Hydrolyzed polymaleic anhydride is a phosphorus-free water treatment chemical. It forms a chelate with calcium and magnesium ions in water. And hydrolyzed polymaleic anhydride can cause lattice distortion. After the anion is adsorbed by the calcium carbonate nucleus, the nucleus can be charged.

Due to the homophobic electrical repelling, tiny grains are dispersed in the aqueous solution. The precipitate is converted into a loose slag with good fluidity. This phenomenon has a good effect on peeling off the old scale.

Hydrolyzed polymaleic anhydride (HPMA) is compatible with other low-phosphorus corrosion and scale inhibitors such as ATMP and PBTCA. The formed composite corrosion and scale inhibitor can be widely used in the treatment of circulating cooling water, boiler water, oil field water injection, industrial water.

Hydrolyzed polymaleic anhydride (HPMA) is the product of partial hydrolysis of polymaleic anhydride. It has been determined that about 60% to 70% of the polymaleic anhydride is hydrolyzed to a carboxylic acid. That is not completely hydrolyzed.

HPMA is shown by the study of the structure-effect relationship of molecular microstructure. The increase in the degree of hydrolysis is advantageous for HPMA chemical improvement in scale inhibition performance. Therefore, a large degree of hydrolysis is ensured as much as possible during synthesis of hydrolyzed polymaleic anhydride.

From hydrolyzed polymaleic anhydride structural analysis, its carboxyl group in the molecule can form compounds with calcium and magnesium ions in water. And HPMA can promote lattice distortion and turn the precipitation into a loose slag with good fluidity.

Hydrolysed polymaleic anhydride is the same as a polymer having a hydroxyl group or a sulfonic acid group. It can be dissociated into hydrogen ions and acid anions after being dissolved in water. The chain molecules are then negatively charged.

This long-chain negatively charged anion is adsorbed by calcium carbonate nucleus and fine crystal grains. Then bring HPMA with a more negative charge.

The crystallites are dispersed into the aqueous solution due to the homophobic electrical repelling. This prevents the fine grains from coagulating to form larger crystals. Thus, HPMA has a dissolution limiting effect. It has high scale inhibition performance when used at low doses.

In addition, the carbonyl group of HPMA has a strong complexation as an electron donor. This changes the normal morphology of calcium carbonate and calcium phosphate crystals. And can prevent hydrolyzed polymaleic anhydride from growing into a larger crystal. Thereby it has the effect of inhibiting scale formation and peeling off the old scale.

HPMA chemical is a class of polycarboxylic acid scale inhibitors. It can be matched with other corrosion inhibitors and scale inhibitors. The molecular weight of HPMA is about 600~1200. The aqueous solution is brownish yellow or brownish red, viscous, acidic liquid. Hydrolyzed polymaleic anhydride (HPMA) is chemically stable. It can be used at temperatures below 350 °C.

Hydrolysed polymaleic anhydride has excellent scale inhibition performance for carbonate and phosphate. It has significant solubility effects and significant dispersion effects. HPMA can be adapted to water quality at different pH values. HPMA chemical is phosphorus-free, non-toxic and environmentally friendly. It can be degraded by microorganisms in the natural environment. The degradation products have no effect on the ecological environment.

The hydrolyzed polymaleic anhydride has the following scale inhibition characteristics.

(1) It is quite effective for calcium carbonate scale. At the same time, it has both lattice distortion and threshold effect (ie, unidirectional conductivity). Even if it is scaled, it is relatively loose. It is easily washed away by water and not formed into a hard scale.

(2) It has high-temperature resistance. Decomposition usually occurs above 350 °C. Can be used at high temperatures.

(3) It has a certain ability to disperse calcium carbonate, calcium phosphate, calcium sulfate and the like.

(4) It can be compounded with a zinc salt. There is a synergistic effect on corrosion inhibition of carbon steel.

(5) It is non-toxic. No significant impact on the environment.

The HPMA chemical corrosion inhibition mechanism is as follows.

The oxygen atom in the polar group (—COOH) and (—OH) in the HPMA molecule can become the adsorption center. It can form a chelate with metal ions in water. Adsorbed on the metal surface. A protective film is formed along the metal surface. Thereby playing a role in corrosion inhibition.

A single polymaleic anhydride is an excellent scale inhibitor. The corrosion inhibition performance is poor. Compared with polyacrylic acid and polymethacrylic acid, HPMA corrosion inhibition performance is slightly stronger. C-P bonds and phosphinic acid groups (-PO₂H₂) are usually introduced to enhance corrosion inhibition performance.

1.HPMA-ATMP Compound

ATMP plays a major role as a water quality stabilizer. One is the cooperation of ATMP. It can both soften water and descale. Second, ATMP interferes with the growth of the CaCO₃ scale layer. ATMP causes a large distortion of the CaCO₃ crystal structure.

2.HPMA-PESA Compound

PESA has a phosphorus-free, non-nitrogen structure. It can be biodegraded in the natural environment. PESA has the dual functions of scale inhibition and corrosion inhibition.

The complex paired calcium carbonate scale of HPMA-PESA has good scale inhibition performance. The concentration, temperature and concentration time of the scale inhibitor have a great influence on the scale inhibition effect.

