Biomass Heating Systems Research Articles

Environmental, economic, and eco-efficiency assessment of residential heating systems for low-rise buildings

Transitioning from fossil fuels to renewable heating is essential for rapidly reducing greenhouse gas emissions. Besides greenhouse gas emissions, other environmental and economic impacts are crucial for successfully implementing renewable heating systems. This study evaluates 13 residential heating systems' environmental, economic, and eco-efficiency performance for a typical German two-story dwelling. The life cycle assessment method is employed to quantify the environmental impacts. Assuming a sustainable supply of biomass-based fuels, biomass heating systems exhibit the lowest environmental impacts, whereas gas heating systems are associated with high environmental impacts. Among heat pump systems, the water-source heat pump demonstrates the lowest environmental impact. Additionally, integrating a PV system into heat pump systems reduces the environmental impacts across all heat pumps. The evaluation indicates that the air-source heat pump is the most economical system, while the pellet boiler with solar thermal support and the heat pump with ice storage incur the highest costs. However, the cost differences among the heating systems are relatively small, making it challenging to establish a clear ranking based solely on economic evaluation. An eco-efficiency assessment, which combines environmental and economic aspects into a single indicator, reveals that the most eco-efficient systems are the air-source heat pump, both with and without a PV system, and the wood gasifier heating system. In contrast, the ice-storage heat pump and the pellet heating with solar thermal support show the lowest eco-efficiency.

Estimation of wood biomass boiler use in cold climate regions on CO2 emissions of light-frame timber structure

Considering Nagano City, as the cold climate region of Japan, the annual heating load was simulated using a model of a two-story timber structure. The results of simulations were used to compare the CO2 emissions according to the energy consumption of five methods of heating as well as primary and secondary energy sources. Actual data from power and gas companies in Nagano and Japanese energy standards were used for the estimations of CO2 emissions of electric heat pump air conditioners, LNG-powered city gas boilers, LPG boilers, kerosene stoves, and wood biomass boilers using pellets as an energy source. Wood biomass boilers showed CO2 emission savings of up to 85 %, 75 %, 75 %, and 76 %, respectively. The operating and equipment costs were estimated based on secondary energy calculations. The kerosene stove had the lowest cost, but CO2 emissions were lowest in the case of using pellet boilers for 30 years. These results clearly show the potential and merit of pellets used in wood biomass boilers as a renewable energy source when compared to fossil fuels. In addition to the CO2 reduction capabilities, the low operating costs of wood biomass heating systems incentivize their use in cold climates.

Energy, exergy, environment and techno-economic analysis of hybrid solar-biomass systems for space heating and hot water supply: Case study of a Hammam building

The main goal of this study is to assess the thermodynamic performance, environmental benefits and economic feasibility of using a new hybrid solar-biomass system (HSBS) for the production of domestic hot water at 60 °C and for the provision of space heating via an underfloor heating system in a Hammam building located in Marrakesh-Morocco. The HSBSs consists of small biomass pellet boilers in combination with three types of solar thermal systems (evacuated tube, flat plate and parabolic trough collectors). A TRNSYS simulation model of a biomass heating system was developed and validated against experimental data. Performance comparisons of the biomass system with various optimal HSBSs were then conducted, and their results evaluated in terms of energy, exergy, environmental, and economic perspectives. Comparisons between various collectors’ technology revealed that the optimum collector areas of 204 m2, 224 m2 and 300 m2 are responsible for the lowest Levelized Cost of Heat (LCOH) corresponding to about 0.0755 $/kWh, 0.0696 $/kWh and 0.0642 $/kWh when using PTC, FPC and ETC, respectively. Furthermore, the optimal HSBS with evacuated tube collectors is the most effective configuration with a solar fraction of 57 %, and a total life-cycle saving cost of 0.509 M$ for a total annual heat demand of 533 MWh. Moreover, the total energy and exergy efficiencies are calculated equal to 40 % and 3.9 %, respectively. The payback period is found to be around 4.9 years, the levelized cost of heat 0.0642 $/kWh, while the annual CO2 avoidance amounts to 656 tons.

