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Enset plant residual fibers can be a good candidate for concurrent valorization aimed at dissolving grade pulp and biogas.

Nanoscale materials with multifunctional properties are necessary for the quick development of high-performance devices for a wide range of applications, hence theoretical research into new two-dimensional (2D) materials is encouraged.

Using solar light we can directly generate renewable energies by using novel two-dimensional semiconductor materials. The green represents renewable energy, the grid part is a solar panel, and the two structures are semiconductor materials.

Global energy security relies on fossil-based resources that are affiliated with the source of global warming, apart from punches of political and economic instabilities. Biomass is a promising alternative carbonaceous feedstock used for the production of clean energy that could have the potential to substitute for fossil fuels. This study aims to present a conceptual design that considers the criteria to identify the upper theoretical limits of biomass conversion, thus providing the potential approach to the conversion of three biomass (by-products: dry molasses, dry bagasse, and dry filter cake) through gasification, in order to contribute the biomass carbon-capturing by the model assessment of stoichiometric mass conversion and energy efficiency indicators into simple thermodynamic energy vectors, such as alcohols, alkanes, and syngas (a mixture of carbon monoxide and hydrogen). Modeling plays up the importance of stoichiometric efficiency of biomass conversion with the supply of oxygen and hydrogen. This realizes that the multi-product diversification of feedstock into syngas, hydrocarbons, and alcohol through integrated process schemes could have the potential to fill the energy gap and help to manage environmental load. In regard to biomass conversion results, the mass conversion and energy conversion efficiencies of dry bagasse have better conversion potential than molasses and F. cake (% mass conversion = 129 in syngas, 54.4 in alkane, and 43.4 in alcohol; % energy conversion = 94.3 in syngas and 93.3 in alkane and alcohol).

Nanoscale materials with multifunctional properties are necessary for the quick development of high-performance devices for a wide range of applications, hence theoretical research into new two-dimensional (2D) materials is encouraged. 2D materials have a distinct crystalline structure that leads to intriguing occurrences. Stacking diverse two-dimensional (2D) materials has shown to be an efficient way for producing high-performance semiconductor materials. We explored a 2D nanomaterial family, an MXO/MoX

The current study investigated the Ethiopian sugarcane bagasse during its delignification using the Kraft pulping process and bleaching by single stage hydrogen peroxide process. The multilevel cat...

The overall aim of this work is to evaluate bio-refinery potential of Enset fiber. The effect of non-catalyzed and alkali-catalyzed hydrothermal processes was investigated to fractionate Enset fiber bundle. The treatments were made at 130 °C, 150 °C, 180 °C, and 200 °C and the composition of the solids regarding lignin and monomeric sugar and of the liquid phase were evaluated. The treated solid was further delignified by using ethanol alkali pulping at 40% ethanol concentration, 15% alkali concentration, 140 °C, 60 min. Temperature-dependent mass loss was observed in both non-catalyzed and catalyzed treatment. The liquor was rich in oligosaccharides with a maximum recovery achieved with the alkali-catalyzed hydrothermal treatment at 130 °C for GOS (12.4 g/100 g of original dry sample) and at 180 °C for XOS (3.4 g/100 g of original dry sample). The fibrous nature of the material was preserved after the treatment. The maximum pulp yield of treated Enset fiber was found to be 61.0% per original sample which is comparable to pulping of original sample 69.1%. Therefore, the hydrothermal treatments can be applied as a first fractionation step in the valorization of Enset fibers, allowing the subsequent use of the solid as a fiber source for pulping.

The present study investigated the Ethiopian sugarcane bagasse during its delignification via the sulfur-free soda pulping process and bleaching by the single-stage hydrogen peroxide process. The multilevel categoric experimental design was used to assess the effects of the three independent process variables (pulping temperature, NaOH concentration and time) on the pulp yield and kappa number, during the soda pulping process. The effect of the independent bleaching variables (bleaching temperature, time and H2O2 concentration) on the pulp yield, brightness and whiteness was assessed by using the response surface methodology (central composite experimental design). The soda pulps from the Ethiopian sugarcane bagasse were of varying yield and kappa number and hence were classified according to the sugarcane bagasse providing the highest pulp yield (pulp-SA) with 88.07% and that providing the lowest pulp yield (pulp-SB) with 85.17%. Their corresponding kappa numbers were 16.73 and 8.27, respectively. The brightness and whiteness for the pulp-SA were 62.02% and 84.43%, respectively, whereas for the pulp-SB, the corresponding values were 71.86% and 90.47%, respectively. The study further shows that the paper produced from the pulp-SA had higher mechanical properties. Thus, the promising valorization of the Ethiopian sugarcane bagasse for paper production using the adopted methodology, namely the soda pulping and single-stage hydrogen peroxide bleaching routes, is validated.

