Conventional Sugarcane Research Articles

Mycorrhizal fungi arbuscular in organic and conventional sugarcane systems

Organic production systems are increasingly gaining market share; however, there are still few studies on their influence on the activity of soil microorganisms in sugarcane. Arbuscular mycorrhizal fungi are extremely sensitive to environmental changes, and their activity can be used as a parameter of comparison and quality between organic and conventional systems. The objective of this work was to evaluate mycorrhizal activity in different varieties of sugarcane under two production systems. This work was carried out in a commercial plantation of the Jalles Machado plant in the municipality of Goianésia in Goiás, Brazil. The values of spore density in the soil, mycorrhizal colonization rate in the roots and easily extractable glomalin were evaluated, and the associated fungal species were identified. There was no effect of sugarcane variety on the number of spores or the glomalin content in the soil. The conventional system presented significantly lower mycorrhizal colonization rates than did the organic system. The varieties cultivated under the conventional planting system showed a greater diversity of arbuscular mycorrhizal fungi, where 12 of the 13 different species of mycorrhizal fungi found in both cultivation systems occurred.

Design and Optimization of Sugarcane Spiral Fertilizer Applicator Based on Response Surface Methodology and Artificial Neural Networks

To address the challenges of poor fluidity and low uniformity in conventional sugarcane fertilizer applicators, a novel dual-directional spiral fertilizer applicator has been developed. The working principle of the applicator is explained, and, after analyzing the agronomic requirements for sugarcane, the parameter range for key components of the applicator is determined. The spiral blade’s diameter, pitch, and rotational velocity are chosen as the experimental factors, with the average fertilizer discharge uniformity as the evaluation criterion. Virtual simulation experiments are conducted using the discrete element method and a quadratic regression orthogonal rotating combined design. Regression models for the evaluation criterion and various experimental factors are obtained. Additionally, a dataset created from these experiments was then used to construct an artificial neural network (ANN) prediction model. Response surface methodology (RSM) and the ANN were both used to analyze and predict the outcomes. The results indicate that the artificial neural network outperforms response surface methodology in terms of better fitting capability and higher prediction accuracy. The determination coefficient, mean squared error, and root mean square error are 0.99629, 0.99163, 0.07763, 0.17498, 0.27862, and 0.41831, respectively. When comparing the two models, the optimal parameter combination is determined to be a diameter of 90.1669 mm, a pitch of 59.7407 mm, and a rotational speed of 53.8944 r/min, resulting in an average fertilizer discharge uniformity of 92.0670%. An experiment with these parameters confirmed the simulated findings, revealing a maximum discrepancy of 2.4%. This study offers valuable insights into optimizing spiral fertilizer applicators.

Quantitative and qualitative evaluation of novel energy cane accessions for sugar, bioenergy, 1 G, and 2 G ethanol production

Traditionally, the sugarcane breeding programs are focused on increasing sugar content, often at the expense of fiber content and biomass yield. However, with the growing interest in 2 G (cellulosic) ethanol and bioenergy production, there has been a paradigm shift toward quantitative parameters. This study investigated the qualitative and quantitative parameters of energy cane clones throughout the harvest season. It hypothesizes that juice composition, fiber content, and maturation curve will vary, reaching a point where these characteristics become more desirable for industrial processes. Three energy cane clones (C33, C34, and C35) derived from a breeding program at the Agronomic Institute of Campinas (IAC) were selected for evaluation alongside a commercial reference cultivar (IAC-942094). The results indicate that energy cane possesses significant potential for biofuel and energy production. Additionally, energy cane clones exhibit higher agricultural yields and greater production of sugars per unit area than traditional sugarcane. The high fiber content in energy cane clones, coupled with their agricultural productivity, makes them excellent sources of lignocellulosic material for both 1 G and 2 G ethanol production and cogeneration of electric energy. Energy cane clones C34 and C35, in particular, demonstrate the potential to increase 2 G ethanol production and the supply of electrical and thermal energy by up to 300% and 250%, respectively, compared to conventional sugarcane. These findings highlight the promising role of energy cane as a sustainable bioenergy production alternative, contributing to improved sustainability indices in the biofuel and biomass energy sectors.

