Feridun BOYLU, Gündüz ATEŞOK

Kömür-su kırışımlarının stabilizasyonunda, karboksimetil selüloz' un (CMC-Na) etkisi

Bu çalışmada, kömür-su karışımlarının hazırlanmasında, stabilizör madde olarak kullanılan CMC'nin (Carboxhymethyl Cellulose), farklı kömürleşme derecesine sahip kömürlerle hazırlanan karışımların stabilizasyonu üzerindeki etkisi incelenmiştir. Çalışmalarda, Soma ve İstanbul linyit kömürleri ve orta uçuculu, bitümlü Zonguldak kömürü (termal kod No. 434) kullanılmıştır. Farklı kömürleşme derecesine sahip Türk kömürleri ile değişik CMC-Na konsantrasyonlarda karışımlar hazırlanmış ve karışım stabiliteleri, penetrasyon deneyleri gerçekleştirilerek saptanmıştır. Yapılan çalışmaların sonucunda, anyonik karakterli polimer olan CMC'nin, kömürleşme derecesi yüksek olan kömürlerle hazırlanan karışımların stabilizasyonunda daha etkili olduğu, linyit kömürleri ile hazırlanan karışımların stabilizasyon özelliğini ise değiştirmediği saptanmıştır. Bununla birlikte, kömürleşme derecesi nispeten düşük olan kömürlerde bulunan inorganik maddenin, hidrofilik yapısından dolayı stabilizasyon üzerinde olumlu etkisinin olduğu belirlenmiştir.

The effect of CMC-Na on the stability of coal-water slurries

Coal-water slurries (CWS) has been investigating as an alternative fuel to petroleum. In coal-water slurry technology, the rheological and stability properties of slurries has been trying to be fixed equal to petroleum. For the rheology of the slurries, the viscosities of the slurries under 1000 mPa.s and the stability of 21 days are found to be suitable for its transportation and storage processes. To control the rheology and stability of slurries, generally some chemicals such as dispersants (viscosity decreasing agent) and stabilizers (chemicals or natural minerals such as attapulgite) are used. However, the chemicals and their effects on stability of the slurries may change depending on coal type and coal properties. In this study, the effect of carboxymethyl cellulose (CMC) used as stabilizer in the preparation of coal-water slurries on the stability has been investigated. Experiments have been carried out on the coal samples which different in rank. Besides two different Turkish Lignites (Soma and İstanbul) also a bituminous coal (Thermal Code No. 434) of Turkish origin (Zonguldak) with medium volatile matter has been used. The results of the experiments showed that polymeric anionic CMC agent has much greater effect on the stability of CWS prepared from bituminous coal. Also, we found that inorganic mineral matters were able to be used as a stabilizer for preventing the sedimentation and separation of CWS.

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