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.

Fertilizer Savings in Palm Oil Plantations with Biochar and Compost from Biogas Waste

Although Indonesia is the largest CPO producer in the world with an area of ​​approximately 13 million hectares of palm oil plantations, but it is estimated that less than 10% have a biogas facility from POME (Palm oil mill effluent). Whereas by utilizing POME for biogas production, besides being able to be converted into electricity or heat, it also produces organic fertilizer in the form of compost and liquid organic fertilizer. The compost can be used as fertilizer in oil palm plantations, where the cost of fertilizer for palm oil operations is the highest cost component. It is estimated that every 10,000 hectares costs approximately Rp. 35.75 billion (around US$ 2.25 million) for fertilizer and for more details, you can read here. The use of compost will certainly reduce the need for fertilizer.

Palm oil utilization scheme for optimizing CPO production

Besides that, solid wastes such as palm oil empty fruit bunch, fiber and palm oil frond are also very potential for the production of energy (electricity and heat) and biochar. Energy production in the form of electricity and heat is by burning pyrolysis byproducts in the form of syngas and biooil into the furnace to heat the boiler. And because the syngas and liquid fuels used in the furnace, so that the combustion process is more perfect and clean emissions. Steam generated from the boiler will then drive the steam turbine and generator so as to produce electricity. Low pressure steam from steam turbine is then used for sterilization or boiling the fresh fruit bunches (FFB). While biochar will be used together with compost and chemical fertilizers to make fertilizer effective in the palm oil plantations so that it becomes a slow release fertilizer. Costs for fertilization are also expected to be significantly reduced, for example by up to 50% by this way. Although biochar is not a fertilizer, it has a function that makes fertilizer use effectively because it holds fertilizer nutrients from leaching, for example from rain water, also maintains moisture and so on.

PKS (palm kernel shell) can even be sold or exported. This is because previously or in general the palm kernel shells used to fuel boilers with fiber, have been substituted with products from the pyrolysis process namely syngas and biooil. The need for palm kernel shells for both the domestic / local and export markets continues to increase all the time. Palm kernel shells / PKS are environmentally friendly fuels because they come from biomass so they are carbon neutral fuels. The use of PKS as a fuel is widely used by a number of industries starting as a heat source for the drying process such as spray dryers in detergent and ceramic plants, boilers in food industries such as soy sauce factory, to power plants such as in Japan, can be read in more detail here. In the world of biomass fuel commodity trading, especially in the international market, PKS is the main competitor of wood pellets. Although the specifications are not much different, the price of PKS is also cheaper because it comes from palm oil mill waste and does not need complex processing units such as wood pellets. And basically with the scheme of utilizing palm oil mill wastes as above, it will maximize the profit from the palm oil mill or CPO mill. 

Energy Independent With Pyrolysis

A community even in remote areas can be energy independent as long as there is an energy source in the area. Biomass energy sources from plants are energy sources that can be obtained almost anywhere. The plant can be planted as a source of raw materials for the production of energy needed. Heat and electricity energy is energy that mostly needed, in addition to energy or fuel for vehicles as a means of transportation. Heat energy is mainly needed for cooking while electrical energy for various purposes in life. Pyrolysis is a technology that can meet the energy needs as above. The diagram below explains the application of pyrolysis to meet these energy needs:

Charcoal is a solid fuel product from pyrolysis. Although solid fuels such as charcoal, are not as practical and easy as gas fuels, the use of charcoal for cooking fuel has many advantages including being safe because it will not explode, smokeless, odorless, has a high calorific value and is an environmentally friendly fuel. While firewood in addition to causing a lot of smoke, smell, low calorie value also interfere with health. Today there are also many countries in Africa that use charcoal for cooking fuel. To make it easier to use and store, the charcoal can be made into briquettes. While fuel for vehicles such as diesel oil and gasoline can be produced from biooil. Vehicles for transportation can operate in the presence of these fuels. The availability of petroleum in Indonesia, which is estimated to be 10 years away, needs to be anticipated and prepared from now on. The current low price of petroleum makes petroleum exports less attractive, especially for Indonesia, which is currently a net importer of petroleum.

Charcoal stoves are widely used in Africa

In the future era when electric vehicles are widely used, electricity production especially for battery charging is prioritized. The energy source for electric cars as environmentally friendly vehicles should also be from renewable energy sources, for more details, please read here. Biomass is a carbon neutral energy source so it does not increase the concentration of CO2 or greenhouse gases in the atmosphere. Woody biomass from the energy plantation is the ideal raw material for the pyrolysis feed. Multipurpose energy plantations are the best energy plantation for this, so that in addition to sustainable production, it also provides other benefits, for more details about multipurpose energy plantations can be read here. Remote areas, especially those with large lands, will have the potential to develop these energy plantations, so that an energy independent community or region can truly be formed and sustainable. Areas in surrounding the palm oil plantations can also utilize biomass waste from palm oil mills and plantations such as palm oil empty fruit bunches (EFB), fronds, etc. for the pyrolysis feed. Indonesia is the owner of the largest palm oil plantation in the world with an area of ​​around 13 million hectares and 1,000 palm oil mills.

