Biomass Energy Conversion Research Articles

Prospects of Bioenergy Production for Sustainable Rural Development in Ghana

Biomass supplies about 80% of the energy needs for cooking and heating in rural Ghana. It is predominantly used in traditional and inefficient forms (firewood and charcoal), which presents environmental and health concerns. In order to better the living standard in rural Ghana, efforts must be made to provide modern energy services. Most rural communities in Ghana are so remote that an extension of the national grid is uneconomical, hence biomass electricity provides a viable alternative. Biomass is pivotal to the socio-economic development of rural Ghana due to its easy accessibility and enormous potential in the production of varied energy forms. In this paper, a comprehensive review of biomass resources, biomass energy conversion technologies and bioenergy production potential for rural development in Ghana is provided. The most important feedstock from an energy perspective was found to be crop residues. Based on 2017 statistics, Ghana has a theoretical potential of 623.84 PJ of energy from agricultural crop residues and 64.27 PJ of energy from livestock production. Evidence from literature suggests that biomass gasification is the best conversion technology to expand electricity access rate for rural households in Ghana. The paper concludes that although ample biomass resources exist, cocoa pod husks (CPH) which is very common in rural Ghana can be pelletized and used as feedstock for rural power generation systems.

Effect of Pith/Fiber Separation, Binders and Hybridization on Energy Density and Physical Properties of Bagasse Briquettes.

Improvements on energy density of loose biomass such as sugarcane feedstock is crucial in the technology of biomass energy conversion and generation. South Africa is one of the producers and refiners of sugarcane. High energy density of sugarcane bagasse biomass through separation and briquetting is imperative in developing adequate streams and quality energy generation from sugarcane upstream milling processes. Unseparated bagasse and separated fractions of fiber and pith possess energy contents of about: 16.14 MJ/kg, 17.73 MJ/kg and 15.74 MJ/kg respectively. Fiber fractions have high energy content than bagasse and pith which demonstrates that pith fraction from bagasse lowers energy density. However, the use of starch and PVA (Polyvinyl Alcohol) as binders during briquetting contributed no significant difference in the overall energy density of the biomass briquettes produced. In the same vein, the addition of 50% charcoal as the hybrid component significantly improves the energy density and the physical properties of briquettes, biomass fractions of bagasse, fiber and pith to: 19.43 MJ/kg, 19.57 MJ/kg and 18.37 MJ/kg respectively. Fiber fraction remains the biomass fraction with highest energy content as compared to other fractions. After briquetting and drying of briquettes to moisture content below 12%, there was a significant improvement on the burning rate, briquetting, binder, hybridization which does improve the biomass briquettes characteristics. Separation of bagasse is crucial under certain conditions since there are no significance differences in the energy density of bagasse fractions. However, the use of PVA and charcoal does pose the necessity of bagasse separation from its fractions for briquetting.

Thermodynamic performance comparison of various energy storage systems from source-to-electricity for renewable energy resources

This study discusses and thermodynamically analyzes several energy storage systems, namely; pumped-hydro, compressed air, hot water storage, molten salt thermal storage, hydrogen, ammonia, lithium-ion battery, Zn-air battery, redox flow battery, reversible fuel cells, supercapacitors, and superconducting magnetic storage through the first and second law of thermodynamics. By fixing an electrical output of 100 kW for all systems, the energy efficiencies obtained for the considered energy storage methods vary between 10.9% and 74.6% whereas, the exergy efficiencies range between 23.1% and 71.9%. The exergy destruction rates are also calculated for each system ranging from 1.640 kW to 356 kW. The highest destruction rate is obtained for the solar-driven molten salt thermal energy storage system since it includes thermal energy conversion via the heliostat field. Furthermore, the roundtrip efficiencies for the electrochemical and electromagnetic storage systems are compared with the analyzed systems, ranging from 58% to 94%. Renewable sources (solar, wind, ocean current, biomass, and geothermal) energy conversion efficiencies are also considered for the final round-trip performances. The molten salt and hot water systems are applicable to solar, geothermal, and biomass. The highest source-to-electricity efficiency is obtained for the super magnetic storage with 37.6% when using wind, ocean current, and biomass sources.