Scenario analysis of strategies to control air pollution

Air quality in Europe has been improving over the last decades. Notwithstanding, urban areas are still facing exceedances of the Air Quality Directive's limit and target values. In this study, we analyzed the effect of two mitigation measures on urban air quality: i) improvement of the biomass residential combustion appliances, and ii) electrification of passenger's cars fleet. Five European cities (Lisbon and Porto - Portugal, Athens - Greece, Kuopio - Finland, and Treviso - Italy) were used as case studies to evaluate the impact of the measures on the fine particle fraction (PM2.5) concentrations. To facilitate decision making and the quick test of new measures, the LIFE Index-Air tool was developed. In this tool, the air pollutant concentrations are predicted by Artificial Neural Networks trained using a set of air quality modelling simulations. The results indicate that the replacement of old biomass heating systems by new improved fireplaces can be more effective in Treviso. On the other hand, the replacement of gasoline and diesel passenger vehicles by electric ones seems to be more effective in reducing PM2.5 concentrations over Lisbon, Porto, and Athens. In Kuopio, both mitigation measures have an identical effect.

A Critical Review on Decarbonizing Heating in China: Pathway Exploration for Technology with Multi-Sector Applications

Coal-fired heating is the main method of heating in China, causing serious air pollution and large amounts of CO2 emissions. Decarbonizing heating is important to reduce carbon emissions, and choosing a suitable heating technical scheme is conducive to the early realization of carbon neutrality in China. Coal to gas and coal to electricity transformation projects were carried out in 2017 and achieved remarkable effects. This study compares the current domestic and international clean heating modes, where gas heating, electric heating, heat hump heating, biomass heating, and solar heating coupling system are taken into account. The heating technology potential and heating support aspects, including the industrial sector, building sector, carbon capture and storage (CCS) technology, and publicity are explored as well. Regarding the actual situation in China, a comparative analysis is also conducted on the different types of heat pumps, and then an optimal heating scheme for urban and rural areas is proposed. It is suggested that the urban area with centralized heating can install ground source heat pumps, and the rural area with distributed heating can apply a coupling system of solar photovoltaics to ground source heat pumps (PV-GSHP). Based on current policies and standards support, this study calculates the carbon emissions of this scheme in 2030 and provides a detailed analysis of relevant parameters. The feasibility and superiority of the scheme are confirmed by comparison and discussion with other studies. Moreover, specific measures in planning, subsidy, construction, and electricity are proposed to implement the heating scheme. This study provides a reference for the mode selection and technical scheme of heating decarbonation in China, and that could be also considered in other regions or countries.

Emissions and Efficiency Limits of Small-Scale Biomass Heating Systems: Regulations, Standards, and Ecolabels

Abstract The household sector has a significant role in the consumption of energy resources and related emissions. The household sector is responsible for around 1/3 of the total energy resource consumption in Latvia. This study aims to determine the level of control measures regarding household boilers by summarising the existing information on legislation and quality labels regulating the efficiency and emissions of household boilers in the EU. The focus is on PM emissions and small-scale heating system regulations in Latvia. The study shows that small-scale biomass heating systems lack proper control measures to limit created emissions. The situation regarding PM emissions is the worst in Latvia, in comparison to the EU and 8 other studied countries.

Characterisation of potential adopters of domestic biomass heating

ABSTRACT Domestic heating systems are an important energy consumption market from a country’s economic and environmental perspective. The domestic adoption of biomass heating systems is increasing in Europe and is considered environmentally friendly in terms of climate change in general, as well as secure in terms of fuel supply and price fluctuation. The results of this study indicate that potential Spanish adopters have a favorable attitude toward this type of heating. A potential adopter can be characterized as a female owner with an income level of €1800 or more, and with a house in a rural area. The most important issue for them is, in general, the annual cost of their heating.