Bagasse Electricity Potential of Conventional Sugarcane Factories

Sugar industries have huge potential to contribute to the sustainable energy transition through electricity generation and production of biofuels. Sugar-producing countries generate huge volumes of sugarcane bagasse as a byproduct of sugarcane production. In this study, the performance of an operating traditional sugar factory is analyzed for electricity generation and export potential. The study presents characteristics and energy potential of modern and traditional sugar factories. The challenges facing a traditional sugar mill are inefficient boilers, less efficient and back pressure steam turbines, and wasteful and inefficient use of steam turbine drives as prime movers instead of modern electric drives for the mills and cane knives. Others are the use of inefficient and energy intensive cane mill rollers instead of the diffusers which have low energy requirements. It was demonstrated that the cogeneration potential of sugar factory is quite significant but currently underutilized. Sugar factories can make significant contribution towards mitigation of greenhouse gas emission mitigation through supply of green electricity to the public grid. The study showed that the factory uses very old and inefficient boilers aged over 39 years which contributes to poor performance and low electricity generation capacity. Modernization is required to increase the generation and electricity export capacity through investment in new and modern high-pressure boilers, replacement of inefficient back pressure boilers (BPSB) with more efficient condensing extraction turbines (CEST), and reduction of factory steam consumption by electrification of mills and cane knife turbine drives among other measures. This study showed that the 3,000 TCD factory can invest in a 15 MW power plant based on current average factory performance indicators and more if the throughput and overall performance is close to design parameters.

Modeling and techno-economic analysis of a hybrid sugarcane plant fed by vinasse biogas and bagasse surplus for electricity generation

The growing demand for electricity from renewable energy sources has motivated sugarcane producers to improve the power generation capacity of their plants. In this regard, the present work aims to contribute to the energy recovery process from two sugarcane byproducts: bagasse and vinasse. A novel hybrid combined cycle is devised to use the bagasse surplus generated during the sugarcane season to produce high enthalpy steam for a dedicated condensing turbine. A gas turbine, fed by vinasse biogas vinasse, is used to provide thermal energy to the steam bottoming cycle. Concomitantly, steam for the sugar and ethanol is produced by the existing sugarcane cogeneration system. This approach allows to increase the plant's electricity generation. From a prescribed milling capacity, a conventional sugarcane plant is modeled and validated at steady-state regime. Then, a hybrid plant, designed to consume the bagasse surplus and the vinasse biogas, is presented, and compared to the conventional plant. During the off-season, in the absence of vinasse and biogas, an off-design option is proposed to keep the system running full-time. Results showed that the hybrid plant electricity generation (kWhel) is 7.2–41.5% higher than the conventional plant. The economic feasibility of retrofitting a typical sugarcane plant (live steam parameters at 68 bar/480 °C, for example), by means of a hybrid combined cycle, points to an internal rate of return of around 22.3% and payback period of 5 years. A parametric analysis was carried out showing that, for a process steam consumption below 540kg of steam per tons of sugarcane milled, there will always be leftover bagasse of the season, regardless of the conventional plant steam profile. The production of vinasse required for the hybrid system ranges from 310 to 375 L by tons of sugarcane milled (TC), values within the range of existing sugarcane plants (156–910 L/TC). In addition, the plant operating time can be extended in the off-season, from 200 to 330 days per year, with electrical efficiency achieving around of 27% in this period. In conclusion, the proposed system moves towards the advancement of clean and sustainable electricity generation in the sugarcane industry.

