Sustainable Production Technologies Research Articles

Freeing land from biofuel production through microalgal cultivation in the Neotropical region

Biofuel production is a key strategy for reducing CO2 emissions globally and is expected to increase substantially in the coming decades, particularly in tropical developing countries. The adoption of sustainable biofuel production technologies that do not place large demands on agricultural or forested lands, has the potential to make a substantial contribution to decreasing greenhouse gas emissions while reducing biodiversity losses and degradation of native ecosystems resulting from high demand for land. With their high productivity per unit area and ability to grow on non-arable lands, microalgal biofuel production systems could become a major sustainable alternative to biofuel production from food crops (first-generation biofuels). However, the potential impacts of microalgal biofuels on food production, biodiversity, and carbon storage, compared to other biofuel production alternatives, are largely unknown. In the present study, the most suitable areas for siting microalgae production farms to fulfill 30% of future transport energy demands were determined within four Neotropical countries with high population densities and high importance for agricultural expansion and biodiversity conservation globally (Colombia, Ecuador, Panama, and Venezuela). These results were contrasted with the best areas for siting oil palm and sugarcane crops to fulfill the same target in future transport energy demands. Microalgal production systems offer the most sustainable alternative for future biofuel production within the Neotropics. Meeting 30% of future transport energy demands with microalgal biofuels reduced land area requirements by at least 52% compared to oil palm and sugarcane. Furthermore, microalgal biofuel production reduced direct competition with agricultural lands, biodiverse areas, and carbon-rich systems within countries, with little overlap with the biodiverse and carbon-rich rainforests. This study can guide decision making towards the identification and adoption of more sustainable biofuel production alternatives in the Neotropics, helping in avoiding unnecessary environmental impacts from biofuel expansion in the region.

Hydrogen Generation from Seawater Electrolysis over a Sandwich-like NiCoN|NixP|NiCoN Microsheet Array Catalyst

Seawater electrolysis presents a transformative technology for sustainable hydrogen production and environmental remediation. However, the lack of active and robust hydrogen evolution reaction (HER...

Energy efficiency analysis of outdoor standalone photovoltaic-powered photobioreactors coproducing lipid-rich algal biomass and electricity

The need for thermal regulation in microalgal photobioreactors is a significant impediment to their large-scale adoption. The energy costs associated with thermal regulation alone can easily result in a negative energy balance. Self-sustaining photovoltaic powered photobioreactors that do not require cooling systems provide an opportunity to maximize biomass productivity, generate local electricity, reduce thermal regulation requirements, and significantly improve the energy balance of the system. Net energy analysis of a spectrally-selective, insulated-glazed photovoltaic photobioreactor (IGP) with an integrated capability for renewable electricity generation used to cultivate Nannochloropsis sp. without freshwater-based cooling resulted in a net energy ratio of 2.96, a figure comparable to agricultural bio-oil crops such as Jatropha and soybean. Experimental data from pilot-scale operation of this novel photobioreactor producing Nannochloropsis biomass under outdoor conditions was extrapolated to a 1-ha IGP installation. Annual biomass productivity reached 66.0-tons dry weight ha−1, equivalent to overall energy output of 1696.2 GJ ha−1. The integrated semi-transparent photovoltaic panels generated an additional 1126.8 GJ ha−1 yr−1 (313.0 MWh ha−1 yr−1). Energy demands from plant building materials, machinery, fertilizers, plant operations, and biomass harvesting constituted total energy input with a combined value of 707.3 GJ ha−1 yr−1. Comparison with a conventional photobioreactor requiring passive evaporative cooling showed novel photobioreactor had a 73% greater net energy ratio. Nannochloropsis cultivation in IGP system ensured co-production of lipid and protein of 34.7 and 25.7-tons ha−1 yr−1, respectively. These results suggest that this novel photobioreactor could be a viable and sustainable biomass production technology for mass microalgal cultivation.

