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. 

Wood Pellet Production, Solution to Urban Wood Biomass Waste Problems

Sorting is 50% of the solution to the problem of urban waste. The best sorting is at the location where the waste is generated, such as in households in housing or residential areas. With sorting, further waste processing will be much easier. The better the sorting is done, the easier the waste processing can be done. The reluctance of the community to sort waste makes the waste problem more complicated, prone to social conflict and protracted. Although difficult and complicated, cultivating waste sorting must continue to be done because if not handled it will become a serious environmental problem. The paradigm of waste processing also continues to change according to conditions, namely related to environmental impacts, availability of landfills, types and volumes of waste, as below.

If urban waste or MSW (municipal solid waste) can be sorted and processed properly, the environment will be clean and healthy. For example, such sorting is leaf waste made into compost, organic waste from the kitchen and leftover food for maggot feed or farming, wood waste in the form of twigs, pieces of wood and so on for wood pellet production, and plastic waste to be pyrolyzed into fuel or naphtha. And to be processed adequately, the volume of waste must also be sufficient and continuous. This is because the procurement of units for waste processing is also quite expensive. Waste processing should also be decentralized, so that it does not pile up in one place. The production capacity of the village or sub-district scale seems quite good and suitable for the manufacture of such waste processing units.

Among the urban waste is wood waste in the form of twigs, pieces of wood and so on that can be used for the production of wood pellets or wood pellets. The wood waste can come from pruning and felling trees, wood processing industry waste or wood that clogs waters such as rivers. The use of wood pellets or wood pellets can be for household cooking or SME industries. The use of wood pellets in addition to being a fuel or renewable energy that is environmentally friendly, easy to store and use and a solution to overcome biomass waste and reduce LPG imports which are worth around IDR 63.5 trillion each year.

Along with the innovation that continues to be done, wood pellet cooking stoves are becoming easier to use, efficient, clean and safe. For local governments, the production of wood pellets from wood waste also provides many benefits, namely as a solution to handling the waste, creating jobs and socializing the use of environmentally friendly renewable energy for the community. If this is successfully done, in the future the utilization of wood waste can continue to be developed.

Production of Briquettes from EFB and MF of Palm Oil for Industrial Boiler Fuels

The need for biomass fuel is increasing all the time, palm kernel shells (PKS) are increasingly expensive and scarce, even though this palm kernel shell (PKS) is the main competitor for wood pellets. When the supply of PKS is limited due to high demand, the price is high, even closer to wood pellets. When this condition is achieved, wood pellets become more desirable than PKS because the quality of wood pellets is better than PKS. In addition to a more uniform shape and size, wood pellets are also drier with a moisture content of around 10%.

In this condition, actually it also opens up opportunities for briquette production. Briquettes and pellets actually use the same type of technology, namely biomass compaction or biomass densification. But briquette production is easier and cheaper than pellets. The level of flexibility of the raw material as a briquette material is also higher than that of pellets. Even some materials that are difficult to make pellets are easy to do with briquette. The size and shape of the briquettes are also more diverse as is the production technology. Briquettes for industrial boiler fuel are briquettes that can be an alternative between PKS and wood pellets.

Besides producing PKS waste, palm oil mills also produce solid waste in the form of empty fruit bunches (EFB) and mesocarp fibre (MF). A number of palm oil mills that use high efficiency boilers will produce a lot of MF. These wastes in the form of EFB and MF can be used as raw material for the production of briquettes. Industrial briquettes with puck shapes that are produced with mechanical press are not only easy to produce but also have a large capacity. The location of the briquette users, which is not too far from the palm oil mill, makes transportation costs cheap, and can compete with PKS and wood pellets.

 Industrial areas and also surrounded by a lot of palm oil mills and plantations such as in Medan, North Sumatra, Indonesia are very potential for the production of industrial briquettes. The briquettes produced are expected to have quality between the PKS and wood pellets as well as the price. The production of industrial briquettes from MF is easier than from EFB. Besides being wet, EFB also needs more effort to reach desired particle size so that it is suitable for the briquetting. Utilization of these wastes in addition to reducing environmental impact will also provide economic benefits.