FAQ

Carbonization furnace EKKO
Who are the main consumers of EKKO?
  • Enterprises engaged in the harvesting and processing of timber, tree plantations.
  • Woodworking enterprises.
  • Plantations: bamboo, eucalyptus, energy willow, etc.
  • Agricultural enterprises, including gardens: all possible agricultural wastes.
  • Other enterprises produce biomass (lignin, peat, etc.), waste of plant origin.
The main consumers of finished products (charcoal)?
  • BBQ
  • Metallurgy
  • Production of silicon
  • Production of activated carbon.
  • BIOCHAR – eco fertilizer
  • Other industries consumers of charcoal
What processes are used to produce charcoal?

The charcoal production process uses processes outside of the furnace and using a carbonization furnace. 

  1. Processes outside the furnace
    • Preparation of raw materials for the carbonization process: grinding of raw materials, for wood – cutting and splitting.
    • Pre-drying of raw materials, it is possible to use air drying “sun and wind”, also “contact dryer” – a device developed by GreenPower, which uses excess heat from the carbonization process to pre-dry the raw material. Pre-drying is not mandatory for the process, but only affects the total productivity of the furnace, in the basic design of the furnace, a drying mode is provided.
    • Loading raw materials into trolleys
    • Loading trolleys with raw materials into the EKKO furnace chamber.
    • Unloading trolleys with charcoal from the EKKO furnace chamber.
    • Charcoal cooling in trolleys.
    • Unloading charcoal from trolleys.
    • Stabilization of charcoal – its interaction with atmospheric air, to ensure the fire safety of charcoal, in order to eliminate the self-ignition factor.
    • Packing of charcoal in a package for delivery to Consumers.
  2. Processes in the furnace
    • Drying of raw materials, removal of moisture (100-150°C) and the initial stage of pyrolysis (150-250°C). If pre-drying outside the furnace is used, this is reflected in the duration of this process. With a pre-drying system, partial moisture removal takes place outside the EKKO furnace chamber.
    • Pyrolysis stage – raw material carbonization (250-450°С)
    • Calcination of charcoal (450-550°C), if it is necessary to increase the content of non-volatile carbon > 77%

The temperature regimes in the furnace are regulated automatically or by the operator, depending on the requirements for the content of non-volatile carbon in charcoal. The change of drying/pyrolysis modes is carried out by the operator manually at the end of the mode according to the indications of the temperature sensor.

What is the duration of the processes in the EKKO?

The duration of the processes in the furnace depends on:

  • Weather conditions: ambient temperature and atmospheric pressure.
  • Raw material parameters: dimensions, temperature, density and moisture content.
  • Process control parameters depending on manual control or automatic settings

Duration of processes in the furnace

Process nameTemperaturesDuration, hours
1Drying and initial stage of pyrolysis *100-250°С6-12
2Pyrolysis*250-450°С6-12
3Charcoal calcination**450-550°С2
4TOTAL:12-26

* The moisture content of the raw material affects the duration of the drying and pyrolysis processes in the furnace. The table below shows the effect of raw material moisture content on the drying time at ambient temperature >10°C, normal atmospheric pressure and air humidity not more than 60%.
**Produced when it is necessary to increase the content of non-volatile carbon > 77%

Influence of raw material moisture on drying time

Absolute moisture content of raw materialsDuration, hours
110-20%2-6
220-40%6-10
340-55%10-12
455-70%12-16

The speed of the carbonization process affects the final properties of charcoal, with an increase in temperature, the speed of the process increases. This can affect the mechanical strength of the charcoal, as well as the percentage yield of charcoal from the raw material. This factor occurs when the relative humidity of the raw material is more than 20%.

How do the parameters of raw materials affect the productivity of the furnace?

The performance of the furnace is primarily influenced by the basic parameters of the raw materials:

  1. Dimensions. Due to the fact that the products of drying and pyrolysis exit through the wood fibers, and the temperature of the wood is supplied from the periphery, reducing the size of the raw material increases the heating surface of the raw material and shortens the path for the exit of the drying and pyrolysis products.
  2. Density. It affects the output of charcoal from 1 m³ of raw materials, as well as the quality of its heating – the higher the density of raw materials, the faster it is heated.
  3. Moisture content. It has a significant impact on the duration of both the drying process and pyrolysis. At the same time, at high moisture content (>30%), simultaneous processes in the trolley, drying and pyrolysis are possible, which reduces the % yield of charcoal, i.e. carbon reacts with steam and goes into a volatile phase.
  4. Temperature. Refers mainly to the Winter period when the ambient temperature is less than 0°C. Since the energy costs for the transformation of ice into water are equal to the energy costs for the transformation of water into steam, in connection with this, the duration of the production cycle increases.

