Susuz Borakstan Sodyum Borhidrür Sentezi: Stokiyometri ve Alternatif İndirgeyici Malzemelerin Etkisi

Abstract

Susuz borakstan, alüminyum ve sodyum hidroksit kullanılarak sodyum borhidrür üretimi, hidrojen atmosferinde çalışan bomba tipi kesikli bir reaktörde incelenmiştir. Çalışmada, stokiyometrik oranların ve kalsiyum karbür ilavesinin verim ve ürün kompozisyonu üzerindeki etkileri değerlendirilmiştir. Kalsiyum karbür kullanılmayan deneylerde, molce %100 fazla alüminyum ve sodyum hidroksit kullanımı reaksiyon verimini %11.31’ den %13.28’ e çıkarmıştır. Ancak, kalsiyum karbür ilavesi reaksiyon mekanizmasını değiştirerek, kompleks faz yapılarının oluşumuna yol açmıştır. FT-IR ve XRD ile yapılan yapısal karakterizasyon, 1 ve 2 numaralı deneylerde elde edilen ürünlerin referans NaBH₄ ile uyumlu olduğunu doğrulamıştır. Buna karşın, 3, 4 ve 5 numaralı deneylerin ürünleri, NaBH₄'e özgü piklerin gözlemlenmediği önemli farklılıklar göstermiştir. Bu bulgular, reaksiyon verimliliğinin artırılmasında stokiyometrik optimizasyonun ve tanecik boyutunun küçültülmesinin (<150 μm) önemini vurgulamaktadır. Gelecek çalışmalar, proses parametrelerinin iyileştirilmesine ve alternatif indirgeme ajanlarının rolünün anlaşılmasına odaklanmalıdır.

Keywords

• Sodyum borhidrür
• susuz boraks
• kalsiyum karbür

Investigation of Sodium Borohydride Synthesis from Anhydrous Borax: Impact of Stoichiometry and Alternative Reducing Agents

Abstract

The production of sodium borohydride from anhydrous borax using aluminum and sodium hydroxide as reactants was investigated in a bomb-type batch reactor under hydrogen atmosphere. The study evaluated the effects of stoichiometric ratios and the addition of calcium carbide on yield and product composition. Experiments without calcium carbide, employing 100% molar excess of aluminum and sodium hydroxide, increased the yield from 11.31% to 13.28%. However, incorporating calcium carbide redirected the reaction mechanism, leading to the formation of complex phase structures. Structural characterization using FT-IR and XRD confirmed the consistency of products from Experiments 1 and 2 with reference NaBH₄. In contrast, products from Experiments 3, 4 and 5 showed significant deviations, with no NaBH₄-specific peaks observed. These findings underscore the importance of stoichiometric optimization and particle size reduction (<150 μm) for improving reaction efficiency. Future studies should focus on refining process parameters and understanding the role of alternative reducing agent.

Keywords

• Sodium borohydride
• anhydrous borax
• calcium carbide

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