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Naphthenic Acid CAS 1338-24-5

Molecular Formula: C7H10O2

Formula Weight: 126.154

ZSpharmac: Naphthenic Acid Supplier

Product Name: Naphthenic Acid
CAS No: 1338-24-5
Purity: 99%

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Basic Info

Product Name:Naphthenic Acid
Other Names:Hexahydrobenzoic Acid
Place of Origin:Shandong, China
Brand Name:ZSpharmac
Type:Cosmetic Raw Materials
Appearance:Clear Colorless to Yellow-Brown Liquid
EINECS No.:215-662-8
Provide:Naphthenic Acid MSDS;
Naphthenic Acid COA

What is Naphthenic Acid?

Naphthenic acid is an acidic substance existing in oil, so it is likewise called oil acid. It is a carboxyl by-product of cycloalkane, as well as its main element is a five-carbon ring. The general formula is CnH2n-1COOH. Some are oily liquids, some are solid, as well as commercial items are dark oily mixes. The molecular weight arrays from 180 to 350, has an unique odor, is virtually insoluble in water, and also soluble in hydrocarbons. Harsh to steels such as lead and also zinc. Unrefined naphthenic acid has low acid worth and high neutral oil material, which impedes its popularization and application. The content of naphthenic acid differs from place to area, and also the general material is 0.3% to 7%. It is a blend of the complying with 3 carboxylic acids: ① saturated monocyclic carboxylic acid (CnH2n-1COOH); ② saturated polycyclic carboxylic acid (CnH2n-3COOH); ③ fatty carboxylic acid (CnH2n +1 COOH). Amongst them, ③ is considered as a contamination as well as does not belong to this post. In ① as well as ②, the cycloalkyl team is mostly pentyl, and a small amount is hexyl. The variety of alkyl groups is generally 1-5, that is, m=1-5. A substituent R might or may not be present on the cycloalkyl group. The carboxyl group is normally not directly attached to the cycloalkyl team, yet is attached to the cycloalkyl team through one or several (mainly n=6 ~ 18) methylene groups. There is generally one carboxyl team, that is, most naphthenic acids are monobasic acids. Naphthenic acid has the generality of carboxyl team, as well as it can react with steel to develop salt, which is called “naphthenic acid soap”.

Naphthenic acid is primarily an acid divided from petroleum items, which can be used to make steel naphthenates, as paint drier and also wood chemical. It is also used to make synthetic detergents, pesticides, special lubricating oils as well as dry cleaning soaps, and can be made use of as a solvent. Given that naphthenic acid is an organic acid including five-membered or six-membered rings, it can react with alcohols to create esters. Utilizing this particular, naphthenic acid as well as n-butanol are made use of as resources to prepare butyl naphthenate plasticizer via esterification. The ring of butyl naphthenate gotten in this way, like the benzene ring of phthalate, can be inserted between polyvinyl chloride particles, and also its longer alkyl side chain can wind around polyvinyl chloride molecules to develop a precise The framework has a better plasticizing impact as well as can be utilized as a supporting plasticizer for polyvinyl chloride.

Naphthenic Acid Property

Boiling point 160-198 °C (6 mmHg)
density 0.92 g/mL at 20 °C (lit.)
vapor pressure 31.4Pa at 25℃
refractive index n20/D 1.45
Fp 149 °C
solubility Practically insoluble in water
pka5[at 20 ℃]
form Liquid
color Clear colorless to yellow-brown
Water Solubility 88.1mg/L at 20℃


Naphthenic Acid Uses

  1. Naphthenic acid is used in the manufacturing of numerous naphthenates.
  2. Naphthenic acid is primarily made use of to prepare naphthenic acid salts, as well as its sodium salt is a low-cost emulsifier, farming growth agent, and also detergent in the fabric market; lead, manganese, cobalt, iron, calcium and other salts are utilized in printing inks as well as layers Desiccants; copper salts, mercury salts are made use of as wood preservatives and chemicals, fungicides; aluminum salts are used for grease, napalm and flares. Its nickel, cobalt, and also molybdenum salts can be made use of as organic synthesis stimulants and also drier, as well as some salts can additionally be used as ingredients for unique oils.
  3. Naphthenic acid is utilized as a resources for the manufacturing of naphthenic acid salts as well as a drying out agent for finishings, and also is additionally used for the conservation of timber as well as cables.
  4. Naphthenic acid is used as drier, bio-auxiliary as well as chemical of paint.

