Renewable Energy Resources and Technologies
Abdurrahman Abubakar; Madihah Binti MD Salleh; Adibah Binti Yahya; Chun Chong Shiong; Shaza Eva Mohamad; Suraini Binti Abd-Aziz; Huszalina Hussin
Abstract
Oil Palm Frond (OPF) juice has been the focus of Malaysian bioenergy producers through acetone-butanol-ethanol (ABE) fermentation. However, due to the high concentration of phenolic compounds in the hydrolysate, usually garlic and ferulic acids, the fermentation medium turns acidic which hinders the ...
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Oil Palm Frond (OPF) juice has been the focus of Malaysian bioenergy producers through acetone-butanol-ethanol (ABE) fermentation. However, due to the high concentration of phenolic compounds in the hydrolysate, usually garlic and ferulic acids, the fermentation medium turns acidic which hinders the growth of most microorganisms. A suitable method of phenolic compound removal with a minimal effect on the sugar stability of OPF juice has been employed using Amberlite XAD-4 resin. During the detoxification process, the effects of temperature and pH on the removal of phenolic compounds and sugar stability were also assessed. The Amberlite XAD-4 resin managed to adsorb about 32% of phenolic compound from the OPF hydrolysate at an optimum temperature of 50 °C and hydrogen ion concentration (pH) of 6. In addition, it maintained as much as 93.7 % of the sugar in the OPF juice. The effect of detoxifying OPF hydrolysate was further tested for biobutanol production in batch culture using strain Clostridium acetobutylicum SR1, L2, and A1. Strain L2 gave the highest improvement in biobutanol and total solvent production by 22.7% and 14.41%, respectively, in medium with detoxified OPF juice. Meanwhile, compared to non-detoxified OPF juice, the acid production of strain L2 significantly decreased by 2.99-fold when using detoxified OPF juice, despite a 1.2-fold increase in sugar consumption. Conclusively, using Amberlite XAD-4 resin to detoxify OPF hydrolysate at pH 6 and 50 °C removed the phenolic compound while increasing the strain L2 capability to improve biobutanol and total solvent production
Renewable Energy Resources and Technologies
Payam Ghorbannezhad; Behnam Dehbandi; Imtiaz Ali
Abstract
Furandicarboxylic acid (FDCA) is recognized as a valuable product of hydroxymethylfurfural (HMF) derived from cellulosic materials as an abundant renewable source. It could find future bioplastic application if a feasible separation process is developed. To find a commercially available solvent, FDCA ...
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Furandicarboxylic acid (FDCA) is recognized as a valuable product of hydroxymethylfurfural (HMF) derived from cellulosic materials as an abundant renewable source. It could find future bioplastic application if a feasible separation process is developed. To find a commercially available solvent, FDCA should be selectively separated from HMF and the downstream process be supported by pyrolysis-gas chromatography-mass spectrometry experiments in line with density functional theory (DFT). Evaluation of the sigma potential and sigma surface analysis demonstrated that benzene and ethyl acetate enjoyed better extraction and HMF selectivity, whereas FDCA exhibited ideal behavior in the presence of DMF and DMSO solvents. It was proved that the hydrophobicity could be changed by improving the hydrogen-bonding interaction between them. Moreover, the up-down selection of classes of solvents based on the experimental data found by GC-MS revealed that polar molecular solvents (ethanol-water) were more compatible with carboxylic acids and alcohol compounds, while n-hexane was a desirable solvent for phenolic compounds. It was found that levoglucosan retained a significant fraction of water compared to other solvents, which need to be considered for further economic and environmental analysis under the multifaceted framework of biomass-derived products.
Renewable Energy Resources and Technologies
Ali Nazari; Morteza Hosseinpour; Mahdi Rezaei
Abstract
In this study, the impact of digestate treatment after Anaerobic Digestion (AD) process in two scenarios is analyzed in the case of an industrial diary unit in the United States. The first scenario involves production of liquid fertilizer and compost, while the second scenario lacks such a treatment ...
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In this study, the impact of digestate treatment after Anaerobic Digestion (AD) process in two scenarios is analyzed in the case of an industrial diary unit in the United States. The first scenario involves production of liquid fertilizer and compost, while the second scenario lacks such a treatment process. Aspen Plus is used to simulate the AD process and evaluate the general properties of biogas and digestate. The results of technical analysis show insignificant changes in the net power production from the CHP unit in Scenario 1. The economic analysis, however, indicates the necessity of digestate treatment for AD systems to be profitable. Furthermore, the results of environmental analysis indicate the mitigation of about 93.4 kilotonnes of greenhouse gas (GHG) emissions in Scenario 1, while AD in Scenario 2 saves only 12 kilotonnes of GHG emissions. In other words, digestate treatment has a more significant environmental impact than the power production and its profitability from CHP unit. The reason could be attributed to the enormous consumption of energy during the production of chemical fertilizers where the digestate treatment process (scenario 1) offsets the utilization of chemical fertilizers in the agriculture industry.
Renewable Energy Resources and Technologies
Krishnarao Rajaram Patil
Abstract
The present study aims to develop different strategies for better utilization of oxygenated Diethyl ether and ethanol as supplementary fuels by blending them with biodiesel as the base fuel in CI engines. The used biodiesel used was readily available Karanja Oil Methyl Ester (KOME), its scientific name ...