Neural network prediction of parameters of biomass ashes, reused within the circular economy frame

Artificial neural networks were used for the prediction of three biomass ash fusion temperatures: initial deformation temperature IDT, hemispherical temperature HT and flow temperature FT based on chemical composition of the ash. Applicability of 400 neural network configurations (of linear, MLP, RBF and GRNN types) was verified statistically. Multilayer perceptron with 12 inputs representing fractions of the ash compounds, 11 hidden neurons and three outputs (IDT, HT, FT) proved to be the optimal neural model configuration. Statistical analysis suggested also, that considering intrinsic dispersion within the raw experimental data (literature data supplemented with the authors’ own results describing the halloysite addition effect), quality of the resulting 3-output IDT-HT-FT model (IDT prediction with R 2 0.615, HT with R 2 0.756 and FT with R 2 0.729) could be regarded satisfactory for the identification and generalization of the discussed relationships. Analysis of the neural model sensitivity in respect to the input variables demonstrated, that the most important factors affecting all ash transition temperatures in the 3-output IDT-HT-FT model were: K 2 O, SiO 2 , CaO and Al 2 O 3 fractions. Moreover, individual sensitivity in respect to IDT, HT and FT temperatures slightly varied (characteristics provided by independently established 1-output networks – IDT model, HT model and FT model, respectively). Statistically verified neural network working as the 3-output IDT-HT-FT model can be applied in various computational tasks in biofuels energy sector required by Industry 4.0 principles, as well as in the selected Circular Economy problems. • Chemical compositions of the ashes were correlated with their melting temperatures. • Ash melting temperatures can be effectively predicted by neural network model. • Predictions of neural models are more accurate compared to statistical models. • Sensitivity of each melting temperature in respect to ash components is different. • The results can improve the technologies of biomass energy conversion.

Lightning for Energy and Material Uses: A Structured Review.

The average atmospheric charge density of Earth is neutral. Charge built up from thunderstorms and lightning phenomena is offset by oceanic surface charging, and offers a source of energy that has not been harnessed broadly. Unfortunately, the total terrestrial energy of the Earth’s atmospheric electrical system is modest (250–500 MW) compared to industrial requirements: Innovations are likely to offer improvements to societal efficiency rather than broad transformations. Direct capture systems located in places with very high occurrence of lightning discharge can generate ≈1 kWh per year on average. Material processing via triggered lightning is limited to techniques that utilize rapid discharges, e.g., metal and glass preprocessing of materials, waste volume reduction, biomass energy conversion, where current prices make plasma‐arc processes prohibitive. Triggered lightning may be used to assist blasting of mountain rock; or as a high‐voltage input for processes such as nuclear fusion. Passive collection of atmospheric electricity is modest but may be used in urban agriculture to increase biomass production. Thunderstorm charge‐separation processes suggest a new class of electricity generators based on kinetic energy and material collision. Ball lightning suggests additional research in dusty plasmas. These methods are all at proof‐of‐concept or early translation stages.

Journal Vol – 15 No -7, July 2020 Journal > Journal > Journal Vol – 15 No -7, July 2020 > Page 6 PERFORMANCE AND EMISSION CHARACTERISTICS OF GASOLINE-ETHANOL BLENDS ON PFI-SI ENGINE Authors: D.Vinay Kumar ,G.Samhita Priyadarsini,V.Jagadeesh Babu,Y.Sai Varun Teja, DOI NO: https://doi.org/10.26782/jmcms.2020.07.00051 admin July 26, 2020 Abstract: Alcohol based fuels can be produced from renewable energy sources and

Journal Vol – 15 No -7, July 2020 Journal > Journal > Journal Vol – 15 No -7, July 2020 > Page 6 PERFORMANCE AND EMISSION CHARACTERISTICS OF GASOLINE-ETHANOL BLENDS ON PFI-SI ENGINE Authors: D.Vinay Kumar ,G.Samhita Priyadarsini,V.Jagadeesh Babu,Y.Sai Varun Teja, DOI NO: https://doi.org/10.26782/jmcms.2020.07.00051 admin July 26, 2020 Abstract: Alcohol based fuels can be produced from renewable energy sources and