Corrosion Mechanism of Naphthenic Acid

The corrosion reaction between naphthenic acid and metal is:

2RCOOH + Fe→ Fe(RCOO)2 + H2

Corrosion products are soluble in oil, and it is easy to dissociate from the metal surface, making corrosion develop in depth. When the metal is in contact with naphthenic acid for a long time and the flow rate of crude oil is large, a characteristic groove-like corrosion can be observed on the metal surface. This is the hallmark that distinguishes naphthenic acid corrosion from other corrosions. If the crude oil contains active sulfide, at high temperature, the active sulfide begins to decompose to produce hydrogen sulfide. Hydrogen sulfide reacts with metals:

H2S + Fe→ FeS + H2

The resulting corrosion product FeS film has a certain protective effect under certain conditions. While the FeS film is dissolved in naphthenic acid, the reaction is:

FeS + 2RCOOH→ Fe(RCOO)2+ H2S

The generated hydrogen sulfide causes corrosion of downstream equipment, and the corrosion cycle formed in this way intensifies the corrosion of metals. When RCOOH-H2S-Fe coexists, the relationship of the corrosion system is shown in Figure 2.

In the figure, n is the number of naphthenic acid methylene groups. The phase diagram is divided into corrosion-free zone (Fe), passivation zone (FeS) and corrosion zone [Fe(RCOO)2]. It can be seen from the phase diagram:

(1) There is a critical pressure in the reaction between naphthenic acid and iron. When the naphthenic acid is lower than the critical pressure, naphthenic acid will not corrode iron. Corrosion occurs when the critical pressure is exceeded.

(2) The partial pressure of hydrogen sulfide will affect the composition of the sulfide film formed on the iron surface, thereby affecting the ability of the film to resist corrosion by naphthenic acid.

(3) As the value of n increases, the molecular weight increases, and the critical pressure for the reaction between naphthenic acid and iron increases. It shows that the corrosiveness of naphthenic acid decreases with the increase of molecular weight.

Factors Affecting Naphthenic Acid Corrosion

01. Effect of acid value

At a certain temperature, the corrosion rate of metal is related to the content of naphthenic acid in crude oil (see Figure 4). The research results show that: at a certain temperature, the corrosion rate of A3 steel in naphthenic acid is: dc/dt=kc3/2. Experience shows that within a certain temperature range, there seems to be a certain critical value between the corrosion rate and the acid value, above which the corrosion rate will be significantly accelerated. For carbon steel, the acid value of crude oil is above 0.5mg/g, and the corrosion rate of A3 steel increases obviously


Figure 4 Effect of acidity and temperature on corrosion

02. Effect of temperature on corrosion rate of naphthenic acid

At low temperatures, naphthenic acid hardly causes corrosion to equipment, but above 200 °C, as the temperature rises, the degree of corrosion to equipment gradually intensifies, which is related to the high activation energy of naphthenic acid and the reaction. The research shows that the activation energy of the reaction between naphthenic acid and A3 steel is: Ea=346kJ/mol, and the relationship between the corrosion rate and temperature of A3 steel is: Ink =a-b/T. Gutzeide’s experiment shows that the corrosion rate of carbon steel and low alloy steel increases twice for every 55°C increase in temperature. The relationship with temperature (see Figure 5). It can be seen from the figure that the corrosion rate of 316 stainless steel is the lowest, and that of carbon steel is the highest. The Deruygs report pointed out that the corrosion of carbon steel starts at 149 °C, and the corrosion rate rises linearly with the increase of temperature. At about 204 °C, the corrosion caused by naphthenic acid is already quite serious, which should be paid enough attention to by refineries. Figure 6 shows the relationship between metal corrosion rate and acid value.