Several optimization models, which consider economic and environmental perspectives, have been developed recently to support the sustainable biomass-to-biofuel supply chain (BBSC) design. All of the economic-environmental optimization models rely on solving long-term planning problems with a conventional hierarchical approach, where tactical decisions are made based on the optimal strategic decisions from the strategic-level model, despite it arousing non-optimal solutions. Moreover, almost all of them have used non-monetary-based environmental indicators, which result in difficulties with clarity when comparing with economic objectives. Therefore, in this work, an effort is made to develop a more reliable planning strategy that offers optimal strategic and tactical decisions simultaneously and maximizes the economic and environmental benefits. Furthermore, the environmental performance of the BBSC has been assessed in terms of monetary value by adopting an ecocost approach after performing an LCA on the system. The integrated model is applied in the real biofuel sector of Ethiopia to optimize the country’s bioethanol and biodiesel supply chain over a 20-year horizon. Despite the abrupt rise in the model size, with it being a real countrywide case with many variables and large quantities of data, an alternative semi-heuristic method that offers a feasible solution to the multi-objective problem is provided.

This research provides an assessment of the Ethiopian sugarcane bagasse (ESCB) and examines its suitability for the pulp and paper production. The study is focused toward carrying out the physical fractionation pretreatment on the ESCB aiming at the reduction of its lignin, extractive, silica and ash content. A measurement on the chemical composition was carried out to determine the cellulose, lignin, holocellulose, ash and silica content. Furthermore, cold and hot water solubility, 1% NaOH solubility and the presence of ethanol–toluene extractives were measured. Chemical composition analysis of sugarcane bagasse revealed a good level of cellulose (≈ 50%) and Klason lignin content (

The present study investigated the delignification of false banana (Ensete ventricosum) fibers obtained as a crop residual material using sulfur-free ethanol-alkali pulping. Response surface methodology with central composite experimental design was used to evaluate the effects of four independent process variables (pulping temperature, time, ethanol concentration and alkali concentration) on pulp yield, kappa number, brightness, whiteness and yellowness of pulp. The major parameters influencing pulp yield and kappa number were found to be the alkali concentration followed by temperature. For the predicted optimal pulping conditions, the pulp yield was 69.9% with 4.9 kappa number and 64.5% brightness. The ethanol-alkali pulp obtained at center conditions was characterized by viscosity and strength properties and compared with Kraft pulp, showing comparable burst, tensile strength and tear strength. Results suggest that the valorization of the Enset fibers for production of well delignified, high yield and resistant pulp is a promising approach.

One approach for the viable production of algal biomass is to couple its production with wastewater treatment plants, power and/or industrial plants. This is intended towards the utilization of the nutrients and the CO2 in the wastewater and in the flue gases of the industry respectively by the microalgae during their growth. In the present study microalgal biomass production was conceptually coupled with a sugar factory. The potential of the wastewater and the flue gas of the factory to support the growth of the microalgae was evaluated. Likewise the possible reduction of pollution by the microalgae was studied. The outputs from the coupled process were determined using the material and energy balance approach with a spread sheet. The cultivation model shows that 12 mg of total nitrogen (TN) and 7.4 mg of total phosphorus (TP) per liter of wastewater could be transferred to the algal growth ponds. It was found that there is a nitrogen deficit in the wastewater. With the supply of makeup nutrient, 120.5 tons/year microalgal biomass could be produced from the coupled process. Application of the assumptions resulted in the reduction of chemical oxygen demand (COD) (mg O2/L) from 2200 to 447, biological oxygen demand (BOD5) (mg O2/L) from 1200 to 207, TN (mg/L) from 15 to 0.6 and, TP (mg/L) from 10 to 1.5 in the wastewater. Integration of the sugarcane processing factories with algal biomass production is important for both biomass production and bioremediation.