Hemin-intercalated layer-by-layer electropolymerized co-deposition of bisphenol A on carbon nanotubes for dual electrocatalysis towards ascorbate oxidation and oxygen reduction

A hemin-intercalated bisphenol A (BPA) electropolymerized film (H-PBPA) is co-deposited on single-walled carbon nanotubes (CNTs) by repetitive differential pulse voltammetry to achieve a CNTs@H-PBPA electrode for the oxidation of ascorbate (AA) and the reduction of oxygen (O2) in fuel cells. Although hemin-based redox reactions are depressed during the growth of PBPA films, the addition of hemin can remarkably promote the oxidation of BPA and the formation of H-PBPA hybrids on CNTs. Compared with hemin or PBPA on CNTs, the as-prepared H-PBPA hybrids show higher redox activity and overall conductivity, and greater dual electrocatalysis towards ascorbate oxidation and oxygen reduction. While simultaneously employing CNTs@H-PBPA as anode and cathode, the ascorbate fuel cell exhibits a 0.75-fold, 2.50-fold or 23.7-fold increase in the maximum power output in contrast to that using CNTs@PBPA, CNTs@hemin or CNTs. The proposed ascorbate fuel cell has the advantages of mild and environment-friendly operational conditions, high stability and power density, and no requirement for noble metals and enzymes. This study presents the first example of carbon nanotube functionalization using hemin as binder and BPA electropolymerized film as redox mediators for biomass energy conversion and utilization.

Biomass Derived Fuels for Gas Turbine Application

The use of biomass-derived fuels as an alternative energy has become a key solution to solve fossil fuels shortage and reduce greenhouse gas emission. With the development on biomass energy conversion, biofuels show great improvement in product yield, fuel quality and combustion characteristics, making it possible for gas turbine applications. The stable combustion flame of the gas turbine makes it adaptable to various biofuels. The main research of utilizing biomass-derived fuels in gas turbine in recent years was summarized. Characteristics and combustion feasibility of typical biofuels were discussed including both liquid phase biofuels and gas phase biofuels. The combustion performance, pollutant emission and combustion optimization of biofuels combustion in gas turbines was analysed. The main problems and effective solutions for biofuel applications were summarized, providing guidance for clean and efficient use of biofuels in gas turbines.

Some design characteristics of micro steam turbines for agricultural biomass energy conversion

The paper continues the study of reconversion of a 400 kW hot water boiler in a steam generator suitable to valorise the energy content of briquettes and pellets of agricultural biomass. After steam parameters selection (pressure, temperature, mass-flow rate), an overview of main steam machines types (axial, radial, screw, piston engine) is done. Further, a parallel design of most wide-spread ones (Laval, Curtis and radial) were performed, at different rotation speeds, in order to find the best configuration in respect with the flow section dimensions, internal efficiency and power (electrical and thermal) output. The results of the paper could be very useful for the investors in agricultural “waste-toenergy” projects in order to select appropriate technology and equipment.

Microwave-assisted catalytic upgrading of co-pyrolysis vapor using HZSM-5 and MCM-41 for bio-oil production: Co-feeding of soapstock and straw in a downdraft reactor

Microwave-assisted co-pyrolysis of low hydrogen-to-carbon and high hydrogen-to-carbon effective ratio materials with the aid of HZSM-5 and MCM-41 is a promising technique to improve the bio-oil quality. The low content of hydrocarbons and short life cycle of catalyst limit the application of pyrolysis technology in biomass energy conversion. The effects of catalytic temperature, and HZSM-5-to-MCM-41, feedstock-to-catalyst, and straw-to-soapstock ratios on the yield and composition of bio-oil were studied in this work. The quality of bio-oil during biomass pyrolysis can be improved by adjusting the operating conditions. The optimal catalytic temperature, and ratios of HZSM-5-to-MCM-41, feedstock-to-catalyst, and straw-to-soapstock were 400 °C, 1:1, 2:1, and 1:2, respectively. The addition of MCM-41 was beneficial in prolonging the life of HZSM-5 since the macromolecular compounds cracked when MCM-41 was added which restrain the generation of coke. The co-pyrolysis of soapstock with straw advanced the deoxygenation of oxygen-containing compounds especially phenol from straw during pyrolysis.

