-base 50 % in the composition and the addition of cellulose- adsorbent with an increasing degree of grinding (35, 39, 43.5, 47.5 0SHR) increases. It was found that the quantitative evaluation of the composition efficiency confirmed the presence of synergism effect, which is typical for the adsorption capacity of methylene blue and increases with increasing the degree of cellulose-adsorbent grinding from 1.07 to 1.12, taking into account the experimental error.


2021 ◽  
Vol 7 (5) ◽  
pp. 56
Author(s):  
Yimin Yang ◽  
Xiaoying Li ◽  
Ziyu Liu ◽  
Dianjun Hu ◽  
Xin Liu ◽  
...  

Nanoparticles prepared by the coprecipitation method were used as raw materials to fabricate Y3Fe5O12 (YIG) ceramics by air pressureless sintering. The synthesized YIG precursor was calcinated at 900–1100 °C for 4 h in air. The influences of the calcination temperature on the phase and morphology of the nanopowders were investigated in detail. The powders calcined at 1000–1100 °C retained the pure YIG phase. YIG ceramics were fabricated by sintering at 1200–1400 °C for 10 h, and its densification behavior was studied. YIG ceramics prepared by air sintering at 1250 °C from powders calcinated at 1000 °C have the highest in-line transmittance in the range of 1000-3000 nm. When the sintering temperature exceeds 1300 °C, the secondary phase appears in the YIG ceramics, which may be due to the loss of oxygen during the high-temperature sintering process, resulting in the conversion of Fe3+ into Fe2+.


2020 ◽  
pp. 128346
Author(s):  
Yuandong Yang ◽  
Shun Yao ◽  
Yingchao Hu ◽  
Jian Sun ◽  
Qiuwan Li ◽  
...  

RSC Advances ◽  
2016 ◽  
Vol 6 (46) ◽  
pp. 39762-39773 ◽  
Author(s):  
Yongfu Guo ◽  
Juan Deng ◽  
Junyan Zhu ◽  
Chao Zhou ◽  
Caiyun Zhou ◽  
...  

In order to improve the BET value and adsorption capacity of graphene oxide (GO), activated GO (GOKOH) was successfully prepared by high temperature solid state activation with KOH, and was used to remove the anionic dye orange IV from water.


2019 ◽  
Vol 19 (3) ◽  
pp. 475-483 ◽  
Author(s):  
Muvumbu Jean-Luc Mukaba ◽  
Alechine Emmanuel Ameh ◽  
Chuks Paul Eze ◽  
Leslie Felicia Petrik

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