Food Estate or Biochar? Indonesia becomes the Champion of Global Climate Solutions?

Currently, there are millions of hectares of land in Indonesia that are in dire need of biochar, namely dry land 122.1 million ha; post-mining land 8 million ha; critical land 24.3 million ha; total around 154.4 million ha. Meanwhile, the potential raw materials for biochar production are also abundant (agricultural, plantation and forestry waste) such as dry empty fruit bunch of palm oil around 30 million tons/year, baggase 2 million tons/year, corn cobs 5 million tons/year, cassava stems 3 million tons/year, waste wood 50 million tons/year, rice husks 15 million tons/year, cocoa shells and so on. With biochar, agricultural productivity will increase from an average of around 20% to even 100%.

If applied on a macro or national scale, say with a 20% increase in production, for example, rice production will increase to 36 million tons/year from the previous 30 million tons/year, corn will increase to 18 million tons/year from the previous 15 million tons/year, crude palm oil or CPO will increase to 60 million tons/year from the previous 50 million tons/year. This will save land use so that the opening of forest land for food crops and (bio)energy such as food estates may not be necessary or at least slow it down.

For example, Indonesia's current CPO production reaches around 50 million tons per year with a land area of ​​around 17.3 million hectares. This means that the average CPO production per hectare is only 2.9 tons or per million hectares produces 2.9 million tons. If biochar is used and there is a 20% increase, it means there is an increase of 10 million tons of CPO per year and this is equivalent to saving around 3.5 million hectares of land, or the use of biochar will slow down forest clearing for palm oil plantations.

There is a rough calculation that with an investment of 10 million US dollars, approximately 200,000 tons of biochar produced with more than 400,000 carbon credits will be produced over a period of 10 years. And for example, with a selling price of biochar of 200 dollars per ton and a carbon credit of 150 dollars per unit (per ton of CO2), then within 10 years, the income will be almost 10 times the investment or it is estimated that in less than 2 years the initial investment has been returned (payback period). Carbon credits sellers or biochar producers also try to get sales contracts for 5-10 years.

Of course when the price of biochar is higher and / or its carbon credit then of course the return on investment will be faster. And that does not include the utilization of liquid and gas products and excess heat from pyrolysis which also have economic potential that is no less interesting. 

Utilization of Excess Energy from Biochar Production with Pyrolysis

Most of the production equipments for biochar are currently obsolete, so that the productivity and quality of the products produced are low, also causing environmental problems, namely air pollution. In equipment with this technology, the production process is also not running efficiently, indicated by the large amount of energy or heat loss so that it is less profitable. Slow pyrolysis technology is the best technology for biochar production because it maximizes the production of a solid fraction (biochar). Meanwhile, other thermal technology group are not so suitable for biochar production, for example fast pyrolysis, the main objective of which is to maximize its liquid product or biooil, gasification is the main objective of maximizing gas or syngas product as well as hydrothermal carbonization (HTC) or wet pyrolysis requiring high pressure operating conditions so that it is difficult to be applied. Modern slow pyrolysis technology will operate autothermal / self sustain fuel, safe, good process control and energy management, so that in this way in addition to energy being used for the pyrolysis process itself, excess energy can also be used for other needs such as electricity or heat production.

There are three main variables for this pyrolysis process, namely heating rate, duration / residence time and temperature. The quality and quantity of biochar are determined by these process variables. For example, biochar production with a temperature of less than 400 C will produce acidic biochar, while biochar production above this temperature will produce alkaline biochar. Currently, the pH of biochar produced ranges from 4 to 12. There are also those who make a category about the pyrolysis temperature for biochar production, namely, low with less than 250 C, medium (250 - 500 C), high with more than 500 C. According to some researches fixed carbon also increased from 56% to 93% at 300 and 800 C pyrolysis temperatures. The surface area also increased from 120 m2 / gram at 400 C to 460 m2 / gram at 900 C. 

And indeed, basically the quality and quantity of biochar is determined by the raw materials used and the conditions of the production process, especially the pyrolysis. In fact, to ensure the quality of biochar, all aspects need to be considered such as raw materials and production processes such as the pyrolysis operating temperature should not be more than 20%, interruptions when production are allowed as long as the conditions of subsequent production parameters are maintained the same as before the restart. The composition of the raw material should not fluctuate more than 15%. And for modern pyrolysis equipment, the excess energy must be utilized with an estimated 35-60% of the energy from the biomass raw material found in pyrolysis gas. A number of agricultural waste processings can use the pyrolysis optimally, including:

1. Palm Oil Industry
The use of pyrolysis technology for palm oil companies, especially in Indonesia, is currently ideal. This is because palm oil mills or CPO mills produce a lot of solid waste biomass namely, empty fruit bunches/EFB, fiber and palm kernel shell. And because palm kernel shell / PKS has a lot of demand both from within and outside the country for industrial fuel and power plants, this PKS should not be used as raw material for pyrolysis or biochar production, but can be directly used as a trading commodity.  The EFB and fiber are used as raw material for biochar and then the biochar is used to improve the soil quality of palm oil plantation so that fresh fruit bunch or FFB productivity increases. Excess energy from pyrolysis is then used as boiler fuel so that it can reduce or even replace all PKS as the the boiler fuel. And because the boiler fuel is replaced with the excess energy pyrolysis, so can be  all of the PKS can be sold. 