Biomass Valorization via Paired Electrosynthesis Over Vanadium Nitride‐Based Electrocatalysts

AbstractPaired electrosynthesis is a promising technology with the potential to generate value‐added products at both electrodes in a cost‐effective manner. Herein, 3D vanadium nitride (VN) and Pd/VN hollow nanospheres are successfully fabricated and coupled to carry out simultaneous electrocatalytic oxidation (ECO) and electrocatalytic hydrogenation (ECH) of 5‐hydroxymethylfurfural (HMF) into 2, 5‐furandicarboxylic acid (FDCA) and 2,5‐bishydroxymethyl‐tetrahydrofuran (DHMTHF), respectively. VN shows excellent ECO performance with high HMF conversion (≥98%), FDCA selectivity (≥96%), and faradaic efficiency (≥84%) after a stability test, and Pd/VN achieves high ECH selectivity for DHMTHF at ≥88% and an HMF conversion of ≥90%, with a faradaic efficiency of ≥86%. VN and Pd/VN incorporated into a membrane electrode assembly in a paired electrolysis system shows potential for large‐scale biomass conversion and upgrading. Theoretical calculations reveal that the higher performance of VN for the production of ECO can be attributed to its lower d‐band center level relative to the Fermi level compared to that of V2O5, which favors HMF chemisorption and activation. This study paves the way for developing paired electrosynthesis technologies with the potential for biomass utilization and energy conversion.

Energy conversion of biomass char: Oxidation rates in mixtures of O2/CO2/H2O

In thermal energy conversion of biomass, the char conversion rate influences the design of industrial systems. Yet there is no consensus on the relative influences of O2, CO2 and H2O on the char conversion rate. The present study aims at clarifying the roles of these oxidizers on biomass char conversion. Single particles of different particles sizes were oxidized in mixtures of O2/N2, CO2/N2, H2O/N2 and O2/CO2/H2O/N2 at various temperatures. The results show that for large particles and high temperatures, CO2 and H2O gasification reactions play a dominant role, while for sufficiently small particles and low temperatures, the O2 oxidation reaction plays a dominant role in mixtures of O2/CO2/H2O/N2. Two different particle models were used to compute char conversions: a detailed single particle model, and a conventional particle model assuming that rates in mixtures of oxidizers can be predicted based on rates of single oxidizers. The results show that the char oxidation rates are strongly overestimated when predicting rates based on single oxidizers, while the detailed model shows a good agreement to the experimental measurements.

Efficiency and Exergy Enhancement of ORC Powered by Recovering Flue Gases-Heat System in Cement Industrials: a Case Study

The recent surge in environmental awareness along with the increased cost of electricity generation has spurred the need for clean energy sources. This has generated significant interest over the last few years via research, investigation, and evaluation looking for sustainable and economical energy sources. The intended objective is to alleviate some of the exhaust gas emissions and greenhouse effects by recovering the waste heat from industrial processes. Among the heat recovery systems, ORC is found to be an efficient and practical power production thermodynamic cycle, owing to its ability to utilize low grade temperature heat sources such as solar energy, geothermal water, biomass, wasted heat and thermal ocean energy conversion. In this study, the recovery of waste heat is utilized to transfer power to the ORC through an intermediate thermal loop in the production of electricity. The WHR was obtained from exhaust flue gases of rotary kiln in a cement plant in Jordan, possessing a temperature range between 280 °C – 380 °C; the organic liquid used in the ORC is R245fa. The effects of varying factors on the ORC’s performance were analyzed and optimized. The cycle results analysis indicate that the possible electrical power production can be estimated to be around 323.33 kWe, values of 15.86% and 193.3 kW were reached for system performance and exergy, respectively. In addition, an economic analysis performed showed that the payback time period is approximately 3.75 years and monetary net savings could reach up to 200,000 JD per annum.

