Glossary

 Multi-Energy Boiler House

• Alternative fuels – all fuels other than traditional fossil fuels (coal, oil, natural gas). these include biofuels or waste oils. their benefits include lower CO₂ emissions and independence from limited fossil resources.
• Biogas – a gas produced in the fermentation process of organic waste (e.g. in biogas plants, landfills, sewage treatment plants). it contains methane and carbon dioxide. it can be burned in boilers or used for electricity and heat production, and when purified, it becomes biomethane.
• Biomass – any organic material that can be burned and used for energy production. this includes wood, wood chips, sawdust, straw, plant residues, or even food waste. biomass combustion is considered climate-neutral, as the CO₂ released during combustion was previously absorbed by plants through photosynthesis.
• Bio-oil – a liquid fuel derived from biomass, e.g. vegetable oil or biodiesel. it can be burned in boilers instead of traditional heating oil, reducing CO₂ emissions.
• Biomethane – biogas that has been purified of carbon dioxide and hydrogen sulfide. it then has the quality of natural gas (over 95% methane) and can be used as a substitute – e.g. to power boilers or injected into the gas grid.
• Boiler house service – a set of operational activities including periodic maintenance such as boiler and heat exchanger cleaning, inspection of fuel feeders, flue gas filtration systems, and automation.
• Booster – in a multienergy boiler plant, this refers to a set of electric heaters installed in the boiler. these allow the unit to operate stably at minimal load (from 0% to 20% capacity) and support the boiler above 100% nominal capacity (up to 120%). this solution increases the flexibility of the entire system and ensures continuous heat supply regardless of load.
• CHP (Combined Heat and Power) – cogeneration of heat and electricity. in a multienergy boiler plant, this means that steam produced in the boiler first passes through an expander, which converts part of its energy into electricity. the same steam – now at lower pressure – is then directed to heating or process applications. this allows simultaneous production of heat and power from a single fuel source, increasing overall efficiency.
• CO₂ emission fees – costs associated with emitting carbon dioxide into the atmosphere. these apply to boiler houses using fossil fuels. multienergy boiler plants burning biomass or biogas are exempt, lowering operating costs.
• CO₂ neutrality – the principle that the amount of CO₂ released during biofuel combustion is offset by the CO₂ absorbed by plants during growth. therefore, biomass combustion does not increase global CO₂ emissions when conducted sustainably.
• Compressed air – a technical medium used in boiler houses for valve and actuator control, bag filter cleaning, or feeding dust into burners. it must be cleaned and dried, so compressors with dryers and buffer tanks are used.
• Decarbonization – the process of reducing or completely eliminating carbon dioxide (CO₂) emissions from economic activities, primarily by replacing fossil fuels with renewable energy sources. in boiler houses, this means transitioning from coal, gas, or heating oil to biomass, biomethane, bio-oil, or electricity from RES. decarbonization reduces a company’s carbon footprint and helps meet EU climate regulations and sustainability goals.
• Diversification – the ability to use various fuels in a single boiler house. this allows a plant to avoid dependence on a single energy source and choose the most economical or environmentally friendly option at a given time.
• Dust burner – a special burner designed for burning biomass pulverized into fine dust (e.g. milled wood pellets). biomass dust must have a fine particle size, usually below 1 mm, for stable and complete combustion. larger particles do not burn fully and reduce efficiency while risking boiler contamination. the dust burner includes a system for feeding and mixing dust with air and safety systems to prevent flame backflow.
• Dust-oil-gas burner – a special burner that allows the combustion of solid fuels in dust form, liquid fuels, and gaseous fuels in the same boiler. this enables quick fuel switching depending on price and availability without modifying the system.
• Electric heaters – components built into the boiler that heat water or steam using electricity. they enable operation at very low loads and provide support during peak demand. they can use cheap energy from RES.
• Flue gas recirculation – a method of reducing harmful nitrogen oxide (NOx) emissions. it involves redirecting part of the flue gases back to the combustion chamber, lowering flame temperature and pollutant formation.
• Hammer mill – a device for grinding pellets or wood chips into fine dust (below 1 mm). such dust can be effectively burned in a dust burner. hammer mills are simple, durable, and biomass-compatible. they are usually installed in process buildings.
• Modulated operation – the boiler’s ability to smoothly increase or decrease output based on demand. this allows stable boiler house operation under low or peak steam load conditions.
• NOx – a group of nitrogen oxides (NO and NO₂) formed during high-temperature combustion. they are harmful to health and the environment (smog, acid rain), so boiler houses must have NOx reduction systems.
• Pellet – a solid fuel in the form of small biomass granules (e.g. compressed sawdust). it has a high heating value, low moisture content, and leaves very little ash. pellet is convenient for automatic boilers due to easy dosing and low-emission combustion.
• Process steam – steam used directly in industrial processes (e.g. for heating, drying, sterilization). its parameters (pressure, temperature) are selected based on production needs.
• Redundancy – duplication of critical system components (e.g. pumps, burners, boilers) to ensure operation even in the event of failure. this minimizes the risk of heat supply interruptions.
• Ruths’ tank – a steam accumulator. it works like a buffer: when there’s excess steam, it stores it; when demand spikes, it returns steam to the system. this stabilizes boiler operation and maintains pressure during critical moments.
• SCADA/DCS – automation and control systems for industrial installations. in multienergy boiler plants, they enable remote monitoring, boiler control, and integration with the plant’s production system.
• Smoke tube boiler – the basic type of boiler used in multienergy boiler plants. it has a large water capacity and tubes (smoke tubes) through which hot flue gases pass. this ensures efficient heat transfer to water and stable operation even with sudden load changes.
• Turnkey implementation – a delivery method in which the supplier is responsible for the entire investment process: design, equipment delivery, installation, commissioning, and staff training. the investor receives a complete boiler house ready to be connected to the plant’s network.
• Water treatment station – a set of equipment that purifies the water feeding the boiler (softening, iron removal, degassing, filtration). this prevents scale and corrosion in the boiler and improves process steam quality.