Dessicated Coconut Factory and Continuous Pyrolysis

There are about 20 dessicated coconut factories operating in Indonesia or estimated to be more than 100 units worldwide. With an average capacity of 2 tons / hour, this dessicated coconut factory requires approximately 16,200 coconuts every hour. The byproducts produced are coconut shell and coconut water. Coconut shells produced are around 6 tons / hour and coconut water 4.2 tons / hour. The dessicated coconut plant needs electricity and heat to sterilize the coconut meat and drying the dessicated coconut. Energy in the form of electricity and heat can be met from the utilization of the coconut shell.

There are several technologies for utilizing these coconut shells so that products in the form of electricity and heat are obtained. The popular technology today is with a steam turbine boiler, with this technology the coconut shell is burned in a furnace and heats water in the boiler so that it produces steam to drive the turbine and then generate electricity through a generator. This technology is the same as in palm oil mills. In palm oil mill the fiber and part of the palm kernel shell (PKS) is used as fuel to produce electricity and steam is also used to sterilize fresh fruit bunches (FFB) before being processed into oil.

Another better technology is continuous pyrolysis. This in addition to producing electricity and heat also produces charcoal product. Coconut shell charcoal is high-quality charcoal and is much needed by a number of industries such as the briquette charcoal industry and activated carbon. In the pyrolysis technology the coconut shell is not burned directly, but is heated in a vacuum condition (absence of oxygen). Pyrolysis products such as syngas and biooil are used for electricity production and can also be heat, heat energy is also produced from the pyrolysis process itself which is exothermic, while charcoal is the main product of the pyrolysis process. 

EFB Biochar and Fertilizer Savings in Palm Oil Plantations

High palm oil plantation productivity and high oil yield has always been a goal in the palm oil business. The nutrient estimates needed to produce 25 tons of FFB / ha / year were 192 N, 11 P, 209 K, 36 Mg, and 71 Ca in kg / ha / year. With the production of 25 tons of FFB / ha / year palm oil or CPO crude will produce around 6.5 tons (25% of FFB). Analogy in the field of animal husbandry where the feed component holds 75% of production costs or is the highest cost component, as well as fertilizer, especially in palm oil plantations. Fertilizer is the most expensive cost or 60% of total maintenance costs. To achieve this productivity, the calculation practically of the need is more or less as follows: an afdeling with an area of ​​1,000 hectares with 1 hectare consisting of 143 trees, so there are 143,000 trees of palm oil. If the dose per tree is 2.5 kg, then the fertilizer needs are 357,500 kg (357.5 tons), with the price of non-subsidized chemical fertilizers for example Rp 10,000 / kg, the cost incurred is 3,575,000,000 (Rp. 3,575 billion or US$ 238,333). If an area of ​​10,000 hectares means fertilizer needs of Rp. 35.75 billion (US$ 2,383,33), whereas if the oil palm plantation is 20,000 hectares, it will reach Rp. 71.50 billion (US$ 4,766,667). Of course an amount that is not small.

The question is what efforts can be made to reduce fertilizer costs but increase palm productivity. One contradictory thing seems to be because it reduces the supply of fertilizer but expects high productivity. This is where we need to examine and explore the facts that occur in the field. With a tropical climate and high rainfall, it makes large leached fertilizers. A condition, for example in hilly and bumpy areas, when the rain falls, the fertilizer that is washed is very large, even in vain fertilization is done because it is not absorbed by the palm trees as the target. The high level of leaching from the use of fertilizers by rainwater makes only available a small amount of available fertilizer in real terms or a number of analyzes said averaging only 50%. With the available fertilizers there are only a few that are also automatically absorbed by the palm trees. When for example washing (leaching) can be reduced by only 30%, it means that the fertilizer that is still available becomes 70%, so that the fertilizer is absorbed more and more and the productivity of the palm oil fruit also increases.

The initial stage that can be done is the cost of the same fertilizer but the productivity of the palm oil fruit can increase up to for example 30%. Furthermore, if this can be achieved, fertilizer consumption will be reduced for example up to 30% but palm oil productivity can be maintained at that level. This is possible when biochar has become a microbial colony and the quality of the soil increases so that uptake of fertilizer is maximal. Biochar is one of the media that can be used for this. An empty fruit bunch that is widely available in palm oil mills and is generally not utilized as a raw material for biochar production. A palm oil mill with a production capacity of 60 tons / hour FFB will produce EFB 13.2 tons / hour so that if the palm oil mill operates 20 hours / day the EFB produced 264 tons / day. The production of biochar with pyrolysis can also produce liquid smoke which can also be used as fertilizer.