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The present study aims to develop different strategies for better utilization of oxygenated Diethyl ether and ethanol as supplementary fuels by blending them with biodiesel as the base fuel in CI engines. The used biodiesel used was readily available Karanja Oil Methyl Ester (KOME), its scientific name being Pongamia Pinnata. Initially, 5 %, 10 %, 15 %, and 20 % amounts of ethanol (volume) were mixed with biodiesel. Further, the optimum selected blend BE15 was mixed with 5 %, 10 %, 15 %, and 20 % DEE by volume to make the ternary blend. This DEE-ethanol-biodiesel blend was tested on the same engine under the same conditions. The experimental results exhibited that the DEE-ethanol-biodiesel ternary blend, BE15DE10, mitigated BTE by 8.89 % and the smoke, NOx, and CO emissions by 15.66 %, 50.7 %, and 18.5 %, respectively, compared with neat biodiesel. The HC emission exhibited a slightly increasing trend. The results summarize the trade-off between smoke and NOx reduction using DEE and ethanol oxygenated fuels. The addition of ethanol by 15 % and DEE up to 10 % by volume to biodiesel could be considered the most favorable blend without any significant modifications in the CI engine.
Renewable Energy Resources and Technologies
Uttam Bista; Bhawana Rayamajhi; Bipasyana Dhungana; Sunil Prasad Lohani
Abstract
Anaerobic digestion is one of the most effective technologies for managing degradable waste, which produces renewable energy and digestate as the byproduct. In this study, sewage sludge (SS), poultry litter (PL), and food waste (FW) were co-digested at ratios (SS:PL:FW 2:1:1) with 8 % total solid content ...
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Anaerobic digestion is one of the most effective technologies for managing degradable waste, which produces renewable energy and digestate as the byproduct. In this study, sewage sludge (SS), poultry litter (PL), and food waste (FW) were co-digested at ratios (SS:PL:FW 2:1:1) with 8 % total solid content at ambient temperature (average 22 °C) and controlled temperature (35 °C) in summer. The synergistic effects of co-digesting substrates enhance the biogas production potential when digested at an optimized ratio. The maximum biogas yield was 688.7 L/kgVSa at the controlled temperature and 462.3 L/kgVSa at ambient temperature. The ambient reactor had a methane composition of 55 %, while the controlled temperature reactor had about 60 %. The results provide approaches to increase biogas production in the anaerobic digestion process through co-digestion and controlled mesophilic temperature. Biogas production from anaerobic co-digestion could significantly transform waste into energy in low-income countries to achieve the objective of clean energy production and environmental sustainability.
Renewable Energy Resources and Technologies
Ararsa Derese Seboka; Fiseha Bekele Teshome; Motuma Tolera Feyissa
Abstract
This study was conducted in the Loka Abaya District of Sidama Region, Southern Ethiopia to assess the environmental impacts of biomass energy production with particular emphasis on charcoal and firewood. The data collection was undertaken using the questionnaire survey administered to 186 randomly selected ...
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This study was conducted in the Loka Abaya District of Sidama Region, Southern Ethiopia to assess the environmental impacts of biomass energy production with particular emphasis on charcoal and firewood. The data collection was undertaken using the questionnaire survey administered to 186 randomly selected households. This task was followed by key informant interviews and an analysis of the literature. The sampled households produced 208 432.9 kg firewood yr-1 for domestic consumption and 261 039.8 kg charcoal yr-1 for sale in town. 2.3 × 10-6 km2 of the forest is cleared to produce a single sack of charcoal. Charcoal and firewood production is totally responsible for the degradation of 39.4 ha of forest per year. The associated emissions of CO2, CO, N2O, CH4, and TNMHC (total non-methane hydrocarbon) during the production and consumption of firewood and charcoal were calculated based on the emission factors indicated by previous studies. The results demonstrated that the trace gases produced during charcoal making were higher than that of charcoal burning. Further, the amounts of greenhouse gases generated during firewood burning were higher than the onesgenerated during charcoal burning. In order to minimize the challenges of deforestation and greenhouse gas emissions caused by charcoal and firewood consumption, a strategy of promoting the utilization of alternative clean energy sources such as solar and biogas should be implemented in parallel to the effort of adoption of improved biomass energy-saving cook stoves.
Renewable Energy Resources and Technologies
Gokul Raghavendra Srinivasan; Aditya Mahajan; Rajiv Seth; Rakesh Mahajan
Abstract
The present study aims to explore the role of characterized hydrocarbons in thermally cracked shell liquid in determining its overall fuel properties and combustion characteristics in a CI engine. For this purpose, waste shell liquid was extracted from waste cashew nut shell by means of cold extraction ...
