• Energy Research

AbstractThis study proposes the energy conversion of vine prunings to supply energy to local wineries, with a focus on the Riunite & CIV branch winery located in Carpi (Modena, Italy), exploring the possibility of generating both electricity and heat through biomass gasification. A Matlab-Simulink model is used to evaluate the energy savings that can be achieved when an energy storage system is coupled with the combined heat and power generation system. Within this context, the results showed that it is possible to save $$\approx $$ ≈ 30% of the electricity and $$\approx $$ ≈ 60% of the thermal energy demanded by the winery. However, the economic viability of the project is hindered by high investment and operation costs. DPB is strongly affected by the cost of biomass and the energy prices, resulting in a profitable investment for electricity prices higher than 0.30 $$\div>$$ ÷ > 0.57 €/kWh according to the different scenarios investigated.

the mixing and surface cleaning performances of an air-water diffuser is tested in a 70 L air-lift bubble column photobioreactor in which single-celled Cyanobacteria Synechocystis sp. fed by sewage sludge waste is cultivated. Results have shown that a water velocity of 0.2 ms-1 in the non-aerated bottom part of the PBR and 0.06 ms-1 in the aerated zone are sufficient to prevent sludge deposition and biofouling on the surfaces. Moreover, water recirculation is observed to have an important role on the sludge mixing and algal homogenization of the photobioreactor. A computational model is then created and tuned using experimental data in order to predict the water and air velocity map in the whole domain. Proceedings of the 27th European Biomass Conference and Exhibition, 27-30 May 2019, Lisbon, Portugal, pp. 268-275

In this work, a simple model was created to estimate the benefits of replacing the LPG, currently used in flame weeding, with the syngas generated from a biomass gasification system. Results shown that 60.1 kg ha-1 of agri-pellet are enough to substitute 16.4 kg ha-1 of LPG when a gasification efficiency of 70 % is considered. The model shown a CO2 generation of 49.8 kg ha-1 for each treatment using the LPG device and 94.5 kg ha-1 for the biomass-powered weeder which is, however, a biogenic source of carbon with a neutral impact on the climate. Moreover, for the gasification facility, a 3.3 kg ha-1 co-production of char was considered which led to the possible stock of 9.6 kgCO2 ha-1 each treatment. Eventually, the proposed model suggests that a net saving of 58.5 kgCO2 ha-1 can be realized if LPG flame weeding treatment is replaced with a syngas-powered flame weeder. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 233-236

Abstract Weed control is an agronomic technique that must be carried out on almost any cultivation, to prevent undesired weeds from competing with crops for nutrients, water, and light and reducing the annual yield. Nowadays, agriculture is experiencing a transition to both sustainable and organic approaches that is driving the increase in non-chemical treatments. Within this framework, thermal methods are gaining attention due to their higher working speed and effectiveness when compared to mechanical ones but thermal devices are still fueled with fossils leading to considerable greenhouse gas emissions. This work investigates the advantages of substituting liquefied petroleum gas (LPG) powered weeder with a portable gasification-based flame weeder fueled with woody biomass. Energy balance, carbon footprint and feasibility aspects are taken into account and the proposed solution is compared with the reference literature of LPG flame weeder. A flame weeder prototype is built starting from the gasification reactor of a commercial micro scale cogeneration unit. The gasifier is then fueled with A2-grade fir pellets and the syngas is burnt in a swirled flare designed for cross-flame weeding in woody crop rows. The biomass-fueled prototype is capable of a thermal flux directed towards the weeds of 208–247 kJ m−2 at a temperature that ranges from 850 to 980 °C. When compared to LPG systems applied to vineyards or orchards, the proposed solution reduces the fuel cost of the 72% and CO 2 emissions up to 118% considering the carbon-negative effect added by a 0.653 kg ha−1 of biochar production for each treatment. Results showed a specific fuel consumption of 52.2 kg ha−1 y−1 that can be self-sustained if vineyards prunings are used as fuel.

This paper exposes the first year of activities regarding an Italian regional project called REBAF (RecuperoEnergeticoBiomasse Alvei Fluviali = Energetic Recover of River Biomasses). The project concerns the modeling, realization and experimental validation of innovative pathways for the exploitation of grass and woodsy biomasses from river maintenance operations. The project is focused on the Secchia river situated in the mid North of Italy. The final goal is to make the river maintenance operations self-sustainability from the economic and environmental point of views. During the first year of the project, the typical biomasses of the Secchia river was recognized and quantified. Poplar was chosen as major representative of the wood biomasses. An evaluation about wood biomass quantity obtainable for every hectare of riverbanks maintenance was made. Several gasification tests of poplar wood chips from river maintenance was done in a small CHP gasifier. The biochar obtained was characterized and it was applied on field to some giant reed plantations in order to evaluate if there will be a productivity increase with biochar as soil amendant. In addition, a model to evaluate the giant reed annual productivity in the Secchia river banks was developed. Proceedings of the 25th European Biomass Conference and Exhibition, 12-15 June 2017, Stockholm, Sweden, pp. 52-57

