Brine monitoring analysis

Since the installation of the retrofit, the brine quality has been monitored using different types of analysis (MS, ICP, EDX, etc.). The filtration efficiency of the GORE-TEX membranes has always met the Bayer specifications, which are significantly less than 100 ppb iron and aluminium. The filter membranes were put into operation in August 1998 and continue in service at this time. 

Electroanalytical techniques are not as widely used in process analysis as spectroscopic or chromatographic techniques, but are used in a number of applications. Conductivity measurements are often made to determine the concentration of ionic species in a solution, e.g., in a water demineralization unit, or to monitor the salt content of brine. Volt-ammetric and amperometric measurements have been used to determine the concentrations of metals in solutions, e.g., waste effluents. Ion-selective electrodes can be used to make potentiometric measurements to determine the concentrations of specific ions, and coulometric measurements have been used in process analysis to measure sulfur-containing compounds. 

With high-quality salts, the quantities of treat chemicals needed to provide the desired excesses often are more than the amounts consumed in the precipitation reactions. The process is monitored by analysis for the reagent concentrations in the treated brine. The analytical techniques are simple, and the usual practice is to have these checks run by the plant operators. Laboratory personnel perform more exhaustive analyses as required. 

The sequence in an injectivity/retention test typically involves four steps. First, the initial core permeability is measured with brine. Then multiple pore volumes of polymer are injected at a constant rate while the pressure drop is monitored and the effluent is fractionated for analysis. Next, brine is injected to flush unretained polymer from the core sample. Finally, the postinjectivity brine permeability is measured. 

The sequence in the treatment of a core with a polymer gel system is similar to that just described and typically involves three steps. First, the initial permeability of the core sample is measured with brine. Then the core is treated with a polymer/crosslinker solution at a constant rate using a dual piston HPLC pump and a transfer cell (see Figure 5) while monitoring pressure with a differential pressure transducer. The core effluent is fractionated for analysis. This includes the determination of polymer and crosslinker concentration, the measurement of sample gelation tendencies, and the investigation of rock/polymer interactions. Finally, after a waiting period to allow gelation, the final permeability of the core is measured with brine to evaluate the effectiveness of the treatment. 

In a 50 ml round-bottomed flask, isobutyryl chloride (1.27 g, 12 mmol) and 10 ml of THF were placed. Next, 20 ml of 0.5 M solution of 2-pyridylzinc bromide (PI) in THF (lOmmol) was added into the reaction flask via a syringe. The resulting mixture was stirred at rt for 4h. The reaction was monitored by GC analysis, quenched with saturated NH4CI solution, and then extracted with ether (30mix3). Combined organics were washed with saturated NaHCOs solution and brine and then dried over anhydrous MgS04. A vacuum distillation gave 0.94 g of 2-methyl-l-pyridin-2-yl-propan-l-one (2d) as a colorless oil in 63% isolated yield. 

A oven-dried Schlenk flask is charged with Pd2(dba)j (0.0075 mmol), Tol-BINAP (0.018 mmol), and NaOtBu (0.65 mmol) [21]. After several vacuum/inert gas cycles, dried THF (2 ml) is added, followed by 2-methylpentan-3-one (0.6 mmol) and 4-bromo-l,l -biphenyl (0.5 mmol) and additional THF (1 ml). The resulting reaction mixture is stirred at 70 °C. The reaction is monitored by gas chromatography (GC) analysis. To quench the reaction mixture, the Schlenk flask is cooled to room temperature and diethyl ether (25 ml) and water (25 ml) are added. The aqueous layer is separated and extracted with diethyl ether (25 ml). The organic layers are combined, washed with brine (40 ml), dried over MgSO, filtered, and concentrated under reduced pressure. The crude product is purified by flash chromatography on silica gel to afford the tide compound as a-white so d (93% yield). M.p. = 48-49 °C ... 

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