The processing of food and beverages, air and water purification, as well as the medical and pharmaceutical industries, all use activated carbon, a highly porous substance. It is a valuable material in these sectors because of its capacity to adsorb and filter out a variety of impurities from liquids and gases.
The selection of raw materials, carbonization, activation, and post-treatment are all steps in the lengthy and intricate activated carbon manufacturing process. Each of these stages will be thoroughly covered in this guide, along with information on the variables influencing the properties and functionality of the finished product.
Raw Material Selection
The first stage in the production of activated carbon is the choice of raw materials. The properties and performance of the finished product are significantly influenced by the quality and characteristics of the raw substance. Coconut shells, wood, coal, and lignite are the most frequently used raw materials for the creation of activated carbon.
Because they have low ash levels and high-quality carbon content, coconut shells are the favored raw material. Another common option is wood, particularly for high-end uses like pharmaceuticals where the purity of the activated carbon is crucial. Although less expensive, coal and lignite are still extensively used in industrial uses.
The raw material’s physical and chemical properties, including its particle size, ash content, and moisture content, must be carefully considered when selecting the raw material. These properties affect the yield and quality of the final product, making it essential to select the appropriate raw material for the intended application.
Carbonization of activated carbon
Carbonization is the procedure that produces activated carbon in step two. In this procedure, the chosen raw substance is heated without oxygen in order to turn it into carbon. Numerous techniques, such as the conventional pit method, the drum method, and the continuous process method, can be used to carbonize.
The raw material is heated using the traditional pit technique in a pit that is covered with dirt. The raw material is heated using a rotating drum in the drum technique. The most effective and popular technique uses a continuous process in which the raw material is heated in a furnace under controlled circumstances.
The volatile components of the primary material, such as water, tar, and other impurities, are eliminated during the carbonization process, leaving behind a carbonaceous residue known as “char.” The char is next squashed and sized using a screen.
Activation of activated carbon
The third step in the activated carbon manufacturing process is activation. In this process, the carbonaceous char is treated with an activating agent to create a highly porous material with a large internal surface area. The activation process can be carried out using physical or chemical methods.
Physical activation involves heating the char in the presence of a gas, usually carbon dioxide or steam. The gas creates small pores on the char’s surface, resulting in a highly porous material. Chemical activation, on the other hand, involves treating the char with a chemical agent such as potassium hydroxide, phosphoric acid, or zinc chloride. The chemical agent creates a highly porous material with larger pores than physical activation.
The choice of activation method depends on the intended application and the desired properties of the activated carbon. Physical activation produces activated carbon with a high surface area and small pore size, making it ideal for applications where small molecules need to be adsorbed. Chemical activation, on the other hand, produces activated carbon with a lower surface area but larger pore size, making it suitable for applications where larger molecules need to be adsorbed.
After activation, the activated carbon is washed with water to remove any remaining impurities and dried to the desired moisture content.
Post-Treatment of activated carbon
The post-treatment phase of the manufacture of activated carbon is the last. In this procedure, different chemicals are used to treat the activated carbon to improve its characteristics and functionality. Impregnation with metals like silver, copper, or zinc during post-treatment can strengthen the antimicrobial effects of the activated carbon. To get rid of any last-minute impurities and improve the integrity of the activated carbon, use acid washing. Heat treatment can also be used to modify the activated carbon’s properties, such as its surface area and pore size.
The post-treatment technique chosen relies on the activated carbon’s desired properties and intended use. The properties and performance of activated carbon can be greatly enhanced through post-treatment, so it is crucial to select the best post-treatment technique for the intended purpose.
Applications of activated carbon
Due to its distinct adsorption characteristics, activated carbon is utilized in a variety of uses. It is frequently employed in the manufacture of chemicals, pharmaceuticals, and air and water purification systems. Activated carbon is used to purify water by removing contaminants like volatile organic compounds, organic compounds, and chlorine. Activated carbon is used in air filtration to eliminate odors and dangerous gases like carbon monoxide and sulfur dioxide.
Activated carbon is employed as a catalyst or adsorbent in the manufacturing of chemicals and medicines. For instance, activated carbon can be used to clean chemicals used in the manufacturing of pesticides and fertilizers or to remove impurities from pharmaceutical goods.
Activation, carbonization, activation, and post-treatment are the final four major stages in the manufacture of activated carbon. Understanding the subtleties of the manufacturing process is crucial because the choice of raw materials and processing circumstances can have a big effect on the properties and performance of the finished product.
Due to its distinctive qualities, activated carbon is a crucial component in numerous industrial uses, and demand is only anticipated to rise in the upcoming years. The significance of comprehending the production of activated carbon and its uses cannot be emphasized.
The properties and performance of activated carbon can be greatly improved, increasing its efficiency in the intended application, by choosing the right raw materials, processing conditions, and post-treatment techniques. To create high-quality, successful, and efficient activated carbon products, manufacturers must carefully consider each stage in the manufacturing process.