Wondering which activated carbon suits your needs best? Activated carbon, renowned for its versatility as a purification agent, significantly contributes to improving air and water quality. It plays a crucial role in various applications, ranging from spill control to drinking water purification. The market offers numerous variations, making it essential to make an informed choice. This comprehensive guide delves into vital information and the intricacies of selecting the ideal activated carbon for your specific needs.1–3 As we investigate the comprehensive guide to activated carbon, it’s imperative to understand the variations: coal-based, wood-based, and coconut-based.4–6

Introduction

Activated carbon finds applications in groundwater remediation, spill cleanup, drinking water filtration, and air purification. Choosing the right activated carbon hinges on factors such as source materials, activation procedures, and the specific requirements of the intended application. Navigating through these complexities is crucial for consumers to make informed decisions when selecting activated carbon.1–3 Let us look at the types of activated carbon and how they are selected for their usage.

Types of activated carbon:


Coal-based activated carbon filtration

Let’s start with coal-based activated carbon. It is a byproduct of anthracite, bituminous, or lignite coal, which is a classic filtering material. Because of its increased microporosity, impact resistance, and ease of regeneration, bituminous coal stands out. Despite its convenience, coal-based filtering has some drawbacks:

  1. Environmental impact: The process of extracting bituminous coal is said to pose a threat to the environment. This includes habitat disruption and the release of explosive gases.
  2. Taste implications: There may be a distinct taste in water because bituminous coal is known to release byproducts during filtration.
  3. Chemical discharge: Because coal-based activated carbon may introduce some compounds into the water, the taste and general quality of the filtered product get impacted.
  4. Limitations in pore size: The larger pores in bituminous coal may compromise its ability to filter out smaller particulates effectively.5

Coal-based activated carbon is produced through the steam activation of coal. This activated carbon has millions of pores on its surface, giving it a large surface area. Additionally, the preferred choice of activated carbon is made from bituminous coal due to its microporosity of 70% to 90% carbon content. It is used in myriad applications, including effluent treatment, wastewater treatment, gas purification, aquarium, and pond water treatment. Moreover, coal-based activated carbon is known for its cost-effectiveness and its efficiency in removing odours. 6

Wood-based activated carbon filtration

Now, wood-based activated carbon is said to be a substitute for filtration methods. It mainly leverages mesopores and macropores, offering advantages such as renewability and effective removal of taste and colour from water. However, certain considerations need to be acknowledged:

  1. Renewable source: This source is renewable because it is sourced from mature trees. However, the long maturity period provides a challenge in terms of immediate availability.
  2. Decolorization and taste elimination: It is great at removing certain contaminants, thus making it suitable for enhancing taste, colour, and odour in water.
  3. Filtering limits: However, the prevalence of mesopores and macropores might limit wood-based carbon from filtering out finer contaminants. Hence, this makes it less ideal for high-grade filtration.5

It is interesting to note that the use of wood-based activated carbon is gradually increasing due to its exceptional decolorizing qualities. This carbon is obtained from specific wood kinds and sawdust and is known for its non-toxic nature, large surface area, and excellent adsorption capabilities. It is widely utilized in drinking water purification and is employed in various industries, including sugar, beverage, and pharmaceutical manufacture. The production methods use phosphoric acid, which has advantages such as high filtration speed and the absence of zinc. Furthermore, babool wood-activated carbon with a 5% ash content has a good reputation due to its excellent microporous structure. Bamboo charcoal, obtained from the Moso bamboo plant, is another excellent source often used in skincare products. 6

Coconut shell activated carbon filtration

A promising sustainable option for carbon block filters is coconut shell activated carbon. It has a higher density of micropores compared to coal, hence providing some advantages:

  1. Renewability and green sourcing: Coconuts are always growing in tropical climates and are a means of a continuous carbon source.
  2. Year-round harvesting: Fortunately, coconut trees can be harvested many times throughout the year, ensuring a steady supply of carbon sources.
  3. Environmental friendliness: The method of harvesting coconut shells for activated carbon is known as a green method. It produces less dust and contributes to sustainable practices.
  4. High porosity and mechanical strength: Because of the high density of micropores in coconut shell-activated carbon, it is said that this enhances its contaminant-filtering properties. Moreover, its microporosity adds on to its mechanical strength and wear resistance.
  5. Produces cleaner water: It is also known for producing the cleanest water among carbon types. To add on, its porosity, total pore volume, and minimal leaching assist in contributing to its excellent filtration performance.5

Coconut shell activated carbon is derived from a process known as steam activation. It has millions of pores on its surface, resulting in an enhanced total surface area. It is known for its pore diameter distribution, which is mostly used in water and gas filtration. Coconut shell activated carbon is said to be used in treating acute poisoning, gastrointestinal issues, and drinking water filtration using carbon filters.6

Selecting the Optimal Activated Carbon Solution

One can never overstate the importance of porosity in identifying the best type of carbon for many applications. For instance, coconut activated carbon has many micropores, coal-activated carbon has many mesopores and micropores, and wood-activated carbon has many mesopores and macropores. Additionally, the molecular size of impurities is another factor, and thus, coconut carbon is mostly favoured for impurities where the molecular size is less than 100 angstroms. As for coal carbon, it is favoured for sizes between 100 and 1000 angstroms, and wood carbon for sizes that are greater than 1000 angstroms.4

Conclusion

In summary, selecting the best-activated carbon requires careful consideration of various parameters, from raw materials and manufacturing techniques to specific application needs. Each type of activated carbon, whether coconut wood, and coal-based offers unique properties and advantages.

References:

1. Activated Carbon—Your Complete Guide To Activated Carbon. (n.d.). Oransi. Retrieved December 21, 2023, from https://oransi.com/blogs/how-it-works/complete-guide-to-activated-carbon

2. How to Choose the Right Activated Carbon—Detailed Guide. (n.d.). Retrieved December 21, 2023, from https://ecofriendcarbon.com/blogs/how-to-choose-the-right-activated-carbon-detailed-guide

3. How to Choose the Right Activated Carbon for the Job. (n.d.). Retrieved December 21, 2023, from https://www.chemicalonline.com/doc/how-to-choose-the-right-activated-carbon-for-0001

4. Coal Activated Carbon | Coconut Shell Activated Carbon | Wood Activated Carbon—Kalpaka Chemicals, India. (n.d.). KALPAKA CHEMICALS. Retrieved January 1, 2024, from https://www.kalpakachemicals.com/news/coal-activated-carbon-vs-coconut-shell-activated-carbon-vs-wood-activated-carbon/

5. Coal vs. Wood vs. Coconut Carbon Filters | CB Tech. (2018, July 18). Carbon Block Technology. https://www.carbonblocktech.com/coconut-wood-coal-filters/

6. Difference Between Wood, Coconut, and Coal Activated Carbon. (n.d.). Retrieved January 1, 2024, from https://ecofriendcarbon.com/blogs/difference-between-wood-coconut-and-coal-activated-carbon