Simulation and experimental investigation of a combined solar thermal and biomass heating system in Morocco

The integration of hybrid renewable energy systems, such as hybrid solar-biomass, to address thermal energy needs in various applications is a promising, efficient and eco-friendly solution that can be successfully applied for traditional baths in Morocco. Indeed, these systems are not widespread in Morocco, since traditional firewood furnaces are still commonly used for heating purposes in many different applications. Accordingly, the main objective of the study is to introduce a new hybrid solar-biomass system designed for space heating and hot water supply in a public bathhouse in Marrakesh, Morocco. This hybrid system includes small-scale pellet boilers and small dimension parabolic trough solar collectors (PTC), which is the first small-size PTC facility proposed for low temperature applications (less than 100 °C) in Morocco. Moreover, the preliminary simulation results of this hybrid solar-biomass system for space heating – case study – using TRNSYS software are presented. The use of such a hybrid system as a new design to retrofit conventional firewood boilers that are widely used for space and water heating in public bathhouses will lead to significant savings in firewood, which will contribute in particular to reducing deforestation in Morocco and will also result in substantial reductions in CO2 emissions.

Low Emissions Resulting from Combustion of Forest Biomass in a Small Scale Heating Device

The paper concerns the analysis of harmful emissions during the combustion process in households. The subject of the analysis is a low emission heating device with an output of 50 kW for burning biomass of forest origin (low-quality hardwoods or softwoods). The proposed boiler is automatically fed from the connected container by means of a screw conveyor. In this way, the optimum amount of fuel is supplied for maximum heat output (adjustment of the ratio of primary air to fuel). The proposed biomass heating system is equipped with a primary and secondary air supply system and exhaust gas sensors. This ensures optimal regulation of the air mixture and efficient and clean combustion. Proper control of the combustion process, control of the air supply by means of a lambda sensor and power control of the system ensure a low-emission combustion process. The system precisely adjusts to the heat demand. This results in highly efficient heating technology with low operating costs. In the presented work, the emission of exhaust gases from the proposed heating device during the combustion of woodchips and beech–oak pellets were measured. It is demonstrated that the proposed design of the boiler equipped with intelligent control significantly reduces emissions when the biomass solid fuels are used, e.g., CO emissions from beech and oak chips and pellets in the low-emission boiler—18 extract pipes shows the value <100 ppm, which is even lower than when gas is burned in the other boilers; on the other hand, the pine chips show even higher emission when burned in the low-emission burner. Consequently, the choice of biomass source and form of the fuel play some role in the emissions observed.

Sustainable biomass pellets using trunk wood from olive groves at the end of their life cycle

Forest biomass is the raw material most commonly used to produce quality pellets for domestic households. However, sustainable forest biomass is not available in all regions, but there are other potential raw material sources for biomass heating systems, based on pellets. There are a large number of olive trees in the Mediterranean area, but these are not used as renewable pellet fuel because the bark cannot be used as raw material to produce quality pellets. The aim of this study is to carry out a methodology to estimate the optimal sustainable bioenergy life cycle, and the amount of sustainable residue available (trunk wood) at the end of the life of the olive grove, by optimizing the benefits, through an analysis of costs and income of the whole life process. The methodology determines the potential value of the trunks of olive trees to be used as biomass, in the form of pellets in domestic contexts and in a specific geographical area. In a case study applied to Andalusia, it has been shown that the optimal renewable life-cycle is 97 years. If policies for agricultural and energy sustainability favouring this model were adopted, this region would produce 160,000 tonnes of pellets per year, and 266,500 tonnes per year, if extended to the whole of Spain. This has a potential for providing 70.17% of the current total pellet consumption. The extension of the model to other Mediterranean countries, such as Greece and Italy, would result in an additional 124,000 and 144,000 tonnes of pellets per year, respectively.

Experimental Study on Biomass Heating System in the Greenhouse: A Case Study in Xiangtan, China

To meet the indoor heat load demand of greenhouses in China rural areas in winter, the authors proposed and designed a novel biomass heating system in greenhouses. The system uses biomass flue gas as the thermal working medium and heats the shallow soil inside the greenhouse through the buried flue gas-soil heat exchanger, thereby improving the indoor thermal environment of the greenhouse. To further study the heating system performance, we built up the heating experimental platform in a plastic greenhouse. Through testing the actual operation effect of the biomass heating system of the plastic greenhouse, no taking any heating measures system, the biomass heating system of the plastic greenhouse can improve the air average temperature and the soil average temperature 5.1 °C and 8.2 °C, respectively. The greenhouse biomass heating system is very economical, compared with the greenhouse without heating system, which can bring a 105% excess return rate for farmers every year. This study has obvious significance to promote the sustainable development of rural agriculture and the efficient utilization of rural biomass resources.