Adoption of Rice Post-Harvest Technologies Among Smallholder Farmers in Osun State, Nigeria

Summary The study assessed adoption of rice post-harvest technologies among smallholder farmers in Osun State, Nigeria. Data were collected from 120 respondents through a structured interview schedule using a multistage sampling procedure. Percentages, means, Chi-square and correlation were used to analyse the data and draw inferences. The results show that about 52.5% of the respondents had favourable perception, while 47.5% had unfavourable perception towards adoption of the rice post-harvest technologies. Rice milling (mean=4.54) and harvesting matured panicles at the right time (mean=4.47) ranked highest among the adopted post-harvest technologies, while majority (65%) of the respondents adopted the rice post-harvest technologies at moderate level and 35% had high level of adoption. Inadequate capital (mean=1.75) and poor extension contacts (mean=1.67) were the major constraints associated with the adoption. Also, there was significant association between sex (χ2= 38.174), marital status (χ2=32.85) and adoption of the rice post-harvest technologies, while age (r=-0.531), household size (r=0.414) and the quantity of rice produced (r=0.345) had significant relationship with adoption of the post-harvest rice technologies. There was moderate level of adoption among the farmers. Financial institutions, governments and non-governmental organisations should provide functional credit facilities and government should employ more extension agents to promote adoption of high-quality enhancing post-harvest technologies for sustainable rice production in Nigeria.

Effects of entomopathogenic fungi on growth and nutrition in wheat grown on two calcareous soils: Influence of the fungus application method

AbstractEntomopathogenic fungi (EF) have so far aroused little interest as plant growth promoters or nutritional enhancers while protecting the plant against insect pests and mites. In this work, we examined the performance of Triticum durum and Triticum aestivum plants pot‐grown on two unsterilized Zn‐poor calcareous Vertisols and inoculated with Beauveria bassiana or Metarhizium brunneum by application to soil or seed dressing. The effects of fungal inoculation were found to depend on crop species, soil type, sampling time and fungus application method. While the height of the control plants tended to be significantly greater than the height of inoculated plants at early and intermediate growth stages, the trend changed at more advanced plant stage of development, 56 days after sowing (DAS). This was supported by the significant increase in aerial dry matter (ADM) in T. aestivum plants treated with B. bassiana by seed dressing (17.4%) or with M. brunneum with soil application and seed dressing (20.6 and 26.9%, respectively) 69 DAS. In T. durum, at harvest, seed dressing with B. bassiana or M. brunneum had an overall positive but not significant effect on ADM or grain yield, whereas direct application to the soil slightly decreased grain yield (6.6 and 5.5%, respectively) and ADM (5.3 and 6.1%, respectively). In T. aestivum, none of the fungus–application method combinations affected yield at harvest significantly. Fungal inoculation had little influence on nutrient uptake, whereas application to soil increased Mn uptake and grain Mn concentration in T. durum. Zinc uptake was significantly increased only in T. aestivum grown on the soil with the lowest Zn content treated with M. brunneum. Grain Zn concentration tended to be inversely related to grain yield. These results support seed dressing with EF as a promising green technology for sustainable crop protection and production with no adverse effects on plant performance.

Effect of socio-economic characteristics of greenhouse farmers on vegetable production in Ogun state, Nigeria

In Nigeria, vegetable production is adversely affected by climate change, pest and diseases attack and unfavourably environmental condition which have made resourceful farmers and government to embark on vegetable production under greenhouse technology. Hence, this study was conducted to assess socio-economic importance of greenhouse technology for sustainable vegetable production in Ogun State, Nigeria. One hundred and twenty (120) vegetable farmers were purposively selected for this study while descriptive statistics and chi-square analysis were used for the data analysis. The results showed that the respondents were 32 – 40 years of age; predominantly male (90.8%), and had formal education (28.3%). Socio-economic importance of greenhouse technology includes increased yield (94.3%), available supplies all the year round (85.7%), cluster marketing formation (72.9%), higher income generation (75.7%), and rural development (91.4%). Paradoxically, greenhouse vegetable production has not been widely spread due to difficult to establish it by individuals and high cost of construction (98.3%); it is too expensive for the low peasant vegetable farmers (86.7%); and awareness of greenhouse vegetable is low in the public markets (85.8%). So also, chi-square results showed that significant relationship existed between the major limitations and socio-economic importance of greenhouse technology at p < 0.05 level of significance. This study recommends that cost of raw materials for constructing greenhouse should be subsidized by the Federal Government of Nigeria while wealthy individuals, farmers’ groups and cooperative societies should invest in greenhouse technology for large scale vegetable farming.Keywords: socio-economic, importance, vegetable, greenhouse, technology

