~ What is Biomass?

Biomass is the sequestered energy from the sun or stored solar energy. When properly released this energy can be used to heat communities, commercial buildings, and large farming operations. The term biomass refers to structural and non-structural carbohydrates and other compounds produced through photosynthesis consisting of plant materials and agricultural, industrial, and municipal wastes and residues.  The components of biomass include cellulose, hemicelluloses, lignin, lipids, proteins, simple sugars, starches, water, hydrocarbons, ash and other compounds. 

Biomass consists of organic residues from plants and animals, which are obtained primarily from harvesting and processing agricultural and forestry crops.

The most cost effective heating is Biomass wastes and by-products that are utilized as fuels for producing energy, instead of becoming landfill waste.

Examples of some of the biomass residues that are utilized in direct combustion power plants are:  forest slash, urban wood waste, lumber waste, agricultural wastes, etc.

~ What is a Biomass Greenhouse Gas Displacement System?

A Biomass Greenhouse Gas Displacement System is a technology for extracting heat energy from biomass in a relatively convenient way. Our system is a bale burner that works efficiently day after day year after year.  Biomass material, which is most often wood in solid chunk or particulate form, or agriculture generated straw, is combusted on a grate.  The fuel is fed continuously and automatically by using a conveyor or blower system.  The heat of combustion is transferred to water in a boiler that is separate from the combustion unit.  Water as hot as 190 degrees Fahrenheit is pumped in a loop to serve the demand for heat either through radiant or forced air heat exchangers.  Relatively close control of combustion and heat output can be maintained by synchronizing and automating the rate of biomass feed, the amount of combustion air intake and the temperature difference in inlet and outlet water temperature.

Greenhouse Gas Displacement Systems work best for large loads operating with a substantial year round baseload, such as a process energy demand.   These systems are more effective when operating at steady-state, near-rated capacity and with a high number of operating hours.  This provides maximum fuel savings to cover the capital costs of a GHGDS.

~ The Benefits of a Biomass GHGDS

A GHGDS can provide substantial benefits to committed users.  First and foremost, there is the potential for LOWER COSTS. 

Biomass GHGDS fuel costs are often much lower than those of conventional fossil fuels.

Comparative costs of heating fuels shows the cost of a sample of fuels used to provide a unit of heat energy based on typical costs in 2000.  Note that these costs compare only the value of heat in the fuel and do not include costs of the heating system.

Energy Source Chart:

Beyond economics there are other

           BENEFITS:

Renewable Biomass:

Biomass fuels are derived from a renewable resource.  Fossil fuel supplies are ultimately finite.  However, with proper management the biomass resource base can be sustained indefinitely.

Environmental Benefits:

Biomass combustion is considered CO2 neutral and so is not considered a major producer of greenhouse gas linked to climate change.  GHGDSs are not major contributors to acid rain.  Most biofuels have a negligible sulphur content.

Available Biofuels at Stable Prices:

Biofuels are widely available.  In most areas of America there is a supply of available biomass materials, either forest or agriculture-based.

Biofuel prices are relatively stable and locally controlled.  Prices have remained steady over the years in spite of wide fluctuations in fossil fuel prices, and are expected to increase more slowly than those of petroleum-based fuels.

Local Economic Benefits: 

Biofuel dollars remain in the local economy.  Biomass fuels are generated locally.  Their collection, preparation and delivery involves greater labor input than fossil fuel distribution.  The economic impact of this activity plus the actual fuel purchase means dollars remain in the local area, creating filter-down economic activity as well as improving the local tax base and building tax revenues.

Heating Comfort: 

Biomass systems often provide high comfort levels.  Because biofuels can be inexpensive, system operators are able to justify increased building temperatures leading to greater comfort and productivity.  With high-priced fossil fuels, there is greater pressure to lower temperatures for fuel cost savings.

Commercially Proven and Flexible: 

Biomass combustion technologies are commercially proven throughout America, having already achieved significant market penetration in residential and large industrial applications. 

Biomass combustion systems are highly flexible.  Solid-fuel systems can be easily converted to burn almost any conceivable fuel (solid, liquid or gaseous), thus providing the user with great flexibility in the future.

