charcoal in general, the agricultural world, especially organic farming has become one of the current users of charcoal. Charcoal in the agricultural world or commonly known as biochar is widely used because it can withstand nutrients or fertilizers from leaching so that it is widely used for the manufacture of slow release fertilizer, then the pores in the char also become the home of microbes that break down various organic materials become fertilizer to the plant, the pores also improve the physical structure of the soil. In addition, biochar can also keep the soil moisture because water is also easily absorbed in the structure of the pores. Biochar also increases soil pH, is also able to absorb carbon dioxide (CO2) from the atmosphere (carbon negative scenario), and can last up to tens or even hundreds of years in the soil. These are the things that encourage the use of biochar in the agricultural world, which in short can increase agricultural productivity or help improve the world food products.
The role of biochar in some ways can indeed be substituted with other materials, for example for the ability to retain water, cocopeat is better than biochar, for the surface area with the number of pores the activated charcoal is much larger than the biochar, and to raise the pH for the soils acid then dolomite lime better. In an application in the field of planting media engineering to obtain the best agricultural media is very likely use a number of materials mentioned above. Optimal results can be obtained based on soil characteristics and plant species. Economic factors are also an important consideration factor after the above technical aspects.
Modern biochar production currently uses thermochemical processes continuously. There are two thermochemical technologies for biochar production namely pyrolysis and gasification. Pyrolysis technology is more widely used because it produces more biochar and better quality. Why with pyrolysis can get 2 things? This is because basically (slow) pyrolysis is a technology used for the production of charcoal or maximizes its solid product, so the process control is also designed for that purpose. While the gasification is designed to maximize its gas product, so the char is only positioned as a by-product. The operating temperature of gasification is also higher (800 C) than pyrolysis (450 C) so that the char is also mixed with ash.
More specifically the indirect heating pyrolysis technology is more widely used for biochar production today. With this technology the pyrolysis process control is easier and the charcoal quality is also better. Application of indirect heating pyrolysis technology for continuous process generally use rotating drum and heated auger type. Biochar production capacity is generally in the range of 2-4 tons / hour. The byproducts of the pyrolysis process are also of high economic value such as bio-oil for fuel, pyroligneous acid (liquid smoke) for fertilizer and biopesticide, as well as syngas for fuel and more specifically for electricity production.