Green technology for sustainable biohydrogen production (waste to energy): A review

Perceiving and detecting a sustainable source of energy is very critical issue for current modern society. Hydrogen on combustion releases energy and water as a byproduct and has been considered as an environmental pollution free energy carrier. From the last decade, most of the researchers have recommended hydrogen as one of the cleanest fuels and its demand is rising ever since. Hydrogen having the highest energy density is more advantageous than any other fuel. Hydrogen obtained from the fossil fuels produces carbon dioxide as a byproduct and creates environment negative effect. Therefore, biohydrogen production from green algae and cyanobacteria is an attractive option that generates a benign renewable energy carrier. Microalgal feedstocks show a high potential for the generation of fuel such as biohydrogen, bioethanol and biodiesel. This article has reviewed the different methods of biohydrogen production while also trying to find out the most economical and ecofriendly method for its production. A thorough review process has been carried out to study the methods, enzymes involved, factors affecting the rate of hydrogen production, dual nature of algae, challenges and commercialization potential of algal biohydrogen.

Legume Biofortification and the Role of Plant Growth-Promoting Bacteria in a Sustainable Agricultural Era

World population growth, together with climate changes and increased hidden hunger, bring an urgent need for finding sustainable and eco-friendly agricultural approaches to improve crop yield and nutritional value. The existing methodologies for enhancing the concentration of bioavailable micronutrients in edible crop tissues (i.e., biofortification), including some agronomic strategies, conventional plant breeding, and genetic engineering, have not always been successful. In recent years, the use of plant growth-promoting bacteria (PGPB) has been suggested as a promising approach for the biofortification of important crops, including legumes. Legumes have many beneficial health effects, namely, improved immunological, metabolic and hormonal regulation, anticarcinogenic and anti-inflammatory effects, and decreased risk of cardiovascular and obesity-related diseases. These crops also play a key role in the environment through symbiotic nitrogen (N) fixation, reducing the need for N fertilizers, reducing CO2 emissions, improving soil composition, and increasing plant resistance to pests and diseases. PGPB act by a series of direct and indirect mechanisms to potentially improve crop yields and nutrition. This review will focus on the: (i) importance of legumes in the accomplishment of United Nations Sustainable Development Goals for production systems; (ii) understanding the role of PGPB in plant nutrition; (iii) iron biofortification of legumes with PGPB, which is an interesting case study of a green technology for sustainable plant-food production improving nutrition and promoting sustainable agriculture.

Modelling adoption intensity of improved soybean production technologies in Ghana - a Generalized Poisson approach.

Soybean is an important cash crop especially for farmers in the north of Ghana. However, cultivation of the commodity is dominated by smallholders equipped with traditional tools, coupled with low or no adoption of improved soybean production technologies. Using primary data collected from 300 soybean farmers across northern Ghana, the study employed count data modelling to estimate the determinants of adoption intensity of sustainable soybean production technologies. The study accounted for potential estimation errors due to under-dispersion and over-dispersion, by using a model based on the generalized Poisson distribution. On the average, a farmer adopted 50% of the identified sustainable soybean production technologies. Age, education, extension visits, mass media through radio, and the perception of adoption of soybean production technologies being risky are significant with positive influence on the adoption intensity of sustainable soybean production technologies. The study therefore recommends among others, that various extension programmes should intensify education on the benefits of adopting sustainable soybean production practices. There is the need to set up many technology demonstration farms to give farmers hands-on training during field days.

The Challenge of Digitalization in the Steel Sector

Digitalization represents a paramount process started some decades ago, but which received a strong acceleration by Industry 4.0 and now directly impacts all the process and manufacturing sectors. It is expected to allow the European industry to increase its production efficiency and its sustainability. In particular, in the energy-intensive industries, such as the steel industry, digitalization concerns the application of the related technologies to the production processes, focusing on two main often overlapping directions: Advanced tools for the optimization of the production chain and specific technologies for low-carbon and sustainable production. Furthermore, the rapid evolution of the technologies in the steel sector require the continuous update of the skills of the industrial workforce. The present review paper, resulting from a recent study developed inside a Blueprint European project, introduces the context of digitalization and some important definitions in both the European industry and the European iron and steel sector. The current technological transformation is depicted, and the main developments funded by European Research Programs are analyzed. Moreover, the impact of digitalization on the steel industry workforce are considered together with the foreseen economic developments.