Forest restoration rehabilitates soil multifunctionality in riparian zones of sugarcane production landscapes

Brazilian sugarcane plays a vital role in the production of both sugar and renewable energy. However, land use change and long-term conventional sugarcane cultivation have degraded entire watersheds, including a substantial loss of soil multifunctionality. In our study, riparian zones have been reforested to mitigate these impacts, protect aquatic ecosystems, and restore ecological corridors within the sugarcane production landscapes. We examined (i) how forest restoration enables rehabilitation of the soil's multifunctionality after long-term sugarcane cultivation and (ii) how long it takes to regain ecosystem functions comparable to those of a primary forest. We investigated a time series of riparian forests at 6, 15, and 30 years after starting restoration by planting trees (named ‘active restoration’) and determined soil C stocks, δ13C (indicative of C origin), as well as measures indicative of soil health. A primary forest and a long-term sugarcane field were used as references. Eleven soil physical, chemical, and biological indicators were used for a structured soil health assessment, calculating index scores based on soil functions. Forest-to-cane conversion reduced 30.6 Mg ha−1 of soil C stocks, causing soil compaction and loss of cation exchange capacity, thus degrading soil's physical, chemical, and biological functions. Forest restoration for 6–30 years recovered 16–20 Mg C ha−1 stored in soils. In all restored sites, soil functions such as supporting root growth, aerating the soil, nutrient storage capacity, and providing C energy for microbial activity were gradually recovered. Thirty years of active restoration was sufficient to reach the primary forest state in overall soil health index, multifunctional performance, and C sequestration. We conclude that active forest restoration in sugarcane-dominated landscapes is an effective way to restore soil multifunctionality approaching the level of the native forest in approximately three decades. Moreover, the C sequestration in the restored forest soils will help to mediate global warming.

Different managements in conventional sugarcane reform in sandy soils: effects on physical properties and soil organic carbon

Sugarcane culture in Brazil has expanded the planting area to degraded pastures and sandy soils. Sugarcane field reform is carried out after five or more harvest cycles, with conventional tillage, followed by planting sugarcane, or growing soybeans or a cover crop. This study aimed to analyze the effects of these different managements in the conventional sugarcane reform on the physical properties and organic carbon in an Argissolo Vermelho distrófico arênico (sandy Ultisol), located at latitude 21° 13’ 40” south, [...]

Advanced technologies for electricity production in the sugarcane value chain are a strategic option in a carbon reward policy context

Sustainable bioenergy production is required to meet the growing demand and environmental concerns. This study addresses current and advanced options for biomass-based electricity generation integrated to a sugarcane ethanol distillery in Brazil and polices that would foster its deployment. The typical combustion and steam cycle system and the integrated gasification combined cycle are the options considered for lignocellulosic biomass conversion into heat and power, associated with carbon capture and storage technologies. Besides conventional sugarcane, eucalyptus and energy-cane are also examined as promising feedstocks to extend operational days and/or increase biomass yields. The considered biomass-based electricity options are able to mitigate climate change impacts and depletion fossil resources. However, decreasing costs is a challenge to overcome for its broader implementation. The assessed strategies may help to guide policymakers on how to feasibly deploy advanced technologies for electricity production from biomass, meeting the future demands for sustainable electricity. The choice of larger processing scales shows an important effect on reducing costs, as well as choosing energy-cane as feedstock, which is also favorable for reducing climate change and land use impacts. Likewise, government policies that reward climate mitigation, as RenovaBio in Brazil, have a prominent role to foster advanced biomass-based electricity production technologies.

KEAMANAN PANGAN KOMODITAS TRANSGENIK: STUDI KASUS SEDIAAN PAKAN HIJAUAN DARI DAUN TEBU OVEREKSPRESI SoSPS1

Sugarcane (Saccharum officinarum L) is a sucrose-producing plantation that has been cultivated in various countries. Genetically modified sugar cane sugar cane plants are sugar cane plants that are assembled biotechnology through overexpression of the SoSPS1 gene. The SoSPS1 gene is responsible for the biosynthesis of sucrose sugar in leaves. Waste in the form of leaves, shoots, and bagasse has not been used optimally as animal feed. Thus it takes a lot of innovation and appropriate technology in the use of sugarcane waste for animal feed, so that it is expected to achieve zero waste farming systems that can be utilized all without being wasted and polluting the environment. As an alternative feed for livestock, then genetically engineered sugar cane must be tested for feed safety. Feed safety testing includes substantial equivalence value and feed digestibility test in which genetically engineered products have nutritional and digestive values commensurate with conventional products. Substantial value of sugarcane planted by genetically engineered overexpression of SoSPS1 gene did not differ significantly compared to conventional sugarcane. However, there are some significant nutritional content, but these values are still in the range of values in the OECD.