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The present study aims to explore the role of characterized hydrocarbons in thermally cracked shell liquid in determining its overall fuel properties and combustion characteristics in a CI engine. For this purpose, waste shell liquid was extracted from waste cashew nut shell by means of cold extraction technique using a simple electrically operated mechanical screw press, which reported maximum extractable oil content as 17.7 %. In addition, it was thermally cracked at 350-400 °C using conventional heating for both lab-scale and pilot-scale extraction. Based on its chemical composition, raw shell liquid contained anacardic acid and cardol, while thermally cracked shell liquid had cresol and methyl oleate as their dominant hydrocarbon compounds. Their composition was found to be 51.84 %, 33.68 %, 43.87 %, and 28.49 %, respectively. According to their contribution, both cyclic and aromatic as well as linear-chained hydrocarbons exhibited significant effect on the fuel properties of the cracked shell liquid, with carbon atoms contributing to its physical and thermal properties, whereas cyclic and aromatic hydrocarbons enhance its flow characteristics. Next, neat and blend samples of this cracked shell liquid with petro diesel reported higher peak in-cylinder pressure by 5.6 % (on average) due to the presence of fatty acid esters, which induced early ignition and provided sufficient time for combustion. Meanwhile, higher emission levels were attributed by both cyclic and aromatic and linear-chained hydrocarbons, citing aromaticity and unsaturation in their molecules, which also resulted in reduced thermal efficiencies by 12.5 % (on average), upon accounting for their inferior calorific content. In conclusion, it is evident that hydrocarbons in these treated shell liquids play a significant role in their fuel properties and engine characteristics.
Renewable Energy Resources and Technologies
Fatemeh Norouzi; Morteza Hosseinpour; Saeed Talebi
Abstract
In this paper, an industrial dairy farm unit was taken as a case study to carry out the applicable technical assessment for the construction of a biogas plant using a combined heat and power (CHP) unit. A comprehensive sensitivity analysis was applied to examine the effectiveness of the operational parameters ...
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In this paper, an industrial dairy farm unit was taken as a case study to carry out the applicable technical assessment for the construction of a biogas plant using a combined heat and power (CHP) unit. A comprehensive sensitivity analysis was applied to examine the effectiveness of the operational parameters and feed composition in the purity and production rate of biogas. Aspen Plus was used to implement the anaerobic digestion process. The results showed that any increase in the digester’s operational performance and mass rate of feedstock water led to the modification of biomethane content, but dropped in biogas mass flow rate. Moreover, an increase in the mass rate of carbohydrates, protein, and organic load rate (OLR) of feedstock reduces methane composition. Besides, increasing the rate of lipids has raised the rate of methane production and its composition.
Renewable Energy Resources and Technologies
Roxana Isabel Bernaola Flores; Carmen Elena Flores Barreda; Diana Carolina Parada Quinayá; Ursula Fabiola Rodríguez Zúñiga
Abstract
Reducing the demand for fossil fuels and the derived products can be achieved through the development of alternative energy sources. This work presents a countrywide study of the energy potential of lignocellulosic biomass sourced from agro-industrial by-products in the country of Peru. Ranking of the ...
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Reducing the demand for fossil fuels and the derived products can be achieved through the development of alternative energy sources. This work presents a countrywide study of the energy potential of lignocellulosic biomass sourced from agro-industrial by-products in the country of Peru. Ranking of the crops that produce the most waste was followed by an energy potential evaluation of carbohydrate conversion and thermochemical conversion. The crops with high calorific values were sugar cane bagasse, wood waste, and coffee husk. The energy potential of the principal lignocellulosic by-products, in terms of tons of oil equivalents per year, resulted from rice straw at 1.45 M, followed by corn residue at 1.13 M and sugar cane residue at 1.10 M. The northern region of Peru generated the highest quantities of rice (straw and husk), banana (husk and rachis), and sugar cane (bagasse and straw) by-products and the southern regions generated the greatest quantities of quinoa residue, all of which could be used as raw materials for biofuels and aggregates for materials. These results indicate that theoretically, this readily available biomass could meet the country's energy demands while promoting sustainability and national energy security.
Renewable Energy Resources and Technologies
Sapna Kinattinkara; Thangavelu Arumugam; Nandhini Samiappan; Vivek Sivakumar; Sampathkumar Velusamy; Mohanraj Murugesan; Manoj Shanmugamoorthy
Abstract
Increased global energy consumption demands the use of more energy resources, aggravating environmental issues. This study focused on analyzing biogas production from a mixture of cow dung, water hyacinth, and food waste and checking the efficiency of the biogas. The efficiency of biogas production was ...
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Increased global energy consumption demands the use of more energy resources, aggravating environmental issues. This study focused on analyzing biogas production from a mixture of cow dung, water hyacinth, and food waste and checking the efficiency of the biogas. The efficiency of biogas production was tested using two alternative settings in the study. The first setup employs Eichhornia crassipes that have been NaOH-treated and mixed with co-digestion substrates such as cow manure and food waste which have been stored at room temperature for 32 days. The second setup contains five different types of substrates such as L1-cow dung, L2- cow dung: water hyacinth, L3-cow dung: food waste, L4-cow dung: water hyacinth: food waste, and L5-water hyacinth. The properties of the Eichhornia crassipes were studied on several biogas substrates, such as pH, temperature, COD, TOC, and NPK tests, as well as total biogas output and methane percentage. The results of the comparison analysis show that the substrate L4 has a high level of NPK (4.7 %) and a higher amount of COD (137600 mg/l). These characteristics enhance the gas yield and methane percentage (85 %). Overall, the water hyacinth mixed with cow dung and food waste exceeded the other four substrates. The total yield of biogas from the first setup was 8.5 litres, the flammability was tested on the 28th day, and the blue flame was obtained. Water hyacinth was removed from aquatic areas and used as an alternative energy source, hence being environmentally friendly.