2. Integrated Coconut Industry

Products from coconut processing such as copra, dessicated coconut, and nata de coco require heat in the production process. Coconut shell charcoal is also a favorite charcoal with a large market demand. The charcoal will usually be further processed into briquettes for energy and activated carbon for various industries. For biochar production, coconut industrial wastes such as coir/fiber, bunch and midrib can be used. Excess energy of pyrolysis can be used for the production of the above products and other advanced products. The low productivity of Indonesian coconut production needs to be improved, one of which is by improving soil quality with biochar. In addition, there are so many coconut plantations in Indonesia that need to be replanted so that improving soil quality to achieve the desired production is increasingly important. 

3. Corn Plantation

Efforts to increase food products need to be taken seriously, this can be done in two ways, first by expanding the land or making new rice paddy fields for production and the second by improving the quality of existing land so that productivity will increase. Biochar is very effective and efficient for the second method above. Besides being used as a human food source, corn is also used for animal feed. With the projection of the human population continuing to increase, the need for food either directly by consuming corn or indirectly from livestock such as meat and eggs. Poultry or chicken feed production ranks first of other animal feed production, or in the world almost half of the animal feed produced is chicken feed. Corn cobs and husks are agricultural waste that can be used for biochar production. Excess energy from the pyrolysis process can be used for drying corn and other advanced processes.

4. Rice Paddy Farming 

Rice or paddy is the staple food of most of the Indonesian population. The area of irrigated rice fields is decreasing throughout the year. This encourages the use of non-irrigated rice fields or dry land for the production of this rice. Biochar is able to improve the quality of dry land soils, such as in corn farming. Rice husks are rice paddy agricultural waste that can be used for biochar production. Excess energy from rice husk pyrolysis can be used for drying the rice paddy itself so that it becomes dry grain ready to be milled, or for other purposes. With the improvement of soil quality, rice productivity can be increased and it is not impossible that food self-sufficiency, especially rice, can be achieved, as has been achieved by Indonesia some time ago.

Rice Husk Pellets or Rice Husk Briquettes?

 

Rice husk truck, photo taken from here

Indonesia's rice production in 2008 is estimated to reach 59.9 million tons of milled dry unhulled rice with a composition of 25% husk, which means that the potential for husks reaches 15 million tons / year. Although the amount is abundant but generally the utilization is still not optimal, this is because the rice husks have low bulk density and low calorific value due to the high ash content. So that the rice husks can be utilized optimally, one solution is densification. With this compacted rice husks can be easier to use, economical in transportation and facilitate storage. A large pile of rice husks also has a strong tendency to burn. The dry husks easily fly like dust so that high concentrations in the room will be flammable and dangerous. Compaction of rice husks will make rice husks larger, denser and heavier so that they do not fly easily or in other words, reduce the risk of the fire.

The need for biomass fuel has increased recently. This encourages the use of agricultural and wood processing industrial wastes. These wastes were initially not utilized and tended to pollute the environment, but now they are being processed a lot for the production of biomass fuels. A positive effort, of course, because in addition to minimizing environmental problems caused by waste, it is also a profitable business activity. Production of biomass fuel can start from medium capacity to large capacity, from a capacity of several hundred tons or thousands of tons per month to hundreds of thousands of tons per month. Although the potential in Indonesia is large, generally the use of these wastes is not maximized so that commercial biomass fuel production is generally still low. 

 Briquettes and pellets are the products of the biomass densification technology. Basically, briquettes and pellets have their own characteristics, although physically they can be easily recognized by the size of the briquette that are bigger than the pellets. The briquette technology is also more diverse than pellets, so that is the case with the output in the form of the briquette product, for more details, please read here. For rice husks for use as industrial fuel, industrial production of briquette with a mechanical press is most suitable. This is because it is technically easier and economically cheaper. Although the rice husk can also be pelleted, it will cost more. This is because rice husks are very abrasive due to the large ash content with the main constituent component in the form of silica. The ring die and roller press on the pelletiser will wear out quickly due to the abrasive material. Production of rice husk briquettes with a screw extruder is also possible and possible, even a number of countries such as Pakistan, Nepal, Bangladesh, Vietnam and Thailand have also done so. But with these abrasive materials the production costs are also high. The briquettes produced by the screw extruder are also long so they usually need to be cut into pieces for use so that the use of the screw extruder also becomes less practical. With a mechanical press, the briquette size can be cut into small pieces easily, making it easier to use.