Study of Solid Biomass Combustion Modeling Using Openfoam

Biomass is an important renewable energy source that has great potential as a substitute for fossil fuels in the short and medium-term, which has led to the development of various methods for its energy conversion, of which combustion is the most widely used. This process has several environmental advantages compared to traditional energy sources, however, there is still a long way to go in terms of process efficiency and emission reduction. In this context, CFD computational models are a powerful tool that allows to study and improve the performance of combustion systems in a safe, fast and economical way, compared to experimental studies. OpenFoam is one of the most important CFD software currently available, however, there are few works that use it to simulate the combustion of solid biomass. In this work an application of the software in modeling of a biomass boiler fueled by grape marc is reported, this model allows predict important parameters like CO, H2O and velocity fields in a 2D domain.

A comparative approach in the utilisation of rice husk and empty palm bunch in the biomass boiler

Growing world’s population has immense contribution towards world economy and energy utilisation. The enormous usage of conventional fuel has contributed many environmental problems such as greenhouse gas emission (GHG), world climate change, and deterioration of human health. Recent study focuses on the generated power from EPB compared with methane in a typical biomass boiler. Also, there are very limited studies on the Air to Fuel (ATF) ratios value in boiler operation. In this paper, empty palm bunch (EPB) and rice husk (RH) have been selected as biomass fuel in the biomass boiler. The same recommended parameters of boiler and turbine was chosen for both EPB and RH feedstocks from previous study. Overall, the study proven to produce about 33% and 25% of energy from EPB and RH of what a methane (CH4) can produce from the same amount of feeding rate, respectively, with EPB producing 13.31% of higher turbine power than RH. This directly contributes to the technical feasibility and adaptability of environmentally friendly elements by seizing the opportunity of carbon emission of conventional fuel and replacing it with natural resources such as EPB and RH which are part of the biomass fuel replacement regime. However, ATF ratio of RH is significantly minimal of what a CH4 and EPB utilised to burn 1 kg of fuel. Therefore, EPB and RH would be suitable for future renewable biomass feedstock in comparison with conventional fuel for power generation purposes.

Primary energy saving potential of a solar-driven ejector cooling system: a case study for a Portuguese residential building

The seasonal energy performance of a cooling system based on an innovative variable-geometry ejector (VGE) is numerically investigated by using TRNSYS. The VGE-based system is mainly driven by solar energy, collected through solar thermal collectors, and is coupled to a residential building located in Porto. A biomass boiler is used as back-up heater. The energy performance of the investigated cooling system is compared with that of a conventional solution, based on a commercial air-to-water chiller. Results point out that, almost 75% of the generator heat demand can be supplied by solar collectors and about 90% of the overall energy input of the ejector-based system is satisfied by renewables. Moreover, numerical simulations confirm how the capability to vary the ejector geometry on the basis of current operating conditions allows to strongly improve the ejector seasonal efficiency. A second series of simulations aimed to further enhance the system performance. A master control logic which extends the VGE operation time in correspondence of favourable ambient conditions was introduced, in order to store additional cooling energy in the cold buffer tank. This strategy has proved to be effective, since the energy consumption of the biomass boiler could be reduced up to 35%.

Feasibility Study on the Spread of NZEBs Using Economic Incentives

Nowadays, environmental and energy issues attract a lot of attention in the civil buildings sector, leading to the emergence of new technologies and new targets, which include Net Zero Energy Buildings (NZEBs). However, despite the great response in scientific research, the spread of NZEBs in Europe is quite limited. This is due not only to the lack of transposition of the related European Directives into the various national legislations, but also to the high initial cost of such high-performance buildings. The aim of this paper is to demonstrate how different energy retrofit strategies on existing buildings can lead to the achievement of the NZEB target if encouraged by tax incentives, at zero or almost zero cost. The introduction of tax incentives by individual EU member states would allow the spread of NZEBs that are still underdeveloped, especially in highly urbanized contexts. A suitable building energy dynamic simulation software has been used. The case study refers to a villa located in Southern Italy and for which different energy retrofit strategies are proposed to reach the NZEB target. For each case, an energy and economic evaluation is carried out to evaluate the feasibility of the interventions, exploiting the so-called “Super-Eco-Bonus 110%” incentive. The main results highlight that among the various solutions, the greatest energy cost reductions are obtained with the use of heat pump generators. Furthermore, the solution with the biomass boiler allows the use of a smaller number of photovoltaic panels to meet the yearly energy balance of the NZEB.

Experiment analysis on the characteristic of empty fruit bunch, palm kernel shell, coconut shell, and rice husk for biomass boiler fuel

It has been a necessary option for most developing countries moving towards renewable energy options as part of the Paris Agreement, which minimizes conventional energy sources’ reliance. In Malaysia, biomass is a profitable renewable option compared to solar and hydro sources for energy production due to the abundance of agricultural biomass availability for immediate use. However, most of the biomass power plants in Malaysia depend on empty fruit bunch as fuel, causing problems when there is a shortage of fuel supply and other circumstances. Variations in the fuels’ properties provide a new challenge to the power plant output; however, mixing biomass fuels can overcome the issue. Hence, this article aims to study the empty fruit bunch (EFB) with other abundant biomass fuels like “palm kernel shell (PKS),” “rice husk (RH),” and “coconut shell (CS)” for biomass boiler fuel. Therefore, the biomass’s composition and characteristics need to be known, which was done through the proximate analysis (PA), ultimate analysis (UA), and high heating value (HHV). As a result of PA, UA, and HHV, RH is the least favourable fuel due to lowest ((moisture (4.92%), volatile matter (63.20%), carbon (42.50%), hydrogen (5.42%), nitrogen (0.43%) and sulphur (0.01%)) and highest ash content (18.19%), whereas CS exhibits the most favourable option with highest (carbon (50.25%) and oxygen (42.57%)) and second highest in HHV (20.53%) compared with PKS. Thus, the experiments have provided the least and highest favourable feedstock ratios option for biomass boiler fuel application.

Demand-Side Optimal Sizing of a Solar Energy–Biomass Hybrid System for Isolated Greenhouse Environments: Methodology and Application Example

The water–energy–food nexus has captured the attention of many researchers and policy makers for the potential synergies between those sectors, including the development of self-sustainable solutions for agriculture systems. This paper poses a novel design approach aimed at balancing the trade-off between the computational burden and accuracy of the results. The method is based on the combination of static energy hub models of the system components and rule-based control to simulate the operational costs over a one-year period as well as a global optimization algorithm that provides, from those results, a design that maximizes the solar energy contribution. The presented real-world case study is based on an isolated greenhouse, whose water needs are met due to a desalination facility, both acting as heat consumers, as well as a solar thermal field and a biomass boiler that cover the demand. Considering the Almerian climate and 1 ha of tomato crops with two growing seasons, the optimal design parameters were determined to be (with a solar fraction of 16% and a biomass fraction of 84%): 266 m2 for the incident area of the solar field, 425 kWh for the thermal storage system, and 4234 kW for the biomass-generated power. The Levelized Cost of Heat (LCOH) values obtained for the solar field and biomass boiler were 0.035 and 0.078 /kWh, respectively, and the discounted payback period also confirmed the profitability of the plant for fuel prices over 0.05 /kWh. Thus, the proposed algorithm is useful as an innovative decision-making tool for farmers, for whom the burden of transitioning to sustainable farming systems might increase in the near future.