Increasing the amount of HPMA-PESA compounding agent can also increase the scale inhibition performance of calcium carbonate. When HPMA-PESA is added to a certain amount, it will tend to be saturated and gentle. This composite formulation was the largest at a concentration time of 10 hours. As the concentration-time is further extended, the scale inhibition rate begins to decrease slowly.

3.HPMA-EDTMPS Compound

EDTMPS water miscible energy is chelated with multiple metal ions. A plurality of monomeric structure macromolecular network complexes is formed. EDTMPS destroys the normal crystallization of calcium scale. HPMA-EDTMPS compound scaling rate is greatly improved.

4.HPMA-PAA Compound

PAA is an excellent scale inhibitor and dispersant. It has a good effect of inhibiting the formation of scale and peeling off the old scale. The reaction can be carried out under alkaline and medium concentration multiple conditions without fouling.

As a new type of composite scale inhibitor, HPMA-PAA has the advantages of good scale inhibition effect and good thermal stability.

5.HPMA and HEDP, AMPS Ternary Compounding

The polymer corrosion and scale inhibitor molecules contain two important groups of “stabilizing groups” and “docking groups”. The docking group is adsorbed on the crystallites. Poor water solubility and strong adsorption. The stabilizing group has a good affinity with the solvent.

A large number of carboxyl groups on HPMA are negatively charged after ionization. It is an excellent stable group. The amide group on 2-acryloyl-methylpropane sulfonic acid (AMPS) has strong adsorption to the scale-forming crystallites. It is an excellent docking group. HEDP easily forms a six-membered ring chelate with metal ions and has a synergistic effect.

HPMA is compounded with APMS and HEDP. Excellent docking groups are introduced in the polymaleic anhydride molecule. The adsorption of the polymer is improved. Thereby increasing the “lattice distortion” and “adsorption dispersion” of the polymer. And temperature resistance and timeliness. Very few scale inhibitors can achieve higher scale inhibition rate.

A 250 mL four-necked flask was charged with a thermometer, a stirrer, a condenser, and a dropping funnel, and a certain amount of maleic anhydride and water was added. The water is warmed to 55 to 60 °C.

After all the maleic anhydride has been dissolved, an appropriate amount of the catalyst is added. The stirrer was turned on while raising the temperature to the reaction temperature. The initiator was added dropwise through a dropping funnel over a period of time.

Pay attention to controlling the temperature during the addition of the initiator. After the completion of the dropwise addition, the reaction was continued for 1 hour to obtain a polymaleic acid product.

The corrosion and scale inhibitor currently on the market is the long-term use of water treatment chemicals. They are more expensive. It ranges from 5,000 yuan to 20,000 yuan per ton. This puts a heavy economic burden on water treatment companies that use corrosion and scale inhibitors.

In order to enable customers to use corrosion and scale inhibitors efficiently, let’s share the method of saving the use of slow release scale inhibitors.

Method one. According to the test parameters of water, the corrosion and scale inhibitors are used in a targeted manner.

If the water quality of the circulating water can be tested, then the corrosion and scale inhibitors should be used according to the test results. In this case, it reduces a lot of unnecessary waste. In addition, it can bring good economic benefits to customers. Therefore, it is best for qualified customers to test the water quality in a targeted manner.

Method Two. Corrosion and scale inhibitor blending.

If there is not much material in the water, it can be blended according to the situation. The ratio of corrosion and scale inhibitor blending should not be too large. Generally controlled within a ratio of 1:1. If there is too much blending, the dilution of the corrosion and scale inhibitor will be lost. Thereby reducing the function of the corrosion and scale inhibitor.

Corrosion and scale inhibitors are a kind of products with better water treatment effect. Mainly used in the water treatment industry in various fields. However, many people do not use corrosion and scale inhibitors effectively. In most cases, the unsatisfactory result is not due to the poor quality of the corrosion and scale inhibitor products. Today IRO water researchers analyze the causes of the effects of corrosion and scale inhibitors.

The most influential reason should be the method used. Many people will add sewage themselves when they use it. Do not follow the above requirements in the instruction manual. This will definitely affect the effect of descaling. If you add less, it will definitely not be clean, but if you add too much, it will probably chemically react to water quality.

It is recommended that you check the instructions in the instructions before using, and understand the concentration of the ratio and then proceed with the treatment. Only after re-understanding the basic situation of corrosion and scale inhibitors can the effect be better.

I suggest you check the instructions before using. After understanding the concentration of the ratio, it is processed. Only by re-understanding the basic situation of corrosion and scale inhibitors can the effect be better.

The second is the problem of water treatment chemical addition.

The addition of a water treatment chemical plays an important role in the operational stability of the reverse osmosis membrane system. The right addition can make the most of it.

1. When adding water to the metering tank, be careful not to exceed the maximum liquid level.

2. The initial addition of the water treatment chemical should first clear the addition box. Close the bottom drain valve of the metering box when cleaning. After the water is cleaned, open the drain valve to drain the water. After two passes, the amount began to increase.

It is important to note that the motor is stopped after the water treatment chemical is evenly stirred. At the same time, open the metering pump inlet and outlet valves and open the metering pump switch. The pharmacy is added before the security filter. After the RO stops running, the metering pump is turned off.