Multiobjective optimization of economic and environmental performance of Fischer-Tropsch biofuels production integrated to sugarcane biorefineries

The mitigation of greenhouse gas (GHG) emissions is a subject of high importance at a global level. The expansion of advanced liquid biofuels use can contribute to increase the sustainable bioenergy deployment while reducing GHG emissions in comparison to fossil fuels. In this study, the economic and environmental performance of a biorefinery involving biomass gasification followed by Fischer-Tropsch (FT) liquid biofuels production associated to sugarcane value chain is explored through a multiobjective optimization approach. The biorefinery configurations investigated include different biomass combinations, and the possibility of integrating the thermochemical processes to a first-generation ethanol distillery or operating it as a stand-alone plant. Different biomass mix considering conventional sugarcane, energy-cane and eucalyptus are considered in the optimization strategy. A Design of Experiments with a second-order polynomial regression technique is used to fit a metamodel from detailed and high-fidelity spreadsheet-based process models. Internal Rate of Return and avoided GHG emissions per agricultural land occupation are used as objective functions. The Pareto-optimal curves show the best performance possibilities and allows to identify the most suitable biorefinery configurations. Results indicate there is an economic benefit from the integration between the thermochemical process and conventional first-generation ethanol mills. An increase in cane and eucalyptus processing capacities tends to improve the economic performance due to the gain of scale. A higher proportion of energy-cane processed leads to better environmental performance as it reduces both the GHG emissions and the demand for agricultural land. In contrast, a greater share of energy-cane present trade-offs on the economic performance in the integrated biorefinery caused by the higher energy demand and lower ethanol production, but a minor effect is observed on the stand-alone configuration.

Assessment of Genetic Diversity in Promising Sugarcane Mutants Developed Through Chemical Mutagenesis

Sugarcane is an important cash crop gaining importance as ideal raw material for bioenergy production. Conventional sugarcane improvement is carried out through intensive crossing and selection breeding within the Saccharum complex. Being highly polyploidy crop the mutation breeding is also integrated for specifically improving the desired genetic trait in sugarcane varieties developed through conventional breeding. In the present work RAPD markers based assessment of genetic diversity and kinship relationships of six promising mutants developed using CoC 671 has been reported. The banding pattern of the PCR amplified products showed polymorphism with the RAPD profile in all six mutants. Mutants CoC 671, TC 2813, TC 2819, TC 2826, TC 2875 formed a separate cluster, and TC 906, TC 922, and TC 906 B formed a separate cluster distinct from the earlier one with the parent (CoC 671) and the standard Check (Co 86023). The genetic distance between the groups was found to be only marginally higher than the respective group distances and the overall mean genetic distance. The similarity indices indicated that there was 15 % genetic dissimilarity between CoC 671 and Co 86032. This may be because CoC 671 was one of the parents for Co 86032. In the present investigation, the genetic similarity value ranged from 0.97 to 0.78 among the mutants. A total of 34 band positions were scored, out of which 15 RAPD bands were polymorphic. From the genetic similarity coefficient based on RAPD band data sharing, it was found that the majority of the clones were almost more than 78% similar to the mother plant. Thus the level of similarity between varieties seemed to be not very high but the mutants could be distinguished from each other easily. RAPD analysis indicated EMS-induced point mutations resulting in specific rectifications without much change in the genetic backbone of genotype CoC 671. Since this analysis was carried out on mutants after multiplying in field for three successive generations, we presume that these mutants/genotypes are stable and express the stable genetic variations.