Hemp cultivation gained an important role in recent years. Two major production chains can be defined, one dedicated to the cultivation of hemp for the production of fiber and wood and the other relating to the production of inflorescences for the market of derivative products containing cannabidiol, better known as CBD. The problem that will be highlighted and addressed in this article is related to the enhancement of cannabis production waste for CBD. In particular, since flowers are the only useful part of crops dedicated to this purpose, to date the stems of plants are considered a difficult waste to exploit. The alternatives are few and one of the simplest and most immediate is certainly the waste-to-energy process of this material; in fact it is not possible to obtain fiber and wood of good quality from the CBD production chain, because these crops are optimized for flower production. Waste-to-energy, on the other hand, requires mechanical pre-treatments in order to use the raw material within the typical thermal conversion systems (e.g. biomass boilers, pellet stoves, gasifiers). The great obstacle to being able to efficiently transform these wastes into fuel, lies in the very nature of the hemp stems as the fibers constituting the outermost part of the plant stems are well known for their good mechanical resistance. These properties however become a problem when the material has to be treated with standard machinery for pelleting and briquetting, as they hind the mechanical components suitable for the purpose giving rise to maintenance and breakdown issues. To solve the problem, the possibility of decreasing the mechanical properties of hemp fibers has to be investigated, so as to permit the transformation of this material into an economically sustainable fuel. It was therefore decided to pre-treat the stems of the plants with a torrefaction process, to sufficiently weaken the fibers to be mechanically treated. Shear resistance was tested with a “piston device” to obtain a qualitative estimate of the mechanical behaviour of the hemp fibers only; in fact it is assumed that to solve the problem, it is sufficient to concentrate on the weakening of the fiber instead of the entire stem of the plant. In conclusion, a first estimate is defined of the minimum energy necessary for the roasting of the plant stems, sufficient to weaken the fibers to make the mechanical transformation of the stems of hemp plants into fuel, possible and economically sustainable. Proceedings of the 29th European Biomass Conference and Exhibition, 26-29 April 2021, Online, pp. 1057-1060

Climate change, environmental degradation, and biodiversity loss are prompting production systems to shift from a fossil-based economy to a circular bio-based one. In this context, biomass gasification is a promising alternative to fossil fuels that can contribute to power generation in rural communities and remote areas as well as provide a sustainable source of energy for developed countries. In this work, exhaust gas emissions (CO, NOx, and SO2) of two syngas-fueled micro-scale generators were measured. The first system is a commercial biomass gasifier genset, whereas the second is composed of a laboratory-scale gasifier prototype and a portable petrol generator. For this second facility, emissions were measured both running on gasoline and on syngas. The comparison was performed both on the pollutant concentration and on their cumulative amount. This comparison was made possible by calculating the exhaust gas flow by knowing the combustion stoichiometry and fuel consumption. The results showed a much lower pollutant concentration running on syngas compared to gasoline. In particular, considering the best configurations, every cubic meter of exhaust gas released running on syngas contains about 20 times less CO and almost one-third less NOx compared to gasoline. Moreover, the cumulative amount of emissions released was also considerably lower due to the lower exhaust gas flow (about 25%) released running on syngas.

Portable petrol powered generator are very popular around the world. They are used mostly when electrical power from the grid is not available, for example in blackout scenarios, remote areas or for temporary use and they are basically irreplaceable in many cases. The idea behind this work is to substitute the fossil fuel as the energy source of these systems with the syngas produced through biomass gasification, that is a carbon negative energy process in order to achieve a complete decarbonisation as soon as possible. Coupling gasifiers and reciprocating internal combustion engine is a very old technology, however there are no small and cheap systems available that can be successfully connected to this kind of generator. The laboratory scale gasifier presented in Lisbon at the 27th EUBCE in the paper titled: “Design and first tests of a micro lab scale (2kg/h) gasifier” after a series of test has been improved enhancing its efficiency, gas quality and power output. A GeoTech GGP 4000 ES petrol powered has been selected to operate with the syngas from the gasification system and its intake manifold has been modified. The gasifier is able to operate with different kinds of biomasses like wood fir pellets, wood chips, vine prunings pellets, hemp hurd etc. The fuel chosen for the test was the standard A1 ENPlus wood pellet. An Iveco air filter was used to preserve the engine from the tars and particulate present in the gas. The energetic consumption was calculated and the thermal power output from the engine exhaust was estimated measuring gas composition and the air flow and entering in the gasifier. The results from the test show that it is possible renew the way the portable petrol generator are used, making them efficient and eco-friendly without increasing dramatically the complexity of the system or the costs. Proceedings of the 28th European Biomass Conference and Exhibition, 6-9 July 2020, Virtual, pp. 396-400