3. Adjust the metering and adding a stroke. Turn the metering stroke adjustment knob counterclockwise to the corresponding scale. Also, pay attention to the water treatment chemical. Check that the drain valve at the bottom of the metering tank is closed. According to the effective volume in the metering box and the actual working output of the metering pump. Add the agent from the inlet of the metering box. Open the inlet valve and dilute to the highest level mark and close the makeup valve.

4. Record water treatment chemicals every month. Check whether the total water intake and the amount of the matching period match, and regularly check the filling system for leaks, and promptly resolve the leak.

The performance of water treatment chemicals configured by different manufacturers may be different, so users should purchase water treatment chemicals according to actual needs.

There are three mechanisms for the action of corrosion and scale inhibitors. Complexation solubilization, lattice distortion, and electrostatic repulsion.

Complexation solubilization

Complexation solubilization is the formation of a water-soluble complex or chelate with a negatively charged molecular chain and Ca²⁺. This molecular chain is formed by ionization of the copolymer after it is dissolved in water. This complexation can increase the solubility of the inorganic salt and thus act as a scale inhibition effect.

Lattice distortion

The lattice distortion effect is to block and destroy the normal growth of the inorganic salt crystals by a part of the functional groups in the scale inhibitor molecule. This slows down the growth of the crystal. Thereby reducing the formation of salt scale.

Electrostatic repulsion

The electrostatic repulsion is like this. The copolymer is dissolved in water and adsorbed on the crystallites of the inorganic salt. The interparticle repulsion is then increased. Thereby hindering their coalescence. These particles are placed in a good dispersion state. Thereby preventing or reducing the formation of scale.

There are many corrosion and scale inhibitors have these abilities. Such as ATMP, HEDP, and DTPMP, etc.

The common classification methods are as follows.

1. Classification according to the suppressed electrode process.

Classification of electrode reactions suppressed by electrochemical corrosion in accordance with corrosion and scale inhibitors. Can be divided into anode type scale inhibitor, cathode type scale inhibitor or mixed type scale inhibitor.

The cathode type corrosion and scale inhibitor moves the corrosion potential Ec of the metal in a negative direction.

The anode type corrosion and scale inhibitor moves the corrosion potential Ec of the metal in a positive direction.

The mixed scale inhibitor has little effect on the corrosion potential Ec. Therefore, the movement of the corrosion potential is small or not moving.

2. Classification according to the type of protective film produced.

According to the type of protective film formed by the corrosion and scale inhibitor in protecting the metal. Can be divided into passivation film type scale inhibitor, precipitation film type scale inhibitor and adsorption film type scale inhibitor.

3. Classification according to chemical composition.

The substances constituting the corrosion and scale inhibitor are classified as inorganic compounds or organic compounds. Can be divided into inorganic scale inhibitors and organic scale inhibitors.

Corrosion and scale inhibitors are mainly used for scale inhibition and corrosion inhibition of circulating cooling water. Mainly used in the following industries.

1. Thermal power plants. The power generation process of a thermal power plant is to heat water through coal in a boiler. Turn water into high-pressure steam. High-pressure steam drives the turbine to generate electricity. After power generation, the high-pressure steam becomes low-pressure steam. The low-pressure steam is returned to the boiler after being cooled by the circulating cooling water in the condenser to liquid water.

2. Chemical plants, fertilizer plants, and petrochemical plants. They cool the heat medium to a cold medium by circulating cooling water

3. Heating water system

4. Metallurgical industry such as steel mills

5. Oilfield production plant. At present, part of the oil produced in the oil field is oil, and the other part is water. After the oil and water are separated, the water is returned to the ground, which is called refilling water. If the refilling water is not added, it may cause fouling to block the corrosion of the pipeline or pipeline.

Each piece of equipment in industrial production has a certain period of use. Because of the high production cost, it is necessary to maintain and maintain the equipment in a very fine manner in order to maintain the service life of the equipment for a long time.

In order to extend the life of the device, people have come up with many methods. One of the methods is to use corrosion and scale inhibitors.

This solvent can effectively reduce the chance of corrosion of the container. Let the inside of the container maintain a very new state for a long time. It also reduces scale formation. Dispose of the debris in the water quickly and rinse it off with the water. Avoid fouling on the inner wall.

At present, the production technology of corrosion and scale inhibitors used by people has reached a very advanced level and has perfect technical support. The secrets and techniques of different manufacturers are different. The most advanced is the use of separation technology.

This technique effectively combines and separates molecules. A very advanced spectral illumination instrument is used. This instrument is capable of emitting light in different wavelength bands. Nuclear magnetic reactions can also be produced. Analyze using the spectra they present. Produce a very comprehensive gallery. There is a staff member to record. This will be fully prepared for a large number of products in the future. Separation technology is very advanced technology.

There are also many types of components contained in corrosion and scale inhibitors. For example, it contains organic phosphorus. There are also some very powerful additives that are all materials that help organic phosphorus work.

There are also corrosion inhibitors that reduce the rate at which copper is corroded. This water treatment agent is very effective for metals containing copper elements. Can be used to disperse the dirt inside, and then better dissolve in water and discharge.

