Biochar to Improve Soil Fertility, Fuel, Industrial Raw Materials or Climate Solutions?

Currently there are still a lot of agricultural wastes (corn stalks, soybean plants, soybean shells and so on) that have not been utilized so that they pollute the environment. Utilizing these wastes so that they become useful products that provide added value is the best solution. What kind of utilization or processing is the best solution for utilizing these wastes? This of course depends on a number of influencing factors such as market readiness, availability and continuity of supply of biomass waste, especially agricultural wastes, technological readiness including technology investment, profits and business continuity, infrastructure and human resources (HR). Production of biochar or charcoal from biomass waste could be the best option. But indeed biochar or charcoal is multifunctional or can be used for a number of uses. Then the question is the use of biochar for what field gives the best results or benefits?

The biochar production is carried out using slow pyrolysis technology. With this technology biochar production can be optimal both in quality and quantity. It is different when using fast pyrolysis technology which produces biooil product or liquid product as the main product, with much less biochar product. Or if you use gasification technology where the main product is gas, so that the proportion of biochar is smaller or it can be considered as a side product, then this will also be less than optimal. These things make choosing the right technology an important thing to be able to give optimal results.

The production of biochar for agriculture has also not become a trend among farmers in Indonesia, so that much of their agricultural waste is not utilized and even pollutes the environment. Another influencing factor is the condition of the agricultural land itself. Dominant and excessive use of chemical fertilizers has damaged agricultural lands so that agricultural productivity continues to decline. And efforts to improve the soil require effort that is not easy and quick so that the fertility of the soil can be restored (recovery) and continues to be maintained for the long term. The combination of using organic materials with certain techniques needs to be done to achieve this. Biochar can also be used to make the use of organic matter more efficient, such as reducing leaching and increasing soil microbial activity. With the increased efficiency of this technique due to the use of biochar, it also minimizes input so that production costs can be further reduced. The integration of agriculture and animal husbandry is a must in order to obtain an adequate supply of organic matter, the quality is maintained and sustainable. Whereas in acid and dry soils, the use of biochar will have a more significant effect.

The use of biochar as an ingredient, especially for bbq and cooking as well as other uses, namely as a reducing agent in steel making. There are not too many uses for BBQ, this is processing or cooking food on a BBQ basis only as a hobby or only for special community segments. And there isn't much biochar for cooking either, or this is more common in Africa, while in Indonesia the option of using firewood or LPG is more common. Likewise, the need for biochar as a reducing agent in steel making is also not much. Meanwhile, the use of biochar for industrial fuels such as boiler fuel and electricity generation is almost non-existent. This is because the production process takes longer (requires a carbonization process), the conversion from biomass to biochar is small (~25%), and the price of biochar is more expensive. Wood pellets and palm kernel shells (PKS) are more of an option for these industrial fuels.

Biochar can also be used as a raw material for various industrial goods for human needs or for the substitution of materials derived from fossils (such as oil and gas) into more environmentally friendly and renewable materials. Materials such as plastic can be replaced with biochar. Particle board, which usually still uses wood waste, can also be replaced with biochar. This trend has not yet occurred, but it is predicted that soon it will become a concern and even a new trend in the industry.

Biochar for climate solutions is likely to become a trend soon. CO2 from the atmosphere is converted into biomass by plants, converted into biochar and stored (sequestration), especially in the soil. The carbon stored in the biochar will not be released into the atmosphere because biochar does not decompose for hundreds or even thousands of years or can be stored permanently. In principle, this is like storing carbon (CO2) with a conservation forest so that it becomes a carbon sink. Trees or plants will absorb CO2 from the atmosphere and be maintained in such a way as to achieve the desired CO2 uptake target then compensated with carbon credits, as well as biochar, how much carbon can be stored (sequestration) then also compensated with these carbon credits. In practice, the use of biochar will be optimal with efforts to enrich the soil on damaged or problematic soils such as post-mining soil, acid soil and diseased soil due to an overdose of chemical fertilizers. Carbon sinks with biochar are easier and cheaper than the carbon capture and storage (CCS) method with CO2 stored beneath in the earth's layers.

To reduce the temperature of the earth by reducing the concentration of greenhouse gases. To reduce 1 ppm of CO2 concentration in the atmosphere is equivalent to absorbing about 15 gigatonnes of CO2. Meanwhile, the costs needed to mitigate major climate change disasters are estimated at USD 1.6 trillion to USD 3.8 trillion each year. To reach the concentration of CO2 in the atmosphere to 350 ppm, around 70,000 biochar the size of the Giza pyramids is needed, assuming that fossil fuels are discontinued. With a volume of the Giza pyramids of 2.6 million m3 and an average biochar density of 200 kg/m3, biochar the size of the Giza pyramids weighs 520 million kg or 520 thousand tons. Huge job of course. Biochar production must grow 5000 times from its current production capacity. With biochar the size of a unit of the pyramids of Giza we need to build 4 pyramids per day (about 2 million tonnes of biochar per day) for the next 100 years and starting now.