FAQs
I-Technical ( Process)
| Q. | What is Biomass Gasifier? | ||||||||||
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| A. | A biomass gasifier is device that converts biomass (wood blocks, wood chips, rice husk, saw dust, and other such agricultural residues) into a combustible gas called “producer gas”. The producer gas has a lower calorific value than CNG/LPG, but still can be used in oven/furnaces where the temperature requirement is up to 900 oC. | ||||||||||
| Q. | What is the gas generated from the Gasifier? | ||||||||||
| A. | The gas generated from the gasifier is called “producer gas”. The main combustible components of the producer gas are Carbon monoxide (20-25% v/v), Hydrogen (8-10% v/v), Methane(2-4% v/v) and small quantities of other higher gaseous hydrocarbons besides other non-combustibles like Carbon dioxide (8-10% v/v) and nitrogen (50-55% v/v). The typical calorific value of this gas is 1200 kcal/m3, which much less than LPG/CNG. Typically flame temperatures of over 1000 oC can be achieved by this gas. | ||||||||||
| Q. | How does a Gasifier work? | ||||||||||
| A. | The gasifier is a thermal reactor which thermally cracks the biomass into a gaseous state by the application of intense heat in a controlled oxygen starved atmosphere. The biomass is fed at the top of the reactor and moves downwards towards the grate by gravity. During this motion, it passes through the “drying”, “pyrolysis”, “controlled combustion” and “reduction” zones in that order. The boundaries of each of the zone above are not rigid but transitional. Moreover, depending on the wood characteristics and the load, the height of each zone also varies. Each of the zones, have a specific reaction component to perform, resulting in the formation of “producer gas” and ash/char mixture at the end of the reduction zone, where the grate is located. | ||||||||||
| Q. | What is the maximum working temperature achievable with producer gas/Gasifier? | ||||||||||
| A. | Applications with temperature requirement up to 900 oC can use producer gas / gasifier without any problems and any change in the existing system. With air preheating, the temperature requirement up to 1100 oC can be met.
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| Q. | How much wood does a gasifier consume? | ||||||||||
| A. |
A chart that gives the wood requirement to replace one unit of conventional fuel:
#Indicative value for applications requiring < 500 oC |
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| Q. | Does the Producer Gas contain sulphur or other harmful gases? | ||||||||||
| A. | No, Producer Gas does not contain sulphur or any other harmful gases. In fact, dust free producer gas can be used direct fired drying oven, without affecting the quality of the product at all. | ||||||||||
| Q. | Is there any pulsation/fluctuation in gas production in gasifiers? | ||||||||||
| A. | No, Gasifiers have a very high thermal inertia, which ensure a very stable gas production. | ||||||||||
| Q. | Is there any pulsation/fluctuation in gas quality in gasifiers? | ||||||||||
| A. | No, the wood/biomass takes over 2 hours to get fully converted to producer gas. Hence, small variations in fuel quality/characteristics get averaged out, and a fairly uniform quality of gas is produced. | ||||||||||
| Q. | Is there any effect of weather/seasons in gas quality in gasifiers? | ||||||||||
| A. | No, as long as the wood quality (moisture content, mainly) is maintained, the atmospheric conditions have negligible effect on the quality of gas generated. |
II. Technical ( Operation)
| Q. | What are the benefits of installing a gasifier? |
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| A. |
There are manifold benefits to be gained from installing a gasifier, including:
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| Q. | What fuels can I burn? |
| A. | Wood /Wood Chips/ briquettes with a maximum humidity of 15% can be burnt in the Infinite Gasifier, lower the humidity the better the combustion efficiency. |
| Q. | Will the installation of gasifier make the work area dirty/unhygienic? |
| A. | The producer gas generated from the gasifier can be piped to reasonable distances (up to 400 ft). Hence, the gasifier can be located in an area that will not affect the actual work area. Therefore, effectively, there will be no difference in the work area. In some cases, the work areas are cleaner as there no oil spillage possible around the burner area. |
| Q. | How is the gasifier installed to work with an oven/furnace? |
| A. | Typically, the gasifier is installed in a location in the factory premises where wood/biomass can be stored and handled. In the oven/furnace, the existing burner is replaced with a specially designed producer gas burner of appropriate design and capacity to match the oven/furnace's requirement. The gas generated from the gasifier is transferred through pipes to the location of the actual usage using high pressure blowers. Thus there is no apparent change, as far as the oven/furnace operation is concerned. |
| Q. | How is the oven temperature control achieved? |
| A. | The oven temperature is controlled by regulating the gas flow into the burner. The regulation is done automatically, use of closed loop control systems by our gas burners. |
| Q. | How is the generation of gas matched with the requirement of the oven? What happens if excess gas is generated? |
| A. | Infinite Vergassen systems have the most advanced control systems of all gasifier made in our country. The control system continuously regulates the generation of the gas to match the requirement of the oven/furnace. Hence, no excess gas is generated – ever. In case all the connected burners are switched off, the gasifier turns down to 30% capacity ( minimum possible load) and the gas produced is flared in the flare burner provided with the system. |