What drives the adoption of sustainable production technology? Evidence from the large scale farming sector in East China

Sustainable agricultural production technologies such as formula fertilizer and soil testing have caught attentions from government agencies and scholars as a potential solution to environmental problems associated with overuse of fertilizers. A lack of motivation from farmers has slowed the adoption of sustainable technologies in China, resulting in continued deterioration of the rural environment. Recently, China’s agriculture is experiencing rapid consolidation due to structural adjustments and labor migration. Large scale farming is becoming a major force for promoting sustainable rural development and agricultural production. This study applies the theory of planned behavior to explain the adoption of formula fertilizer and soil testing technology among 690 large scale producers in Eastern China. The path analysis shows the attitude, subjective norm (perceived social pressure), and perceived behavior control (perceived ability or risk) significantly increase farmers’ adoption intention. The only path that determines the actual behavior directly is behavioral intention. These findings suggest that, in addition to social, economic and institutional factors, policies aiming at promoting sustainable agricultural production should address the psychological dimensions of technology adoption. Effective approaches should be developed to cultivate farmers’ positive attitudes, social norms consciousness, perceived abilities, as well as reduce perceived risks to increase their interests in adopting the technology.

VOLATILE FATTY ACIDS FROM ORGANIC WASTES AS NOVEL LOW-COST CARBON SOURCE FOR Yarrowia lipolytica

Microbial oil biosynthesis is envisaged as a promising technology for sustainable production of chemicals and fuels. Sugar-based substrates are the most typical carbon sources used for this purpose where metabolic pathways and stoichiometry are well known. However, the use of low-cost substrates is crucial for the economic viability of the process. Volatile fatty acids (VFAs) are considered to be a novel low-cost carbon source for microbial lipid production. They can be utilized by oleaginous yeasts to produce and store fatty acids in form of intracellular lipid bodies. In this work, Yarrowia lipolytica growth and substrate consumption were evaluated using the major VFAs present in anaerobic effluents. Individual VFAs as well as synthetic mixtures were tested at different concentrations to determine uptake rates and potential toxicity. Increasing VFA chain length resulted in greater biomass yield although, when added individually, 4 g Carbon/L VFA (e.g. 6.45 g/L of caproic and 10 g/L of acetic acid) caused inhibitory effects. Remarkably, biomass growth increased by 2.5-fold on real anaerobic fermentation effluent compared with synthetic mixtures. When real digestate was supplemented with synthetic VFAs up to 26.5 g/L, the inhibitory effect of the acids was counterbalanced. The results provided evidence of robustness of Y. lipolytica towards low-cost fermentation effluents and present this yeast as a promising candidate for the sustainable production of microbial oil using real digestates.

Sustainability assessment and decision making of hydrogen production technologies: A novel two-stage multi-criteria decision making method

A novel two-stage multi-criteria decision making (MCDM) method is proposed with the aim to select the most sustainable hydrogen production technology (HPT) by considering the preference information on both attributes and alternatives. In the first stage of the method, the initial sustainability ranking of the alternative HPTs was achieved by using the FBWM (Fuzzy Best-Worst Method) to determine the weights of the criteria and the fuzzy TOPSIS (Technique for Order Performance by Similarity to Ideal Solution) method to prioritize the sustainability of alternative HPTs. While, in the second stage, a novel Preference Ranking Linear Programming Method (PRLPM) was used to acquire the final sustainability ranking according to the alternative preference information by following the principle of the outranking method. The proposed method was illustrated by a case study with 8 HTPs, demonstrating that the developed two-stage MCDM method can reflect the alternative preference of the decision-maker more accurately for selecting the most preferred alternative among various HTPs.

