Ayhan Abdullah Ceyhan

Preparation of High Surface Area Activated Carbon from Elaeagnus angustifolia Seeds by Chemical Activation with ZnCl2 in One-Step Treatment and its Iodine Adsorption

The present study was conducted with the preparation of activated carbon through one-step chemical activation using zinc chloride (ZnCl2) as the activating agent from Elaeagnus angustifolia seeds (EAS). The effect of impregnation ratio, activation temperature, and activation time on activated carbon surface area was discussed. The properties of activated carbon were characterized by N2 adsorption (BET), thermogravimetric analyses (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The best conditions for preparing activated carbon were identified to be temperature of 500°C, impregnation ratio of 150%, impregnation time of 48 h, and activation time of 60 min with BET surface area of 1836 m2/g. The adsorption capacity was demonstrated by the iodine numbers.

Effects of different temperatures and additives on the metastable zone width precipitation kinetics of NaBO2

In this study, the sodium metaborate, which is applicable in various industrial areas, and its metastable zone width that is very important for its production by crystallization, and its nucleation are investigated to obtain the necessary thermodynamic parameters. The polythermal and isothermal method has been used for the measurement of metastable zone width. Metastable zone width of NaBO2 has found at 9°C at average and cooling rate do not have any effect on it. In addition, the effect of sodium metaborate on the hydrogen storage capacity of sodium borohyride solutions that is known as one of the best hydrogen sources today is investigated at the various concentrations of sodium borohyride in the medium. Results have shown that three different areas emerged as the percentage of NaBH4 in the solution increased.

Baryum klorür ve sodyum metaborat reaksiyonu ile baryum metaborat sentez parametrelerinin incelenmesi

Bu çalışmada baryum metaborat üretimi için gerekli optimum şartlar belirlenmeye çalışılmıştır. Üretim, baryum klorür dihidrat (BaCl2.2H2O) ve sodyum metaborat tetrahidrat (NaBO2.4H2O)’ın sulu ortamdaki reaksiyonu ile gerçekleştirilmiştir. Üretim için en uygun sıcaklık, NaBO2/BaCl2 oranı, karıştırma hızı, karıştırma zamanı, dinlendirme zamanı, çözücü tipi ve derişimi, etil alkol etkisi gibi parametreler incelenmiştir. Elde edilen kristallerinin karakterizasyonu, X-ışını kırınımı (XRD), taramalı elektron mikroskobu (SEM) ve partikül boyut ölçüm cihazları yardımıyla yapılmıştır. Kristallerin yapı suyu içerikleri ise TG-DTA analizleri ile belirlenmiştir. Baryum metaborat sentezi için en yüksek verim değeri %88 olarak bulunmuştur. Sentez açısından en uygun şartlar ise; reaksiyon sıcaklığı 80 oC, 400 rpm karıştırma hızı, 60 dk karıştırma ve 60 dk dinlendirme zamanı olarak tespit edilmiştir. BOR ISSN: 2149-9020

The pyrolysis process of biomass by two-stage chemical activation with different methodology and iodine adsorption

ABSTRACT Current concerns with the high energy/cost nature of activated carbon production have encouraged research into alternative activated carbon production methods to reduce the environmental impact. The purpose of this study is to produce the activated carbon from biomass (carob bean seed husk, CBSH) by chemical activation with a different methodology using zinc chloride. Two different activation temperature methodologies for the preparation of activated carbons were applied at the ranges of 30–80 and 200–350°C. The effects of the pre-activation and activation temperatures, duration time, and the impregnation ratio on the surface and chemical properties of activated carbon were investigated. Studies were conducted on the adsorption of iodine from the prepared activated carbon. The highest iodine adsorption number was achieved as 874 mg/g. Langmuir surface area was 1544 m2/g. The structural morphology of activated carbons was evaluated with a scanning electron microscope. The surface chemical characteristics of activated carbons were determined by the Fourier transform infrared (FTIR) spectroscopic method.