The establishment of a micro-scale heat market using a biomass-fired district heating system

BackgroundLocal biomass potential in Southeastern European countries is relatively high. Nevertheless, biomass residues such as wood leftovers, straw and energy crops are often not properly managed or inefficiently utilised for energy purposes in individual house heating or domestic hot water preparation. This is more relevant in rural areas, where the utilisation of biomass resources is mainly based upon traditional technologies, has low efficiency or is carried out by using individual bases without local energy supply management. Usage of biomass residues in combination with other renewable energy sources is in agreement with the targets of the EU’s Energy and Climate Goals and promotes rural development and a circular economy.MethodsFor this purpose, local heating and domestic hot water preparation demands, as well as the available biomass potentials, were analysed and mapped by using a geographic information system (GIS). A model for analysing the optimal operation of the district heating boiler with a relatively high share of solar energy, which is backed up by either a short- or long-term heat storage, was developed. The model takes the supply and the return temperatures from the DH network into account and decides whether the excess of solar heat produced by the prosumers can be delivered into the network. This reduces heat overproduction and enables a smooth and uninterrupted operation of the system. Such configuration would benefit both the DH Company and the prosumers. The DH Company would have the opportunity to buy cheaper excess heat from the prosumers rather than to start its own and relatively slow biomass boiler.ResultsIn this paper, several scenarios are proposed for the Romanian village Ghelinta. The target village is characterised by a small-scale biomass district heating boiler with thermal storage and prosumers with either solar thermal collectors or locally installed heat pumps. Integration of seasonal thermal storage and local prosumers can smooth out the biomass district heating boiler operation and bring additional socio-economic benefits for the bioenergy village communities. This could be the first step towards the establishment of a micro-scale thermal energy market.ConclusionsAnalysis has proven that the proposed system configuration is socio-technically feasible, even for micro-scale systems, as apparent in the Romanian target village Ghelinta. The main objective of this research is to analyse the implementation of a small-scale biomass and renewable energy-based district heating system and to prove the concept of bioenergy villages from a technical and economical perspective. Furthermore, the role of residential household prosumers has been analysed. Based on outcomes, the transferability of the results is also discussed, while several suggestions for stakeholders who implement such projects were formulated for future research as well.

The main determinants of adopting domestic biomass heating systems

PurposeUnderstanding the antecedents of biomass heating adoption by domestic users is important for both public authorities and businesses because of the impact of this technology on energy consumption. The purpose of this study offers an overview of the predictors of biomass adoption based on the most relevant theories, gleaned from pro-environmental decision-making research.Design/methodology/approachThe proposed model was tested using the partial least squares technique. The study was conducted with a sample of 528 owners of detached houses who did not use biomass technology.FindingsThe results showed that intention to adopt this type of heating system is determined by individual values, environmental concerns, attitudes, perceived control, personal and social norms, perceptions of the technology’s attributes, of the benefits of biomass and access to economic aid.Practical implicationsCompanies in the biomass heating sector (manufacturers, installers, biomass producers and distributors) and public bodies should take a proactive approach toward the economic and environmental situations they currently face.Social implicationsEconomic aid or subsidies should be made available to influence the adoption intention of potential owners; and the availability of the aid and the requirements that must be met to access, it should be publicized through advertisement campaigns.Originality/valueThis study includes comprehensive academic and managerial implications crucial for the introduction of domestic biomass heating systems.