Renewable Energy Resources and Technologies
Toyese Friday Oyewusi; Gabriel Alebiowu; Elizabeth Funmilayo Aransiola; Ayowumi Rita Soji-Adekunle; Busayo Sunday Adeboye
Abstract
Briquettes from agro-residues have been promoted as a better replacement to firewood and charcoals for heating and cooking in the rural communities. In view of this, a study was carried out to investigate the effect of pretreatment methods on physical properties and heating values of briquettes produced ...
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Briquettes from agro-residues have been promoted as a better replacement to firewood and charcoals for heating and cooking in the rural communities. In view of this, a study was carried out to investigate the effect of pretreatment methods on physical properties and heating values of briquettes produced from corncob. To accomplish this work, the experiment was designed as a 2×3×3×3 completely randomized with three replicates. The parameters are pretreatment methods (carbonized and uncarbonized), binder types (cassava, corn and gelatine), binder concentrations (10, 20, 30%) and compacting pressure (50, 100 and 150 kPa). A charcoal kiln was fabricated to obtain the pretreatment through pyrolysis and a punch and die was also fabricated to enable the briquette densification. The physical properties tested were limited to moisture content (MC), density and compressive strength and were determined using a conventional method. The heating value of the briquettes produced was determined using bomb calorimeter. The results showed that average moisture content ranged between 5.29-6.58% and 12.75-13.72%, mean relaxed density varied from 813-925 kgm-3 and 963-1166 kgm-3, compressive strength ranged between 2.27-5.07 MPa and 5.97-10.12 MPa and heating value ranged between 28.85-32.36 MJkg-1 and 27.58-28.80 MJkg-1 for carbonized and uncarbonized briquettes, respectively. Briquettes produced from carbonized corncob had a better moisture content and heating value, while briquettes produced from uncarbonized corncob had higher density and compressive strength. The study shows that pretreatment methods under different binder types and concentrations and the compacting pressure significantly affected briquette’s physical properties and heating values.
Renewable Energy Resources and Technologies
Ayowumi Rita Soji-Adekunle; Betiku Eriola; Abraham A. Asere
Abstract
This study used ternary substrates consisting of honne, neem, and yellow oleander (HONOYO) oil blend to produce methyl-esters for sustainability of raw materials for biodiesel synthesis. A biomass-based catalyst from calcined mixed agro-wastes consisting of kolanut pod, cocoa pod, and plantain peel ash ...
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This study used ternary substrates consisting of honne, neem, and yellow oleander (HONOYO) oil blend to produce methyl-esters for sustainability of raw materials for biodiesel synthesis. A biomass-based catalyst from calcined mixed agro-wastes consisting of kolanut pod, cocoa pod, and plantain peel ash was employed to transesterify the blend. A two-step method was adopted to convert HONOYO into methyl-esters. Taguchi L9 experimental design tool was used to ascertain the interactive effects of microwave irradiation power (W), Methanol/oil ratio (MeOH), time (min), and agro-wastes synthesized catalyst ASC (wt %) on the yield of methyl-esters from HONOYO. Results demonstrated that at 3:1 MeOH, microwave power of 150 W, ASC of 1.5 wt %, and reaction time of 1 minute, a yield of 80.96 % was achieved. HONOYOB satisfied ASTM D6751 and EN 14214 standards. Performance evaluation of the process input variables suggests weight of ASC as the most significant process parameters for HONOYOB yield. This work authenticates that biomass catalyst from agricultural wastes can adequately be applied to synthesis biodiesel effectively from blends of non-edible oils to supplement fossil diesel.
Renewable Energy Resources and Technologies
Sharareh Esmaeili; Kambiz Tahvildari; Barat Ghobadian; Masoud Dehghani-Soufi; Sanaz Mohammadzadeh Koumleh; Tirth Panchal
Abstract
The presence of increasing concerns and enforcement of growing regulations over environmental pollution are nowadays at play. The pollution arising from mineral oils is among the major concerns. With the gradual reducation of the world oil reserves, an increasing pressure comes into play for finding ...
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The presence of increasing concerns and enforcement of growing regulations over environmental pollution are nowadays at play. The pollution arising from mineral oils is among the major concerns. With the gradual reducation of the world oil reserves, an increasing pressure comes into play for finding sustainable alternatives. Being appealing alternatives, vegetable oils consist of different fatty acids; however, they cannot be applied directly to internal combustion engines owing to their poor oxidation stability and high pour point value. Biolubricants are considered to be a new generation of lubricants, which are renewable and biodegradable and are produced from the chemical modification of vegetable oils. There are few studies investigating the feasibility of using the mixture of fatty acids as biolubricant feedstock. In this study, epoxidation, oxirane ring opening with palmitic acid and p-Toluenesulfonic acid, esterification reaction with octanol, and reaction of the remaining hydroxyl group with stearic acid were applied to modify the mixture of oleic and linoleic fatty acids and produce biolubricant. For this purpose, the IR spectrums of each epoxide, monoester, diester, and triester products were obtained and analyzed. At the end of the experiments, monoester, diester, and triester were obtained with 94 % yield, with 96 % yield, and with 98 % yield, respectively. Eventually, the final product was found with physicochemical properties comparable with the physicochemical properties of the lubricant standard ISO VG10.
