Citric acid anhydrous is an important organic acid that is odorless and easily soluble in water. It is widely used in various food applications as an important food additive. Not only that, it is also widely used in industries such as industry, agriculture, and cosmetics.
This guide provides a comprehensive overview of citric acid anhydrous, covering its characteristics, forms, production methods, applications, safety, environmental impact, price, market, etc.
Characteristic:
The following table summarizes the basic properties of anhydrous citric acid for a quick reference to its chemical and physical characteristics.
| Items | Parameters |
| Chemical formula | C6H8O7 |
| Molecular weight | 192.12 |
| Density | 1.67 g/cm3 at 20 °C |
| Melting point | 153-159 °C (lit.) |
| Boiling point | 248.08°C (rough estimate) |
| Flash point | 100 °C |
| Water solubility | soluble in Water (1174g/L at 10°C, 1809g/L at 30°C, 3825g/L at 80°C). |
| Vapor pressure | <0.1 hPa (20 °C) |
| Vapor density | 7.26 (vs air) |
| Solubility | Citric acid is also soluble in absolute (anhydrous) ethanol (76 parts citric acid/100 parts ethanol) at 15 °C. |
| Refractive index | 1.493~1.509 |
| Acidity coefficient | 3.14(at 20℃) |
| pH value | 3.24(1 mM solution);2.62(10 mM solution);2.08(100 mM solution); |
| Storage conditions | 2-8°C |
| Stability | Stable. Incompatible with alkalis, strong oxidizing agents, reducing agents, and metal nitrates. |
Physical form:
The common physical form of anhydrous citric acid is translucent crystals or white fine powder crystals.
Production method:
There are two main methods for preparing anhydrous citric acid: microbial fermentation and chemical synthesis.
Microbial fermentation is to use sugary substances such as glucose or molasses as fermentation substrates, and use certain fungi (such as Aspergillus niger) or bacteria to ferment sugar substances to produce citric acid.
The chemical equation of the reaction is: C6H12O6 → C6H8O7+ CO2 + H2O.
| Advantages: |
| 1. Environmental protection and sustainability |
| 2. Wide range of raw materials and cheap |
| 3. High product quality |
| 4. Mild reaction conditions |
| Disadvantages: |
| 1. Long fermentation time |
| 2. Complex microbial culture conditions |
| 3. Wastewater treatment issues |
There are two ways to produce anhydrous citric acid by chemical synthesis:
1. Oxidation method: Glucose or other sugar-containing substances undergo oxidation reaction to produce citric acid. This reaction can be carried out by different catalysts and reaction conditions to improve the selectivity and yield of the reaction.
Crystallization and refining treatment are then carried out to remove impurities and moisture to obtain high-purity anhydrous citric acid solid.
The chemical equation of the reaction is: C6H12O6→C6H8O7+CO2+H2O.
| Advantages: |
| 1. Controllable reaction conditions |
| 2. Widely used in industrial applications |
| Disadvantages: |
| 1. High catalyst cost |
| 2. Wastewater treatment |
| 3. Complicated product purification |
2. Hydrogenation method: Also using glucose or other sugar-containing substances as starting materials, the diketone structure in citric acid is hydrogenated to produce citric acid.
Then, impurities and water are removed by crystallization and refining to obtain high-purity anhydrous citric acid.
The chemical equation of the reaction is: C6H8O7+H2→C6H10O7.
| Advantages: |
| 1. Wide applicability |
| 2. High product stability |
| Disadvantages: |
| 1. High cost of hydrogen |
| 2. Difficult to control reaction conditions |
Application:
1. Food Industry
Acidity Regulator: Citric acid is widely used as an acidity regulator to enhance and improve the taste of food, especially in beverages, juices, carbonated beverages, jellies, candies and other products
Antioxidant: Citric acid can be used as an antioxidant to help extend the shelf life of food and maintain the color and nutritional content of food.
Coagulant and Stabilizer: In food processing, citric acid can be used as a coagulant and stabilizer to help improve the texture and stability of food, such as in jams, jellies, salad dressings and other products.
Chelating Agent: Citric acid can combine with metal ions to form stable complexes, which are used to improve the texture and taste of food, or to adjust the acid-base balance of food.
2. Pharmaceutical and Health Products Industry
Pharmaceutical Additives: Citric acid is used in the pharmaceutical industry as an acidity regulator for the preparation of drugs and drug solutions.
Nutritional Supplements: Citric acid can be used in nutritional supplements and vitamin C tablets as a stabilizer and flavoring ingredient.
3. Cosmetics Industry
Regulator: Citric acid can be used as a regulator in cosmetics to help adjust the pH value and acid-base balance of the product, improve the stability and feel of the product.
4. Cleaner and Detergent Industry
Chelating Agent and Buffer: Citric acid as a chelating agent can help cleaners and detergents remove scale and metal ions, and can also be used as a buffer to adjust the pH value of the product.
