Kinetics study on reactive extraction of formic acid using tri-n-octyl amine diluted in n-butyl acetate

Formic acid is the simplest yet commercially valuable organic acid. It is widely used as a stabilizer and sterile agent in food industries. Reactive extraction is highly effective and selective technique for the recovery of formic acid from dilute solutions. Kinetics study provide rate controlling step (reaction rate or diffusion) that is required to visualize the intrinsic reactive extraction mechanism. Kinetics study of formic acid (0.1–0.4 kmol/m3) extraction with tri-n-octyl amine (TOA) (0.11–0.67 kmol/m3) in n-butyl acetate (NBA) was investigated at temperature 308 ± 1 K. Kinetics study was carried out in a Lewis cell. Effect of formic acid concentration, TOA concentration, speed of stirring, and phase volume ratio were investigated to find the reaction regime. Diffusivity coefficient (DA) of formic acid in NBA was found 3.20 × 10−7 m2/s. Reaction rate constant was evaluated to be 0.616 m3/mol s. The physical mass transfer coefficient (kL) was evaluated to be 0.8278 × 10−6 × N 3.387. The reaction was independent on hydrodynamic parameters and falls under fast reaction regime. The reaction was found first order with respect to both formic acid as well as TOA, occurring in the diffusion film. The findings of the present work are helpful in the selection of commercially viable extraction system and in the design of extractors.

Liquid-liquid extraction of Zr(IV) from sulphuric acid medium using tri-n-octyl amine in kerosene

The extraction behavior of Zr(IV) with tri-n-octyl amine (TOA) in kerosene was studied through a new method of solvent extraction. The mechanism of extraction and the species extracted were identified. Quantitative extraction of Zr(IV) with TOA in kerosene was studied by changing different parameters such as acid variation, diluent effect, metal concentration variation, extractant variation, effect of salting out reagent concentration and effect of temperature. It was observed that the percentage of extraction of Zr(IV) increased when the concentration of TOA and the percentage of extraction also increased when the metal ion concentration increased. The percentage of Zr(IV) became 97.4% with 0.1 M TOA from 3.0 M sulphuric acid. Kerosene was found to be effective diluent for the extraction of Zr(IV) with TOA.

EKSTRAKSI KONSENTRAT NEODIMIUM MEMAKAI TRI OKTIL AMIN THE EXTRACTION OF NEODYMIUM CONCENTRATES USING TRI OCTYL AMINE

Telah dilakukan ekstraksi konsentrat Nd hasil olah pasir monasit. Tujuan penelitian ini memisahkan Nd dari pengotornya : Y, Ce dan La. Sebagai fasa air adalah konsentrat Nd(OH)3 dalam HNO3 dan sebagai ekstraktan atau fasa organik adalah tri oktil amin (TOA) dalam kerosen. Variabel yang diteliti konsentrasi HNO3, konsentrasi umpan, konsentrasi TOA dalam kerosen, waktu pengadukan dan kecepatan pengadukan. Dari hasil penelitian optimasi proses ekstraksi neodimium dari konsentrat Nd(OH)3 hasil olah pasir monasit dengan ekstraktan TOA, diperoleh kesimpulan sebagai berikut: konsentrasi HNO3 yang optimum 2M, konsentrasi umpan 5 gram/10 mL, konsentrasi TOA dalam kerosen 6 %, waktu pengadukan yang optimum 15 menit, kecepatan pengadukan 200 rpm. Pada kondisi ini diperoleh Kd Nd = 0,56; efisiensi ekstraksi Nd = 35,70%; FP Nd-La = ≈6,48; FP Nd-Ce = 3,72 dan FP Nd-Y = 1,38.Kata kunci : ekstraksi, tri oktil amin (TOA), neodimium ≈

A Facile Route for Synthesis of Octyl Amine Capped Silver Nanoparticle

This paper presents a simple and convenient procedure for the preparation of octyl amine capped silver nanoparticles. AgNO 3 has been reduced by octyl amine with benzene or toluene as solvent at 100°C to produce silver nanoparticles. Octyl amine plays its role both as reducing and capping agent and thus provides the advantage of avoiding the use of extra stabilizing agent. Time dependent formation mechanism of silver nanoparticle has been investigated. Thermo gravimetric analysis (TGA) shows weight change due to loss of capping agent. The reaction can easily be monitored from variation of color with time. The method is easy and reproducible. Very low concentration (1 mM) of metal ion is used. The particles synthesized were characterized by UV-Visible, FTIR, TGA, TEM and X-ray diffraction studies.