Thermal Energy Evaluation of Biomass Heating System

The drying capacity of the system, fuel and air required for the drying was estimated. Based on the quantification of fuel and air required in the drying application, the dryer surface area and combustor furnace size were computed. The net heat duty of the heat exchanger for the parallel flow type exchanger was estimated in the experimentation. The exchanger design parameters were computed for the LMTD, net heat transfer area, number of tubes and diameter, and heat transfer coefficient was determined in the study. The system was developed as per the design specification in respect of each component. The biomass-based air heating system consisted of biomass combustor equipped with pre-heating arrangement and smoke tapping unit, air distribution system and rotary tray drying bin. The power transmission system was designed and developed for rotating tray arrangement for the live and static load during the operation. The thermal energy performance of the system was worked out during the experimentation for drying of green gram for the set operational parameters like air flow rate, temperature and fuel feed rate for the various combination of treatment. In investigation, the heat supplied by the combustor in various treatments for the set air flow rate, temperature and fuel feed rate is estimated in drying application. The heat gain by air, heat supplied to the drying bin, net heat utilized in the various treatments is estimated. The loss of heat from the combustor, in air distribution system and total system heat loss is computed in the experimentation for drying application. The component wise heat loss was estimated during the operation for the treatments. The overall energy balance for the drying was examined during the study.

Influence of Policy, Air Quality, and Local Attitudes toward Renewable Energy on the Adoption of Woody Biomass Heating Systems

Heat produced from woody biomass accounts for a significant portion of renewable energy in the United States. Economic and federal policy factors driving institutional adoption of woody biomass heating systems have been identified and examined in previous studies, as have the effects of state policies in support of biomass heating. However, plans for a number of mid- to large-scale biomass facilities have been abandoned after being proposed in communities with many of the factors and policies considered favorable to the adoption of such systems. In many of these cases, opponents cited potential negative impacts on local air quality, despite being generally in favor of renewable energy. This study employed a zero inflated negative binomial (ZINB) statistical model to determine if state policies, air quality, and local attitudes toward renewable energy have a significant effect on the adoption and retention of distributed-scale biomass combustion systems used for institutional heating. State policy appears to have a negligible effect, while the influences of historic and current air pollution and local emissions appear insignificant. However, local attitudes in favor of renewable energy are associated with the adoption and retention of distributed-scale woody biomass heating systems. This is an indication of the importance of local support in determining the fate of future biomass energy projects.

Economic and policy factors driving adoption of institutional woody biomass heating systems in the U.S.

Abundant stocks of woody biomass that are associated with active forest management can be used as fuel for bioenergy in many applications. Though factors driving large-scale biomass use in industrial settings have been studied extensively, small-scale biomass combustion systems commonly used by institutions for heating have received less attention. A zero inflated negative binomial (ZINB) model is employed to identify economic and policy factors favorable to installation and operation of these systems. This allows us to determine the effectiveness of existing policies and identify locations where conditions offer the greatest potential for additional promotion of biomass use. Adoption is driven by heating needs, fossil fuel prices, and proximity to woody biomass resources, specifically logging residues, National Forests, and fuel treatments under the National Fire Plan.

A sustainable energy for greenhouses heating in Italy: wood biomass

More than 0.7 million ton of oil equivalent is the total requirement for thermal energy in the Italian greenhouse vegetable industry, derived mostly from fossil fuels, which corresponds to 2 Mt CO2 emissions. The technology of wood biomass system is a good candidate for heating greenhouses, since this resource is considered as 'greenhouse gas' (GHG) neutral when converted to heat, excluding the GHG generation during harvesting, transportation, and pre-processing of raw materials. Besides, the CO2 enrichment in greenhouses from the exhaust gas of a biomass heating system can bring benefits for greenhouse production, along with optimal management strategies to reduce fuel consumption. Unfortunately, CO2 enrichment from the exhaust gas of biomass boilers is still challenging and expensive, considering that wood biomass boilers generate a higher volume of particulate matters (PM) and ash emissions than other fossil fuels. However, wet scrubbers and other recent flue gas conditioning devices could help to reduce costs and make this process more feasible. In the Italian peninsula, the power energy load for greenhouses heating was estimated to be between 30 and 175 W m-2, while the thermal energy consumption varies between 21 to 546 kWh m-2 year-1 according with internal air temperature and climatic zones. In general, the total cost of a heating system with boiler, loading system, accumulator, control system and safety, installation, and heat delivering can vary from a maximum of 1400 € kW-1 for systems with power up to 100 kW, 600-800 € kW-1 for power over 100 kW, to a minimum of 400 € kW-1 for systems with power over 1000 kW. Thus, a techno-economic assessment is highly recommended to ascertain the economic feasibility of wood biomass boilers for the greenhouse industry, as related to the economic incentives by the National Decree of 28 December 2012, so-called “White Certifies”.

