原油及車用燃油中硫分析測試儀

XRF熒光測硫儀Compass-4294光譜儀

1. 背景與簡介

過去幾年國內多個重點城市出現嚴重的霧霾天氣，引發了市場對中國油品質量的廣泛質疑。隨著國家對環境保護的重視和民眾對公共健康意識的提高，對降低車用燃油、船用和鍋爐用燃油、航空煤油中的硫含量提出了更高的要求。石油產品中的多種硫化物是導致空氣污染的重要因素;而在PM2.5監測中，硫化物也是一個組成部分。加強對石油產品中含硫量的嚴格控制，空氣中PM2.5微顆粒的濃度會相應降低。

對車用燃油中硫含量控制，是減少城市空氣污染的主要舉措之一。國家自2011年7月1日開始實施輕型汽油車排放的國IV標準，并將于2014年1月1日在國內實施相應的國IV標號汽油。目前，北京、上海、廣州等大城市已經在使用國IV標號汽油，并開始著手準備使用國V標號的汽油。國V標號的汽油硫含量小于10mg/kg。

能量色散型X射線熒光光譜儀已經被廣泛的應用于石油煉化企業、產品質量監察、環境監測監察和檢測公司分析實驗室，做為油品中硫含量的快速分析工具

本應用方案展示了能量色散X射線熒光光譜法Compass4294測定石油產品中硫含量.結果表明,該方法不僅快速,簡便,而且準確度和精密度較好.適用于測定包括石腦油,中間餾分漬,燃料油,渣油,潤滑油基礎油和無鉛汽油在內的碳氫化合物中的硫含量.濃度范圍從2ppm到5w%

2. 儀器參數

為硫分析設定了工廠優化的測試條件。客戶無需標定設備即可即時現場檢測樣品。

該技術可實現低檢測限和高精度，而無需消耗氦氣，真空泵。也無需復雜而耗時的化學樣品制備。只需將樣品放入樣品杯中，即可上機測試，整個測試過程*無損，測試時間僅需130秒，且結果準確。

3. 準確性研究

為了研究Compass 4294的準確性，對市售的含50 ppm硫的燃油參考材料進行了十次測量。

連續進行20次50 ppm的測試，測試值顯示在下面的報告中。

> 50 ppm硫的測試性能

4. 精密度研究

為了研究Compass 4294的精度，分析了兩個含硫量分別為0.1％和1％的標準原油樣品。下面顯示的結果表明，指南針4294可對各種石油樣品進行精確測量。

XRF設備的另一個重要參數是分析的可重復性。

> 0.1％和1％硫的測試性能

5.測試程序和校準演示

一系列進口石油標準品已在工廠用于標定EDXRF熒光光譜儀Compass4294。客戶可以運行樣品測試，而無需在現場進行任何進一步的校準過程。

只需執行四個步驟即可進行測量。如下圖所示，了解如何準備和放置樣品進行分析的圖片

1-1，準備樣品杯。用6 um聚酯薄膜薄膜在分析側將樣品杯蓋好。在保護測試窗口平臺上還預先設置了相同的聚酯薄膜，以避免任何意外樣品泄漏到分析儀中。

1-2，通常將來自每種標準品的3-5毫升油倒入分析儀的杯子中直至加注線。

1-3，將樣品杯放在指南針XRF樣品裝載器上，它*適合樣品杯尺寸。

1-4，單擊“開始"按鈕以運行分析。結果將在130秒后顯示。

使用一組已知硫濃度的市售重質燃油標準品來進行校準。

下面的圖2-2顯示了百分比水平下高濃度范圍的油中硫的相關曲線。

用線性函數近似該數據。 R2是確定系數。理想的相關性的R2值為1。

5. 結論

本應用案例介紹了一種新型分析儀表Compass4294 ---X射線熒光光譜儀在原油及汽車用油中硫量監測的應用。它是基于能量色散 X 射線熒光光譜的測量原理,進行原油中硫含量測定的,與傳統色譜法相比,在實際應用中具有簡便、準確、快捷的特點