Acuity analysis of the vegetable experts to determine the priorities in sustainable vegetable production technologies

Vegetables are short duration and profit-making crop for the farmers especially small and marginal one. By adopting vegetable-based cropping system, farmers can earn more profit from smaller piece of land by enhancing the cropping intensity. Efficient production technologies are very important to utilise scarce natural resources and minimize the cost of production

Economic viability assessment of sustainable hydrogen production, storage, and utilisation technologies integrated into on- and off-grid micro-grids: A performance comparison of different meta-heuristics

In recent years, there has been considerable interest in the development of zero-emissions, sustainable energy systems utilising the potential of hydrogen energy technologies. However, the improper long-term economic assessment of costs and consequences of such hydrogen-based renewable energy systems has hindered the transition to the so-called hydrogen economy in many cases. One of the main reasons for this is the inefficiency of the optimization techniques employed to estimate the whole-life costs of such systems. Owing to the highly nonlinear and non-convex nature of the life-cycle cost optimization problems of sustainable energy systems using hydrogen as an energy carrier, meta-heuristic optimization techniques must be utilised to solve them. To this end, using a specifically developed artificial intelligence-based micro-grid capacity planning method, this paper examines the performances of twenty meta-heuristics in solving the optimal design problems of three conceptualised hydrogen-based micro-grids, as test-case systems. Accordingly, the obtained numeric simulation results using MATLAB indicate that some of the newly introduced meta-heuristics can play a key role in facilitating the successful, cost-effective development and implementation of hydrogen supply chain models. Notably, the moth-flame optimization algorithm is found capable of reducing the life-cycle costs of micro-grids by up to 6.5% as compared to the dragonfly algorithm.

Application of Membrane Separation for Cleaning and Concentration of Nanolignin Suspensions in a Biorefinery Environment

Biorefining is a key technology for the sustainable production of chemicals, fuels and energy from abundant lignocellulosic resources. Within the concept, production of micro- and nanoscaled lignin particles recently gained increasing interest due to their excellent properties and potential application in high-value products. Fabricated via direct precipitation of Organosolv extracts, Nanolignin suspensions need to be increased in concentration and cleaned from impurities. Additionally, solvent background needs to be exchanged from hydroalcoholic solution to pure water for most applications. This work focuses on the application of ultrafiltration in diafiltration mode for this separation task. Experimental operation on lab-scale apparatuses demonstrate the reduction of Ethanol and impurities like sugars, dissolved lignin and sugar degradation products accessed by TOC analysis. Most important, the size of Nanolignin particles is not changed during 9 h of operation. Nevertheless, significant performance degradation due to compaction of polymeric membrane material as well as fouling resulting from deposited lignin particles has been monitored. Consequently, a rigorous optimisation of operating pressure and the development of an adequate membrane regeneration procedure is mandatory.

Assessing alternative crop establishment methods with a sustainability lens in rice production systems of Eastern India.

Sustainability of rice production systems is a prime concern for Asia to maintain food security and to support economic growth. This gain in productivity not only depends on agricultural inputs but also depends on social and environmental factors. To address these emerging issues, new resource- and capital-efficient and profitable technologies have been introduced. The conventional method of rice production (puddling and manual transplanting, PTR) is considered as highly input intensive. As an alternative, dry direct seeded rice (DSR) using seed drill has been promoted to save labor and production costs compared with PTR. Similarly, machine transplanted rice (MTR) has been also considered and promoted in many rice growing countries of South and East Asia. Economic, environmental, and social performances of DSR and MTR (alternative rice establishment technologies) were compared to the PTR using Sustainable Rice Platform (SRP) defined 12 Performance Indicators (PIs) (version 1.0) as a gauge to measure their sustainability. For that, a household survey was conducted on 652 households in Odisha India during 2016. The gaps, i.e., the target to achieve better sustainability, were computed for most of the indicators from the difference between top 10th percentile and the population mean value of the indicator. The results indicated a yield gap of 1.35 t ha−1, a profit gap of $273 ha−1, labor productivity gap of 21 kg day−1, nitrogen (N) use efficiency gap of 22 kg grain kg−1 N, phosphorus (P) use efficiency gap of 105 kg grain kg−1 P, and water productivity gap of 0.00010 kg grain L−1 water in rice production systems in Odisha. Among the compared technologies, MTR results in the highest yield, profit, labor productivity, nitrogen-, phosphorus-use efficiency, and water productivity (at par), and is positive for children’s welfare and the overall energy productivity, indicating better sustainability and has the potential to replace PTR. Direct seeded rice has the highest yield gap (1.57 t ha−1; 38%) but has the lowest production cost (can reduce the cost of production by $130 ha−1), and the highest greenhouse gas (GHG) reduction potential. SRP PIs are capable for assessing the sustainability of rice establishment technologies except for a few indicators, for example food safety and workers health and safety, which are more applicable to watershed and household level indicators, respectively. The SRP PIs provide scientific evidence and practical impetus for the selection and promotion of sustainable rice production technologies.