Renewable Energy Resources and Technologies
Mohammad Hosseinpour; Hassan Ali Ozgoli; Seyed Alireza Haji Seyed Mirza Hosseini; Amir Hooman Hemmasi; Ramin Mehdipour
Abstract
In this study, the partial alteration of fuel consumption of combined cycle power plants was investigated and analyzed using an innovative model. This system is applicable using the fuel derived from the biomass gasification process. For this purpose, energy modeling of an advanced gasification system ...
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In this study, the partial alteration of fuel consumption of combined cycle power plants was investigated and analyzed using an innovative model. This system is applicable using the fuel derived from the biomass gasification process. For this purpose, energy modeling of an advanced gasification system to supply a share of the gas fuel was fulfilled. The results demonstrated that by considering the reasonable capacities for the design, up to 10 % of natural gas fuel could be replaced with syngas. In addition, heat recovery of the plant stack in the Kalina low-temperature cycle enhanced the total efficiency by up to 1.7 %. Therefore, the competitive advantage of the proposed cycle was enhanced compared to conventional power generation systems. A parametric study of the components affecting the integrated cycle performance including alternative biomass fuels, moisture content of biomass fuel, steam-to-biomass ratio, and equivalence ratio of the gasifier was performed, and the permissible values of each factor were obtained. Thus, by utilizing the proposed approach, it is possible to gradually substitute the consumed fossil fuels of power plants with renewable resources to achieve the objectives of sustainable energy development.
Renewable Energy Resources and Technologies
Toyese Oyegoke; Emo Obadiah; Francis Adah; John E. Oguche; Geoffrey T. Timothy; Ismail A. Mantu; Abubakar D. Ado
Abstract
In recent times, limitations and adverse effects of fossil fuels have significantly attracted researchers' attention to green fuels worldwide, especially in developed nations. As a way of assessing this actualization of biorefineries establishment in developing nations, this report surveys the works ...
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In recent times, limitations and adverse effects of fossil fuels have significantly attracted researchers' attention to green fuels worldwide, especially in developed nations. As a way of assessing this actualization of biorefineries establishment in developing nations, this report surveys the works done by various researches towards this great course in terms of promoting and gaining the attention of both government and private investors about the technical and economic feasibility of embracing the use of biofuels, a case of bioethanol in Nigeria. Different classes of feedstocks were reviewed for the laboratory-scale, process scale-up, pilot plant, and techno-economic studies regarding ascertaining the technical and economic feasibility of local setup of a functional biorefinery in Nigeria, which would be beneficial environmentally and economically. The literature survey unveiled that the Bioethanol yield obtained from sugarcane-juice (72.7 %), banana-stems (84.0 %), and cassava (92.0 %) were found to be of highest potential amongst other sugar-based, lignocellulosic, and starch-based feedstock, respectively. The survey further unveils that the volume of process scale-up and economic feasibility studies does not correlate well with the laboratory-scale studies. The bulk of the research works on bioethanol has given preferential attention to laboratory studies. Only a few studies have looked into the commercialization (i.e., scale-up) of the laboratory findings and the economic implications. Presently, only sugarcane and a few cassavas are reported in the literature so far. It is, therefore, necessary for further studies to give attention to the investigation of the commercializing locally developed technologies and the exploration of their economic benefits.
Renewable Energy Resources and Technologies
Shiva Shadpour; ALi Pirouzi; Mohsen Nosrati; Hoda Hamze
Abstract
Long mixing time, high power consumption, and small mass transfer coefficients are common problems in the photobioreactor design for microalgae culture which have a great effect on system efficiency and performance, CO2 stabilization, and biomass production. In this study, a special design of the triangular ...
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Long mixing time, high power consumption, and small mass transfer coefficients are common problems in the photobioreactor design for microalgae culture which have a great effect on system efficiency and performance, CO2 stabilization, and biomass production. In this study, a special design of the triangular external loop airlift photobioreactor was studied. The bioreactor's geometry was such that the angle between hypotenuse and the horizontal side ( ) could vary. This configuration created an effective gas-liquid countercurrent flow in the downcomer section. In the present research, hydrodynamic and mass transfer of the reactor were investigated on the microalgae productivity under different design and operating parameters. The optimum conditions for the enhancement of Chlorella vulgaris productivity were explored by analyzing the mixing time ( ), volumetric power consumption (P/V), mass transfer coefficients ( ), bubble diameter (d), and gas holdup ( ) as responses. The results showed that the hypotenuse angle of = 59o and the superficial gas velocities of the = 0.0050 m.s-1 for the downcomer and = 0.008 m.s-1 for the riser of the reactor were the best conditions to achieve the highest biomass productivity. The responses’ values obtained in the optimum condition were as follows: = 19.67 (h-1), = 23.79 (h-1), = 23.76 (h-1), = 0.41, and = 62.83 , which had a smaller deviation than the actual values. The highest concentration of Chlorella vulgaris ( 1.4 g.l-1) achieved in this work was obtained in a shorter span of time (11th day of cultivation) based on the growth curve in optimized conditions.