Fig.5 Corrosion rate of various materials in naphthenic acid


Fig.6 Relationship between metal corrosion rate and acid value

03. Effect of flow rate on corrosion rate of naphthenic acid

Flow rate and flow regime are very important factors affecting naphthenic acid corrosion. The turbulence created in refinery equipment’s elbows, tees and pumps accelerates corrosion of the equipment. When the gas volume is greater than 60% and the steam velocity is greater than 60m/s, the corrosion is the most serious. Under such conditions, the corrosion rate of certain equipment, such as furnace tubes, elbows, and pipelines, can increase by two orders of magnitude. At a certain temperature, the relationship between the corrosion rate and the flow rate of a certain material in crude oil seems to have a critical speed, below which the corrosion rate of naphthenic acid is very low. Experience shows that: in the absence of turbulent flow, when the flow velocity is less than 25-30m/s, carbon steel is resistant to naphthenic acid corrosion. The flow rate parameters of crude oil in domestic refinery equipment are controlled: the flow rate of the low flow rate to oil line shall not exceed 62m/s; the flow rate of the high flow rate to oil line shall not exceed 94m/s.

About That Product:
If you need Naphthenic Acid, a cosmetic raw material, please contact our service staff directly, and we will provide you with high-quality products at the best price.
As an experienced Naphthenic Acid manufacturer and supplier, ZSpharmac will provide Naphthenic Acid raw materials to customers all over the world for a long time.
Over the years, the company has been adhering to the spirit of “integrity management, strict quality control, customer first”, and has won unanimous praise from domestic and foreign customers.

Company Profile and Corporate Culture

Company Profile:

ZhiShang Chemical is owned by ZhiShang Group is a professional new-type chemicals enterprise combined into research and development, production and sales .

The company’s competitive product is pharmaceutical raw materials and intermediates (especially carbohydrate derivatives Series), In recent years, the company has made a major breakthrough in food and feed additives, plant extraction, industrial chemicals industry .

The company insists on the spirit of “sincere management, strict quality control, customer as god” , get consistent high praise from customers at home and abroad.

Corporate Culture:

Help China Chemicals to benefit the happiness of human life
Become the most trusted chemical supplier in the world
Striver – oriented, enrich employees, customer first, deep service, seek development
Be prepared for danger in times of peace, forge ahead actively, unity and cooperation, and be brave to fight

About Us

The production base is located in Zhangqiu chemical industry park and Tai’an high-tech chemical industry park. laboratory and workshop in strict accordance with the GMP standard and the product fit national ISO9001 and ISO2000 standards.

“Zhishang” products are exported to Europe, North and South America, the Middle East, Asia Pacific and Africa area, so as to establish a long-term and stable cooperation relationship with customer in the world.

Company Info
  • Business Type: Manufacturer
  • Product Range: Cosmetic raw materials
  • Products/Service:Cosmetic raw materials (flavors and fragrances,antioxidant products, moisturizing and hydrating, whitening agents, cosmetic additives)
  • Total Employees: 51~100
  • Capital (Million US $): 10000000RMB
  • Year Established: 2016
Production Capacity
  • No. of Production Lines : 8
  • No. of QC Staff : 5 -10 People
  • OEM Services Provided : yes
  • Factory Size (Sq.meters) : 3,000-5,000 square meters
  • Certificate: ISO9001 , CE , GMP , API , MSDS
  • Factory Location : Diao Town Industry Park, Zhangqiu City, Jinan City, Shandong Province, China.


Pre-Sales Service

* Prompt reply and 24 hours online, professional team to provide best price and high quality product.

* Sample testing support.

* Every batch of products will be tested to ensureits quality.

*The packing also can be according the customers` requirment.

*Any inquiries will be replied within 24 hours.

*we provide Commerical Invoice, Packing List, Bill of loading, COA , Health certificate and Origin certificate. If your markets have any special requirements, let us know.


After-Sales Service

*The fact of logistics information monitoring.

* Any questions about the product can be consulted at any time.

*Product has any problem can return.


Do you accept sample order?

We will make samples before mass production, and after sample approved, we’ll begin mass production. Doing 100% inspection during production, then do random inspection before packing.



You can get free samples for some products,you only need to pay the shipping cost or arrange a courier to us and take the samples. You can send us your product specifications and requests,we will manufacture the products according to your requests.

What’s your MOQ?

Our MOQ is 1kg. But usually we accept less quantity such as 100g on the condition that sample charge is 100% paid.

Do you supply product report?

Yes. We’ll give you product analysis report before shipping.

  Is there a discount?

Different quantity has different discount.


1. ≤50kg, Express delivery recommended, usually called as DDU service;

2. ≤500kg, Air shipping recommended, usually called as FOB, CFR, or CIF service;

3. >500kg, sea shipping recommended, usually called as FOB, CFR, or CIF service;

4. For high value products, please select air shipping and express delivery for safe.

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