用能量色散X射線熒光光譜儀Compass4294代替傳統的燈硫法 (GB/T380 - 88)和管硫法 (GB/T387- 90 )測定石油產品硫含量 ,取得了與傳統方法相一致的分析準確性和重復性.該方法具有快速,經濟等優點 ,是一種比較理想的測定石油產品中硫含量的光譜儀

Sulfur-in-oil Analyzer Compass 4294 Application Note- Sulfur

1. Background and Introduction

 Fuels & oils monitoring- Compass 4294 XRF

For ships operating outside designated Emission Control Areas, IMO has set a limit for sulphur in fuel oil used on board ships of 0.50% m/m (mass by mass) from 1 January 2020. This will significantly reduce the amount of sulphur oxide emanating from ships and should have major health and environmental benefits for the world, particularly for populations living close to ports and coasts.

Since 1 January 2015, the sulphur limit for fuel oil used by ships operating in Emission Control Areas (ECAs) designated by IMO for the control of sulphur oxides (SOX) has been 0.10% m/m.

The powerful Energy Dispersive X-ray Fluorescence (EDXRF) Compass 4294 serial Sulfur analyzer of ESI Instrument are capable of more sensitive and precise analysis than can be expected from a laboratory class analyzer. This application note demonstrate the Compass 4294 test performance of sulfur in different oil and fuel samples.

2. Instrument parameter

Factory optimized test conditions are set for sulfur analysis. This industry leading

technology enabling low detection limits and high precision without the need for consumable helium gas, a vacuum pump, or extensive sample preparation.

4. Test procedure and Calibration demonstration

A serial of commercial available oil standards were used to calibrate the EDXRF spectrometer at factory. Customer can run the sample test without any further calibration process on-site.

Only four steps are needed to make the measurement. See pictures of how to prepare and put the sample for analysis as below picture

1-1, Prepare the sample cup. The cup was closed on the analytical side with a 6 um thin Mylar film. The same Mylar was also preset on the protection test window platform to avoid any accident sample leak into the analyzer.

1-2, Typically 3-5 ml oil from each standard was poured into the analyzer’s cups up to the fill line.

1-3, Put the sample cup on the compass XRF sample loader, which is perfectly fit wit the sample cup dimension.

1-4, Click the ‘start’ button to run analysis. Results will be shown after 130 seconds.

>A set of commercially available heavy fuel oil standards with know sulfur concentrations were used to setup the calibration.

Figures 2-2 below shows the correlation curves sulfur in oil for high concentration ranges in percentage level.

This data was approximated with linear function. R2 is the coefficient of determination. An ideal correlation would have an R2 value of 1.

The red points are sulfur standards: Blank, 0.01%, 0.075%, 0.1%, 0.5%, 2% and 5%. The perfect R2 value(0.999921) demonstrate the good linear with wide concentrate range of sulfur.

Figures 2-3 below shows the correlation curves sulfur in oil for low concentration ranges in ppm level.

The red points are sulfur standards: Blank, 5ppm, 10ppm, 30ppm and 100ppm. The perfect R2 value(0.999664) demonstrate the good linear and high sensitivity for the low sulfur concentration analysis.

5．Conclusion

Sulfur analysis using ASTM D4294 and ISO 8754 continues to be an important measurement for refinery and independent laboratories around the world. Global regulation trends toward lower sulfur fuels demonstrate the need for a rapid and precise analysis solution. Based on the test results obtained above, it is proved that the Compass 4294 is capable of measuring sulfur in oil or fuel samples complying with the most strict standard.

On board fuel oil management is an important element of preventing operational issues and sulphur non-compliance.Improper handling of fuel oil on board may lead to non-compliance with MARPOL requirements,even if the fuel oil received was compliant. With it’s compact and portable design, Compass 4294 becomes essential tool to do on board oil quality control for sulfur.