5. Other Industrial Applications
Metal Cleaner: Citric acid can be used as a chelating agent in cleaning agents to help remove rust and dirt on metal surfaces.
Safe use and handling:
Food grade anhydrous citric acid has some special safety procedures to be aware of. Below is a guide to personal protective equipment, storage (caking), transportation, and first aid measures.
Personal protective equipment
- Eye protection: Use chemical safety glasses or masks to prevent citric acid from splashing into the eyes and causing irritation or damage.
- Skin protection: Wear chemical-resistant gloves and long-sleeved clothing to prevent citric acid from contacting the skin and causing allergic or irritating reactions.
- Respiratory protection: In the operation environment of high concentration of citric acid, consider using appropriate respiratory protection equipment, such as a gas mask or mask.
Storage
- It should be stored in a dry environment to avoid moisture or hygroscopicity. Humid conditions may cause anhydrous citric acid to clump or lose crystallinity, affecting its use and solubility.
- Avoid exposing citric acid to direct sunlight, as ultraviolet rays and heat in the sun may affect its stability and color.
- Citric acid is stored in sealed containers or packaging to prevent moisture and other contaminants from entering the air to extend its shelf life and maintain quality.
- Avoid storing citric acid near fire sources and away from oxidants to reduce possible safety risks.
Among them, when dealing with citric acid lumps, if the lumps are small in area, you can use a slight rubbing method to deal with it. If the lumps are too large, you can use the method of turning the bag over or throwing the bag. If the above methods do not work, you can contact our Thailand Xitrical-professional citric acid factory for exchange.
Transportation
- Mode of transportation: It can be transported by various modes, including road, rail and sea.
- Storage conditions: Use sealed, moisture-proof packaging materials, avoid direct sunlight, and avoid mixing with other chemicals or incompatible substances.
- Compliant labeling and documentation: Ensure packaging has correct product labeling, ingredient listings and safety information to comply with regulatory requirements for transportation and food safety.
First aid measures
- Skin contact: Immediately rinse the contact area with plenty of water for at least 15 minutes. Gently rub the skin to help remove the citric acid. Avoid rubbing the skin hard to avoid irritation or aggravation of damage.
- Eye contact: Immediately rinse eyes with running water or saline, keep eyes open and try to keep rinsing for at least 15 minutes. If wearing contact lenses, remove them immediately.
- Respiratory contact (inhalation): Move the affected person to fresh air quickly to ensure unobstructed breathing. If breathing is difficult, seek medical help immediately.
Interpretation of the anhydrous citric acid market:
As of July, the quotations of upstream citric acid companies were stable, and the actual order prices were slightly lowered. The operation of enterprises maintained normal levels, and the inventory of some manufacturers was relatively concentrated.
In terms of demand, domestic sales were average, and the difference between foreign trade contracts and the previous period was not large.
In terms of price, the current mainstream ex-factory quotation of monohydrate citric acid is 4700-5000 yuan/ton, the ex-factory quotation of anhydrous citric acid is 5000-5300 yuan/ton, and the ex-factory quotation of sodium citrate is 4800-5100 yuan/ton.
In July, the citric acid industry is undergoing routine capacity adjustments and equipment maintenance, which may lead to a theoretical reduction in future supply. At the same time, the upstream suppliers are generally not very active in locking orders for shipments, which means that market prices may face certain pressure.
On the other hand, the production cost of citric acid continues to rise, mainly due to a slight increase in the price of raw material corn. This has left many companies facing losses. Taking the supply and demand situation into consideration, if downstream demand continues to not improve, the citric acid market is expected to remain stable but slightly weak in the short term, and prices will hardly rise or fall significantly.
Factors that affect price:
- Raw material costs: The main raw material of anhydrous citric acid is corn, and the price increase of upstream raw materials will directly lead to the price increase of citric acid.
- Supply and demand relationship: Changes in the supply and demand relationship in the market have an important impact on prices. If market demand is greater than supply, prices may rise; conversely, if supply is sufficient and demand is insufficient, prices may fall.
- Production capacity and supply chain stability: The expansion or restriction of production capacity and the stability of the supply chain will have an impact on prices. Disruptions or delays in the supply chain may lead to insufficient supply in the short term, pushing up prices.
- Policies and regulations: Food-grade anhydrous citric acid must meet strict food safety and quality standards. Changes in policies and regulations may affect production costs or market access, thereby affecting prices.
- Competition landscape: The competition landscape in the market will also affect prices. When competition is fierce, companies may compete for market share through price wars, resulting in price declines; conversely, when market concentration is high, prices may be more stable or rise.
- Changes in freight costs: The cost of land transportation has not changed much, while the increase in ocean freight has exceeded the price of the product itself in recent months, especially from the production site to the consumer market, so transportation costs account for a large part of the total cost.