| Q. | Do we need skilled personnel for operating the gasifier? |
| A. | No, the main work of the operating personnel would be wood feeding, ash removal, filter media removal and refilling. These are all periodical tasks to be done every ½ hour. One skilled technician would be required for maintenance and trouble shooting. The technician would be trained by us, in all aspects of gasifier operation, controls, maintenance and trouble shooting. The person should have basic working knowledge on the working of common devices like motors, pumps, blower, compressors, pneumatic cylinders etc. |
| Q. | What is the gas pressure at the burner? |
| A. | The gas pressure at the burner is very low and is typically 50 mmWC. |
| Q. | What is the gas temperature at the burner? |
| A. | The gas temperature at the burner is not less than 150 oC, but can be as high as 250 oC, depending upon the distance from the gasifier. |
| Q. | What is the start-up time required for the gasifier? |
| A. | The gas production starts within 10 minutes, up to 75% capacity can be achieved within 30 minutes and 100 % in one hour. |
| Q. | What is the time required for shutting down? |
| A. | The gasifier can be shut down practically within 5 minutes. However, very small amount of gas and water vapor will continue be released and will have to vented for sometime after shut-down. |
| Q. | What is the maintenance schedule for your gasifiers? |
| A. | Scheduled maintenance twice a month is essential for trouble-free, uninterrupted operation of the gasifier. |
| Q. | What is the time required for scheduled maintenance? |
| A. | Typically 6-8 hours. |
| Q. | What is to be done if there is a gap in oven/furnace operation of less than one hour? |
| A. | The gasifier can be turned down to its minimum capacity (30%) and the gas generated may be flared. This will ensure 100% gas availability almost immediately (within 10 minutes). |
| Q. | What is the quality of required wood for gasifier operation? |
| A. | Any species of wood can be used in a gasifier, subect to the following: -Moisture content < 15% (on weight basis) -Size of wood shall be as required by the gasifier (depending on the model). Larger models can accept wood block of up to 90x90x90 mm size. -Avoid wood with bark as much as possible- this is because bark has much higher ash content and tends to have more foreign material/dust that wood itself. |
| Q. | How do we find the moisture content in wood? |
| A. | Wood moisture meters are easily available in the market. These meter are conductivity based and can provide instantaneous readings. |
| Q. | How to ensure that the wood moisture content is less than 20%? |
| A. | Batch type wood dryers are supplied with every Inifnite Vergassen system. These dryer use waste wood as fuel and can reduce the moisture content in wood to as low as 5%. |
| Q. | If we have two or more than two oven – what would be your suggestion – One Gasifier for all ovens or one gasifier for each oven? |
| A. | This would depend upon the location of the ovens, the complexity piping and the capacity of individual ovens. If the ovens are not far apart, and the piping is not complex, and the total capacity required is within our manufacturing range, a single large capacity gasifier may be provided with more than one oven. |
III. Commercial
| Q. | What is the Space required for installing a gasifier? |
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| A. | The space required would depend on the system capacity. Typically, a 1000 kWth system, replacing 70 kg/h of Furnace oil can be installed in area of 750 ft2 with an additional 750 ft2 for wood storage and drying. |
| Q. | What is the typical delivery time of gasifier after placement of order? |
| A. | Maximum Three months from date of order acceptance. |
| Q. | What is the time required for installation of gasifier? |
| A. | Typically the gasifier can be installed within 15 days, if all the civil work required is complete at the time of start of installation. The time required for completing the piping work would depend on the site conditions – length, complexity etc. |
| Q. | What are the payment terms? |
| A. | 50% of contract price as advance at the time of placement of order Balance payment at the time of dispatch. |
| Q. | Are any approval required for installation of gasifier? |
| A. | No special approvals are required for installation of gasifier to the best of our knowledge. |
| Q. | What is the quantum of subsidy available for gasifier and what is the procedure for availing it? |
| A. | The MNRE (Ministry of New & Renewable Energy, Govt. Of India) provides a subsidy of Rs 2,00,000/- for every 300 kWth of installed capacity on prorate basis. An application for subsidy has to submitted to MNRE (Govt. of India) along with a detailed project report. On obtaining sanction from the MNRE, one may install the system. The subsidy would be released after submission of requisite documents including performance report of one month of successful operation. |
IV.Infinite Vergassen Gasifier - Special Features
| Q. | The Infinite Vergassen Advantage |
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| A. | The Infinte Vergassen has a range of special features that gives it a distinctive edge in gasifiers for thermal applications. |
| Q. | Dry Gas System |
| A. | The Infinite Vergassen design incorporates a completely dry gas generation, handling & distribution system as scrubbing the gas with water is not necessary. Thus, there is no sticky "tar" and tar contaminated effluents to be handled / disposed. |
