The New Trends in Biochar Production and Its Applications

Contemporary technologies have paved the way for the development of various innovative methods for the qualitative and quantitative production of biochar.

FREMONT, CA: With the growing popularity of carbon sequestration and bioenergy production, researchers and industries have been exploring various applications of biochar, including its potential uses in environmental remediation, wastewater treatment and as a component in construction materials.

Advancements in pyrolysis technology have improved the efficiency and scalability of biochar production. New methods aim to optimise the process, reduce energy consumption, and create high-quality biochar from diverse feedstocks.

Biochar has gained significant attention due to its potential benefits for soil fertility, carbon sequestration and climate mitigation. It has been utilised in horticulture, urban farming and green infrastructure projects to enhance soil quality, reduce nutrient leaching and improve plant growth in urban environments. Furthermore, it has been considered a form of carbon sequestration, as it stores carbon through pyrolysis carbon capture and storage (PyCCS).

Even studies have been going on focusing on the waste gases like carbon dioxide emitted during biochar production for carbon capture and utilisation purposes, potentially leading to a closed-loop carbon negative process.

Various newly emerged technologies have been applied in biochar production to improve efficiency, sustainability and scalability. A continuous pyrolysis system is one such technology which allows a continuous flow of feedstock into the pyrolysis reactor, leading to higher production rates, improved energy efficiency and better control over the biochar quality. These systems are equipped with automated controls, enabling precise regulation of temperature, residence time and other process parameters, leading to better control over the pyrolysis process and the quality of biochar produced. Therefore, compared to traditional batch pyrolysis systems, continuous pyrolysis systems are more energy-efficient, better in emission controls, heat recovery mechanisms, and minimising air pollution and waste during the process.

Microwave pyrolysis is another method which heats the feedstocks more rapidly and uniformly, potentially reducing processing times and energy consumption. The precise control over temperature allows fine-tuning the process to achieve specific biochar properties tailored for various applications. Being safe and cleaner compared to other high-temperature processes, the risk of accidental fires or emissions of harmful gases is at low possibility in microwave pyrolysis.

The technology has been adapted for academic and industrial fields for outstanding thermal characteristics because of quick, particular, and uniform warming while at the same time offering diminished sintering temperature that improves steam gasification. Microwave pyrolysis is more suitable for dry feedstocks and offers rapid and uniform heating and energy efficiency advantages. Therefore, for wet feedstocks that may be challenging to process using conventional pyrolysis methods, Hydrothermal carbonisation(HTC) has been used.

In HTC, biomass is subjected to high temperatures and pressure in a water-rich environment, typically at temperatures ranging from 180 to 250 degrees Celsius. This process is valuable for creating different carbonaceous materials with various sizes, shapes and surfaces. Also, biochar produced with the HTC method helps in the retention of nutrients like nitrogen and phosphorus, which enhances soil fertility. Demand for biochar has opened numerous technological interventions such as electro-modification, flash pyrolysis, torrefaction and more. All these technologies accelerated the quantity and quality of biochar, escalating its applications in various industries.

Considering the applications of biochar, the most common use of biochar is as a soil health conditioner. Biochar acts as a soil additive, prevents nitrogen loss, and keeps the soil fertile. Moreover, it also enhances the physical structure of the soil, especially water absorption and holding capacity, allowing nitrogen-fixing bacteria to make habitat inside biochar pores, leading to increased nodulation and nitrogenase activity. However, the overuse of biochar set unfavourable conditions for microbial growth and ultimately inhibited bacterial and fungal coding gene copies. To counter this possibility, a proper soil condition analysis must be taken.

Apart from carbon sequestration and nutrient enrichment, biochar reduces the disease severity of different pathogen types and even induces system-wide defence responses in host plants. In the scenario where the demand for sustainable agricultural practices has been driving the world to counter the dependency on chemical fertilisers, the application of biochar will be an efficient opportunity to develop a healthy agricultural practice irrespective of the region.