NGHIÊN CỨU KHẢ NĂNG XỬ LÍ AMMONIA BẰNG ZEOLITE 4A ĐƯỢC TỔNG HỢP TỪ SILICA TRO TRẤU

2021 ◽  
Vol 18 (12) ◽  
pp. 2178
Author(s):  
Lê Vĩnh Phong ◽  
Nguyễn Thị Kim Anh
Keyword(s):  

            Công trình sử dụng vỏ trấu – một dạng phế phẩm nông nghiệp như một nguồn nguyên liệu tiềm năng để chiết xuất silica, nhằm tổng hợp zeolite 4A có khả năng hấp phụ ammonia trong khí thải, ứng dụng xử lí môi trường. Trong bài báo này, mẫu tro trấu thu được có độ tinh khiết cao, với tỉ lệ SiO2 chiếm 97,10% theo khối lượng. Kết quả phân tích XRD và SEM cho thấy, mẫu zeolite 4A tổng hợp được kết tinh dưới dạng những khối lập phương đặc trưng, cùng diện tích bề mặt riêng được phân tích bằng phương pháp BET là 2,549 m2/g. Đồng thời, nghiên cứu còn đánh giá khả năng xử lí ammonia của mẫu zeolite 4A đã tổng hợp bằng cách thiết lập mô hình thí nghiệm. Dưới các điều kiện tối ưu của mô hình, mẫu zeolite 4A cho hiệu suất xử lí ammonia lên đến 70,16%, cùng dung lượng hấp phụ tích lũy và thời gian đạt đến điểm cân bằng và điểm bão hòa lần lượt là: 5,75 mg/g và 180 phút; 7,26 mg/g và 330 phút.  

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 360
Author(s):  
Pauls P. Argalis ◽  
Laura Vitola ◽  
Diana Bajare ◽  
Kristine Vegere

A major problem in the field of adsorbents is that binders (kaolin clay, bentonite) introduced to bind zeolites and ensure the needed mechanical strength, are not able to sorb gases like CO2 and N2, and decrease the overall adsorption capacity. To solve this problem, one of the pathways is to introduce a binder able to sorb such gases. Thus, in this study, the physical and mechanical properties of a novel binder based on metakaolin and its composite with zeolite 4A in the granular form were studied. Metakaolin was used as a precursor for alkali-activated binder, which was synthesized using an 8M NaOH activation solution. Raw materials were characterized using granulometry, X-ray diffraction (XRD), and differential thermal analysis (DTA); and final products were characterized using density measurements, a compressive strength test, XRD, Brunauer–Emmett–Teller (BET) analysis, and scanning electron microscopy (SEM). Alkali-activated metakaolin was found to be efficient as a binding material when data for morphological properties were analyzed. A relationship was observed—by increasing the liquid-to-solid ratio (L/S), compressive strength decreased. Zeolite granule attrition was higher than expected: 2.42% and 4.55% for ZG-0.8, 3.64% and 5.76% for ZG-1.0, and 2.73% and 4.85% for ZG-1.2, measured at 4 and 5 atmospheres, respectively.


REAKTOR ◽  
2008 ◽  
Vol 12 (2) ◽  
pp. 68 ◽  
Author(s):  
Tutuk Djoko Kusworo ◽  
Ahmad Fauzi Ismail ◽  
Azeman Mustafa ◽  
Kang Li

The permeation rates of O2, N2, CO2 and CH4 has been studied for polyimide-polyethersulfone (PI/PES) blends-zeolite mixed matrix membranes synthesized in our laboratory. The study investigated the effect of zeolite loading and different zeolite type on the gas separation performance of these mixed matrix membranes. Frequency shifts and absorption intensity changes in the FTIR spectra of the PI/PES blends as compared with those of the pure polymers indicate that there is a mixing of polymer blends at the molecular level. Differential scanning calorimetry measurements of pure and PI/PES blends membranes have showed one unique glass transition temperature that supports the miscible character of the PI/PES mixture. The PI/PES-zeolite 4A mixed matrix membrane with 25 wt % zeolite loading produced the highest O2/N2 and CO2/CH4 selectivity of around 7.45 and 46.05, respectively.


1973 ◽  
Vol 77 (7) ◽  
pp. 906-910 ◽  
Author(s):  
Allen A. Amaro ◽  
Karl Seff
Keyword(s):  

2011 ◽  
Vol 347-353 ◽  
pp. 246-251
Author(s):  
Xing Yong Liu ◽  
Min Li ◽  
Hong Chen ◽  
Wei Wei

Pure form,single phase and high crystalline zeolite 4A samples were synthesized during hydrothermal treatment of by-products in polysilicon production process. The effects of the different crystallization time on the degree of crystallinity, skeleton structure, morphology, size of the particle and its distribution of zeolite 4A samples were investigated using XRD,FT-IR,SEM and Zetasizer. The results indicated that the zeolite 4A sample featured high crystallinity degree, excellent dispersivity, high purity and single structure.


2005 ◽  
Vol 253 (1-2) ◽  
pp. 57-66 ◽  
Author(s):  
W. Zhu ◽  
L. Gora ◽  
A.W.C. van den Berg ◽  
F. Kapteijn ◽  
J.C. Jansen ◽  
...  

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