Influence of raw material parameters and weather conditions on the productivity of the EKKO-2 

PARAMETERRAW MATERIAL TYPE
Wood briquetteBirch woodOak woodGasuarina wood
1Weight of absolutely dry raw material1200 kg/m3500 kg/m3650 kg/m3720 kg/m3
2Absolute moisture of the raw material8%60%70%20%
3Season/ambient temperatureSummer/
+25℃
Winter/-15℃Spring/+10℃Summer/+30℃
4Trolley filling rate0,70,70,7
5% of non-volatile carbon in the charcoal85%75%80%80%
6Weight of raw material loaded into the trolley600 kg1 870 кг2 080 kg1 890 kg
7Weight of the unloaded charcoal form the trolley200 kg340 kg400 kg500 kg
8Duration of the operational cycle6 h24 h24 h16 h
9Productivity per month48 000 kg20 400 kg24 000 kg45 000 kg
How many staff are required to operate a charcoal production site? 

EKKO is designed for 24/7 operation, i.e. around the clock. It is necessary to provide for a round-the-clock work schedule. One production shift can be: 8 or 12 hours. To service 1-3 furnaces, you need: 1 operator and 1-3 auxiliary workers. 

Tasks of ancillary workers:

A. Loading raw materials into trolleys

B. Installation of trolleys for pre-drying, if provided

C. Loading the trolleys into the EKKO furnace chamber

D. Unloading the trolleys from the chamber and placing the trolleys in the cooling zone

E. Unloading charcoal from trolleys

Task of operator: 

A. Monitors and records the operating modes of the equipment

B. Charcoal combustion site management

C. Provides assistance to ancillary workers

The number of personnel for the processes of preparation of raw materials and packaging of finished products depends mainly on the selected equipment and its level of automation.

How to mechanize and automate production as much as possible in order to reduce labor costs and increase productivity?? 

When the furnace automation is operating, the operator only needs to decide when to unload charcoal and load raw materials and, if necessary, throw firewood into the furnace when working on raw materials with high moisture content. It is necessary to separate the two processes of furnace maintenance and take into account their impact on the performance of the site:

А. Site logistics 

  1. Loading trolleys with raw materials. A large number of man-hours are involved in the process of loading the trolleys with raw materials. To mechanize this process, it is recommended to use a wood splitter with a conveyor for preparing and loading firewood into trolleys. When using a conveyor, the quality of the stacking of raw materials is reduced, which reduces the weight of charcoal in the trolley, but the duration of the production cycle is reduced.
  2. Moving trolleys around the production site, namely: to and from the carbonization furnace, to the cooling zone, to the zone for unloading charcoal from the trolleys, and to the zone for loading raw materials into the trolleys. To move the trolleys are used mobile platforms which move along a special railway using an electric winch.
  3. Unloading charcoal from trolleys. Can be done using a forklift or tipper from GreenPower to unload the charcoal from the trolleys.

B. Production process at EKKO

The furnace is equipped with a reliable instrumentation system. It also provides for maximum automation of process control (see video), excluding the human factor and allowing maximum control of the maintenance personnel.

When more than 3 furnaces are installed on the site, it is recommended to carry out video surveillance of the site and control the site from a separate operator room. To do this, we have implemented a system for remote control and monitoring of the charcoal burning complex, i.e. control is carried out from the operator’s room, data on the operation of the furnaces are sent to the server and recorded on the flash card of each furnace.

Is the consumption of firewood in the furnace at 0.1 m3 / day on the site?

The consumption of firewood for the furnace is minimal, this is due to the technology of the furnace to ensure the carbonization process.

Due to the use of preliminary drying of raw materials and the variable mode of operation of the “drying and pyrolysis” chambers, that is, the separation of these processes in the “EKKO” chambers, the possibility of complete combustion of pyrolysis gas and efficient distribution of the generated heat for carrying out the drying and pyrolysis processes is applied. This makes the furnace both environmentally friendly and significantly saves fuel for the process to maintain the required temperature conditions. Ideally, when the duration of the drying and pyrolysis process coincides, then there is enough pyrolysis gas for the technical process, this is ensured with an absolute moisture content of the raw material <30%. That is, the consumption of firewood can be from 0 to 0.1 m³ / day.

What is the performance of the furnace and how to determine it for specific conditions?

The productivity of the EKKO-2/EKKO-4 furnace is 20-50 t/month / 40-100 t/month of charcoal (productivity depends on the parameters of raw materials and a little on weather conditions).

With the help of the following “Table of % charcoal output” and “Table of wood density”, and also using data on the relative moisture content of raw materials, it is easy to calculate the yield of charcoal from a certain type of wood using the formula:

Weight of charcoal = (weight of raw materials – moisture content of raw materials) * % charcoal yield

For example, for oak with a moisture content of 15%, the yield of charcoal with 85% non-volatile carbon content will be:

(700kg/m³ – 15%) * 35% = 208 kg/charcoal (charcoal weight)

In the table below, “Table of % charcoal output”, these parameters are indicated depending on the final temperature of the process and the content of non-volatile carbon in the charcoal. At the same time, at high moisture content (>30%), simultaneous processes in the trolley, drying and pyrolysis are possible, which reduces the % yield of charcoal, i.e. carbon reacts with steam and goes into a volatile phase.

