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Biomass Gasifier

Infinite Gasification systems are a simple and reliable solution for bringing down the fuel cost by over 50%.

The Gasifier unit is essentially a chemical reactor, where several thermo-chemical processes such as pyrolysis, combustion, and reduction take place.It converts solid biomass into clean combustible gas(producer-gas) by means of a process known as thermal gasification .

The gasification system can be physically isolated from the combustion system & the producer gas can be piped from the gasifier (which may be located outside the plant building) to the ovens/furnaces etc located in the plant building and hence the handling of fuel and ash removal can be away from the actual working area.

The producer gas produced by Gasifier can be burnt in specially designed burners, in place of fossil fuels like F.O/L.D.O/Diesel/LPG/CNG. Thus, expensive liquid/gas fuels can be effectively replaced by low cost wood/Biomass without any changes in operations, temperature profile, temperature control and cleanliness in the plant area.

Most biomass materials like Wood , Charcoal , Rice Husk etc can be converted into a gaseous fuel known as producer gas, which comprises carbon monoxide, hydrogen, carbon dioxide, methane, and nitrogen. This gas has a lower calorific value (10001200 kcal/nm3) compared to natural gas or liquefied petroleum gas, but can be burnt directly with high efficiency and good degree of control without emitting smoke. The producer gas flame temperature can be as high as 1100 oC. Each kilogram of air-dry biomass (10% moisture content) yields about 2.5 nm3 of producer gas. In energy terms, the conversion efficiency of the biomass gasifier process is in the range of 80%90%.

Infinite Gasifier offers all the advantages associated with using gaseous and liquid fuels such as clean combustion, compact burning equipment, high thermal efficiency and a good degree of control just like conventional diesel burner.

What Is Biomass Gasification?

The Old Method: Conventional Combustion

We know very well that the direct burning/ combustion of wood / biomass, is a complete oxidation process, which primarily produces heat (thermal energy). The by-products are solid waste, and carbon dioxide (CO2), NOx, CO, and particulate emissions most of which are potentially hazardous to the environment..

Combustion is an inefficient conversion process when generating power alone-some advanced designs are improving efficiency. It requires water if generating power with a steam turbine

Combustion is of limited value, it's dirty, and it makes the control and capture of CO2 very difficult, if not impossible. Because of the relentless rise in oil and gas prices worldwide, We believe that gasification offers significant economic and environmental advantages as an unconventional source of energy in a carbon constrained world.

The New Technology: Gasification

Gasification is a flexible, reliable, and commercial technology that can turn a variety of low-value feedstocks into high-value products, help reduce a country's dependence on imported oil and natural gas, and can provide a clean alternative source of energy.

The gasification process renders the use of biomass relatively clean and acceptable in environmental terms. The gasifier does not generate emissions: engines exhaust gas is cleaned in a catalytic converter and then, in case that the concerning heat is used for biomass conditioning, sent to the dryer where it is further bio-filtered.

In this process organic or fossil fuel based carbonaceous materials converted into producer gas ,a low calorific power (1000-1200 kCal/m3 ) mix of Carbon monoxide 18%-20%, Hydrogen 15%-20% Methane 1%-5%, Carbon dioxide 9%-12%, Nitrogen 45%-55%.

This is achieved by reacting the material at high temperatures (>700 C), without combustion, with a controlled amount of air/ oxygen.

Gasification process

It includes four stages, each occurring in one of the four separate zones within the gasifier: drying, pyrolysis, oxidation and reduction zone.

Drying

In the drying zone, moisture in the feedstock is evaporated by the heat from the lower zones at a temperature of 150-200 degrees C. Vapours move down and mix with vapours originating in the oxidation zone. A part of the vapours is converted into oxygen under the following chemical reaction: ? + H2 O <=> CO +H2 with the remainder being retained in the producer gas.

Pyrolysis

Located below the Drying Zone, temperatures here reach 400 to 650 degrees C. Pyrolysis reactions occurt temperatures above 250 degrees C. During pyrolysis, large molecules such as cellulose, polycellulose and lignin, are broken down into medium-chain hydrocarbons and carbon (charcoal). Pyrolysis products then move down towards hotter areas within the gasifier, some of these burn while the others break down further into smaller molecules and atoms such as hydrogen, methane, carbon monoxide, ethane, ethylene, and others.

Oxidation

At this level, air is injected into the gasifier, leading to the following chemical reactions:

C + O2<=> CO2

H + 1/2O2<=> H2 O

These reactions release large amounts of heat (401.9KJ/mol and 241.1 KJ/mol) that increase the temperature inside the gasifier to 900 - 1,200 degrees C. This assists with burning off a substantial part of tars that would otherwise condense further downstream.

