Alchemy BFB is a ready-made, functional plant. The project is handled from design through to commissioning of all equipment and systems connected to the operation of the plant, this includes:

• Power plant design and detailed engineering
• Fuel reception area, handling and processing
• Ash removal
• Steam boiler / hot water boiler
• Turbine generator
• Instrumentation and automation
• Complete power plant construction
• Erection, commissioning, training and maintenance services

The supplier network encompasses the leading component and system manufacturers of the energy business. Therefore, in the case of auxiliary equipment supplied, the Alchemy system is complemented by the best know-how in the business.

Seven ready made BFB plants are available within the standard power range of 5 – 100 MW. In addition to the standard power range, solutions can be tailored according to the customer’s specific needs. All power ranges are available for heat and steam plants. We also offer power plants for the combined generation of heat and electricity (CHP) up from 12 MW.

In the Alchemy BFB system, the fluidisation is generated by introducing a flow of preheated air through the grate’s air nozzles, which makes the sand bed become fluidised. The biomass/waste fuel is added to the sand bed by a fuel feed system, which is located above the fluidised bed. The preheated air acts as the primary combustion air. Additional combustion air is injected into the upper combustion zone of the furnace to burn the pyrolysis gases efficiently. The sand bed enhances the mixing of fuel and the transfer of heat.

The Alchemy BFB plant utilises a natural circulation boiler with a water pipe structure in which the water-cooled bed grate is integrated within the pressure vessel of the boiler. This reliable and low-maintenance structure can be utilised in the combined generation of electricity and heat (CHP) and in the generation of district heat and process steam.

The Alchemy BFB includes the efficient removal of coarse material (metal, stones, concrete) off the grate. The specially designed grate leads to a significantly improved operation and effective combustion than in the most typical fluidised bed boilers available on the market. In order to minimise emissions, it is always ensured that the residence time of the combustion gases in the furnace is sufficient for complete combustion.

The bubbling fluidised bed boiler is excellent for multi-fuel usage. The fuel mixture can contain several different fuels from wood-based products through to typical black bag bin waste.

Suitable Fuels

The most typical fuels used in our solutions are wood-based fuels, such as wood chips, bark and sawdust. However, other suitable feedstocks are waste and recycled fuel including black bag waste. The fuel handling equipment is always specifically designed to suit the requirements of the customers particular range of fuel inputs. The Alchemy BFB solution also allows the use of wet fuels, such as moisture contents of 65 % for wood and up to 70 % for milled peat, without any auxiliary combustion. Normally, the moisture content of the fuels used in the system varies between 35 – 65 %.

Advantages of the BFB system

The Alchemy BFB solution is a very efficient and economical solution. The ability to be able to use so-called difficult combustible fuels makes our fluidised bed system and excellent choice over and above similar systems in the market. This is clearly demonstrated when using recycled or waste wood, because the Alchemy BFB grate’s ability to utilise fuels containing a significant amount of metal impurities is remarkably good. These types of fuels are available at low-cost. Furthermore, our combustion solution also enables the utilisation of fuels with very low calorific value, which also directly leads to more cost-effective energy production. The advantages of the Alchemy BFB include; low emissions of carbon monoxide, hydrocarbon and nitrogen oxides, as well as a high level of efficiency. Moreover, the structure of the boiler is simple and low-maintenance. The Alchemy BFB is a modern way of utilising biomass and recycled or waste fuels.