What affects the performance of the furnace? 

There are 3 main factors that affect the performance of a furnace:

  1. Human factor.
    The main influence on this factor is the level of mechanization, control and automation of the site, as described above. The main influence is the time of changing the trolleys in the furnace, that is, the unloading of the trolleys with charcoal and the loading of the trolleys with raw materials. For example, if the charcoal is ready at 4:00 (am) and the trolleys are unloaded at 9:00 (am), the actual loss of productivity is more than 10 hours! This is due to the fact that the excess heat released as a result of the carbonization process is not used efficiently, namely for drying and the initial stage of pyrolysis. In this regard, the operator is forced to use furnace wood to maintain the thermal regime, and its calorific value is lower than pyrolysis gas. As a result of a system (daily) error, a monthly performance loss can be up to 50%!
  2. Dimensions and moisture content of raw materials. It is recommended to prepare the wood in advance and store it in a warm, dry place (preferably in the sun) in order to partially reduce the moisture content. If this is not possible, we recommend retrofitting the furnace with a “pre-dryer” developed by GreenPower. This will significantly reduce the cycle time when working on wood with a moisture content of more than 40%. It must be taken into account that moisture leaves the wood along its fibers, the shorter this path is, the faster the drying mode will be and, accordingly, the production cycle will be shorter and the furnace productivity will be higher. It is recommended to use firewood with a length of no more than 300 mm and a diameter of no more than 120 mm, which can be produced using a wood splitter
  3. The output of charcoal from raw materials depends on the following factors
    • Content of non-volatile carbon in charcoal. The output of charcoal is approximately 27-40% of the mass of absolutely dry wood, depending on the content of non-volatile carbon in charcoal, the lower the content, the higher the percentage of charcoal output from wood. This parameter depends on the end temperature of the pyrolysis, in the table below “Table of % charcoal output”, these parameters are indicated depending on the end temperature of the process and the content of non-volatile carbon in the charcoal.
    • Density of raw materials used for the process. From denser raw materials, the % output of charcoal is higher than from less dense ones, for example, a high output of charcoal is obtained from Pini-kay briquettes (density> 1,2 and moisture content 4-6%). It should also be taken into account that the density of absolutely dry raw materials affects the output of charcoal.

Table of % charcoal output

Final temperature, °СCharcoal
Output, weight %Carbon content, weight %
37040,175,5
40038,179,5
43036,682,8
45035,685,1
53033,690,2
80027,196,0

Table of wood density depends on the moisture content %

Wood speciesMoisture content, %
152025304050607080100Fresh
1Larch6706907007107708208809309901100940
2Poplar460470480500540570610650690760700
3Beech68069071072078083089095010001110960
4Elm tree6606806907107708208809309901100940
5Oak70072074076082087093099010501160990
6Hornbeam81083084086093099010601130119013301060
7European Spruce450460470490520560600640670750740
8Walnut6006106306507007508008509001000910
9Linden500530540540580620660710750830760
10Locust81083084086093099010601190130013301030
11Alder530540560570620660700750790880810
12Maple70072074076082087093099010501160870
13European ash69071073074080086092093010301150960
14Siberian fir380390400410440470510540570630680
15Scots Pine510520540550590640680720760850820
16Caucasian fir440450460480510550580620660730720
17Alpine stone440450460480510550580620660730760
18Birch6406506706807307908408909401050870
19Aspen500510530540580620660710750830760
How to calculate the output of charcoal from the volume of wood?

First you need to understand that the weight of charcoal is considered not from the volume, but from the mass of raw materials. At the same time, depending on the region, raw materials can be purchased by cubic meters, stacked ​cubic meters or by weight. To calculate the yield of charcoal not from the mass of wood, but from its volume, you must first convert the volume of firewood to the mass of dry wood. In this case, it is necessary to take into account the concept of a stacked ​cubic meters and a cubic meter. In one stacked cubic meter, depending on the fraction, there can be 0,6-0,8 cubic meters of wood. It is customary to calculate 0,7 stacked cubic meter = 1 m³.

For a more accurate calculation, you need to install: moisture content of raw materials and weight of raw materials in one trolley. Then take into account that one trolley can hold 1,8-2 m³/firewood. 

Then use the formula: Weight of charcoal = (weight of raw materials – moisture content of raw materials) * % charcoal output

At the same time, at moisture content (>30%), simultaneous processes in the trolley, drying and pyrolysis are possible, which reduces the % yield of charcoal, i.e. carbon reacts with steam and goes into a volatile phase.

