Designation: D4929 ? 17
Standard Test Method for
Determination of Organic Chloride Content in Crude Oil
原油中有機氯化物含量測定的標準試驗方法
1. Scope 范圍
1.1 The procedures in this test method cover the determination of organic chloride (above 1 μg/g organically-bound chlorine) in crude oils, using either distillation and sodium biphenyl reduction, distillation and microcoulometry, or distillation and x-ray fluorescence (XRF) spectrometry.
1.2 The procedures in this test method involve the distillation of crude oil test specimens to obtain a naphtha fraction prior to chloride determination. The chloride content of the naphtha fraction of the whole crude oil can thereby be obtained. See Section 5 regarding potential interferences.
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1.5 Procedure C covers the determination of organic chloride in the washed naphtha fraction of crude oil by x-ray fluorescence spectrometry.
1.1 本試驗方法中的程序包括使用蒸餾和聯(lián)苯鈉還原、蒸餾和微庫侖法或蒸餾和X射線熒光(XRF)光譜法測定原油中的有機氯化物(大于1μg/g有機結(jié)合氯)。
1.2 本試驗方法中的程序涉及蒸餾原油試樣,以在氯化物測定之前獲得石腦油餾分。從而可以得到整個原油石腦油餾分的氯化物含量。關(guān)于潛在干擾,見第5節(jié)。
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1.5 程序C包括用X射線熒光光譜法測定原油洗滌洗石腦油餾分中的有機氯。
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4. Significance and Use 意義和用途
4.1 Organic chlorides do not occur naturally in crude oil. When present, they result from contamination in some manner, such as disposal of chlorinated solvent used in many dewaxing pipeline or other equipment operations.
4.1.1 Uncontaminated crude oil will contain no detectable organic chloride, and most refineries can handle very small amounts without deleterious effects.
4.1.1.1 Most trade contracts specify that no organic chloride is present in the crude oil.
4.1.2 Several pipelines have set specification limits at <1 mg ?kg organic chlorides in the whole crude, and <5 mg ?kg in the light naphtha, on the basis of the naphtha fraction being 20 % of the original sample.
4.1.2.1 To ensure <1 mg ?kg organic chloride in the crude oil, the amount measured in the naphtha fraction shall be <1/f (where f is the naphtha fraction calculated with Eq 3).
4.1.3 Organic chloride present in the crude oil (for example, methylene chloride, perchloroethylene, etc.) is usually distilled into the naphtha fraction. Some compounds break down during fractionation and produce hydrochloric acid, which has a corrosive effect. Some compounds survive fractionation and are destroyed during hydro-treating (desulfurization of the naphtha).
4.2 Other halides can also be used for dewaxing crude oil; in such cases, any organic halides will have similar impact on the refining operations as the organic chlorides.
4.3 Organic chloride species are potentially damaging to refinery processes. Hydrochloric acid can be produced in hydrotreating or reforming reactors and the acid accumulates in condensing regions of the refinery. Unexpected concentrations of organic chlorides cannot be effectively neutralized and damage can result. Organic chlorides are not known to be naturally present in crude oils and usually result from cleaning operations at producing sites, pipelines, or tanks. It is important for the oil industry to have common methods available for the determination of organic chlorides in crude oil, particularly when transfer of custody is involved.
4.1 原油中不存在天然的有機氯化物。當存在時,它們以某種方式污染造成,例如處理許多脫蠟管道或其他設備操作中使用的氯化溶劑。
4.1.1 未受污染的原油將不含可檢測的有機氯化物,大多數(shù)煉油廠可以處理非常少量的有機氯化物,而不會產(chǎn)生有害影響。
4.1.1.1 大多數(shù)貿(mào)易合同規(guī)定原油中不含有有機氯化物。
4.1.2 在石腦油組分為原始樣品的20%的基礎上,有幾條管道規(guī)定了整個原油中<1 mg/kg和石腦油中<5 mg/kg的有機氯化物的規(guī)格限值。
4.1.2.1 為確保原油中的有機氯化物含量<1 mg kg,石腦油中測得的含量應小于1/f(其中f是用式3計算的石腦油分數(shù))。
4.1.3 原油中的有機氯化物(如二氯甲烷、四氯乙烯等)通常蒸餾成石腦油餾分。有些化合物在分餾過程中分解,產(chǎn)生鹽酸,有腐蝕作用。一些化合物在分餾過程中幸存下來,并在加氫處理(石腦油脫硫)過程中被破壞。
4.2 其他鹵化物也可用于原油脫蠟;在這種情況下,任何有機鹵化物對煉油作業(yè)的影響與有機氯化物相似。
4.3 有機氯化物對煉油過程有潛在危害。鹽酸可在加氫處理或重整反應器中產(chǎn)生,并在煉油廠的冷凝區(qū)積聚。意外濃度的有機氯化物無法有效中和,可能造成損害。已知原油中不存在天然的有機氯化物,通常是生產(chǎn)現(xiàn)場、管道或儲罐清潔作業(yè)的結(jié)果。對于石油工業(yè)來說,有共同的方法來測定原油中的有機氯化物是很重要的,特別是在涉及移交保管的情況下。
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32. Precision and Bias 精度和偏差
32.1.1 Repeatability—The difference between successive results obtained by the same operator with the same apparatus under constant operating conditions on identical test materials would, in the long run, in the normal and correct operation, exceed the following values only in one case in twenty.