Biomass gasification of hybrid seed Miscanthus in Glasgow’s downdraft gasifier testbed system

Global energy problems, rise in CO2 emissions and their implications on climate change are well documented. Renewable energy provides a crucial role in reducing these emissions whilst providing sustainable energy; energy conversion of biomass forms a valuable part of a renewable energy portfolio, with capability for baseload provision, and gas and electricity production. Gasification is the thermochemical conversion of biomass (carbonaceous material) into producer gases. A small-scale throated downdraft gasifier was designed and manufactured at the University of Glasgow and built to easily assess the gasification performance under different conditions e.g. feedstock variety and with different instrumentation and control strategies. Various feedstock varieties of Miscanthus (OPM12, MxG, and OPM53) were gasified under the same equivalence ratio (ER 0.30). The elemental compositions of each Miscanthus varied with their genetic properties. A Gasifier Control Unit (G.C.U) was installed on the experimental gasifier to measure parameters: temperature, pressure, liquid flow and mass flow. The gasifier was operated in batch mode; to improve repeatability the throat, grate and assembly were cleaned after each experiment. The experimental work reported in this research is mainly focused on the comparative study and analysis of the producer gas compositions, carbon conversion efficiency, higher heating value (HHV), lower heating value (LHV), cold gas efficiency and gas yield with the different biomass feedstocks. The ultimate and proximate analysis was done for all Miscanthus varieties along with ash analysis. The major outcome of this research was to investigate the impact of feedstock variety on gasification performance and identify preferred Miscanthus varieties to grow at scale with optimised gasification.

Perspective of biomass energy conversion in Bangladesh

This paper presents the state of the art of the current status, techniques used for conversion, possible future prospects, policies and challenges of biomass energy in the context of Bangladesh. It is seen that the utilization of biomass energy is increasing day by day. Biomass has the potential capacity to contribute around 400 EJ/yr in the future global energy supply by the year 2050 ensuring the adaptability of Sustainable Development Goal 7 (access to affordable, reliable, sustainable and modern energy for all). However, in many cases, lack of modern technology augmented by socioeconomic challenges is creating a tremendous hindrance to the way of extracting and utilizing the biomass energy at a higher efficacy. The authors believe if well-researched plans and techniques are adapted specifically for Bangladesh, and followed accordingly, it is possible to mitigate this hindrance to a great extent. The authors have also proposed some recent techniques that might be feasible in the context of Bangladesh.

Modeling a process combining a cereal dryer with a bioenergy unit for equipment design in developing countries

AbstractThis study describes the development of a process model combining a biomass energy conversion unit with a cereal‐based products’ dryer. Heat and mass transfer and pressure drops, which occur during the process, are identified using two experimental set‐ups. The tool can predict the behavior of a heat exchanger and simulate drying of agglomerated products. The model is then used to evaluate the process performance in its installation context, by means of indicators, based on which six design solutions are studied. The results obtained provide initial guidelines for installing a processing unit in the South and clearly show the usefulness of this sort of process design aid tool. It may be integrated into a multiobjective optimization environment, in order to design a high‐performance process, tailored to the context of developing countries.Practical applicationsIn Sub‐Saharan Africa, agri‐business companies carrying out drying operations are experiencing difficulties obtaining efficient equipment, providing their energy supply, and guaranteeing the quality of the finished products. Research activities have already enabled the manufacture and installation in Burkina Faso and Mali of prototype dryers built on the principle of flat‐bed dryers but heated by gas combustion, an expensive and nonsustainable energy. At present, a biomass heat generator and heat exchanger still need to be manufactured locally. Hence the objective of this work is to be able to use the process model as a design aid tool for installations combining the three pieces of equipment. Local manufacturing support will be incorporated during the development of high‐performance design solutions to work toward creating and installing sustainable drying units in West Africa.