Renewable Energy Resources and Technologies
Rasoul Aydram; Hossein Haji Agha Alizade; Majid Rasouli; Behdad Shadidi
Abstract
Reduced emissions of greenhouse gases and global warming can be made possible by discovering alternative energies and reduced dependence on fossil fuels. Biogas is considered as one of the alternatives to fossil fuels. This study investigates anaerobic co-digestion for the development of biogas with ...
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Reduced emissions of greenhouse gases and global warming can be made possible by discovering alternative energies and reduced dependence on fossil fuels. Biogas is considered as one of the alternatives to fossil fuels. This study investigates anaerobic co-digestion for the development of biogas with sheep blood and cheese whey. Digested cow manure was used as inoculum. Using the Design Expert 10 program and within the context of mixture design, the experiments were designed. Then, 22 experimental digesters with a volume of 500 mL were considered for doing the experiments considering the design output provided by the software. Each one was filled with 300 mL of different compositions of three matters. The digesters were kept in the mesophilic temperature range (37 °C ) for 21 days. Biogas was measured using the BMP test on a daily basis. According to the experimental findings, the best composition included 35 % sheep blood, 35 % cheese whey, and 30 % inoculum. This biogas composition produced a biogas yield of 146.66 mL/g vs. The amount of methane production in this compound was 73.33 mL/g vs. After modeling, the Design Expert software predicted an optimal composition including 44 % sheep blood, 24 % cheese whey, and 32 % inoculum. Biogas yield of this prediction was 143 mL/g vs. The findings show that in order to overcome acidification in digestion of matters such as cheese whey, a composition of matters with higher pH stability can be used to increase the amount of biogas and methane produced in a particular period. Furthermore, using inoculum accelerates the digestion operations due to existence of many microorganisms and saves time and energy.
Renewable Energy Resources and Technologies
Farid Jafarihaghighi; Hasanali Bahrami; Mehdi Ardjmand; Mehrdad Mirzajanzadeh
Abstract
The present study uses three generations of biodiesels and studies their effects on physical properties and exhaust gases. They are comprised of Palmaria palmate oil (third generation), Eucheuma spinosum oil (third generation), Eucheuma cottonii oil (third generation), Common wormwood oil (second generation), ...
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The present study uses three generations of biodiesels and studies their effects on physical properties and exhaust gases. They are comprised of Palmaria palmate oil (third generation), Eucheuma spinosum oil (third generation), Eucheuma cottonii oil (third generation), Common wormwood oil (second generation), Marjoram oil (second generation), Peganum harmala oil (second generation), Zingiber officinale oil (first generation), Anethum graveolens oil (first generation), and Cacao bean oil (first generation). Results show that first-generation oils gain a higher level of Calorific value around 41.16 MJ/kg than other generations. The longest carbon chain is observed by the first generation with higher unsaturated fatty acids than other generations (94.11 %). The first generation gains a higher level of density around 882 kg/m3 than other generations. Also, the first generation gains a higher level of flash point around 193 ˚C than other generations. The third generation gains a high level of cetane number at about 69, compared to other generations. The first generation gains a minimum level of cloud and pour point around -3 ˚C and -2 ˚C compared to other generations. Moreover, the third generation gains the lowest level of viscosity about 2.51 CSt compared to the first generation. The third generation gains the lowest level of NOx around 371 ppm compared to other generations. Finally, the third generation gains the lowest level of soot, CO, and HC around 0.47 Vol. %, 0.018 Vol. %, and 4.82 ppm, compared to other generations.
Renewable Energy Resources and Technologies
Abolfazl Taherzadeh Fini; Abolfazl Fattahi
Abstract
Energy crisis in the world motivates countries to hire new and renewable energies. One of the main and valuable renewable sources of energy is agricultural waste. This is widely disposed of through the world during the harvest, packing, and transportation. In many countries, agricultural waste is considerably ...
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Energy crisis in the world motivates countries to hire new and renewable energies. One of the main and valuable renewable sources of energy is agricultural waste. This is widely disposed of through the world during the harvest, packing, and transportation. In many countries, agricultural waste is considerably weighty. Nonetheless, most of that is used for animal feed or herbal fertilizer and no useful value is added. Despite its location in an arid region, Iran produces various citrus, cereals, and vegetables in high tonnage. The waste of the agricultural product, especially those disposed of by the food processing industries, such as fruit juice factories, remains also useless. The potential of the residues to extract biofuel is investigated in the current experimental study. Six samples of abundant agricultural products in Iran are chosen: sugarcane, grape, potato, orange peel, date, and mulberry. The processes of pretreatment, hydrolysis, and fermentation are performed and the extracted juice is directed to the distiller to gather bioethanol. To evaluate the distilled juice purity, a gas chromatography test is carried out. It is shown that date and mulberry can produce a maximum of 29.5 and 23 ml (ethanol)/100 g (dry waste) as the most efficient agricultural products.
