Recovery of Boron from Natural Gas Brines by Chelating Resins

Abstract

The adsorption behaviour of, boron in aqueous solution on commercially available chelating resins with N-methyl(polyhydroxyhexyl)amino groups was investigated by means of batch and column tests. This study was undertaken for the development of a process employing a chelating resin to recovery boron from brines accompanied by natural gas. The resinsused as boron adsorbents were Amberlite IRA-743, Diaion CRB 02, Duolite ES 371 and Uniselec UR-3500. All resins exhibited a satisfactory adsorption ability for boron in aqueous solution. the optimum pH range between 8 and 10 was obtained from the batch tests. The column tests were performed by loading the model sample corresponding to natural gas brines to the resin bed 10 cm³ (10 mmφ x 130-140 mm). When the model sample of (100 mg/dm³ boron) was passed through the column at the space velocity(SV) of 15 h-1, the break-through points at 30, 25, 35 and 20 dm³/dm³-Resin were obtained for IRA-743, CRB 02, ES 371 and UR-3500, respectively. The elution of boron adsorbed on the resins was accomplished by passing one bed volume of 1 mol/dm³ sulfuric acid solutions and subsequently 5 bed volumes of water at the SV of 7.5 h-1. The cyclic operation of column was found to be satisfactory when all resins were regenerated with 1 mol/dm³ sodium hydroxide solution. The results indicate that the four resins tested can be applied to. the process for recovery of boron as boric acid from natural gas brines.