Exergy efficiency of light conversion into biomass in the macroalga Ulva sp. (Chlorophyta) cultivated under the pulsed light in a photobioreactor.

Marine macroalgae are a potential feedstock for biorefineries that can reduce dependence on fossil fuels and contribute to bioeconomy. New knowledge and technologies for efficient conversion of solar energy into macroalgae biomass are needed to increase biomass yields and energy conversion efficiency. In this work, we show that the green macroalgae from Ulva sp. can grow under the pulsed light in a photobioreactor with higher exergy conversion efficiency in comparison to cultivation under constant light with the same intensity. In the tested frequencies, 1-40 Hz and duty cycles (DC) 1-100%, DC has a stronger impact on the growth rate than frequency. The efficiency of light transformation into biomass increased with decreasing DC. Pulsating with DC 20% led to 60% of the biomass chemical energy yield for the respective constant light (DC 100%). Models of Ulva sp. growth rate and exergy conversion efficiency as a function of pulsating light parameters were developed. These results open new directions to enhance solar to chemical energy conversion through macroalgae by controlling the light distribution in the macroalgal biomass.

都市域廃棄物を用いたエネルギー転換システムの開発 （第3報）反応管鋼材の暴露試験

都市域廃棄物を用いたエネルギー転換システムの開発 （第3報）反応管鋼材の暴露試験

Performance quantification of a cyclonic boiler using biomass sawdust

Fossil fuels such as oil, coal and natural gas represent the prime energy sources at any place of the world. These fuels are largely used at steam systems for industrial applications to produce steam and heat through the burning process. Concern about the damage that gases emitted by burning processes can cause on the breathing air as well as in the atmosphere has encouraged studies on renewable fuels in order to reduce harmful emissions to the environment. In this context, any organic matter derived from plants, knows as biomass is an alternative to decrease the environmental issues. Cyclonic combustor well known as fluidized bed reactor promotes high efficiency combustion but experimental data are hard to obtain in the literature. This work presents data from a small laboratory boiler with a cyclonic combustor chamber equipped with an innovative calorimeter to measure steam quality. Data measured leads to the quantification of boiler thermal efficiency and gas species concentration. Experiments were performed using Cedrella fissilis biomass as sawdust which was previously characterized. Results showed a thermal efficiency of 44%, biomass energy conversion through combustion of 98% and CO emissions in the eluded gases were around 139 ppm. It was observed that the boiler operation is efficient to test different Amazonian biomass species as well as to provide new experimental data.

Fischer-Tropsch route for the conversion of biomass to liquid fuels - Technical and economic analysis

The techno-economics of biomass gasification systems for the production of Fischer-Tropsch (FT) based liquid fuels are analysed by estimating the overall mass and energy conversion of biomass to liquid (BTL) fuel. The investigation of BTL systems for 1000 kg/h biomass gasification system and an expected liquid hydrocarbon output of 1500 tonnes are estimated. The cost analysis, based on the annualized life cycle of the systems, includes a steam-oxygen based biomass gasification plant paired with the FT unit. The gasifier considered in this analysis is the downdraft reactor design, operating on oxygen-steam gasifying medium at an equivalence ratio of 0.1 and a steam-to-biomass ratio in the range of 0.8–1.2 to generate syngas with H2/CO ratio of 2.1:1, ideally suitable for the cobalt based fixed bed FT reactor. The mass and energy balance reveal that for a once-through FT reactor configuration, substantial energy exists in the gas phase, which includes C1-C5 hydrocarbons and unconverted syngas. The study suggests that the product gas be utilized in an IC engine and converted to electricity, for in-house power demands and for the sale of excess electricity to the grid. The analysis indicates a market competitive liquid fuel production with CO conversion greater than 60%, at a cost ranging from INR 35–40/litre (0.5–0.6 USD/litre) alongside electricity as a major co-product in the BTL system. This study examines the economics of building economically affordable and environmentally favourable BTL systems of smaller throughputs with particular reference to India.