Energy is one of the essential inputs for socio-economic, and geo-political strategies in nation building. Among potential interests, lignocellulosic biomasses constitute a prime source of biofuel and other value-added products. The thermochemical approach resolve to the degradation of cellulosic biomass into fragments of lignin, hemicellulose and cellulose. From the fragmented components, extraction of fermentable and hydrolysable sugars could be obtained through various combined process steps and finally converted into desired products (alcohols, alkanes, CO, H2). In this research, an average of wet bagasse (C30H120,11O53,84) with 49.28% moisture content; dry bagasse (C30H46,65O17,11); dry molasses (C30H56O28) and dry filter cake (C30H51.14O22.7), were taken for the conversion analysis, with sulphur and nitrogen remained neglected. Adopting gasification as a proposed approach on all of the incoming wet bagasse (16.53 kg/s), mobilizes 6907 kg of water or 5.03% of total water in it. Since, the factory is characterized by low energy efficiency, using a large fraction of the bagasse produced as fuel in the cogeneration system to supply the process energy requirements. The possibility of selling surplus electricity to the grid and utilizing surplus byproducts as an input for the other processes has motivated to enhance more efficient cogeneration systems and process thermal integration.

This study investigated the potential use of Eucalyptus Bark (EB) powder as an adsorbent in batch mode experiments for removal of Cu2+ from Ezana (Meli) wastewater. The discharge of untreated gold mining wastewater contaminated by Cu (II), which is threatening ecosystems and carcinogenic to the human. Since the removal by using adsorption method is cost effective and environmentally friendly, it has been widely studied by many researchers. Characterizations of Eucalyptus Bark were analyzed using proximate analysis, Fourier transform infrared (FTIR) and X-ray diffractometer (XRD). Various characterization techniques showed that the effluent discharged from the factory contains: total suspended solid (TSS), turbidity, Electrical conductivity (EC), Total dissolved solid (TDS), COD, Temperature, pH, cyanide WAD with 2+> Cu (II) >Pb (II) >Mn> Cr (VI) >Zn > Co > Ni > Cd in ppm. The selected parameters were pH, adsorbent dosage and contacting time. The highest percentage of Cu (II) removal achieved was 92%. In this study, the adsorption data were well-fitted to the Langmuir isotherm model.

Additional file 1:. Appendices

Biofuel derived from biomass on account of being renewable energy source and having high potential to substitute fossil fuels, have attracted considerable interest in both developed and developing countries like Ethiopia. However, the lack of optimal design and planning of the biomass-to-biofuel projects in countries like Ethiopia results in poor economic attractiveness of the sector. Therefore, this study presents a novel economic optimization model to design and plan biomass-to-biofuel supply chain (BBSC) at strategic and tactical level simultaneously. The problem is formulated as spatially explicit, multi-feedstock, multi-period and multi-echelon mixed integer linear programming model that seeks to maximize the NPV of the entire supply chain. The proposed model covers all the entities along the supply chain including biomass cultivation, feedstock pretreatment, conversion into bioethanol or biodiesel, as well as distribution, transportation and storage of the biomass, products and byproducts. A county-level case study in Ethiopia is provided to demonstrate the applicability of the model. Results show the effectiveness of the model as a quantitative decision-making or planning tool to design different BBSC configurations. Optimal location, technology, and capacity of the preprocessing facility, biorefinery and biofuel distribution centers are determined simultaneously with inventory levels, material flows and transportation capacities between network nodes of the supply chain.

Magnetic materials have been extensively used for the extraction of heavy metal ions from contaminated aqueous streams. This inherent characteristic of the magnetic particles has received considerable attention in recent years. The external magnetic field employed in the sorption process overcomes many hindrances established during the application of conventional sorbents for metal ion removal. Recent studies illustrate the severity of arsenic toxicity to be a major environmental health hazard in the contaminated ground water. Available literature has been reviewed to highlight the problem, including its malignancies. Magnetic sorbents with demonstrated high specific surface area and specific affinity for metal ions have been exceedingly beneficial for removing the toxic arsenic ions. In addition to this, these sorbents have demonstrated a promising performance in practical applications also. This review paper aims to summarize the magnetic structures and all recent progress in the research of novel magnetic materials for arsenic removal making it a promising technique in the frame of engineering chemistry is showcased herein and reviewed scrupulously. Keywords: Adsorbents, Magnetic material, Arsenic removal, Sorption, Water treatment

