巨象車很大 wrote:
了解潤滑油(機油)的...(恕刪)
標記一下，真是好文，回家慢慢看。
標記一下，真是好文，回家慢慢看。
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成本比PAO低,但品質更好
一般的機油都是從原油加工所生產的,原油中的雜質多,品質差
天然氣比原油在全球的產量多,天然氣的硫含量比原油低
所以從天然氣加工所生產的機油,品質更高
世界前五大石油公司 Chevron 雪佛龍/Shell殼排/ExxonMoibl艾克森美福/bp英國石油/ConocoPhilips康非石油 都有自己的 GTL 專利技術
可參台灣科技大學教授的此篇研究
http://www.tri.org.tw/oil/file/article16-970430.pdf
費托合成法 GTL 生產天然氣為原料轉化成 機油產品
比第三類加氫裂解的基礎油更好
同時達到 合PAO第四類基礎油的各項標準
http://www.machinerylubrication.com/Read/422/gas-to-liquids
“Fischer-Tropsch GTL synthetic fluids are positioned for the future,” Henderson concluded. “They have an outstanding combination of viscometric, volatility, low-temperature and compositional properties that exceed the American Petroleum Institute’s Group III ‘Best of Industry’ while matching PAO standards. GTL has demonstrated excellent performance in critical GF-3 engine tests while initial driveline testing is consistent with PAO. I’m very encouraged for the future of GTL.”
GTL 機油與其他基礎油的比較
所以全球前五大石油公司的機油,品質都不錯
全球前五大石油公司依序為
美國埃克森美孚(ExxonMobil)旗下機油品牌另有Mobil美福機油 、Esso愛索機油
荷蘭殼牌(Shell)旗下機油品牌另有Pennzoil 金鍾機油、Quaker State 快剋機油
英國國營石油(BP，旗下機油品牌另有 Aral啞拉機油、Castrol加實多機油
美國雪佛龍(Chevron)旗下機油品牌另有 Texaco 德士古機油、Caltex加德士機油)
美國康菲(ConocoPhillips)旗下機油品牌另有PHILLIPS 非利浦66機油, conoco , 76機油 , Kendall 機油
法國道達爾(Total SA，旗下品牌另有 elf 意而富機油 、 Fina筷拿機油
Group III Versus PAO Performance
http://www.uns-oil.ru/userfiles/Base%20Oil%20Technology%20Evolution.pdf
Historically, PAOs have had superior lubricating performance characteristics
such as V.I., pour point, volatility, and oxidation stability that could not be achieved with
conventional mineral oils. Now, in modern base oil manufacturing, V.I., pour point,
volatility, and oxidation stability can be independently controlled. Modern Group III
oils today can be designed and manufactured so that their performance closely matches
PAOs in most commercially significant finished lube applications.
As well-designed Group III base oils become abundant in the marketplace, the
performance gap between Group III and PAO (Group IV) is closing. Here are some key
examples:
Pour Point – Pour point is the one property where Group III oils allegedly fall
short of PAO. While it is certainly true that the pour point of the neat Group III base oil
is substantially higher than that of a PAO of comparable viscosity, it is important to
understand that the pour point of the fully formulated lubricant (base oils plus additives)
is the critical property. Base oils manufactured with modern isomerization catalysts
respond very well to pour point depressant additives. For example, turbine oils
formulated with conventional Group II base oils (-12°C base oil pour point) are available
with a formulated pour point of -36°C. Fully formulated Group III based lubricants can
be made with pour points of -50°C or below.
Products such as motor oils made with the lighter-grade PAOs, on the other hand,
typically have higher pour points than the base fluid, so the gap in final product pour
point between PAO-based and UCBO-based lubricants is much smaller than in the base
fluids themselves. Moreover, it is entirely possible with modern Group III
manufacturing technology to produce base oils of even lower pour point. However, this
is not common practice in the industry, because it is more economical to meet finished
lube low temperature performance using pour point depressant additives rather than
using special Group III oils having exceptionally low pour points.
Cold Crank Simulator – Viscosity in engine journal bearings during cold
temperature startup is a key factor in determining the lowest temperature at which an
engine will start. Cold Cranking Simulator (CCS) viscosity, as measured by ASTM
Method D 5293, is determined under conditions similar to those experienced in engine
bearings during starting. For base oils, this viscosity is determined almost entirely by
viscosity and V.I. Since Group III stocks typically have V.I. comparable to that of 4 cSt
PAO, one would expect comparable CCS performance. This is demonstrated in Figure
3, where it can be seen that a 4 cSt Group III base oil, with a kinematic viscosity of 4.2
cSt at 100°C and a V.I. of 129, and PAO 4, with a viscosity of 3.9 cSt and V.I. of 123,
have similar CCS values, both about half that of a 4 cSt Group II base stock of about 100
V.I. This performance makes the Group III stock very effective for formulating fuelefficient
multi-viscosity engine oils in the 0W-20 to 0W-50 range, one that has
historically been achieved only with PAO-based product.
以前0w-20 0W-30 0W-40 到 0w-50 必須 PAO才能生產
現在第三類基礎油也能生產0w-20 0W-30 0W-40 到 0w-50的機油
Noack Volatility – Noack volatility of an engine oil, as measured by ASTM
D 5800 and similar methods, has been found to correlate with oil consumption in
passenger car engines. Strict requirements for low volatility are important aspects of
several recent and upcoming engine oil specifications, such as ACEA A-3 and B-3 in
Europe and ILSAC GF-3 in North America. Figure 4 shows that from a blender’s
perspective, Group III base oils are similarly effective as PAOs for achieving these low
volatility requirements in engine oil applications. The V.I. of modern Group III oils
typically match or exceed PAO, so they can match the volatility of PAOs at a reasonable
distillation cut width.
Oxidation Stability – Oxidation and thermal stability are among the most
important advantages that “synthetics” bring to the table. Better base oil stability means
better additive stability and longer life. High stability is the key to making the premiumquality
finished oils of the future with longer drain intervals. Here Group III oils
routinely challenge PAO performance.
The stability of modern Group III stocks depends mostly on their V.I., because
V.I. is an indication of the fraction of highly stable isoparaffinic structures in the base oil
[10]. However, because modern Group III stocks also undergo additional severe
hydrofinishing after hydrocracking and hydroisomerization, they achieve an additional
boost in stability because only trace amounts of aromatics and other impurities remain in
the finished stocks. On the other hand, PAO performance seems to depend largely on
residual olefin content. Olefins are an intermediate in PAO production that contribute to
instability.
Figure 5 illustrates that base oil quality can have a big impact on the oxidation
stability in turbine oils. The Turbine Oil Stability Test (TOST), or ASTM D 943,
measures the time required for a turbine oil to oxidize to the point where the total acid
number reaches 2.0 mg KOH/g. Unadditized Group I base oil fails in about 200 hours.
A modern high-quality turbine oil formulated with Group I base oil typically fails in less
than 7000 hours. A high-quality Group II formulated oil can run more than twice as
long before it fails.
The benefit of all-hydroprocessed Group III base oils in oxidation stability is
illustrated in Figure 6 for hydraulic oils formulated by using the same additive system in
four different base oils. Here, the time required to reach an acid number of 2.0 (defined
by neutralization of 2.0 mg of KOH/g of oil) in the Universal Oxidation Test (ASTM
D 4871), a common measure of oil oxidation, was substantially longer for the Group III
formulation than for either the Group I or II products. Moreover, the performance of the
Group III product was essentially the same as that for the oil formulated with PAO.
謝謝說明
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