The role of scale inhibitors in circulating cooling water systems

Chemical treatment of circulating cooling water not only stabilizes water quality but also improves production efficiency.

1. Reason: Various salts such as bicarbonate, carbonate, sulfate, and silicate are dissolved in natural water. When natural water enters the circulating water system as supplemental water, it is concentrated by evaporation and the ion concentration in the water increases. Especially bicarbonate. This salt is the main component of scale adhesion in cooling water.

2. Treatment measures: Add high-efficiency slow scale inhibitor to hinder and destroy the normal growth of inorganic salt crystals such as calcium carbonate and magnesium carbonate. Slows down the growth rate of the crystal. Thereby reducing the formation of salt scale.

The scale inhibitor forms a water-soluble complex or a crab compound with Ca²⁺, Mg²⁺, etc., so that the solubility of the inorganic salt is increased, which acts as a scale inhibition effect and is not easily deposited on the metal surface.

1. Reason: The second major problem to be solved by circulating cooling water is the corrosion of metal equipment. The surface of the metal (carbon steel, stainless steel, copper, etc.) is in contact with water, and the water contains various impurities such as dissolved oxygen and CO₂.

The potential difference produces an electrochemical reaction. Thereby causing corrosion damage to the metal. Corrosion results in reduced equipment life and corrosion products forming fouling. Reduce heat transfer efficiency. Unexpected shutdown due to leakage of the heat exchanger.

2. Treatment measures: There are many ways to control the corrosion of the circulating water system. The addition of a water treatment chemical method is one of them. It is by adding and maintaining a certain amount of corrosion inhibitor to the circulating water.

The corrosion and scale inhibitor provides a dense continuous metal oxide film or other types of film on the metal surface. In order to suppress the corrosion process, thereby achieving the purpose of corrosion. The corrosion and scale inhibitor can greatly reduce the corrosion rate of the equipment and greatly extend the life of the equipment. Experiments show that after the heat exchanger pipeline equipment is prevented by the corrosion inhibitor, the service life of the equipment is extended by about 40% on average.

1. Reason: The open circulating water system has sufficient light, suitable temperature and abundant nutrient source to promote the growth of microorganisms. This leads to biological slime and corrosion, and the damage that microbes bring to the system is nothing more than dirt and corrosion. When expressed, it is often mixed with the dangers of scale and electrochemical corrosion.

Microbial slime is composed of microbial cells and viscous substances (polysaccharides, proteins, etc.) that are bonded together. Open circulation cooling water system. The most common faults caused by slime-producing bacteria. The second is the problems and treatments of algae, mold (filamentous bacteria), and jersey bacteria (filamentous fine water system).

2. Treatment measures: For the circulating cooling water system, it can cooperate with the system to prevent scale and improve the corrosion inhibition effect. It is necessary to regularly add bactericidal algaecide for treatment.

For this circulatory system, oxidizing and non-oxidizing bactericides are used alternately. It can prevent the resistance of bacteria to algae. Improve the sterilization effect.

Over-casting and slime stripping agent allows slime composed of slime, sludge, algae secretions, and algae to be discharged with water to achieve strong peeling and cleaning so that the surface is clean and prevent corrosion under scale.

In summary, it can be fully understood that the scale inhibitor plays an important role insufficient, corrosion inhibition, sterilization, and algae elimination in the circulating cooling water treatment system.

People in the field of environmentally friendly water treatment know how important water treatment chemicals are. We can use it to achieve indicators that are not available in the biological processing sector. Water treatment chemicals can be called a magic weapon for our sewage treatment engineers.

1. The application field of water treatment chemical

Applications of water treatment chemicals include industrial water, municipal/drinking water treatment, sewage, and wastewater treatment, and desalination. In the industrial water field, it is mainly used in industrial circulating water treatment and industrial boiler water treatment.

Common methods for industrial boiler water treatment are water treatment outside the pot and water treatment inside the pot. The chemicals used mainly include corrosion and scale inhibitors, oxygen scavengers, water supply, and alkalinizers, ion exchangers, regenerants, softeners, alkalinity regulators, detergents, and the like.

The water treatment chemicals involved in municipal/drinking water treatment generally include bactericidal algaecides, flocculants, corrosion inhibitors, and the like. Water treatment chemicals involved in sewage treatment generally include flocculants, sludge dehydrating agents, defoaming agents, chelating agents, decolorizing agents, and the like.

Mainstream technologies for seawater desalination include distillation and membrane processes.

The membrane is easily clogged during use. So it is necessary to add a scale inhibitor, a detergent, a flocculant, a scale inhibitor and a dispersant to the water. The distillation method is easy to produce scale and reduce evaporation efficiency. The water can be softened by adding polyphosphate, organic phosphoric acid, phosphinopolycarboxylic acid or the like to the raw water. The chelation of calcium, magnesium ions and other metal ions makes it difficult to precipitate and prevent the formation of scale.

2. Type of water treatment chemicals

The water treatment chemicals include the flocculating agent,  corrosion inhibitor,  scale inhibitor,  biocide,  detergent,  pre-filming agent, the antifoaming agent, decolorizing agent,  chelating agent,  oxygen scavenger, and an ion exchange resin.