At what distance can I install equipment from the settlement?

There are no harmful emissions into the atmosphere when using GreenPower carbonization furnaces, you can verify this by requesting an emission protocol. Environmental friendliness is ensured by burning pyrolysis products in a furnace to maintain the carbonization process and afterburning their residues in a vortex afterburner. 

According to international standards, it is possible to install the carbonization furnace at a distance of 500 meters from the residential sector. To reduce this distance, it is necessary to measure the emissions of the furnace and obtain the appropriate permission from the local authorities. In practice, there are no harmful emissions from the furnace; also, during the operation of the furnace, “odors” and “liquid pyrolysis products” are not emitted.

In what time the EKKO can be produced??

The contract provides the production of one unit of EKKO delivery set within 60 working days from the date of receipt of prepayment. However, as a rule, an order can be completed much faster, it all depends on the production load at the time of the order.

What is the warranty period for your EKKO? And what is the average operating period of your furnace?

If you follow the requirements of production technology and lead a careful attitude to equipment, the life cycle is from 5 to 10 years. After 3 years of operation, it is possible to carry out repair work, for example: replacing the kiln valves, trolleys repair, it is important to understand that repair work does not exceed 10% of the cost of the kiln. In this case, all units exposed to aggressive environments are made of a special type of steel.

For all equipment manufactured by GreenPower, we provide a 1-year warranty only if the Customer is fllow the requirements of operating conditions and process technology. The warranty covers all equipment and delivery set manufactured by GreenPower and third parties.

Furnace consumables and the procedure for their replacement

Recommended replacement schedule for consumables and accessoriesTechnical inspections
Name of detailName of worksName of worksПериодичность

1
Gas channelCleaning, depending on soiling ~ 1-2 times/6 monthsDensity in the closed position of the dampers of the gas channel from the chamber to the fire chamber 7 and 8DAILY

2
Steam pipesReplacement of pipes, graphite packing, 1 time/6 monthsCleaning the channel to release steam from the chamber30 days
Steam valvesReplacement, seals of steam valves, 1 time/6 monthsCleaning the channel to release steam from the chamber30 days
3Chamber door sealReplacement, depending on the level of wear ~ 1 time/6-12 monthsChamber door sealDAILY
4Damper heat carrierReplacement of assembled damper of the afterburner (2 pcs.) and afterburner damper (1 pc.), depending on the level of wear ~ 1 time/6 monthsThe level of wear of the dampers of the fire chamber and afterburner
30 days
5Trolley wheelsReplacement of trolley wheels, depending on the level of wear ~ 1 time/6-24 monthsRotation of the wheel around the axleDAILY
Do you have official documents (passports, instructions, etc.) on the equipment? And whether it is necessary to certify the equipment?

 Yes, of course we have! Each EKKO has a serial number and is accompanied by a full package of documents. To date, our equipment has officially received environmental approval for operation in Europe, Asia, Africa and South America, where they were successfully launched.

What are the terms of purchase and delivery?

Payment to GreenPower is 60% advance payment and 40% upon loading

For foreign countries: The cost is indicated on the terms of delivery FCA, Kharkiv. The price includes a certificate of origin for the goods, which exempts the furnace from import duties in many countries, as well as customs procedures associated with the export of the furnace.

Indicate the exact place of unloading the furnace, and we will offer the best delivery option for the price.
The cost of the furnace launch and staff training is not included into the total sum. The travelling expenses, accommodation and daily allowance of the start-up engineers are not included into the total sum and are to be covered by the client separately. 

The customer independently, according to the instructions provided and under the remote guidance of a GreenPower technical specialist, performs installation work to install the furnace and prepare the site for launch. If there is a need for installation supervision by a GreenPower specialist, then this service is possible and is negotiated with the Customer separately. 

What kind of discount do you provide?

Discounts are provided starting from an order of 3 units furnaces.

What is the consumption of electricity??

The main energy source for the operation of these furnaces is pyrolysis gas, the energy consumption is necessary only for the electric equipment of the kiln (control panel, valve actuator) and is no more than 0.1 kW / h, the network is 220V. Maximum power consumption may be related to recycling equipment

Is there excess heat from the reaction, and how is it possible to use it?

Excess heat is generated when using raw materials with an absolute moisture <30%, if the moisture is higher, all the heat from the reaction is used for the drying process. Excess heat can be used for:

– Pre-drying of raw materials for pyrolysis in order to increase productivity

– Manufacture of “firewood” with humidity < 20%

– Heating air or water for domestic purposes.

If you indicate for what purposes you would like to use the excess heat from the furnace, as well as the parameters of the raw materials used (kind of wood, moisture content of raw materials) and the desired volume of charcoal production per month, we can make this calculation.

