Biomass and its derivative - biogas - have been used as a heat source for ages. The traditional and still most widely spread way in which biomass is used though - the burning of wood for heating – has a very low efficiency and is a source of air polluting emissions. Yet, biomass is an important source of renewable energy which cannot be discarded and the global efforts are concentrated in changing the way it is used, optimizing its efficiency.
In addition to wood, the types of biomass used for energy have expanded with energy crops grown especially for heating, as well as with waste biomass from the agriculture, food industries and even from waste water treatment plants.
Technologies for the use of biomass and biogas
Here is an overview of the most widely spread technologies for use of biomass – for heat only and for combined heat and power.
Biomass boilers can be made to run on a single type of biomass - wood pellets, wood chips, or even sunflower husks, but there are also combined ones. Biomass boilers require regular cleaning.
Biogas boilers function in the same way as natural gas boilers, with a difference only in the burner unit. The boiler body is practically the same.
Gas boilers (natural gas or biogas) can be ordinary or condensing boilers. Ordinary boilers can deliver the heat in the form of hot water or steam. Condensing boilers reach higher efficiency than ordinary boilers but can be used only for hot water.
Biomass boiler plants
When there is not enough indoor space for the boiler and all of its required accessories such as expansion vessels, pumps, pipes, etc. a containerized boiler room can be installed outdoors. All the equipment is conveniently packed, protected, integrated and tested before it is delivered to the end user ready to use. In addition, the boiler plant can feature a biomass storage and automatic feeding units.
COMBINED HEAT AND POWER
Combined heat and power installations powered by biomass or biogas have the double benefit of a renewable primary energy source and a highly efficient engineering technology.
Cogeneration from biomass. Biomass steam boiler and a steam turbine
Cogeneration from biomass (used directly as a heat source, without being transformed into biogas) happens through its burning in a steam boiler, and then the generated steam is used in a steam turbine, which produces electricity.
Cogeneration from biogas. Biogas internal combustion engine and a generator
Biogas cogeneration plants can be designed with a biogas steam boiler and a steam turbine, similar to the structure of biomass cogeneration plants described above. The other, more popular configuration for smaller size plants involves an internal combustion engine and a generator, plus a number of additional components – waste heat recovery unit, water circuits, etc. To learn more about this type of cogeneration plants, visit our page on cogeneration.
Biogas cogeneration plants include a biogas production facility (biomass storage areas and feeding lines, anaerobic digestion tanks and biogas storage tanks, biogas feeding line, etc.) and a biogas CHP module, where the biogas is actually used for the production of heat and power.
Specialized software is used to monitor all components of the process – from the biogas production to the waste heat recovery and the required maintenance actions.
It is available also for the boiler facilities, which are not as complicated as the combined heat and power facilities but can still benefit from remote monitoring and control.