Compost Production with Biochar to Improve Compost Product Quality and Business Profit

Although compost and biochar production both utilize and recycle organic waste, there are several differences: compost production through aerobic fermentation is a biological process, while biochar production through pyrolysis is a thermal process. Furthermore, regarding raw materials, ideal compost production requires a moisture content of 60–70%, high nutrient content, and low lignin content, such as food waste and animal manure. Conversely, ideal biochar production requires a moisture content of 10–20% and a high lignin content, such as woody biomass.

Recent research suggests that adding biochar to the composting process accelerates composting, reduces greenhouse gas emissions such as methane (CH4) and nitrous oxide (N2O), reduces ammonia (NH3) loss, increases aeration and reduces compost density, and reduces odor. The biochar itself is not damaged or decomposed during the composting process but enriches it with various nutrients.

To achieve optimal results, the biochar dosage must be appropriate to the amount of organic matter used in the compost. Using too much biochar will disrupt the composting biodegradation process, and using too little biochar will diminish the positive effects mentioned above. With the appropriate dosage, biochar can accelerate the composting process. This is because it increases the homogeneity and structure of the mixture and stimulates microbial activity in the composting process.

This increased microbial activity will increase the temperature and speed up the composting process. Several studies have shown that adding 5% to 10% of the biochar volume at the start of composting can speed up the composting process by 20%. While the average compost production time is 2 months (9 weeks), adding biochar at the above dosage can speed up the composting process by 20%, or approximately 1.6 months (7 weeks). With the shorter production time and better compost quality, the added biochar can lead to a higher selling price, potentially equivalent to premium compost. This can offset the cost of adding biochar to the compost production process.

The pores in biochar reduce the bulk density of the compost and aid aeration during composting. For nitrogen-rich compost materials such as livestock manure, adding biochar can reduce N loss during composting, particularly NH3. The unpleasant odor is caused by the release of NH3 during composting, and for this reason, many composting facility developments are rejected by local residents. In a study, adding 20% ​​biochar (mass basis) to poultry litter reduced NH3 concentrations in gas emissions by 64% and N loss by 52% without negatively impacting the composting process.

When used, compost decomposes, with nutrients absorbed by plants, while biochar remains in the soil for centuries. This makes biochar a long-term solution for improving soil quality. Using biochar in compost offers both short-term and long-term benefits. The short-term benefit is as an organic fertilizer, while the long-term benefit is improving or stabilizing soil quality and sequestering carbon. CO2 absorbed through photosynthesis becomes biomass, or organic matter, as the raw material for biochar, and the carbon in biochar remains stable for hundreds of years, and is not released into the atmosphere during this time.

There is no data yet showing the calculated amount of compost production in Indonesia per year. However, the potential for compost production from domestic organic waste is very large, reaching around 60% of the total national waste generation which reaches more than 60 million tons per year or more than 36 million tons of organic waste as raw material for compost. There are a number of parties carrying out compost production in various regions in Indonesia, both government and private parties who contribute to compost production, with varying production capacities. With the very abundant organic raw materials (more than 36 million tons/year), the production of biochar-enriched compost can be carried out so as to maximize the quality of compost and other benefits.

This can be achieved by building a biochar production unit or installing a pyrolysis unit at the organic waste source. Organic waste materials that are less suitable for composting can be used for biochar production. Several companies are already planning to do this. Read the related article here. 

Premium Wood Pellet Production From Plywood Factory Waste

Indonesia's plywood or plywood production is estimated to be more than 10 million cubic meters annually, which is produced from hundreds of plywood factories, even Indonesia once dominated the world's wood industry in the period from 1980 to 1995. There are five provinces as the largest plywood producers in Indonesia, namely East Java, East Kalimantan, Central Java, South Kalimantan and West Kalimantan. And six other provinces that are starting to develop, namely Banten, Papua, Central Kalimantan, South Sulawesi, Riau and Jambi. Most of the plywood is for the export market.

The volume of wood waste in the plywood industry is quite large, reaching almost 55% or more than 5 million tons per year of the national plywood production. The potential for this waste is quite large and has great potential to be processed into premium grade wood pellets. Why is wood pellet an option and why does it have to be premium grade? Wood pellets are the choice for the solution to the plywood waste problem because in addition to an easier production process, machine investment is also cheaper. This is because the wood waste from the plywood factory is dry, so it does not require a drying process. The dryer is not only quite expensive but also the operational costs. Premium quality is also possible due to the low ash content, because the wood for the plywood production has been debarking so that the ash content can be reduced to below 1%.

Size reduction / down sizing is the first thing that needs to be done with the plywood waste. After the particle size is appropriate, which is the size of sawdust (~3-5 mm), then the wetting process is carried out until the moisture content reaches about 10%. This is because the wood waste from the plywood factory is usually too dry, with a moisture content of 4-5% so that it does not meet the requirements for pelleting. Raw materials that are too dry make pellet gluing not optimal, so that pellets become brittle and even pellets are not formed at all. The wetting process is carried out with a water sprayer to reach the moisture content level. After the water content reaches about 10%, then the raw materials enter the pelletiser to be pressed or molded into pellets.

The premium grade wood pellet market segment is different from standard or utility grade wood pellets according to the table above. The use of premium grade wood pellets is for heating, especially in winter in countries with four seasons. The main reason for using premium grade wood pellets for this purpose is the very low ash content. With a low ash content, ash cleaning becomes less frequent. In general the production of premium grade wood pellets is more difficult than standard or utility grades, but especially in the plywood industry with the conditions of the raw materials as above, it is much easier and more prepared for the production of premium grade wood pellets. A golden opportunity for those who realize and understand it.

Will PKS for Export Disappear from Circulation and be Replaced by Wood Pellet?

 The need for palm kernel shell (PKS) is increasing due to the increasing need, especially for the export market, making the price even more expensive, even matching the price of wood pellets. Nearly all of the biomass plants in Japan have experienced delays in their operations, now come online for more details can be read here. This has led to an increase in the price of the PKS.

Palm kernel shell (PKS) is a biomass fuel that is the main competitor for wood pellets, because the quality or specifications have many similarities. Previously, PKS were always cheaper than wood pellets, even in the international market some time ago the price of PKS was only about half the price of wood pellets. But currently the price of PKS equals even slightly above wood pellets. This of course will make users switch to wood pellets because of better quality such as lower moisture content, higher calorific value, uniform size and shape, and generally lower ash content.

When users flock change to wood pellets, the PKS commodity for export will get smaller in portions and even disappear altogether. Moreover, wood pellets from Vietnam and Russia are known to be cheap with large capacities. Vietnam is even the largest producer of wood pellets in Asia with a production of more than 1 million tons / year. Of course, this condition is very sad for exporters who have been doing business by exporting the PKS. The high tax and levy in Indonesia make it more difficult for exporters in Indonesia, whereas in Malaysia they do not exist. The most important thing that must be done is to be able to maintain the price of the export PKS so that the PKS is still worth it with its quality. It is not easy, of course.