Despite biofuels’ significance in substituting petroleum products in the transportation sector, many countries, including Ethiopia, have not taken advantage of their biomass resources potential to develop biofuel. This is attributed to several challenges, in which the economic unattractiveness, especially the requirement of excessively high initial investment costs, is the major one. To address this challenge, a quantitative-based design and planning of the biomass-to-biofuel supply chain (BBSC), which is backed by optimization, is compulsory. Henceforth, this study intends to develop an optimization model that seeks to maximize the profit and minimize the investment cost of the BBSC. The optimization model is applied to the real case of Ethiopia's BBSC to provide a planning support tool for the policy-makers over a 20-year horizon. Although several economic optimization models developed so far, this contribution broadens the preceding research endeavors by considering the following efforts simultaneously. An integrated strategic-tactical level model is developed to prevent non-optimal and infeasible results, which might arise from separate models. Adverse to the integrated strategic-tactical models developed so far, a multi-product BBSC that produces bioethanol and biodiesel with the associated co-products and a comprehensive supply chain, which incorporates a decentralized preprocessing unit, along with the other relevant components, is considered. The investment decisions related to location, technology, and capacity of facilities happen on yearly basis, unlike many studies that consider this decision only at the beginning of the planning period. The model size boosts as it is a real and comprehensive national-level case study. Therefore, a new approach is proposed here to analyze the compromise between the objectives in a justifiable computational time with efficient optimization resolution. A sensitivity analysis is also carried out on biomass purchase price and availability, as well as biofuel demand and selling price.

The beneficiation methods for Ethiopian Kenticha pegmatite–spodumene ores were assessed through mineralogical and quantitative analyses with X-ray diffraction (XRD) and energy-dispersive X-ray fluorescence (EDXRF). The tantalite in the upper zone of the Kenticha pegmatite–spodumene deposit is 58.7wt% higher than that in the inner zone. XRD analysis revealed that the upper zone is dominated by manganocolumbite, whereas the inner zone is predominantly tantalite−Mn. Repeated cleaning and beneficiation of the upper-zone ore resulted in concentrate compositions of 57.34wt% of Ta2O5 and 5.41wt% of Nb2O5. Washing the tantalite concentrates using 1vol% KOH and 1 M H2SO4 led to the removal of thorium and uranium radioactive oxides from the concentrate. The findings of this study suggest that the beneficiation and alkaline washing of Kenticha pegmatite–spodumene ores produce a high-grade export-quality tantalite concentrate with negligible radioactive oxides.

This research aims at the utilization of an agro-industrial waste, the brewery spent grains (BSG) for the extraction of a natural antioxidant, the ferulic acid. Brewery spent grain was initially treated with dilute sulfuric acid, and then subjected to alkaline hydrolysis using NaOH, prior to ferulic acid extraction and purification. X-ray diffraction analysis of the raw and hydrolyzed BSG showed the evidence for a possible release of phenolic extractives. The effect of extraction time (100, 120 and 140 min), temperature (60, 90, and 120 °C), and alkali concentration (1, 2 and 3% (w/v) on the ferulic acid yield was optimized by the Box Behnken Design, using Response Surface Methodology. Accordingly, the experimental ferulic acid yield obtained at optimized conditions (90 min, 120 °C and 2% (w/v) NaOH concentration) was determined to be 46.17 mg/100 g BSG. The total phenolic, flavonoid, protein and reducing sugar content of ferulic acid extract were measured. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical assay. Fourier Transform Infrared Spectroscopy (FT-IR) and High-Performance Liquid Chromatography (HPLC) analysis confirmed the presence of ferulic acid. Results of this present research provides an alternative insight into the waste management of BSG through ferulic acid extraction.

Crystallite size is one of the fundamental factors controlling the magnetic property of magnetic nanoparticles. In this study, magnetite nanoparticles were produced from Ethiopian iron ore and the effect of solvent extraction parameters on the crystallite size were investigated by considering classical nucleation theory. First, the iron ore was crushed and unwanted gangues were discarded, then followed by further grinding to get a black powder. Finally, the magnetite nanoparticles were produced using solvent extraction and co-precipitation method. For the solvent extraction, tri-butyl phosphate (TBP) and tri-octyl phosphine oxide (TOPO) was used as an extractant, while 2-ethyl-hexanol, and heptanol were used as a modifier and diluent, respectively. The synthesized nanoparticles was characterized using XRD, SEM (EDS), TGA, and FTIR. The results show that leaching temperature and modifier concentration have a significant effect on the crystallite size of the nanoparticles. Comparison of the crystallite size using the Scherrer equation reveals the mean crystallite size of the sample extracted using TBP is smaller than the sample extracted using TOPO.

Physicochemical Problems of Mineral Processing; ISSN 2084-4735