~ Introduction to:
Vidir Biomass Greenhouse Gas Displacement System

VIDIR BIOMASS INC. has spent many years designing and developing its biomass gasification technology, and is now proud to introduce the VIDIR BIOMASS GREENHOUSE GAS DISPLACEMENT SYSTEM, a new concept in open system hot water and air furnaces.

The VIDIR BIOMASS GHGDS is an updraft, atmospheric pressure gasification system that features

winner of the
INNOVATOR’S AWARD
Rural Forum 2005
Brandon, MB, CANADA

- high output efficiency

- low greenhouse gas emissions

- minimal operator intervention requirements

Given a remarkable appliance efficiency rating of up to 85%, co-inciding with a low cost biofuel, makes the VIDIR BIOMASS GHGDS a superior heat and energy producer ideal for any large scale operation with high energy requirements.

The VIDIR BIOMASS GHGDS  is totally mechanized with a high level of automation and computerization to maintain minimal supervision and maintenance during the operation of the unit.

Designed and manufactured by VIDIR BIOMASS INC.  Vidir will custom build the gasifier system to meet the individual energy requirements utilizing biomass as fuel.

Biomass being utilized in the GHGDS is post-harvested baled wheat straw.  Compared to any other fuel, straw is one of the cheapest and most accessible resource that is totally renewable. The gasification process in the GHGDS will convert biomass to hot water or air and models range in a variety of sizes from 3,000,000 BTU’s and up.  The smallest system producing three million BTU’s per hour and operating at full capacity requires approximately 500 pounds of straw per hour with moisture content from 10 to 15%.

~ Main System Components

1. Bale magazine (baled straw conveying system to automatically support gasifier with fuel)

2. Disintegration machine (straw shredder and product conveyor system)

3. Primary combustion chamber (including ash removal system, grate system and air distribution system)

4. Secondary combustion chamber (including silicone potassium tray for manual removal)

5. Hot water heat exchanger (including automatic cleaning system and tray for clean-out)

6. Exhaust system (including main blower to control air flow and exhaust clean vapour)

7. Main computerized control system (which combines all necessary electrical devices to control each function with limited supervision)

~ Design Features

~ Fuel Storage

Baled wheat straw can be stored outdoors or indoors.  Indoor storage protects the fuel from precipitation (and often from freezing) and can eliminate varying moisture content and decay in the fuel supply.

~ Fuel Disintegration

The fuel processing begins in the shredder where the straw is disintegrated into smaller, manageable particles.  Interruptions or delays in reclaiming fuel are directly related to fuel properties, i.e. poor flow, compaction, frozen chunks, oversize material and contaminants, and therefore, fuel preparation is critical to the overall operation of the system.

~ Fuel Transfer

From the disintegration machine, the particulate fuel is moved by a belt conveyor to the fuel injection system.

The fuel injection system feeds the fuel directly into the primary combustion chamber utilizing a mechanical plunger. 

The back flow of combustion flames and gases through the fuel entry is controlled by an automated trap valve.

~ Primary Combustion Chamber

The primary combustion chamber is an enclosed area where drying, pyrolysing and oxidizing occurs.  The fixed rotating grate supports the fire bed and allows for underfire air to be blown up through the fuel.  Effective oxygen supply and control is critical to ensure complete combustion.

Ash collects below the grate and is removed automatically by an auger.  In general, ash from biofuel burning is not considered a hazardous waste and can be placed in local landfills.  However, most ash is an excellent soil additive and can be provided to local gardeners and farmers or can be spread on farms or in forested areas.  Proper ash management is critical, as non-combustible inorganic (mineral) content of biomass can become significant, depending on the type of fuel utilized.  Inherent ash is generally low in clean wood (0.5%), higher in bark (3.5%) and significant in annual crops such as straw (6.2%), but usually consistent within a fuel type.  Ash content is usually expressed on a dry basis, i.e. the weight of ash as a percentage of the total moisture-free fuel weight.

~ Secondary Combustion Chamber

The hot exhaust gases exit at the top of the primary combustion chamber and pass through a refractory duct that includes an oxygen mixer and into the secondary combustion chamber.  As the gases are being transported from the primary to the secondary chambers, the injection of oxygen ignites the gases, allowing gas combustion to take place in the secondary chamber.  The

quantity of heat released during the biofuel gas combustion is drastically increased to approximately 2,500 degrees Fahrenheit.