Silicon attenuates the effects of water deficit in sugarcane by modifying physiological aspects and C:N:P stoichiometry and its use efficiency

Climate change has increased the occurrence of droughts and the use of deficient irrigation associated with silicon (Si) can be a strategy to mitigate water deficit in crops; however, the mechanisms involved have to be understood. The objective of this study was to evaluate whether the application of Si via fertigation associated with leaf spray mitigates the effects of water deficit by improving the physiological aspects and modifying C: N: P stoichiometry, inducing an increase in nutrient use efficiency in the ratoon of two sugarcane species (Saccharum officinarum- conventional sugarcane and S. spontaneum- energy cane). Two experiments were carried out in a greenhouse, using conventional sugar cane (variety-RB 966928) and energy cane (variety-VX2). In both experiments, the treatments were arranged in a 2 × 2 factorial scheme, without water deficit and with severe water deficit (30% of soil water retention capacity) without and with application of Si via fertigation associated with leaf spray, both in a concentration 2.5 mmol L−1, arranged in randomized blocks. At 80 days after ratoon regrowth, the following parameters were evaluated: Si content and accumulation, efficiency of using C, N and P, C: Si, C: N and C: P ratios, quantum efficiency of PS II, relative content of water, leaf water potential, leaf area, number of leaves and tillers and dry matter production. In the absence of Si, water deficit affected the physiological variables and the growth of the two sugarcane species. The supply of Si via fertigation associated with foliar spraying of soluble Si increased the absorption of this element in the ratoon of conventional sugarcane and energy cane, regardless of water condition. Si attenuated the effects caused by severe water deficit because of the increase in the relative water content and water potential, thus decreasing oxidative stress, impacting photosynthesis efficiency and also modifying the C: N: P stoichiometry, increasing use efficiency for these nutrients and the growth of the two study species.

Development of an efficient protocol for production of healthy sugarcane seed cane through Meristem culture

Healthy seeds are a prerequisite for improving the productivity of sugarcane crop. The best way to ensure the production of disease-free sugarcane seeds is via a technique called ‘Meristem Culture’ (Tissue Culture). An efficient protocol for meristem culture of sugarcane has been developed in this study. The potting mix for the survival of meristem cultured plantlets in a greenhouse was standardized, and agronomy for growing tissue culture plantlets in the field was developed. Multiple shoots were observed on Murashige and Skoog's (MS) medium supplemented with BAP 0.2 ​mg/l and Kinetin 0.1 ​mg/l. Best rooting was observed on MS media supplemented with IAA 1 ​mg/l and NAA 1 ​mg/l. Soil mixture containing [Soil ​+ ​Vermiculite ​+ ​Sand in 4: 1: 1 proportion (by volume)] ​+ ​Vermicompost @ 25% by volume of medium ​+ ​NPK is best suited for hardening tissue cultured plants in a greenhouse. Two feet distance between 2 plants and 3 feet distance between 2 rows was found as an appropriate method for planting tissue cultured plantlets in the field. Setts obtained from tissue cultured plants planted at 15 ​cm spacing gave higher yield than the other spacing. Setts obtained from micro-propagated plants (M) gave the highest yield as compared to setts from conventional sugarcane raising. The protocol developed in this study, shows potential for development of sugarcane meristem cultured plantlets and use of these plants for planting in field to obtain healthy sugarcane seed.

Diversifying the portfolio of sugarcane biorefineries: Anaerobic digestion as the core process for enhanced resource recovery

The continuous search to combine clean energy supply with the efficient exploitation of bioenergy sources is one of the most recurring efforts to meet global energy demands on an environmentally friendly basis. Sugarcane biorefineries play a central role in this context by providing sugar, ethanol and bioelectricity. However, the high energy required in ethanol production limits resource recovery efficiency in conventional sugarcane processing, motivating the investigation of approaches that maximize energetic gains. This study proposes the application of anaerobic digestion (AD) as the core processing step in sugarcane biorefineries, providing performance data for the biomethanation of juice, molasses and vinasses from different sources, namely, first generation (1G; annexed and autonomous) and second generation (2G) ethanol production. A detailed scenarization-based assessment was also carried out, comparing the proposed AD-based schemes with conventional production chains. Relatively similar performances were obtained in the experimental step, irrespective of the compositional differences of the substrates. However, the energetic potential of juice- and molasses-based methane production was at least 2-fold higher than the ones of all types of vinasses (282.81–627.84 vs. 57.10–131.52 MJ TC−1). Scenario comparison indicated the production of biogas and sugar as the most efficient energetic exploitation (94.4%) of sugars from sugarcane. Finally, the energy returned on energy invested ratio estimated for biogas-derived electricity exceeded that of ethanol production by 400%. Thus, AD-based biorefineries have great potential to meet the energy efficiency criteria of sustainable development goals in the coming decades.