Reduction

In the reduction zone, the thermal energy generated in the Oxidation zone is converted into chemical energy in the following reactions:

C + CO2<=> 2CO C + H2 O <=> CO + H2

CO + H2<=> CO + H2 O

C + 2H2<=> CH4

CO + 3H2<=> CH4 + H2 O

These reactions are endothermic and reduce the temperature of gas exiting the Oxidation zone as it passes through the bed of charcoal at the bottom of the gasifier. Producer gas in its final chemical composition is formed in this zone. Upon leaving the gasifier this gas has temperatures of 250-500 degrees C and can be fed to burners or, after additional cleaning and cooling, fired in internal combustion engines.

ADVANTAGE OF INFINITE GASIFIER

Infinite gasification systems have a number of unique features that make them an ideal solution for Industrial Heat & Power.

Simple, Easy Operation, Easy to load, Simple to start
All you'll need to start the Infinite Gasification System is a fire lighter and some light sticks. The Gasifier manages the rest of the start-up procedure making sure that the fire builds up as quickly and efficiently as possible.

Clean Producer Gas
Since Infinite gasifiers produce an exceptionally clean Producer gas, heat exchangers remain clean and require minimal maintenance and downtime. Clean Producer gas can also be used to directly fire heating and drying applications such as Sesame seed dryers, Biscuit wafer plant, Singeing machine, & rotary dryers, dry kilns, lime kilns etc or can be fed into Gas engine for power generation.

Low Particulate Emissions
Infinite gasifiers produce extremely low particulate emissions (typically (50 mg/m3) that may eliminate the requirement for air pollution control equipment such as multicones, electrostatic precipitators (ESPs) or bag house filters depending on the fuel type .

High efficiency
Due to the unique design Infinite Gasification systems achieves extremely high efficiencies, up to 91% on some models.

Indirect Gas Cooler
The Infinite system uses only indirect gas cooler and thereby eliminates water based gas cleaning. Thus, there is no sticky "tar" and tar contaminated effluents to be handled / disposed.

Hot Gas Filter System
The Infinite Vergassen incorporates a unique hot gas fine filtration system (optional), a first of its kind, which can clean hot gases (temperatures upto 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.

Compact foot print
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 is required.

High Turn-Down Ratio
The output of the gasifier can be reduced upto 1/3 of its maximum capacity while still maintaining stable operation.

Quick Start and Shutdown
The Infinite Vergassen series has extremely quick start capability and reach 75% of its capacity with 30 mins of cold start and 15 minutes of restart (within 12 hours of shut down). Typically the shutdown time is less than 15 minutes.

Idling Capability During Low Load Periods
Infinite gasifiers quickly ramp down into an idling mode where they can remain on standby for extended periods, such as a weekend shutdown, without consuming fuel, and then be brought back to full capacity within two hours. This enables operators to save fuel and avoids shutdown and restart during periods of low heat demand.

Fuel Flexibility
Infinite gasifiers can accommodate a wide range of wood fuels including wood Chips , Wood Blocks, Biomass Briquettes, & other biomass from powdered to 5-inch minus sizes

Low Capital Cost
Infinite energy systems cost less because they are simpler in design, contain less equipment and have fewer moving parts. The ash collection system is also fully automatic, simpler, less expensive and easier to operate compared to conventional gasification systems.

Low O &M Cost
Infinite systems are less expensive to operate and maintain because of their simple design and requirement for less equipment. Lower gas velocities and temperatures in the gasifier result in longer life and less refractory maintenance. Reduced particulate scouring results in less wear on the refractory in the gasifier.

Superior operational control, high turndown ratio, idling capability, producer gas control and ability to eliminate ash melting, all contribute to making Infinite gasifier systems very simple and easy to operate compared to conventional gasification/ combustion processes. This results in minimal operator intervention and contributes to low operating cost.

Easy, Automated Operation (Modern, user-friendly controller )
Infinite systems are fully automated for unmanned operation with state-of-the-art controls. The Infinite Gasifier comes with an easy-to-use controller which manages the complete Gasification process and regulates supply to the burner/engine system. The control system is designed to provide safe, efficient operation of the energy system

Depending on the client's requirement, the Infinte Vergassen's operations may be totally or partly automated. The optional automation modules include:

  • 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.
  • Automated filter operation: To prevent problems such as choking and dust carry over from the filter.
  • Load following control (optional): the gas generation ( and consequently fuel wood consumption) is automatically controlled to follow the thermal load requirement.
  • Wide Range of Burners to suit any application (Fully Automatic Burners)