An Original and Applied Method for Recovery of Caprolactam from PETKİM Waste Water

Year 2014, Volume: 4 Issue: 1, 37 - 40, 31.03.2014

Hasan Eryılmaz

Abstract

Synthetic Yarn Industries of Türkiye produce materials including PP, PES, acrylic and nylon-6 type
yarns. Of these materials, Nylon -6 yarn is used in textiles and speci cally in sh-net productions. In 1970’s there
was an increasing demand for Nylon-6 in native nylon producers in Turkey. In order to meet these demands in 1976,
Petkim built a factory and started to produce monomer caprolactam which is the raw material of Nylon-6. In this
factory, there were ve different waste water solitions that carry signi cant amount of unrecovered caprolactam
which creates environmental pollution as well as economical lost. In order to recover caprolactam, the following
method has been developed and applied to the PETKİM waste water at the Laksan recovery plant in Türkiye. First
of all, PETKİM caprolactam waste water has been saturated with industrial salt (NaCl), and then extracted with
benzene.At the beginning of the recovery process,these salty solutions were extracted totally threefold volume
benzene in three-step batch method. After about ten years, the salty solutions were extracted with only equal
volume benzene in a reverse current continuous column as a more improved one-step method. Benzene, separeted
from caprolactam by distillation, was reused at the next extractions and NaCl, crystallized from saturated waste
waters by open-air evaporation, was also reused at the next saturations. 

Keywords

Caprolactam, benzene, NaCl, extraction, saturation, recovery

PETKİM Atıksuyundan Kaprolaktam Geri Kazanımında Uygulanmış Özgün Bir Metot

Abstract

Türkiye’deki sentetik iplik sanayi; PP, PES, akrilik gibi iplik türleri yanında, naylon-6 iplik de
üretmektedir. Bu iplik, tekstil sanayinde ve özellikle de balık ağları yapımında kullanılmaktadır. Naylon-6’nın
hammaddesi monomer kaprolaktamdır. Yerli iplik üreticilerinin hammadde ihtiyacını karşılamak için, Petkim
1976’da kaprolaktam fabrikasını kurup işletmeye almıştır. Bu fabrikadan çıkan 5 tür atıksuda, geri kazanılamayan
önemli bir miktar kaprolaktam da bulunmakta, ekonomik kayıp ve çevre kirliliği oluşturmakta idi. Aşağıdaki
orijinal metot, bu atıksulardan kaprolaktam geri kazanmak için Laksan A.Ş.’de geliştirilmiş; başta kaprolaktam
ve naylon-6 geri kazanma tesisi, daha sonra naylon teknik iplik üretme tesisi olan Laksan’da endüstriyel olarak
uygulanmıştır. Bu metotda, kaprolaktamlı Petkim atık çözeltisi, önce sanayi tuzu (NaCl) ile doyurulmuş; sonra
kesikli metotda 3 kademede toplam üç kat benzen ile ekstrakte edilmiş; yaklaşık on yıl sonra devreye alınan tek
kademeli, sürekli (kesiksiz) ve daha verimli metotta da, ters akımla çalışan dik kolonda, sadece eşit hacimde benzen
ile ekstrakte edilmiştir. Laktamdan distilasyonla ayrılan benzen, yeni ekstraksiyonlarda; açık havada havuzlarda
atık çözeltinin buharlaşmasıyla kristallenen tuz da, yeni gelen Petkim atık çözeltilerinin tuzla doyurulmasında,
tekrar kullanılmışlardır.

Keywords

Kaprolaktam, benzen, tuz, ekstraksiyon, doyurma, geri kazanma

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