Sugar derived from genetically modified sugarcane

Sugar is an ancient food and currently one of the most used ingredients in human nutrition and in the food industry. In tropical regions, sugar is produced mainly from sugarcane, while temperate countries produce sugar preferably from sugar beets. Due to its widespread use, the forthcoming adoption of genetically modified (GM) sugarcane varieties may raise questions about the quality and classification of the sugar produced. Here, we describe the several varieties of sugar and their specific uses and legal classifications. Regardless of whether they are produced from beet or from sugarcane and their final use, sugar consists of highly purified substances composed almost entirely from a disaccharide (sucrose) whose molecules consist of two monosaccharide residues: glucose and fructose. The differences between commercial sugar types are primarily in sucrose content (> 99.00 to 99.80 °Z), moisture content, ICUMSA color, conductivity ashes and reducing sugar. Neither DNA nor proteins can be detected at relevant levels in the different types of sugar. Therefore, sugar from genetically modified sugarcane varieties is virtually identical to sugar produced from conventional sugarcane, and the adoption of GM sugarcane varieties should not cause any change to the current use of sugar in human nutrition and in the food industry.

Abundance, biomass and community composition of soil saprophagous macrofauna in conventional and organic sugarcane fields

Tropical island saprophagous invertebrates have received little attention despite their important role in sustaining soil fertility. Soil biodiversity in the agroecosystems of the Lesser Antilles is subject to various anthropic and environmental perturbations; therefore, it is crucial to promote agricultural practices that help preserve it. Here, we investigate the effect of conversion to organic farming in sugarcane production on soil saprophagous invertebrates in a Martinique plantation (Lesser Antilles). The abundance, biomass and diversity of communities were measured in three fields undergoing organic conversion and in two control fields under conventional production. Invertebrates were sampled both by pitfall trapping and Tullgren extraction. The results indicated that abundance was significantly higher in fields undergoing conversion (342 ± 78 ind.m−2) compared to fields under conventional farming (146 ± 34 ind.m−2). The response of the whole community's biomass to organic conversion was not significant, reflecting a contrasting response of each invertebrate taxa: isopod biomass was the most impacted, earthworm biomass was moderately impacted and diplopod biomass was not significantly affected. A total of 25 morphospecies for all taxa were distinguished in this study. However, the diversity did not differ and community composition remained similar under both farming practices. The response of invertebrate abundance and biomass could be either due to the direct toxicity of herbicides intensively used in conventional sugarcane cultivation or to the indirect effects of herbicides modifying micro-habitat parameters (weed biomass, amount of mulch and litter humidity). In conclusion, the study shows that organic farming has a beneficial effect on soil saprophagous invertebrates even after a short period of conversion (between one and two years), which is promising for restoring soil biological processes in the context of agroecological transition.

Epigeic fauna (with emphasis on ant community) response to land-use change for sugarcane expansion in Brazil

The epigeic fauna, ground surface-dwelling invertebrates that inhabit leaf-litter, acts on multiple soil processes and key ecosystem services and is threatened by global land-use change (LUC). In Brazil, LUC for sugarcane expansion over extensive pasture has been taking place for promoting bioenergy production; however, conventional sugarcane cultivation includes monoculture, periodic soil tillage and agrochemicals may alter the quantity and quality of crop residue inputs, soil habitats and communities of soil fauna. Thus, a field study at three sites in central southern Brazil was conducted to evaluate if the expansion of sugarcane cultivation affects soil epigeic fauna. In each site, we sampled epigeic fauna in areas under LUC from native vegetation to extensive pasture, and from that to sugarcane. The epigeic fauna was collected using pitfall traps and then quantified and classified in taxonomic groups (Order, Class, Family). In addition, as a focal organism group, ants were classified at the species level. Overall, 13 taxonomic groups were identified, in which the Formicidae family was the most abundant group (i.e., 67% of individuals), followed by Diptera (13%), Araneae (5%) and Coleoptera (4%). Land transition from native vegetation to pasture increased fauna abundance by 27% but reduced the diversity of epigeic fauna community by 43%. In contrast, sugarcane expansion over extensive pasture reduced fauna abundance (−22%), did not alter the diversity of the invertebrate community at a broad taxonomic level, but decreased species richness of the dominant taxa (ants) by 55%. Ant individuals were classified into 37 species, allowing to verify that sugarcane cultivation over pastures decreased both the abundance and richness of ants and altered community composition. Ant species Ectatomma brunneum were more sensitive to LUC and, therefore, could be characterized as potential indicators of disturbed environments. We demonstrate that sugarcane expansion over pasturelands reduces the total abundance of the soil epigeic fauna, and that effects on fauna diversity vary from broad to fine taxonomic resolutions. Further studies are needed to evaluate if the declines in fauna abundance and ant species richness impair specific soil functions and soil-related ecosystem services.