 LOADING / DELIVERY / UNLOADING / INSTALLATION ЕККО
  • The price of the carbonization furnace is indicated on the terms of FCA, Kharkov. This means that the price includes loading work and cargo customs clearance.
  • Disassembled dimensions: Length – 5850, Width – 2550, Height – 2300
  • The weight of the furnace with 2 trolleys and components is 7000 tons, the weight of the trolley is 400 kg
  • Device for transportation: in one car or sea container it is possible to load 2 kiln of incomplete configuration or 1 kiln of a complete set, it is possible to ship 3 complete sets in 2 transport units
  • To unload the furnace from transport, it is necessary to use a crane with a lifting capacity of at least 10 tons
  • Assembly and installation of the furnace. The furnace is delivered in assembled form, only assembly and installation are required: dampers, afterburner, chimney and instrumentation, all this is installed and configured within one working day.
Continuous carbonization furnace BIO-KILN
Main elements of the BIO-KILN and their brief description
  1. Conveyor is equipped with raw material level sensors in the storage hopper (2). Designed for mechanized
    loading of raw materials into the storage hopper (2). Loading into the bunker can be done manually using
    human labor, but it should be borne in mind that, depending on the productivity of the furnace, it is necessary
    to load one bag of 50 liters every 2-5 minutes. The conveyor can be replaced by a bucket loader.
  2. Storage hopper is used to reserve raw materials and metered loading of raw materials using a vibrating
    feeder (3), by means of a bucket conveyor – bucket elevator (4) into the furnace loading hopper (5).
  3. Vibrating feeder. It works in automatic mode, provides separation of “garbage” from raw materials in order
    to reduce ash in raw materials – finished charcoal. It also loads raw materials from the storage hopper (2) into
    the bucket elevator (4), receives a signal about the need to load and stop loading raw materials from raw
    material level sensors located in the furnace hopper (5).
  4. Bucket elevator – vertical bucket conveyor, operates in automatic mode, provides loading of raw materials
    from the storage hopper (2) by means of a vibrating feeder (3), receives a signal about the need to load and
    stop loading raw materials from raw material level sensors located in the furnace loading hopper (5).
  5. Loading hopper is equipped with raw material level sensors, an inspection hatch, and a steam outlet pipe.
    Serves for primary heating of the raw material and loading it into the carbonization chamber through channels
    (10) for raw materials.
  6. Carbonization chamber. Raw materials move down the channels of the raw materials, heated from two sides
    by “thermal channels”, through which heat moves up, as the raw materials move down, it turns into charcoal.
    Channels of the raw materials are connected at the bottom with unloading devices (9), which provide
    automatic unloading of finished charcoal into the cooling hopper (7). Unloading devices (9) provide automatic
    unloading of finished charcoal into the cooling hopper (7). The unloading signal comes in automatic mode,
    depending on the temperature of the charcoal, depending on the settings of the automatic mode. The
    temperature regime for unloading finished charcoal is set by the operator in the automated control system,
    depending on the requirements for the content of non-volatile carbon in charcoal.
  7. Stabilization hopper with air cooling system is used to cool the charcoal, when filling the hopper, the
    cooled charcoal is automatically unloaded using a screw conveyor (8). The hopper is equipped with charcoal
    level sensors and an air cooling system for charcoal (through the wall).
  8. Screw conveyor provides automatic unloading of cooled charcoal from the stabilization hopper with air
    cooling system

11. Vibrating feeder with aspiration system. Provides the separation of the small fraction of charcoal, which
contains the maximum amount of ash, as well as the stabilization and cooling of charcoal. It also provides for a
charcoal dust aspiration system with a cyclone for “catching” charcoal dust.

Flow diagram of raw materials and heat carrier

Raw materials for carbonization and its direction of movement

Raw materials at different stages of the carbonization process

Raw materials after unloading from the carbonizer, stage of cooling and stabilization. Extraction of heat energy possible

Heat carrier formed as a result of combustion pyrolysis products, providing heating of raw materials through the channel of the wall

Waste heat carrier after the afterburner, can be used for the drying process of raw materials and other thermal processes

Processes in BIO-KILN

  1. Drying of raw materials, removal of residual moisture (100-150°С)
  2. The initial stage of pyrolysis (150-250°С)
  3. Stage pyrolysis – carbonization (250-450°С)
  4. Charcoal calcination (450-600°С), which ensures the carbon content up to 92%. Can be increased to a maximum of 95%
  5. Cooling charcoal to a temperature that ensures the absence of combustion of charcoal in contact with air.

  Depending on the residence time of the feedstock in the feedstock channel, the temperature of the feedstock depends, which, as a result of its movement along the feedstock channel, becomes charcoal. The change of modes occurs as the raw material moves along the height of the channel, due to the residence time in it.