Renewable Energy Resources and Technologies
Mehdi Zare; Barat Ghobadian; Seyed Reza Hassan-Beygi; Gholamhasan Najafi
Abstract
In CI engines, the evaporation rate of fuel on various hot surfaces, including the combustion chamber, has a significant effect on deposit formation and accumulation, the exhaust emissions of PM and NOx, and their efficiency. Therefore, the evaporation of liquid fuel droplets impinging on hot surfaces ...
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In CI engines, the evaporation rate of fuel on various hot surfaces, including the combustion chamber, has a significant effect on deposit formation and accumulation, the exhaust emissions of PM and NOx, and their efficiency. Therefore, the evaporation of liquid fuel droplets impinging on hot surfaces has become an important subject of interest to engine designers, manufacturers, and researchers. The aim of this study is to investigate the evaporation characteristics based on droplet lifetime and critical surface temperature (the maximum heat transfer rate) of diesel and biodiesel fuel droplets on hot surfaces. In order to determine the effects of diesel fuel, canola oil biodiesel, and castor oil biodiesel, the droplets impinging on the hot surfaces of aluminum alloy (7075) and steel alloy (1.5920) and the evaporation lifetime of diesel and biodiesel fuels were measured. Statistical analysis (ANOVA and Duncan’s multiple-range test) was carried out using SAS software. The results showed the maximum critical surface temperature of 450 °C for the castor oil biodiesel on steel 1.5920 surface and the minimum one for diesel fuel (350 °C). In this case, both surfaces had the same droplet lifetimes of approximately 2 s. The results of ANOVA showed the significant effect of the surface material and fuel type on the evaporation lifetime of fuel droplet at 1 % probability.
Renewable Energy Resources and Technologies
Saeed Hosseinpour; Seyed Alireza Haji Seyed Mirza Hosseini; Ramin Mehdipour; Amir Hooman Hemmasi; Hassan Ali Ozgoli
Abstract
In this study, an advanced combined power generation cycle was evaluated to obtain sustainable energy with high power and efficiency. This combined cycle includes biomass gasification, the Cascaded Humidified Advanced Turbine (CHAT), and the steam turbine. The fuel consumed by the system is derived from ...
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In this study, an advanced combined power generation cycle was evaluated to obtain sustainable energy with high power and efficiency. This combined cycle includes biomass gasification, the Cascaded Humidified Advanced Turbine (CHAT), and the steam turbine. The fuel consumed by the system is derived from the gas produced in the biomass gasification process. The biomass consumed in this study is wood because of its reasonable supply and availability. The economic analysis conducted in the present research has produced significant gains. The proposed cycle with current prices intended to sell electricity in Iran has a positive Net Present Value (NPV). Therefore, the presented cycle in terms of energy supply has good economic value. Due to the significantly higher purchase/sale price of electricity from renewable power plants in developed countries in Europe or the United States, the power generation cycle proposed in this study may be more economically feasible in other regions than Iran. Of course, with a slight price increase in electricity sales in Iran (3 US₵ kWh-1), the proposed system will have acceptable NPV. Because of the complicated equipment used in high-pressure and low-pressure turbines and compressors sets, the equipment used in this cycle requires a higher initial investment cost than conventional power generation systems. The results showed that the investment cost per unit of energy was approximately 909 USD kW-1.
Renewable Energy Resources and Technologies
Amir Goshadrou
Abstract
Glycyrrhiza glabra residue (GGR) was efficiently subjected to concentrated phosphoric acid (PA) pretreatment with/without surfactant assistance, and promising results were obtained following separate enzymatic hydrolysis and fermentation (SHF) of the biomass. Pretreatment was carried out using 85 % PA ...
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Glycyrrhiza glabra residue (GGR) was efficiently subjected to concentrated phosphoric acid (PA) pretreatment with/without surfactant assistance, and promising results were obtained following separate enzymatic hydrolysis and fermentation (SHF) of the biomass. Pretreatment was carried out using 85 % PA either at 50 or 85 °C with 12.5 % solid loading for 30 min. In parallel experiments, the intact GGR was impregnated in 2 % (w/w) surfactant (Polyethylene glycol) aqueous solution prior to the PA pretreatment. Consequently, the pretreated materials were subjected to enzymatic hydrolysis (50 °C, 72 h) using 25 FPU/g cellulase, and the most digestible biomass was nominated for conversion to bioethanol. Substantial improvement in digestibility of GGR (~92 % hydrolysis yield) was observed following surfactant-assisted PA pretreatment, whereas digestibility yield from the untreated biomass was only 16.1 %. Consequently, the ethanol production form GGR was significantly enhanced by 19.7-fold through separate hydrolysis and fermentation of biomass. Different analytical approaches including water retention value, Simons’ staining, and crystallinity together with FESEM imaging revealed that the improved surface hydrophilicity, increased substrate accessibility to enzyme, and decreased crystallinity could be the major effects of PA pretreatment, leading to higher susceptibility of GGR to enzymatic hydrolysis and subsequent ethanol production.