Why can biochar be used to increase palm oil productivity and even reduce fertilizer consumption? This is because biochar with its pores with a surface area of ​​about 200 m2 / gram can hold the fertilizer from washing, maintain moisture and many soil microbes that can live in these pores thus improving the physical and chemical properties of the soil. Biochar can last up to hundreds of years in the soil so it does not need to be added every year when the amount is sufficient. Biochar implementation can be started from small scale to massive scale. To process empty fruit bunches (EFB)  in the palm oil mill into biochar, a continuous pyrolysis equiment is needed, to be more clearly read here. To monitor the effectiveness of biochar on oil palm plantations today can use internet technology or IoT (Internet of Things) and for more details can be read here and here.

Carbon as Basic Element

Carbon material is basically obtained in all living things. Carbon usually binds to hydrogen to form hydrocarbon chains. Fossil fuels are very familiar referred to as hydrocarbon sources. The fossil fuels also come from animals and plants that are buried for millions of years. After going through a very long process, it finally became hydrocarbon compounds that are widely known today. At this time also if we decompose biomass, hydrocarbon compounds will be produced or specifically with carbonization or pyrolysis will produce charcoal material whose main element is carbon. If we see today most of our daily necessities come from plastic. The plastic is a derivative product of fossil material from both the oil compound and the gas. Coal also when processed with pyrolysis will produce coke, benzol and syngas. Coke is very similar to charcoal whose main ingredients are carbon, benzol as well as biooil which can be used for fuels and various materials and chemicals. Syngas as well as being used for energy can also be used for the production of various chemicals and materials.

Why should charcoal be made? By making charcoal because it will be a stable material, easily stored and easily converted. When stored in a biooil form, in addition to unstable material, storage is also more difficult. While the storage in gas form is technically even more difficult. Charcoal conversion can be physically used as briquettes, pellets and activated charcoal. While chemical conversion is a fuel that can produce heat for various energy sources, either directly or further modified through various thermochemical processes. Small-scale generators are now widely used such as ORC (organic rankine cycle), stirling engine and gasification can use the charcoal as fuel.

Municipal solid waste consisting of various types of garbage, most of which are organic waste, that is from living and inorganic creatures from fossil sources. When viewed from industrial chemical point of view, it means that city waste is a source of carbon material. In this case we do not distinguish whether the carbon material is from organic material or renewable sources or from fossils which are non-renewable sources. With continuous pyrolysis technology, the waste can be converted into the main product in the form of charcoal, and by-products such as biooil, pyroligneous acid (liquid smoke) and syngas. The syngas can also be used for power plants and heat sources. Charcoal is then a carbon source that is flexible in its use and the easiest to store.

General rules in the form of overcoming the problem are prioritized rather than the benefits that can be produced are also suitable to be applied in solving the city garbage problem. But if the benefits side can be optimized in such a way that is certainly what is more expected and becomes the main choice. Continuous pyrolysis problem solving provides the best solution for the city waste problem, because not only is the problem resolved effectively and efficiently, but the added value of the products produced provides attractive economic.

See Modern Charcoal Production Today

More specifically than the use of charcoal in general, the agricultural world, especially organic farming has become one of the current users of charcoal. Charcoal in the agricultural world or commonly known as biochar is widely used because it can withstand nutrients or fertilizers from leaching so that it is widely used for the manufacture of slow release fertilizer, then the pores in the char also become the home of microbes that break down various organic materials become fertilizer to the plant, the pores also improve the physical structure of the soil. In addition, biochar can also keep the soil moisture because water is also easily absorbed in the structure of the pores. Biochar also increases soil pH, is also able to absorb carbon dioxide (CO2) from the atmosphere (carbon negative scenario), and can last up to tens or even hundreds of years in the soil. These are the things that encourage the use of biochar in the agricultural world, which in short can increase agricultural productivity or help improve the world food products.

The role of biochar in some ways can indeed be substituted with other materials, for example for the ability to retain water, cocopeat is better than biochar, for the surface area with the number of pores the activated charcoal is much larger than the biochar, and to raise the pH for the soils acid then dolomite lime better. In an application in the field of planting media engineering to obtain the best agricultural media is very likely use a number of materials mentioned above. Optimal results can be obtained based on soil characteristics and plant species. Economic factors are also an important consideration factor after the above technical aspects.

Modern biochar production currently uses thermochemical processes continuously. There are two thermochemical technologies for biochar production namely pyrolysis and gasification. Pyrolysis technology is more widely used because it produces more biochar and better quality. Why with pyrolysis can get 2 things? This is because basically (slow) pyrolysis is a technology used for the production of charcoal or maximizes its solid product, so the process control is also designed for that purpose. While the gasification is designed to maximize its gas product, so the char is only positioned as a by-product. The operating temperature of gasification is also higher (800 C) than pyrolysis (450 C) so that the char is also mixed with ash.

More specifically the indirect heating pyrolysis technology is more widely used for biochar production today. With this technology the pyrolysis process control is easier and the charcoal quality is also better. Application of indirect heating pyrolysis technology for continuous process generally use rotating drum and heated auger type. Biochar production capacity is generally in the range of 2-4 tons / hour. The byproducts of the pyrolysis process are also of high economic value such as bio-oil for fuel, pyroligneous acid (liquid smoke) for fertilizer and biopesticide, as well as syngas for fuel and more specifically for electricity production.