Extreme high temperatures are maintained in the combustion chambers by lining the chambers with refractory, which radiates and reflects heat back into the fuel layer.  The refractory also protects the walls and base of the chambers from the high temperatures in the combustion zone.

When agricultural-based straw is being utilized as the primary biofuel, a small accumulation of silica and potassium debris settles in the removable tray at the bottom of the secondary combustion chamber that requires periodic clean out. 

~ Heat Exchanger

The extreme heat from the secondary chamber is transferred to the heat exchanger or water-tube boiler that has a series of tubes through which water passes with the heat on the outside of the tubes. Because it is one of the best conductors of heat, water is the medium being used to transport the heat through insulated underground pipes to its desired location and supply precise heat for any public, commercial, residential or agricultural building.

Because it is moved by combustion gas flow, fly ash can deposit on the heat exchange surfaces in the boiler.  This ash must be regularly removed to maintain good heat transfer performance.  A series of scrubbers are designed to automatically clean the boiler tubes and to specifically collect the fly ash in the particulate collection system.

~ Exhaust System

An induced-draft exhaust system is utilized to complete the final gasification process.  The induced-draft system uses a large blower located in front of the stack which sucks the exhaust gases out of the boiler and forces them up the stack.  The draft of this fan is regulated in relation to the combustion air to maintain a very slight negative pressure in the combustion chambers so that gas flow is continuous and that no combustion gas leaks occur.

~ Instrumentation

Instrumentation is important for efficient operation, response to energy demand and safety.  The complete feed and gasification process requires a complex control system strategy by using computers and micro-processors to match heat delivery with demand. A key task of the control system is determining the rate at which fuel and air are fed to the primary combustion chamber to ensure efficient combustion.  Control is achieved when fuel and air are automatically modulated simultaneously to maintain the correct ratio under high or low demand. 

Start-up and shutdown sequences are programmed, and alarms will sound in upset conditions.

~ System Requirements

1. Electrical power (3 phase system with AC continuous power)

2. Air requirement (compressor 100-120 PSI, 7-10 CSF)

3. Cold water source (50-70 PSI, 2-4 gallons/minute)

4. Concrete floor and building structure (brick or metal)

5. Shelter (or building structure) to cover the disintegration and conveyor system

6. Ash bin (to contain ashes being removed from the gasifier primary chamber)

~ System Maintenance

The Vidir Biomass GHGDS requires a low level of maintenance and management.  Tasks such as ash disposal, general cleanup (usually in the fuel storage and handling area), checking heat exchanger water levels, checking the fuel delivery system for oversize material build-up, plus monitoring primary and secondary combustion chamber temperatures, along with stack temperature are done daily.  The computer system will signal the operator in upset conditions or for out-of-range readings.

In addition, there are regular maintenance tasks that are performed on a periodic basis that may vary from weekly to monthly to even yearly.  These can include:

• replenish depleted fuel supply

• mechanical component lubrication

• inspection and adjustment of chains, gearboxes, blowers, etc.

• silica removal from secondary chamber

• debris removal from heat exchange

• refractory inspection and repair

• testing of safety devices

Most of the routine maintenance can be carried out by the system operator or by the general on-site maintenance staff.  It is highly recommended that the system be inspected by a Vidir service technician on an annual basis.

~ System Life Expectancy

In theory, the VIDIR BIOMASS GREENHOUSE GAS DISPLACEMENT SYSTEM can last indefinitely, since the components can be replaced as they wear out or deteriorate.  In the forest industry, wood combustion systems have been in operation for over 50 years.  In practice, 15 to 20 years is used as a reasonable biomass combustion system life expectancy for the purpose of life-cycle costing.

~ Emissions

Dillon Consulting Limited was retained by Vidir Biomass to conduct source testing on the gasifier exhaust stack to quantify combustion gas emission rates.  These measured emission rates were conducted with the gasifier operating at the maximum system designed production rate of approximately 500 pounds (227 kg) of straw feed stock per hour.

The following gases were measured from the exhaust gas stream:

• Oxygen (O₂);
• Carbon Monoxide (CO);
• Sulphur Dioxide (SO₂);
• Oxides of Nitrogen (NO, NO₂, NO_X);
• Carbon Dioxide (CO₂).

The following table summarizes the results of the combustion gas concentrations in the Vidir gasifier exhaust stream.