  The temperature regime for unloading the finished charcoal is set by the operator, depending on the initial parameters of the raw material and the requirements for the content carbon in the charcoal.

What affects BIO-KILN productivity?
  1. The content of non-volatile carbon in charcoal. With an increase in the content of non-volatile carbon in charcoal, the productivity of the furnace decreases, with a decrease – it increases.
  2. Models of the furnace. The main difference between the 1st, 2nd and 3rd models is performance and overall dimensions. Also, models 2 and 3 differ from the 1 model in a high speed of reaching the operating mode.

There is a dependence of the content in charcoal: non-volatile carbon-volatile carbon-ash. For example, with an ash content of 10% and a volatile carbon content of 10%, non-volatile carbon will be 80%

What processes are used to produce charcoal in the BIO-KILN?

The processes can be divided into “outside the furnace” and “in the furnace”. Processes taking place outside the furnace can be automated as much as possible and performed almost without the participation of staff.

Processes outside the furnace:

  1. Preparation of raw materials for the carbonization process
    1. Grinding of raw materials, if the size of the raw material is more than 35 mm
    2. Separation of raw materials, if necessary, to minimize the ash content and the presence of debris in the raw material
    3. Drying at humidity> 15%; Drying can take place using excess heat from a furnace in a shaft or rotary furnace;
  2. Stabilization and additional cooling of raw materials after the carbonization process. Various variants of these processes are possible. For example, it is possible to stabilize and cool in mesh boxes or on a moving conveyor.
  3. Packing charcoal into containers for delivery to Consumers, according to their requirements. There are various options for packing and packaging finished products: manual, semi-automatic and automatic.
What type of raw materials can be recycled in BIO-KILN?

The main requirement for raw materials: moisture <15%, fraction 5-40 mm, the main requirement is the flowability of raw materials.

  1. Seeds and fruit trees seeds (olive seed, etc.)
  2. Nutshell (any)
  3. Wood chips (5-40 mm) and moisture < 15%
  4. Pellets and small briquettes
The main consumers of finished products (charcoal)?
  • Charcoal briquette manufacturers for hookah
  • Charcoal briquette manufacturers for BBQ
  • Activated carbon manufacturers
  • Consumers: charcoal briquette for hookah, charcoal briquette for BBQ, activated carbon
  • Manufacturers / consumers BIO-CHAR
How many staff are required to operate a charcoal production site?

BIO-KILN is designed for working 24 hours a day, 7 days a week, all year round without stopping.  Accordingly, you need to provide a round-the-clock work schedule. With the maximum level of furnace automation, in one shift, 1 operator and 1 auxiliary worker are required to service from 1 furnace.

What type of fuel is used for the process?

In fact, the fuel is self-raw material, additional fuel is used to “ignite” the gas released from the process – only when the furnace is started. Additional fuel is wood or gas, they are used only to bring the stove to the mode, within 12-24 hours, depending on the carbonization furnaces model.  After that, the furnace runs on pyrolysis gas – released as a result of the reaction. At the start, you need 25-50 liters/propane-butane gas. In addition, the furnace produces additional heat energy.

What is the productivity of the furnace and how to determine it for specific conditions?

The productivity is depending on the following factors:

  1. Models of the carbonization furnace: BK-1 – 30-60 ton/month; BK-2 – 60-100 ton/month; BK-3 – 80-140 ton/month; The productivity of the furnace depends mainly on the parameters of the raw materials and the content of non-volatile carbon in the final product.
  2. The content of non-volatile carbon in charcoal. The lower the non-volatile carbon content, the higher the kiln’s performance. For example, for the BK-2 model, the productivity, with a non-volatile carbon content in the charcoal 70-72%, will actually be twice as high (up to 90 t/month) than with a non-volatile carbon content in the charcoal 90-92% (50 t/month)
  3. Bulk density of raw materials. Bulk density depends on the density of the raw material and its fraction. With an increase in the bulk density, the productivity of the furnace increases.
  4. Moisture of raw materials should be less than 15%, with a decrease of moisture content – productivity increases, with an increase of moisture content – productivity decreases, ultimate moisture content – 20%. But it makes no sense to dry raw materials to a moisture content of less than 10%.
 What is the charcoal output per ton of raw materials?

Charcoal output is approximately 27-40%, from the weight of absolutely dry raw materials, depending on the content of non-volatile carbon in charcoal, the lower the content – the higher the % of charcoal output. This parameter depends on the final pyrolysis temperature, as can be seen from the table below.  

Table of % charcoal output

Final temperature, °СCharcoal
Output, weight %Carbon content, weight %
37040,175,5
40038,179,5
43036,682,8
45035,685,1
53033,690,2
80027,196,0

It is worth noting that the high content of non-volatile carbon leads to a long burning time and the absence of smoke when burning charcoal, as the content of non-volatile carbon mainly affects the performance of the furnace.