2.1 Flocculant

Just remember three things. The first point is that flocculants are mainly used to strengthen solid-liquid separation in the field of sewage treatment. The second point is that a coagulant can be added to enhance the flocculation effect. The third point is that flocculant is the cheapest and most efficient method of phosphorus removal.

2.2 Coagulant

Just remember two things. The first point is that the role of the coagulant is to adjust or improve the coagulation conditions; the second is that it can increase the grain size, density, and firmness of the flower.

3. Corrosion and scale inhibitor

Corrosion and scale inhibitors, as the name implies, are a kind of water treatment agent for relieving scale and corrosion of circulating water equipment such as boilers. The medicament is composed of an alkaline substance and an organic compound. A corrosion inhibitor is added to prevent the heated surface from being corroded.

The alkaline substance in the medicament passes through a chemical reaction in the boiler. It reacts with calcium and magnesium salts in water to form water slag. After sedimentation, it is discharged to the outside of the boiler through the sewage function. The corrosion and scale inhibitor can reduce the concentration of calcium and magnesium ions in the water so that no scale is formed in the boiler.

4. Detergent

The cleaning agent is a volatile solvent that dissolves the permeate. It is used to remove excess permeate from the surface of the workpiece being inspected. Some cleaning agents are specifically designed to remove metal hydroxides, calcium carbonate and other similar scales attached to the surface of polyamide and film component membranes. Check the wash tank, piping and security filters, and install new filter cartridges before using the cleaner.

5. Fungicide

The bactericide is mainly an agent that eliminates harmful bacteria such as bacteria and microorganisms. Internationally, it is usually used as a general term for the treatment of various pathogenic microorganisms.

3. To choose the type of water treatment chemical according to the situation

There are many types of water treatment chemicals, and we have to choose according to the situation.

At present, the types of water treatment chemicals mainly include corrosion inhibitors, scale inhibitors, biocides, and flocculants. Among them, corrosion inhibitors and scale inhibitors are close to the international advanced level in the field of variety development.

The formulation of the water stabilizer for industrial circulating cooling water is mainly phosphorus, accounting for 52~58%, molybdenum formula accounting for 20%, silicon system formula accounting for 5%~8%, and tungsten system formula accounting for 5%. Other formulas account for 5% to 10%.

The concept of green chemistry is re-evaluating the role and performance of existing water treatment chemicals. For products that are already well known for these functions, biodegradability is the most important indicator of evaluation.

There are many types of water treatment chemicals.

There are still some differences in the field of application of different types of pharmaceuticals. The concept of green chemistry is entering the field of vision of more and more people. Therefore, we will have higher requirements for these products from now on. This will enable our water treatment chemicals to develop better.

The development and changes of water treatment chemicals are still very obvious. We cannot ignore the development of this product because it will bring you many incredible changes.

Source:

https://www.irohedp.com/water-treatment-chemicals-ultimate-guide-2019

There are numerous types of organic phosphonic acids, however in their own molecular structure they have a phosphonic acid group straightly attached to a carbon atom. And also molecule may also contain groups just like -OH, -CH₂ or even -COOH.

For this reason, the quantity of phosphonic acid groups held in the molecule is decided. The organic phosphoric acid is usually classified in to a diphosphonic acid, a triphosphonic acid, a tetraphosphonic acid, a pentaphosphonic acid etc. Based on the kinds of molecular structure, the organic phosphoric acid may be even further divided into a methylidene phosphonate category, a homocarbodiphosphonic acid category, a hydroxy acid phosphonic acid type, and other atomic phosphonic acid type.

Organic phosphoric acid is really a fresh product created in the later 1960s. On the other hand, it had been largely used in circulating cooling water treatment solution within the Nineteen seventies. This is because it contains the benefits listed below.

At first, they all have a C-P bond in their molecular structure, which bond is much stronger than the P-O-P bond in polyphosphate. Thus, it’s nice chemical stableness. It is not really very easily hydrolyzed, and it’s also resistant against high temperature. While in the use, it will not cause orthophosphoric acid to be overproduced as a result of hydrolysis.

Secondly, it possesses a crucial effect similar to polyphosphate. It is only a few mg/L of organic phosphonic acid that could stop the precipitation of numerous hundred or so mg/L of calcium carbonate.

During certain use, it can be learned that the use of an organic phosphonic acid in combination with a polyphosphate is preferable to any existing individual types. In addition to polyphosphate, it as well has a nice synergistic effect along with a number of chemicals.

Because of this, during practical apply, most people usually choose the chemical method while using best synergy.

Besides the above advantages, the organic phosphonic acid also has excellent corrosion inhibition qualities at high quantities. And it is a non-toxic or even particularly low-toxic chemical. As a result, there’s no need to worry about environmental pollution in the time of apply.

Commonly applied organic phosphonic acid

There are several different types of organic phosphonic acid, nevertheless the next widely apply agent within circulating cooling water are listed below.

1. ATMP

The chemical product name is amino trimethylene phosphonic acid. ATMP 50 features great chemical stableness, is tough to hydrolyze, and is also resistant to high temps. When it is formulated together with zinc salts and copolymers, it has a superior synergistic effects along with a solubility limit effects.