| Q. | Hot Gas Filter System |
| A. | The Infinite Vergassen incorporates a unique hot gas fine filtration system (optional), a first of its kind, which can clean hot gases (temperatures up to 600 oC ). The dry gas filtration has an efficiency of over 96% for particulates over 10 micron size. It can typically produce a clean gas with less than 80 micrograms per m3 of particulate matter. |
| Q. | Compact foot print |
| A. | The Infinite Vergassen series is an extremely compact gasifier. A typical 600 KWth system complete with reactor, gas cleaning & handling system would occupy a space of only 20ft x 20ft (Excluding fuel storage). The system design is such that the support structure and access platforms and ladders are integrated. The reactor does not require any foundation. So, only site preparation and light civil work (flat concrete flooring and approx.15 cu.ft foundation for blower) would be required. |
| Q. | Wide Range of Burners to suit any application |
| A. | We have a wide range of burners which are specially designed for specific applications. Each type of burner is designed so as to meet the requirement of flame profile, flame temperature and other furnace characteristics. We also have in our range, fully automatic producer gas burners for use in applications such as baking ovens, POP kilns, hot air generators etc. where temperature control is critical. The automatic burners are fully loaded with safety features and interlocks to have reliable, safe and completely automated operation. |
| Q. | Quick Start and Shutdown |
| A. | The Infinite Vergassen series has extremely quick start capability and reach 75% of its capacity with 30 minutes of cold start and 15 minutes of restart (within 12 hours of shut down). Typically the shutdown time is lees than 15 minutes. |
| Q. | Automation |
| A. | We have a range of optional automation features available. The automation system is designed so as to reduce the skill levels required of the gasifier operator, simultaneously ensuring, smooth trouble-free and uninterrupted operation of the gasifier system. Depending on the clients' requirement, the Infinte Vergassen's operations may be totally or partly automated. The automation modules include: 1. Reactor Pressurtrol: To maintain the required gas quantity and quality accurately. 2. Load synchronizer: To control and regulate gas generation to match the load requirement. This eliminates possibility of excess gas pressurization / low heat availability and also eliminates the need to flare excess gas. 3. Automated filter operation: To prevent problems such as choking and dust carry over from the filter. |
V. Gasifier safety
Producer gas, the mixture of carbon monoxide, hydrogen, methane and other gases, may be hazardous, if it is not handled and used properly. Poisonous component of producer gas is
carbon monoxide. All hazards associated with use of producer gas are described here.
Fire hazards
Fire risks have been minimized by taking following precautions
| Fire Risk causes | Precautions taken |
|---|---|
| High surface temperature | Insulation of hot parts of system |
| Sparks during Re-fuelling | Use of double sluice filling device |
| Backfiring from nozzles | Installation of nozzle covers |
Explosion hazards
Explosion can occur if the producer gas is mixed with sufficient amount of air to form explosive mixture. This problem is relevant in case of gasifiers with large filters where considerable quantity of gas is stored. Our systems are specially designed to minimize these risks. In our design, gas is never stored and so the probability of explosions is eliminated.
Other possible reasons for mild explosions are:
| Mild Explosion Risk causes | Precautions taken |
|---|---|
| Air penetration during Re-fuelling | Use of double sluice filling device to minimize air ingress |
| Air leakage into cold gasifier still containing gas which can ignite | Ventilate cold system before igniting the fuel |
Toxic hazards
Producer gas consists of carbon monoxide, which is slightly toxic as it combines with hemoglobin in the blood, preventing oxygen absorption and distribution. Carbon monoxide concentration of 50 PPM produces no effect. As concentration increases, there arise problems of headache and dizziness. No chronic symptoms can occur as the result of prolonged inhalation of relatively small amounts of carbon monoxide. Fortunately, there is less chance of gas escape during operation as gasification system works under suction. However, situation is quite different during starting and closing installations. To avoid the trapping of gas, it is recommended to install the gasifier plant in the open air or well ventilated areas.
Environmental hazards (Effluent Generation)
During the gasification of biomass, ashes and condensate (mainly water) are produced.
Solid Effluents
Ashes and dust (inert mineral matter) do not contribute to any environmental hazards and can be safely disposed. The ash generation varies with the feed stock but in general is less than 6% for most woods.
Liquid Effluents
The Infinite Vergassen has minimal water consumption. The water is mainly used for purpose of gas sealing only. The water gets contaminated with a bit of mineral matter during the process and has to changed periodically (every fortnight).
The Infinite Vergassen does not incorporate water based gas cooling and hence the typical problems related to tar condensation, water contamination by tar and its disposal do not arise.Gaseous Effluents
Typical Emission Composition of producer gas
- Nitrogen 70%
- Oxygen 6%
- CO2 14%
- H2O 9%
- Other 1%