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Recycling of Metalworking Fluids
Published in Jerry P. Byers, Metalworking Fluids, Third Edition, 2018
Water content can quickly be determined by performing a Karl Fischer titration. This is an automated titration with very high accuracy; it is repeatable and reproducible. A benchtop Karl Fischer titrator is shown in Figure 14.6.
Negative impact of humidity on the flowability of steel powders
Published in Particulate Science and Technology, 2022
Lorenzo Marchetti, Pelle Mellin, Christopher Neil Hulme
There are no accepted standards for measuring the water content of metallic powders. However, Karl Fischer titration is appropriate to analyze water content in several media. A test solution containing iodine is used and the iodine is consumed by any water present. The amount of iodine in the solution is monitored with a double-platinum electrode, which enables the total water content of the test solution to be deduced. From this, the water content of the sample can be determined with high precision (ASTM International 2016). Karl Fischer titration is also fast and sensitive to very small water contents. Gravimetric measurements may not be precise enough to detect water contents that are as small as can be absorbed by metallic powders from the atmosphere, but Karl Fischer titration has already been used to analyze the water content in metallic powders (Lefebvre et al. 2020).
Esterification of enzymatically treated macaw palm oil catalyzed by heteropolyacid supported onto Nb2O5
Published in Biofuels, 2022
Sara A. Machado, Cristiano E. Rodrigues Reis, Heitor B. S. Bento, Ana K. F. Carvalho, Tales A. Costa-Silva, Leyvison Rafael V. da Conceição, Domingos S. Giordani, Heizir F. de Castro
The density of the products was measured using a digital densimeter DMA 35 N EX (Anton Paar, Graz, Austria), set at 15 °C, using 2.0 mL of the ester mixture. The values of absolute viscosity were measured using a Brookfield LVDII viscometer (Brookfield Engineering, Middleboro, Massachusetts) using a CP 42 cone at 40 °C with an approximate sample volume of 0.5 mL. The kinematic viscosity of the samples was calculated as being the ratio between the absolute viscosity and the density. The water content of the ester mixture was measured through Karl-Fischer titration [28]. The content of ethyl esters in the organic mixture was evaluated using a gas chromatography (GC) system (Clarus 580, Perkin Elmer, Waltham, Massachusetts) [29]. The GC system was equipped with a Flame Ionization Detector and an Elite 5 column (Perkin Elmer, Waltham, Massachusetts), composed of 5% diphenyl and 95% dimethylpolysiloxane with a length of 30 m and 0.25 mm of internal diameter. N2 was used as carrier gas at a flux of 1.00 mL·min−1. The percentage of ethyl esters in the mixture was calculated using eq. 3, in which %EE is the percentage of ethyl esters, ∑A accounts for the total area of the peaks of ethyl esters, AIS and CIS being the area and concentration of methyl heptadecanoate, used as internal standard, respectively, and Csample as the concentration of the product sample injected into the GC for analysis.
Effect of temperature on the physicochemical characteristics of pine nut shell pyrolysis products in a screw reactor
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Liyuan Qin, Ye Shao, Zhiwei Hou, Enchen Jiang
A proximate analysis of PNSs and biochar was conducted based on the Chinese National Standards GB/T28731-2012, and the analysis of the C, H, N and S contents was performed using an elemental analyzer (EA3000, Eurovector, Italy). The specific surface area (SSA) and pore size distribution were characterized by a 3H-2000 PSI instrument (Beishide Instrument, China), and the Brunauer, Emmett, and Teller (BET) method was also used to calculate the SSA of the biochar product. The biochar surface morphology was observed by a scanning electron microscope (SEM, S-3400N, Hitachi Science Systems, Japan). The wood vinegar and tar compositions were analyzed using gas chromatography and mass spectrometry (GC-MS, Agilent 6890, USA). The water content of the liquid product was determined via Karl–Fischer titration. For the noncondensable gas products, the volume fraction of each gas was detected by gas chromatography (GC-TCD, Agilent 6820, USA). The biochar and tar HHVs were measured by an oxygen bomb calorimeter (YX-ZR 9302, Youxin Instrument Manufacturing Co., Ltd., China). The total HHV of the noncondensable gases was calculated by summing each gas concentration with its corresponding HHV.