This chemical also provides superior corrosion inhibition overall performance at high amounts. And it’s a non-toxic, pollution-free agent. ATMP 50 has got excellent dispersion and also scale inhibition properties for calcium carbonate scale.

2. EDTMP

The actual chemical name is ethylene diamine tetramethylene phosphonate. It could chelate along with a plurality of metal ions to create a plurality of monomer structure macromolecular system complexes, which are freely spread inside waters to eliminate the calcium scale crystal.

3. HEDP 60

HEDP chemical is an organic phosphonic acid of the same carbon diphosphonic acid type. It’s molecular structure doesn’t have N. Its chemical name is hydroxyethylidene diphosphonic acid. HEDP could form stable complexes with various metal ions like steel, copper and zinc, and may melt oxides on steel surfaces.

4. DTPMA

DETPMP is really an organic phosphonic acid created in the Nineteen eighties. It’s chemical term is diethylene triamine penta methylene phosphonic acid.

It’s always characterized by its mix along with Mm²⁺, which has great corrosion inhibition capability both for carbon iron and copper alloy. Because Mm²⁺ isn’t covered by environmental laws, the ingredients of the chemical has got attracted excellent attraction internationally.

DTPMP, such as the previously mentioned organic phosphonic acid. It can also chelate along with a plurality of metal ions. The organization of 2 or more three-dimensional macromolecular ring complexes, loosely spread in water, damages the development of calcium carbonate crystals, and thus playing a part of scale inhibition.

5. Phosphonic Acid

The phosphonic acid molecule contains both a phosphate group -PO(OH) ₂ and a hydroxyl group -COOH. According to them all during the combination

You will find lots of varieties in the place and also number of items. In our own company’s formulation, PBTC scale inhibitor can be used much more. It’s chemical title is 2-phosphonobutane-1 2 4 trihydroxy acid.

6. Organic Phosphonate

There are numerous different types of organic phosphonates, however, following groups are found in their molecular structure:

Because organic phosphates are certainly toxic to aquatic animals and slowly hydrolyze, the hydrolyzed products are also able to degrade naturally and therefore haven’t any impact on the environment.

Organophosphates are generally used in combination with some other chemicals such as polyphosphates, zinc salts, lignin and benzotriazole.

The above is a thorough overview with the widely used agents during circulating cooling water. When you have questions on the water treatment chemicals, please email us.

The water treatment chemicals include a corrosion inhibitor, a scale inhibitor, a bactericide, a cleaning agent, a degreaser and compound product thereof. These chemicals are not only diverse but also very different in nature, and require a large number of analytical methods.

With the advancement of the times and science and technology, the types and functions of water treatment chemicals have also been greatly developed.

Due to the limitations of analytical techniques and analytical instruments, and others reasons. Some new agents are very similar to the same type of old drug control indicators and analytical methods. Although there are national or industry standards, it is difficult to make an effective distinction.

In actual work, we found that HEDP and PBTCA have the above problems in the analysis method. Their analytical principles are the same and the analysis steps are very similar. Under the current conditions, it is not effective to identify both.

For this reason, some experiments were carried out and some supplementary identification methods were done. I hope to make up for the deficiencies of the existing analytical methods to a certain extent.

HEDP is known as 1-hydroxyethylidene-1 1-diphosphonic acid. It is the first generation of organic phosphonic acid scale and corrosion inhibitor.

Industrial production was achieved in the 1960s. HEDP is a replacement for early inorganic phosphorus water treatment chemicals. It is structurally stable and does not decompose under normal photothermal conditions. HEDP is also an important chelating agent, which has a certain scale inhibition effect and also has a certain corrosion inhibition ability.

However, HEDP is more sensitive to oxidative biocides. It is easy to break down. It is limited in the treatment of high concentration multiple cooling water.

HEDP has a high phosphorus content. It may cause environmental eutrophication pollution during use. As environmental protection requirements become more strict, the use of HEDP will be limited.

In addition, iron ions in water have a significant effect on the corrosion inhibition of HEDP. When the iron ion concentration is greater than 3 mg/L, the corrosion inhibition of HEDP decreases exponentially with the increase of iron ion concentration.

PBTCA is known as 2-phosphonobutane-1 2 4-tri2carboxylic acid. From a structural point of view, it contains one – PO₃H₂ and three -COOH.

PBTCA is a highly effective scale inhibitor. PBTCA also has a strong scale inhibition effect under the harsh conditions of high temperature, high hardness, and high pH. Especially in the presence of Fe³⁺, its scale inhibition and corrosion inhibition performance are better than other organic phosphonates.

PBTCA has a good synergistic inhibition effect with zinc salts and polyphosphates.

In addition, PBTCA has a low phosphorus content and is difficult to form insoluble organic calcium phosphonate scale. It has good antioxidant properties and good stable zinc action.

PBTCA is stable in nature. It is not easily damaged by acid and alkali, is not easy to hydrolyze, and is resistant to high temperatures. PBTCA is also resistant to oxidative biocides.

With the improvement of water treatment effect requirements and the increasingly strict requirements of environmental protection regulations, the application of PBTCA has received more and more attention.

PBTCA and HEDP have no difference in appearance and are all colorless or light yellow transparent liquid. Their quality control indicators are also very similar.