Waste Gases

• BAT (Best Available Techniques) – a european union standard defining optimal technologies for emission reduction and energy efficiency improvement. ics installations fully comply with strict BAT requirements for industrial burners and boilers.
• BMS (Burner Management System) – a safety and automation system for burners. it controls burner start-up, operation, and shutdown, ensuring safe burner and boiler operation.
• Boiler efficiency – the ratio of the chemical energy in the fuel (based on its heating value) to the thermal energy recovered in the form of steam.
• CO (carbon monoxide) – a toxic gas formed during incomplete combustion. low CO emissions indicate complete and efficient combustion.
• Co-firing – the process of burning two fuels simultaneously in the same combustion chamber. in ics installations, this typically means burning waste gas with a small addition of natural gas.
• Ecotube® – technology for reducing nitrogen oxides and CO by optimizing the combustion process and using the SNCR method
• HiTAC (High Temperature Air Combustion) – fuel combustion in preheated air at high temperatures. it results in uniform heat distribution across the chamber (volumetric combustion), eliminating sharp flames. this helps reduce NOx and CO emissions.
• HRS (High-cycle Regenerative System) – a regenerative system that cyclically heats combustion air using hot flue gases. mainly used in metallurgy and high-temperature furnaces.
• HTB Burner (High Temperature Burner) – an industrial burner used in HiTAC technology. it ensures uniform heat distribution, high durability, and low emissions.
• HTB-WG Burner – a special version of the HTB burner designed for waste gas combustion. it is a dual-fuel burner that uses waste gas as the main fuel and natural gas as auxiliary/backup fuel.
• IED (Industrial Emissions Directive) – an EU directive regulating industrial emissions. it defines maximum allowable levels of NOx, SO₂, and dust for power boilers.
• LHV – low heating value
• NOx (nitrogen oxides) – pollutants formed during combustion (NO and NO₂). high temperatures favor their formation. thanks to HiTAC technology, NOx emissions in ics installations are very low.
• Reburning – a method for reducing NOx emissions in industrial boilers. it involves creating an additional combustion zone with low oxygen (a reduction zone). additional fuel (e.g. natural gas, waste gas) is injected into the hot flue gases above the burner, where it reacts with NOx to reduce it to molecular nitrogen (N₂). then, in another zone, more air is added to burn off the remaining fuel and reduce CO.
• SCR (Selective Catalytic Reduction) – a catalytic method for NOx reduction using a catalyst. more advanced than SNCR, but more expensive and less common in waste gas combustion.
• Semi-adiabatic chamber – a highly insulated combustion chamber where flue gases are not immediately cooled by boiler surfaces. this allows maintaining the high temperature required for burning low-calorific gases.
• SNCR (Selective Non-Catalytic Reduction) – a technology for NOx reduction that involves injecting ammonia or urea into hot flue gases. it can be added to ics systems when stricter emission standards are required.
• Throat gas – also known as blast furnace gas, a by-product of pig iron production in the metallurgical industry. it has very low calorific value (approx. 1.5–2.5 MJ/Nm³) and high impurity content. it’s difficult to burn alone, but ics’s volumetric combustion technology allows it to be used without a constant supply of natural gas (natural gas is typically used only for start-up/emergencies).