Formula for calculating the yield of charcoal from raw materials:
Charcoal output = (raw materials weight – raw materials moisture) * % charcoal output

For example, for a walnut shell with a moisture content of 15%, the charcoal output with 93% non-volatile carbon content will be: 

(1000 kg – 15%) * 27% = 230 kg/charcoal

At what distance can I install equipment from the settlement?

There are no harmful emissions into the atmosphere when using GreenPower carbonization furnaces, you can verify this by requesting an emission protocol. Environmental friendliness is ensured by burning pyrolysis products in a furnace to maintain the carbonization process and afterburning their residues in a vortex afterburner. 

In what time the BIO-KILN can be produced?

The contract provides the production of one unit of BIO-KILN delivery set within 60 working days from the date of receipt of prepayment. However, as a rule, an order can be completed much faster, it all depends on the production load at the time of the order.

What is the warranty period for your BIO-KILN? And what is the average operating period of your furnace?

If you follow the requirements of production technology and lead a careful attitude to equipment, the life cycle is from 5 to 10 years. After 3 years of operation, it is possible to carry out repair work, for example: replacing the kiln valves, trolleys repair, it is important to understand that repair work does not exceed 10% of the cost of the kiln. In this case, all units exposed to aggressive environments are made of a special type of steel.

For all equipment manufactured by GreenPower, we provide a 1-year warranty only if the Customer is follow the requirements of operating conditions and process technology. The warranty covers all equipment and delivery set manufactured by GreenPower and third parties.

Do you have official documents (passports, instructions, etc.) on the equipment? And whether it is necessary to certify the equipment?

 Yes, of course we have! Each BIO-KILN has a serial number and is accompanied by a full package of documents. This equipment is not subject to mandatory certification, a certificate of the absence of mandatory certification of Russia is sent upon request. To date, our equipment have officially received environmental approval for operation in Europe, Asia, Africa and South America, where they were successfully launched.

Is there excess heat from the reaction, and how is it possible to use it?

From 200 to 1000 kW / h, depending on the raw material and furnace capacity. Excess heat comes out in the form of clean flue gases (without harmful emissions) with a temperature of more than 1000°C, depending on the required thermal processes, it can be used to heat water, oil, air, process steam, etc. Upon additional request, we will offer the optimal solution for your process.

Equipment for drying
Which dryers does GreenPower offer?

The design of the drying equipment is determined by the choice of raw materials for drying.

  • Chamber dryer for drying wood (firewood) and charcoal briquettes.
  • Drum dryer for small raw materials – sawdust, wood chips, etc. 
  • Shaft dryer can be used for wood chips and wood.
What can a chamber dryer be used for?

Chamber dryer can be used for: 

  • Wood drying, for the carbonization process in carbonization furnace of the ЕККО type.
  • Pre-drying the wood significantly shortens the carbonization process in the carbonization furnace and improves the quality of the charcoal. Which in general increases the productivity of furnaces. Optimum drying temperature <200°C. The duration of the drying process corresponds to the duration of the carbonization process in the furnace.
  • Wood drying for fireplaces. Promotes improvement of burning and storage of wood. Typically, the moisture content is adjusted to 15-20%. Optimum drying temperature <150°C.
  • Drying charcoal briquette for BBQ or hookah. Briquetting line included. Optimum drying temperature <100°C.
  • Heating of industrial or household premises. It is possible to receive both hot water and hot air.
What is the heat carrier (where does the heat come from) for the chamber dryer?
  • Separate fire chamber device or a gas (liquid-fuel) burner, for example when using a dryer for fireplace wood 
  • Excess heat from the carbonization furnace EKKO, with a pre-drying system, is used in this case to increase the furnace capacity to pre-dry the wood.
  • Excess heat from the carbonization furnace BIO-KILN, with system for extracting excess heat from the furnace is used to dry charcoal briquette for BBQ or hookah. It is also possible for heating industrial and household premises.
What is the efficiency of GreenPower dryers?

Drum dryer. The maximum effect of the drying plant is ensured by supplying the same amount of thermal energy to each individual piece of raw material. This process is maximally provided by the design of drum drying, where the raw material is in a pseudo-suspended state. However, the use of drum drying for wood is almost impossible due to large pieces of raw materials.

Chamber dryer. In chamber dryers, this effect is ensured by the efficient mixing of heat in the chamber. And also due to the use of recirculation – the repeated use of heat for the chamber, that is, heat is chasing around, moisture is periodically ejected from the chamber.

Main scope of GreenPower dryers?

Dryers are used for: 

  • preparation of raw materials for the carbonization process, which significantly reduces the production cycle time and improves the quality characteristics of charcoal;
  • production of dry firewood for use in fireplaces;
  • preparation of raw materials for the briquetting process.
What kind of dryer would be optimal for preparing firewood for the carbonization process?