The most important indicator of the “active component” analysis principle is also the addition of sulfuric acid and decomposer under heating conditions. Convert macromolecules to phosphates. After adding the quinoxaline ketone solution, a quinoline phosphomolybdate precipitate is formed. After filtration, washing, drying, weighing, minus the content of orthophosphorus and phosphorous, the active component is obtained. The two are not only the same analysis principle but also the analysis steps.

The difference is that PBTCA also requires the use of a nuclear magnetic resonance (NMR) spectrometer to measure specific chemical shifts on each 13C NMR spectrum to determine its structure. The specific chemical shift on the 13P NMR spectrum was measured to determine its purity.

This cannot be done with existing analytical tools. If there is doubt about the sample, the analysis of each indicator alone cannot distinguish between the two.

In this regard, after analysis, it was found that even though the active components of both were 50%. However, due to the different molecular structures of HEDP and PBTCA, the phosphorus content of the two is different.

Whether spectrophotometry for determining total phosphorus content in existing circulating water can be utilized. They are decomposed under certain conditions to become phosphate. The total phosphorus content is then determined, and a preliminary determination can be made based on the difference in total phosphorus content.

The above is about the introduction of water treatment chemicals HEDP and PBTCA quality inspection. If you have any other questions, please feel free to contact us.

In the middle and late stage of oilfield exploitation, the amount of water injection increased. The water content of crude oil increased, and the water quality became increasingly complex. This makes the quality of crude oil worse and worse, and the composition of scale changes from single to complex. Crude oil processing conditions have also become worse.

In addition to CaCO₃, CaSO₄, SrSO₄, and BaSO₄ scales, there are also FeS, MgCO₃, MgSO₄, Mg(OH)₂, Ca₃(PO₄)₂, SiO₂ and the like. The scaling problem of oilfield equipment and pipelines has become increasingly prominent, which has seriously affected the normal operation of the plant and the economic benefits of the enterprise.

When the scale is severe, it will also cause blockage of pipes or equipment, forcing the enterprise to stop production and to descale. This not only shortens the operating cycle of the device but also may bring hidden dangers to the safe production of the device.

Therefore, the scaling problem of oilfield equipment and pipelines has become a major bottleneck affecting the safe, stable, long-term, full-load production operation of the equipment. It is of great significance to study the normal production of oil fields by studying scale inhibitors that can effectively prevent or reduce scaling.

Threshold effects are also known as low dose effects or solubility effects. A simple understanding is that low-dose scale inhibitors have a good scale inhibition effect. When the concentration of the scale inhibitor is greater than a certain value, the increase in scale inhibition effect is not obvious.

The threshold effect is a macroscopic representation of the scale inhibition effect. It reflects the scale inhibition mechanism to a certain extent. The stylization theory of crystal growth suggests that crystal growth is carried out by the development of a relatively small number of active growth points.

These small amounts of active growth points are the kink locations of the crystal lattice. Therefore, as long as the scale inhibitor is adsorbed at a small amount of active growth point, it is difficult for the small crystal of the scale to continue to grow.

When the tiny crystal nucleus of the scale is generated in the water, the scale inhibitor is adsorbed at the interface of the crystal or doped in the lattice of the crystal lattice. The scale inhibitor makes the crystals not grow normally in strict accordance with the lattice arrangement, the crystals are distorted, the lattice is distorted, and the aggregation between the crystal grains is difficult.

The deposits formed by these lattice distortion crystals are difficult to form a dense and strong scale layer. They can only exist in the form of loose, soft scales. This allows the deposit to be easily washed away by the water stream, preventing it from depositing into hard scale.

The anionic or non-ionic polymer adsorbs on the grains of the scale in the water, changing the original charge state of the grain surface. This causes the microcrystals to carry the same electric charge, and the electrostatic repulsion prevents the microcrystals from growing up and colliding with each other to grow and deposit. Or the polymer macromolecule adsorbs the microcrystals therein, “wrapping” the grains that may be scaled, and avoiding its aggregation and deposition.

These scaled grains can be stable in a dispersed state. They can flow with water, thus avoiding deposits and scaling.

The polyacrylic scale inhibitor can form a film co-precipitated with the inorganic crystal particles on the metal heat transfer surface. When the film is increased to a certain thickness, it is broken on the heat transfer surface, and a certain size of the scale layer leaves the heat transfer surface. The growth of the scale layer is suppressed due to the continuous formation and rupture of such a film.

The scale inhibitor is enriched in the diffusion boundary layer near the nucleation growth to form an electric double layer and hinder the coalescence of scale-forming ions or molecular clusters on the metal surface. Moreover, the bond between the scale inhibitor and the nucleus (or cluster of scaly molecules) is unstable.

An organic phosphonate refers to a phosphorus atom directly attached to a carbon atom. The C-P bond in the phosphonic acid is strong. Therefore, it has high chemical stability and thermal stability. It is also difficult to hydrolyze under high temperature and high pH conditions.

Most organic phosphonates are non-toxic or low in toxicity. Commonly used are HEDP, ATMP, PBTCA, EDTMP and the like.

Organic phosphonates also have a threshold effect as polyphosphates. That is, only a few milligrams of organic phosphonate can be added to 1 L of water to prevent the precipitation of hundreds of milligrams of calcium carbonate. Its scale inhibition performance is better than polyphosphate.