Particulate and gaseous emissions from different wood fuels during combustion in a small-scale biomass heating system

Woodchip is widely used as fuel in dedicated biomass and, even in some conventional energy generation plants. However, there are concerns about atmospheric air pollution from flue gases emitted during wood biomass combustion, particularly oxides of nitrogen (NOx) and particulates <10 μm diameter (PM10). In the United Kingdom (UK) a small scale biomass heat generation support scheme, the Renewable Heat Incentive (RHI), has been introduced. Qualifying criteria for this scheme have included limits for flue gas emissions of NOX and PM10 of 150 and 30 g per gigajoule (g/GJ) of energy input, respectively. In an experiment, three locally available types of Willow (Salix spp) and one of Sitka spruce (Picea sitchensis) woodchips, showed significant differences in physical and chemical constituents, gaseous and particulate emissions. During combustion in a 120 kW biomass system, air flows, flue gas temperatures and energy output correlated with gaseous emissions, NOx with raw fuel ash, nitrogen, phosphorus and potassium content, as did all flue gas particulate fractions. PM10 ranged from 30.3 to 105.7 g/GJ and NOx from 91.2 to 174.3 g/GJ. Sitka spruce produced significantly lower emissions of PM10 and NOx (27.5 and 52.6% less, respectively) than the three willow fuels, from which emissions were above the RHI emissions limits.

Microenvironmental air quality impact of a commercial-scale biomass heating system

Initiatives to displace petroleum and climate change mitigation have driven a recent increase in space heating with biomass combustion. However, there is ample evidence that biomass combustion emits significant quantities of health damaging pollutants. We investigated the near-source micro-environmental air quality impact of a biomass-fueled combined heat and power system equipped with an electrostatic precipitator (ESP) in Syracuse, NY. Two rooftop sampling stations with PM2.5 and CO2 analyzers were established in such that one could capture the plume while the other one served as the background for comparison depending on the wind direction. Four sonic anemometers were deployed around the stack to quantify spatially and temporally resolved local wind patterns. Fuel-based emission factors were derived based on near-source measurement. The Comprehensive Turbulent Aerosol Dynamics and Gas Chemistry (CTAG) model was then applied to simulate the spatial variations of primary PM2.5 without ESP. Our analysis shows that the absence of ESP could lead to an almost 7 times increase in near-source primary PM2.5 concentrations with a maximum concentration above 100 μg m−3 at the building rooftop. The above-ground “hotspots” would pose potential health risks to building occupants since particles could penetrate indoors via infiltration, natural ventilation, and fresh air intakes on the rooftop of multiple buildings. Our results demonstrated the importance of emission control for biomass combustion systems in urban area, and the need to take above-ground pollutant “hotspots” into account when permitting distributed generation. The effects of ambient wind speed and stack temperature, the suitability of airport meteorological data on micro-environmental air quality were explored, and the implications on mitigating near-source air pollution were discussed.

Feasibility of biomass heating system in Middle East Technical University, Northern Cyprus Campus

AbstractGlobal interest in using biomass feedstock to produce heat and power is increasing. In this study, RETScreen modelling software was used to investigate the feasibility of biomass heating system in Middle East Technical University, Northern Cyprus Campus. Weiss Kessel Multicratboiler system with 2 MW capacity using rice straw biomass as fuel and 10 units of RBI® CB0500 boilers with 144 kW capacity using natural gas as fuel were selected for the proposed biomass heating system. The total cost of the biomass heating project is US$ 786,390. The project has a pre-tax and after tax internal rate of return (IRR) of 122.70%, simple payback period of 2.54 years, equity payback period of 0.83 year, a net present value of US$ 3,357,138.29, an annual lifecycle savings of US$ 262,617.91, a benefit-cost ratio of 21.83, an electricity cost of $0/kWh and a GHG reduction cost of −204.66 $/tCO₂. The annual GHG emission reduction is 1,283.2 tCO₂, which is equivalent to 118 hectares of forest absorbing carbon. The de...