The choice of dryer will depend on the design of the carbonization furnace.

For EKKO, it is optimal to use chamber dryers or direct drying in EKKO furnace trolleys using a pre-drying system.

For BIO-KILN it is possible to use almost any type of drying, however, the best choice would be a continuous dryer: shaft or drum.

What is the source of thermal energy for the drying process?

The source of thermal energy can be:

  • carbonization furnace, that is, thermal energy is generated by burning pyrolysis products in wood, residual or excess heat is used to dry raw materials.
  • fire chamber device, can run on virtually any fuel to generate thermal energy, usually wood is used.
What temperature is used for drying in GreenPower equipment?

150-230°С. This is due to the fact that at a temperature of 250°C, an exothermic reaction begins, and when the raw material is heated to >250°C, it may ignite.

How is moisture distributed in different parts of the tree?

In different parts of the tree, water is distributed very unevenly. There is more of it in the sapwood than in the core; the kopel part of the stem contains more moisture than the top part. A tree growing on swampy soil contains more moisture than a tree growing on dry soil. In winter, there is slightly more moisture in the tree than in summer.

What are the types of absolute moisture content of wood?
NameAbsolute moisture content, %Formation conditions
Wet woodMore than 100 %Prolonged exposure to water
Freshly cut50-100 %Variable by season of harvesting
Air-dried15-20%Prolonged period in exposure to warm, dry natural air
Chamber-dried wood6-10%Dried in artificially controlled environment
How does moisture content affect wood pyrolysis?

For wood pyrolysis, moisture content is of paramount importance. Since the yield of valuable charring products is the smaller and the heat consumption for the technological process is the greater, the higher the water content in the charred wood.

What is relative and absolute humidity?

Absolute humidity of wood — is the ratio of the weight of moisture contained in wood to the mass of absolutely dry wood, expressed as a percentage.

Example: If a 300 gram sample weighs 200 gram after drying, then its absolute humidity is (300-200)/200*100% = 50%

Relative humidity of wood — is the ratio of the weight of moisture contained in wood to the weight of raw wood, expressed as a percentage.

Example: If a 300 gram sample weighs 200 gram after drying, then its relative humidity is (300-200)/300*100% = 33%

What determines the drying of wood in natural conditions?

During natural drying, in contact with the outside atmospheric air in motion, the relative humidity of which is less than 100%, the wood dries out. The rate of natural drying is the higher, the higher the air temperature, the lower its relative humidity and the faster its movement. In one minute, an unequal amount of moisture is released from 1 cm2 of different surfaces of wood: most of all – from a cross section of wood, less – from a longitudinal split, and least – from a surface covered with bark.

Can wood naturally dry to a completely dry state?

No, it is impossible

Which layers of firewood, external or internal, dry out faster? Why is this happening?

The external layers of wood dry much faster than the internal ones. When thick and damp logs are quickly dried, the external layers are dry, while the internal layer are just beginning to lose moisture.

How does the pre-drying system for carbonization furnaces EKKO work?

Excess heat is taken directly from the chimney after the afterburner. At the same time, the better the wood was dried, the more excess heat will be for pre-drying, that is, the drying will be more efficient. We recommend first drying the wood in a pre-dryer, and then loading it into the carbonization chamber when starting work on the kiln. It should be noted that the temperature in the chimney can reach 200-1200°C, atmospheric air is used to lower the temperature. That is, the heat is diluted with cold air, as a result of which the temperature of the heat carrier drops to the required one. This process occurs automatically, the operator only sets the required temperature.

The generated heat carrier can be used for chamber dryer or direct drying in trolleys. Chamber dryer significantly increases the efficiency of wood drying, in comparison with trolleys.

How does the system for extracting excess heat from BIO-KILN work?

Excess heat is taken directly from the chimney after the afterburner. The temperature in the chimney can reach 800-1200°C, atmospheric air is used to lower the temperature. That is, the heat is diluted with cold air, as a result of which the temperature of the heat carrier drops to the required one. This process occurs automatically, the operator only sets the required temperature.

The generated heat carrier can be used for chamber dryer, drum dryer or shaft dryer.

What causes cracks in wood during drying?

Due to intensive moisture removal from wood. To avoid the formation of cracks, it is necessary to lower the temperature of the heat carrier for drying and increase the drying time.

How does the density of wood affect thermal conductivity?

The external layers of wood dry much faster than the internal ones. When thick and damp logs are quickly dried, the external layers are dry, while the internal layer are just beginning to lose moisture.

As a result, the drying of wood is uneven. This causes the formation of cracks in it, extending from the

external surface inward along the radius. Cracks in wood are also formed due to faster drying of the heartwood compared to sapwood.

Is the thermal conductivity of wood higher along the fibers or across the fibers?

Along the fibers