32.1.1.3 Procedure C—Values can be obtained for organically-bound chlorine for any given concentration above 1 mg/kg Cl (in the original crude oil specimen) as specified in Table 2. See Table 3 for calculated values. See Note 8 for details of the ILS.
32.1.1 重復性—從長期來看,在正常和正確的操作中,同一操作員在相同的試驗材料上使用相同的儀器在恒定操作條件下獲得的連續(xù)結(jié)果之間的差異僅在二十分之一的情況下超過下列值。
32.1.1.3 程序C—如表2所示,任何給定濃度超過1 mg/kg Cl(在原始原油樣品中)時,可獲得有機結(jié)合氯的值。計算值見表3。ILS詳情見注8。
32.1.2 Reproducibility—The difference between two single and independent results obtained by different operators working in different laboratories on identical material would, in the long run, exceed the following values only in one case in twenty.
32.1.2.1 Procedure C—Values can be obtained for organically-bound chlorine for any given concentration above 1 mg/kg Cl (in the original crude oil specimen) as specified in Table 2. See Table 3 for calculated values. See Note 8 for details of the ILS.
32.1.2 再現(xiàn)性—從長遠來看,在不同實驗室工作的不同操作員在相同材料上獲得的兩個單獨和獨立結(jié)果之間的差異在二十分之一的情況下僅會超過以下值。
32.1.2.1 程序C—如表2所示,任何給定濃度超過1 mg/kg Cl(在原始原油樣品中)時,可獲得有機結(jié)合氯的值計算值見表3。ILS詳情見注8。
TABLE 2 Precision Equations, Procedure C XRF
表 2 精密方程式,程序C XRF
Repeatability r, mg/kgA |
MWDXRF r = 0.643*X0.44 (19) MEDXRF r = 0.591*X0.44 (20) EDXRF r = 0.934(X + 0.4)0.48 (21) |
Reproducibility R, mg/kgA |
MWDXRF R= 1.235*X0.44 (22) MEDXRF R = 1.500*X0.44 (23) EDXRFB R = 2.000(X + 0.4)0.48 (24) |
AWhere X = mg/kg chloride
A式中 x=mg/kg氯化物
TABLE 3 Calculated Precision Values, Procedure C XRF
表 3 計算精度值,程序C XRF
Cl, |
Repeatability r, mg/kgA |
Reproducibility R, mg/kgB |
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mg/kg |
MWDXRF |
MEDXRF |
EDXRF |
MWDXRF |
MEDXRF |
EDXRF |
1 |
0.6 |
0.6 |
1.1 |
1.2 |
1.5 |
2.4 |
2 |
0.9 |
0.8 |
1.4 |
1.7 |
2.0 |
3.0 |
3 |
1.0 |
1.0 |
1.7 |
2.0 |
2.4 |
3.6 |
4 |
1.2 |
1.1 |
1.9 |
2.3 |
2.8 |
4.1 |
5 |
1.3 |
1.2 |
2.1 |
2.5 |
3.0 |
4.5 |
6 |
1.4 |
1.3 |
2.3 |
2.7 |
3.3 |
4.9 |
8 |
1.6 |
1.5 |
2.6 |
3.1 |
3.7 |
5.6 |
10 |
1.8 |
1.6 |
2.9 |
3.4 |
4.1 |
6.2 |
12 |
1.9 |
1.8 |
3.1 |
3.7 |
4.5 |
6.7 |
AValues calculated from Eq 19 for MWDXRF, Eq 20 for MEDXRF, and Eq 21 for EDXRF.
BValues calculated from Eq 22 for MWDXRF, Eq 23 for MEDXRF, and Eq 24 for EDXRF.
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