Organic phosphonates are cathodic corrosion inhibitors and a class of non-stoichiometric scale inhibitors. It has a significant solubility effect. When used in combination with other water treatment agents, it also exhibits an ideal synergistic effect.

It has excellent coupling ability for many metal ions (such as Ca²⁺, Mg²⁺, Cu²⁺, Zn²⁺, etc.). Even for inorganic salts of these metals such as calcium sulfate, calcium carbonate, magnesium silicate, etc., organic phosphonates also have good deactivation.

ATMP, which forms a stable complex with metal ions. Good chemical stability, not easy to hydrolyze. It has good thermal stability, good scale inhibition at 200 °C, and corrosion inhibition. ATMP is often used in combination with polycarboxylic acids and is an excellent corrosion and scale inhibitor for treating oilfield scale.

DETPMP has a strong inhibitory effect on CaSO₄•1/2 H₂O scale. By using the seed growth method, the concentration of CaSO₄•1/2 H₂O can be completely inhibited when the concentration is about 10^-7 mol/L.

Most of these scale inhibitors mentioned above can be used in oil field operations. They are an ideal oil field scale inhibitor for better corrosion and scaling of oilfield equipment and pipelines.

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Relying on the formation of natural pressure oil production is called “primary oil recovery.” As the formation pressure drops, it is necessary to use the water injection pressure method to produce oil called “secondary oil recovery”.

According to calculations, primary oil recovery can only reach 20%-30% recovery, and secondary oil recovery can only reach one-third of formation reserves.

In order to extract the remaining reserves, physical, chemical and biological methods are needed to enhance the recovery factor, called EOR, or “third oil recovery”. Most of the developed oil fields have entered the middle and late stage of oil recovery, but they are still in the stage of secondary oil recovery.

Oil and gas water treatment is mainly oily sewage treatment.

In particular, the water-bearing process requires a large amount of water to re-inject the formation, and the use of oily wastewater re-injection will cause pollution of the underground oil layer and requires pre-treatment. Water injection and oil recovery are commonly used, so sewage treatment reinjection is extremely important for oil recovery.

Demulsifiers

Although there are many types of demulsifiers, the main types of demulsifiers are the following: oils and derivatives, sulfonates, petroleum sulfonates, alkyl naphthalene sulfonates, alkylphenol ethoxylates, polyoxyethylenes. , a polyoxypropylene block copolymer, sodium naphthenate, and the like.

Fungicide

The bactericide used in oilfield refilling water includes organic and inorganic, inorganic is mainly chlorine, and organic includes aldehyde, quaternary ammonium salt, phenol, imidazoline, strontium salt and the like. The use of fungicides in water treatment in oil fields is less than in foreign countries. Mainly used quaternary ammonium salt fungicides and their compound products.

In recent years, many units have cooperated with oil fields or developed some new fungicides. Usually, the dosing concentration is several tens of milligrams per liter.

Corrosion inhibitor

In the oilfield development process (especially secondary oil recovery), the sewage from the crude oil is an important source of oilfield water injection.

However, due to the high salinity of the sewage, the high temperature, and the dissolution of certain corrosive substances, the sewage treatment equipment, and pipelines are seriously corroded, and corresponding anti-corrosion measures are required.

Adding corrosion inhibitors is commonly used at home and abroad.

A simple, economically viable method. A variety of corrosion inhibitors have been developed for different corrosive media, mainly organic salts of fatty amines, fatty amides, adducts of fatty amines and ethylene oxide, imidazoline derivatives, quaternary ammonium salts, amine-substituted thio phosphonates, phosphinates or thioethers, nitrogen-containing polycyclic rings with lipophilic groups.

Flocculant

Inorganic substances mainly include iron salts and aluminum salts such as ferric chloride, aluminum sulfate, ferrous sulfate, polyaluminum chloride, potassium vanadium; organic compounds are mostly water-soluble polymers, such as cellulose, galactomannan Glycans, partially hydrolyzed polyacrylamides, and the like.

For example, high-molecular-weight polysaccharides such as high-molecular-weight polysaccharides and cellulose derivatives in Shengli Oilfield, CG-A high-efficiency flocculant, are widely used in oil fields.

Scale inhibitor: The oil field mainly uses HEDP acid, ATMP and hydrolyzed maleic anhydride. 1000 meters 3 usage is about 6 public halls.

Drag Reducing Agents

Multi-line polymer. In the 1980s, Chengdu University of Science and Technology developed a high-grade acrylic drag reducing agent, which has a good effect in Daqing Oilfield; many research units are engaged in this research. However, it has not been applied on a large scale.

The oil and gas water control method includes water softening technology, magnetic anti-scaling technology, and adding water treatment chemical corrosion and scale inhibitor. It is generally accepted that the most promising measures to control corrosion and scaling are suitable corrosion inhibitors and choices for scale inhibitors.

The high-efficiency compound scale inhibitor is developed for the specificity of oilfield wastewater. Considering the corrosion and scale inhibition and oil production working conditions, it can effectively control oil and gas water pollution. The dosage is small, the cost is low, the corrosion inhibition and scale inhibition effect are good, and the product has good value.