Characterization of Bone Char and Carbon Xerogel as Sustainable Alternative Bioelectrodes for Bioelectrochemical Systems

Bioelectrochemical systems (BES) are growing future sustainable energy and chemical production technologies that combine biological catalytic redox activity with classic abiotic electrochemical reactions and physics. Several aspects of these systems, such as cell configuration, applied voltage, electrode materials, inoculum/substrate, and low-cost electrodes to facilitate scaling, have been studied and reported. This work focuses on the development of inexpensive materials with desirable characteristics for use as electrodes for BES. The two selected carbon-based anode materials were carbon xerogels and bone char; both have different surface morphologies and are carbonaceous materials with precursors that allow control of their porosity. Industrial-grade raw material and cattle bone waste were used to fabricate the anodes. The electrochemical properties of the bone char and carbon xerogel electrodes were characterized by the open circuit voltage (OCV), electrochemical impedance spectroscopy, and cyclic voltammetry. Chronoamperometry was recorded for 25 days to follow the setup bioanodes. When the microbial bioanode process was completed, the bioelectrodes were immersed into fresh inoculum/substrate, and BES were operated for 10 days at the OCV until a relatively constant cell voltage output was achieved. The results show that the carbon xerogel surface area (468 m2/g) is 5 times higher than bone char, but the xerogel surface roughness is lower than that of the char. Similar to the electrochemical properties, the current density of the xerogel (25 mA/cm2) is 4 times less than that of the bone; therefore, the biofilm growth is promoted on the bone char surface. Our findings show that the bone char bioanode has a capacitance feature of 1.65 F/m2, which is even higher than the double layer capacitances of carbon-based materials reported in the literature. Hence, it is possible to use BES for simultaneous production and storage of renewable electricity.

Influence of Surface State on the Electrochemical Performance of Nickel-Based Cermet Electrodes during Steam Electrolysis

Due to their fuel flexibility and high efficiency, solid oxide cells are a promising technology for sustainable energy production and storage. Nickel in combination with yttria-stabilized zirconia (YSZ) or gadolinium-doped ceria (GDC), forming Ni-YSZ or Ni-GDC cermets respectively, are the most widely adopted electrodes in solid oxide fuel cell fabrication. Currently, there is an increasing interest in cermet electrodes for hydrogen generation through high temperature steam electrolysis using solid oxide electrolysis cells (SOECs). However, durability remains a major issue for reliable operation of SOEC systems. A variety of processes accountable for permanent performance degradation of SOECs has been identified based on post-mortem cell analysis. Besides, transient/reversible degradation processes are typically examined by indirect methods, like impedance spectroscopy. The reason is that the application of material characterization techniques during SOEC operational conditions is challenging. In this wor...

Temperature dependence of power generation of empty fruit bunch (EFB) based microbial fuel cell

Microbial fuel cell has been considered a new emerging technology for renewable and sustainable electricity production. The energy can be extracted from organic waste materials which time independently increase in mass. In the present study, it was demonstrated that lignocellulosic material such as empty fruit bunch (EFB) can be used to produce electricity. Clostridium cellulolyticum and Bacilli E1 were used to activate EFB degradation and electricity generation respectively. It was also demonstrated that the present EFB based MFC was affected in terms of power produced with much higher power was obtained at 37.5 ℃ with power value of 825 ± 3.08 mW/m2 compared to 25 and 50 ℃, which produced 756 ± 1.14 mW/m2 and 345 ± 1.78 mW/m2. At elevated temperature (50 ℃) showed decrease of power density value compared to lower temperature operated MFC, which is believed to be microbial metabolism dependent