Renewable Energy Resources and Technologies
Thenmozhia Pitchai; Rekha Babu; Saravanathamizhan Ramanujam; Iyappan Kuttalam
Abstract
Agricultural residues are potential renewable biomass sources for bio-energy production. The objective of the work is to determine the pyrolysis kinetic parameters of corn cob biomass. Three different heating rates of 10, 20, and 30 °C/min were taken into account in the thermogravimetric analysis. ...
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Agricultural residues are potential renewable biomass sources for bio-energy production. The objective of the work is to determine the pyrolysis kinetic parameters of corn cob biomass. Three different heating rates of 10, 20, and 30 °C/min were taken into account in the thermogravimetric analysis. The Kissinger, Flynn Wall Ozawa (FWO), and Kissinger Akahira Sunose (KAS) model-free methods were employed to calculate the kinetic parameters by the use of the data obtained from TGA. The thermal decomposition process shows three basic phases of pyrolysis: removal of moisture content, primary and secondary pyrolysis. The experimental values were compared with the obtained values from FWO and KAS models; implying that the model values were in good agreement with experimental results. The values of kinetic parameters obtained from Kissinger, FWO, and KAS methods are very similar to their average values of 115, 136, and 131 kJmol-1, respectively. Gas Chromatograph-Mass Spectroscopy (GC-MS) analysis of pyrolysis products is obtained, showing that bio-char and bio-oil contain 10 and 15 different compounds, respectively.
Renewable Energy Resources and Technologies
Tazkieh Gilvari; Behzad Aghabarari; Mohammad Pazouki
Abstract
This study investigated the esterification reaction of different carboxylic acids (Acetic acid, Palmitic acid, and Oleic acid) and ethanol by ZnO, Al2O3-ZnOmixed oxide, and phosphotungestic acid (10 wt %) immobilized on the Al2O3-ZnOmixed oxide. The heterogeneous catalysts were characterized by XRD, ...
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This study investigated the esterification reaction of different carboxylic acids (Acetic acid, Palmitic acid, and Oleic acid) and ethanol by ZnO, Al2O3-ZnOmixed oxide, and phosphotungestic acid (10 wt %) immobilized on the Al2O3-ZnOmixed oxide. The heterogeneous catalysts were characterized by XRD, BET, FE-SEM, and EDX techniques. Optimum yield was achieved by using 10 % HPW/Al2O3-ZnOas the best catalyst, and the effects of the amount of catalyst, molar ratio of acid to alcohol, reaction temperature, and time were investigated to ensure the ideal yield of esterification reaction of acetic acid and ethanol. The results showed that the esterification of acetic acid to its ethyl ester was carried out in 3.5 hours, with an alcohol-to-acid-molar ratio of 2 and a temperature of 80 ˚C with yield 98 %. Moreover, the 10 % HPW/Al2O3-ZnOcatalystshowed well activity in biodiesel production by the esterification of palmitic and oleic acids and the reaction yield did not decrease with an increase in alkyl chain lengthin acid molecules, remarkably.
Renewable Energy Resources and Technologies
Bahman Heydari; Shahin Rafiee; Elham Abdollahzadeh Sharghi; Seyed Saeid Mohtasebi
Abstract
The aromatic and dark-colored spearmint essential oil wastewater (SEOW) generally contains a large amount of organic matter, including chemical oxygen demand (COD), phenolic compounds, and inorganic contents. In this study, the pollutant removal performance and biogas production rate of an up-flow anaerobic ...
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The aromatic and dark-colored spearmint essential oil wastewater (SEOW) generally contains a large amount of organic matter, including chemical oxygen demand (COD), phenolic compounds, and inorganic contents. In this study, the pollutant removal performance and biogas production rate of an up-flow anaerobic sludge blanket (UASB) reactor used for the treatment of SEOW were investigated. During the 102 days UASB operation at hydraulic retention time of 60 hours, the organic loading rate (OLR) was increased from 0.14 to 2.69 kg COD/m3.d by increasing the influent SEOW concentration. With increasing OLR from 0.14 to 2.69 kg COD/m3.d, the concentrations of COD and phenol in the influent of the UASB reactor increased to 6720±383 mg/L and 383±88 mg/L, respectively. At OLR equal to 2.69 kg COD/m3.d, the steady-state average removal efficiencies of COD and phenol were 72.0±1.4 and 63.1±6.7 %, respectively. The stability of the anaerobic system was confirmed by the average steady-state ratios of the volatile fatty acid/alkalinity and pH in the UASB reactor, which were less than 0.4 and 7.5±0.1, respectively, at different OLRs. The optimum OLR was found to be 2.69 kg COD/m3.d, where 26.9±1.7 L/d production of biogas containing 63.0±5.2 % and 22.4±4.2 % methane and carbon dioxide, respectively, was obtained. Moreover, at OLR equal to 2.69 kg COD/m3.d, the biogas yield and net heating value were 462.2±46.9 L/kg CODremoved and 24.7±5.2 MJ/m3, respectively. The results of the current study reveal the substantial potential of the UASB reactor in terms of pollutant removal performance and biogas production for the treatment of SEOW.
