About Aalborg Energie Technik

AET assists our customers to achieve a viable business case through good feasibility, high efficiency, high availability, low emission impact, low maintenance costs and above all - a well-functioning plant.

Biomass fuel flexibility
The AET biomass technology makes it possible to use many different types of biomass fuel - separated or in combination. The biomass fuels originate from forestry, agriculture, residual products from process industries / machining industries or are based on industrial waste.

Examples of different types of biomass fuels in existing plants are:

• Uncontaminated wood: GDF-Suez - Cofely - BCN, Western Wood E.P., Linz Mitte
• Waste wood & dust: FunderMax, Kronoply, Pfleiderer-Gütersloh
• Wood, straw / chicken litter: Zignago Power, EPRL-Fibrogen, EPRL-Fibropower, Slagelse.
• Conversion: Coal & biomass: Randers KVV, Boehringer Ingelheim

High reliability/efficiency and low maintenance
The AET Biomass Boiler is designed to be:

• Extremely reliable (+99 %)
• High boiler efficiency (92%)
• Very low maintenance costs
• High fuel flexibility.

See example of an AET Biomass Power Plant with +99% reliability and 92% boiler efficiency or read more about the benefits of the AET Boiler Concept.

Environmental friendly with low emissions
With a supply from AET either to a cogeneration plant, CHP plant and/or power plant the solution for the renewable energy solution can be very environmental friendly as emissions are low from AET boiler plants (see example of emissions for contaminated wood); as AET is one of the most innovative boiler suppliers in the world.

REFERENCES

AET power plants or combined heat and power plants (some with district heating). AET's objective is to be the most attractive long-term supplier in the biomass boiler market for the potential customer involved; either it is for a power plant or combined heat and power and maybe with district heating.

AET do supply turnkey biomass boiler islands and even a full EPC. For all our supplies and plants we focus on:

• Process integration / heat balance optimization
• High availability and low emissions
• In-house functional and detailed design
• Fuel flexibility
• Open, efficient and proactive corporation
• Professional and experienced project management

We believe that the above and our good track record will result in a good project and business case for the customer.

Below you will have an overview of the plants and click for further details to the individual projects:

*PP = power plant, CHP = Combined heat and power CHP-DH = combined heat and power with district heating

AET COMBUSTION SYSTEM

The most important decision in the design of a well-functioning biomass fired plant is the choice of combustion system.  

The fuel challenge: Some biomass fuels have ash content with a strong tendency to slag and block the heat transfer surfaces. Others contain foreign matter that requires special measures in the fuel handling to protect the equipment, and in the combustion process to protect the environment.

The AET furnace, boiler and combustion system design is based on more than 25 years of experience in combustion of many different types of biomass, varying widely in fuel quality and properties. AET has experience with wood chips, demolition wood, waste wood, sawdust, sander dust, railway sleepers, cuttings from forest, olive stones, shea nuts, bark as well as straw, poultry litter, compost, sludge, meat and bone meal etc.

Full control of the design at AET

AET have many years of design experience with combustion systems for biomass, experience from maintenance of many plants as well as operational experience at Western Wood Energy Plant.

AET has always had in- house design of the Boiler Concept:

• furnace
• overfire air system
• superheaters
• economiser
• ducting
• etc.

The emissions were previously acceptable, but there was also opportunties for improvement. Many years ago AET therefore decided to insource the functional and detailed design of the major combustion components with success:

• Dosing bin
• Rotary valves for fuel
• Spreader stoker (single fuel or more fuels - combi spreader)
• Dust firing system
• Travelling grate
• SNCR DeNOx. SNCR DeNox is also supplied to other boiler types.
• Re-injection of fly ash
• Integrated Coarse ash seperator

The AET Combustion System has improved the emissions, availability and maintenance costs remarkably. As an example AET can by these in-house design products full-fill the most stringent emission criteria for clean wood with any secondary measures. At the same time it simplifies the responsibility to one point only.

Our references all show long-standing high availability

Some of the most important qualities in the AET design are:

• Very low flue gas emissions
• Very high availability
• Very long operating time (>8000 hours) between shutdown for manual cleaning
• Robustness towards foreign objects (stones, metal, glass) in the fuel
• Low power consumption
• Good fuel burnout
• High boiler efficiency
• Low maintenance costs

AET has chosen the right technology for biomass utilisation

The fuel is pneumatically transported into the combustion zone using AET-BioSpreaders for wood chips and, if necessary, using AET dust firing system for pulverised fuel. Small particles burn in suspension while larger particles land evenly on the grate forming a fast-burning layer of fuel.

The grate, which forms a "floor" in the furnace, is an AET-BioGrate travelling grate. The continuously moving grate carpet slowly transports the burning fuel layer towards the boiler front where the ash falls into the ash pit. The grate speed can be adjusted to account for variations in fuel quality and ash content.

Approximately 50% of the combustion air (the primary air) is led to the grate and flows through small air nozzles in the grate bars. The secondary air is injected into the combustion zone through several rows of air nozzles, strategically placed to ensure an efficient mixing of air and combustion gasses. This staged combustion enables low NOx emissions to be achieved.

Unlike a mass burning grate which has separate zones for drying, gasification, combustion and fuel burnout, the travelling grate operates with a more evenly distributed combustion over the entire grate.

The optimal combustion temperature is obtained by low excess air ratio, air preheating and/or flue gas recirculation.

Several local and international customers has recognised that the AET combustion system is unique and giving the optimal basis for their business.

Welcome to see more details on our webpage: www.aet-biomass.com