Superior performance for the measurement of Ultra-low sulfur diesel(ULSD) for control and certification of 10 – 15 ppm S at the pump, as well as lower levels for product release at the refinery.
Regulations around the world have limited the amount of sulfur in various fuels and oils. In some regions, sulfur in diesel is limited to 10 – 15 ppm, while other areas of the world are working to bring sulfur levels down to 50 ppm and lower.
Aside from automobiles, trucks, and some bunker fuels, ULSD is also used as a starter fuel in coal-fired power plants in some regions and as a backup fuel for electricity generation in nuclear power plants. Thus, a fast, reliable method of measuring and monitoring sulfur concentration throughout the petroleum industry is vital.
TheNEX CG II在90°笛卡尔几何EDXRF中使用完全极化来测量ULSD的行业可靠的工具。极化在测量中产生了极低的背景，从而允许在超低范围内可靠测量的检测极限，以满足国际测试规范和EPA测试标准的需求。
Image Credit: Rigaku Corporation
Instrumentation
型号：Rigaku Nex CG II
X-Ray tube: 50 W Pd-anode
Excitation: Indirect with polarization
检测器：大区域SDD
分析时间：300秒
环境：氦气清洗
Film: Polypropylene 4 μm
ASTM, EPA and International Norms
Rigaku Nex CG II EDXRF分析仪符合几种国际规范和EPA测试标准，用于使用单色EDXRF测量石油，燃料和ULSD中的硫。
表格1。资料来源：Rigaku Corporation
The units ppm and mg/kg can be used interchangeably
Sample Preparation
Ensure each sample is homogeneous and stable. Shake the sample gently and allow bubbles to settle. Fill a 32 mm XRF sample cup with 4.0 g of sample to ensure consistent sample depth. Polypropylene film (4 μm) is used to ensure optimal X-Ray transmission. Make the measurement immediately after filling the cup.
校准
经验校准是使用六个市售认证的柴油校准标准组成的套件。
表2。资料来源：Rigaku Corporation
Image Credit: Rigaku Corporation
Precision
仪器的可重复性（精度）通过使用每个测量的300秒分析时间对每个样品进行静态位置的10个重复分析确定。
Table 3.资料来源：Rigaku Corporation
美国EPA测试标准40 CFR 80.584
以下结果表明，使用ASTM标准测试方法D7220和良好的实验室实践，设施可以使用设施使用NEX CG II来满足EPA ULSD标准。
表4。资料来源：Rigaku Corporation
Detection Limits
The empirical method was used to determine the detection limit. In the empirical method, ten repeat analyses of a blank diesel sample containing no sulfur are taken with the sample in a static position, and the standard deviation is determined. The lower limit of detection (LLD) is then defined as three times the standard deviation.
Table 5.资料来源：Rigaku Corporation
LLDs shown are typical and may differ depending on measurement time used and the overall elemental composition of the sample being tested.
结论
本文介绍的结果表明Rigaku Nex CG II EDXRF分析仪使用笛卡尔几何极化提供了单色激发，以实现卓越的性能，以测量ULSD，以控制和认证在泵处的10-15 ppm s，以及在炼油厂控制的较低水平。
The versatility of the NEX CG II makes it an ideal tool for measuring many other elements, oils, and fuels as well. It is well suited for measuring ultra-low chlorides by ASTM D4929, ultra-low metals by ASTM D8252, lube oils, wear metals in oils, and used oil and waste oils to meet the demands for ultra-low measurements throughout the petroleum and recycling industries.
This information has been sourced, reviewed and adapted from materials provided by Rigaku Corporation.
For more information on this source, please visitRigaku Corporation。