The True Cost of Sugar: Economic trade-offs in conventional, organic and Fairtrade sugarcane and sugar beet production.

Sugar is an important economic commodity that is produced and consumed around the world. The impacts of different production methods differ on social, economic and environmental aspects. This research focuses on the economic trade- offs in conventional, organic and Fairtrade sugarcane production in India and sugar beet production in the Netherlands. Previous research provides insights into single production methods, but a complete comparison between different production methods is currently lacking. Data was collected using both literature research and interviews in the Netherlands and India. After developing a Multi-Criteria Analysis, it is concluded that organic sugarcane and Fairtrade sugarcane rank slightly higher than conventional sugarcane on the economic criteria. However, conventional sugar beet and organic sugar beet rank higher on all economic aspects, with conventional sugar beet ranking the highest. The main differences between the production methods can be seen in the innovation, and to a lesser extent the in the production.

Techno-Economic and Environmental Assessment of Biomass Gasification and Fischer–Tropsch Synthesis Integrated to Sugarcane Biorefineries

Large-scale deployment of both biochemical and thermochemical routes for advanced biofuels production is seen as a key climate change mitigation option. This study addresses techno-economic and environmental aspects of advanced liquid biofuels production alternatives via biomass gasification and Fischer–Tropsch synthesis integrated to a typical sugarcane distillery. The thermochemical route comprises the conversion of the residual lignocellulosic fraction of conventional sugarcane (bagasse and straw), together with eucalyptus and energy-cane as emerging lignocellulosic biomass options. This work promotes an integrated framework to simulate the mass and energy balances of process alternatives and incorporates techno-economic analyses and sustainability assessment methods based on a life-cycle perspective. Results show that integrated biorefineries provide greenhouse gas emission reduction between 85–95% compared to the fossil equivalent, higher than that expected from a typical sugarcane biorefinery. When considering avoided emissions by cultivated area, biorefinery scenarios processing energy-cane are favored, however at lower economic performance. Thermochemical processes may take advantage of the integration with the typical sugarcane mills and novel biofuels policies (e.g., RenovaBio) to mitigate some of the risks linked to the implementation of new biofuel technologies.

Molasses vs. juice: Maximizing biohydrogen production in sugarcane biorefineries to diversify renewable energy generation

Diversifying the portfolio of bioenergy-related products in sugarcane biorefineries is required to increase substrate conversion efficiency and market reach. The suitability of producing biohydrogen (bioH2) through the thermophilic dark fermentation of juice and molasses was assessed as an alternative to conventional sugarcane processing. The energetic potential of applying anaerobic digestion with phase separation to process molasses was also investigated. Molasses outperformed juice as substrate for continuous bioH2 production due to a more balanced nutrient content, whilst nitrogen deficiency directly hindered juice fermentation. An optimal COD/N ratio (∼100) could maximize bioH2 production from both juice and molasses. Continuous bioH2 production from molasses fermentation was optimized at pH and organic loading rate values of 5.38 and 86 kg-COD m−3 d-1, which are consistent with acidogenic systems inoculated with sugarcane vinasse-derived consortia. Metabolite profiles suggested that capnophilic lactic fermentation coupled to lactate-based butyrate production were the primary conversion pathways. Bioenergy generation from molasses (bioH2 + methane) exceeded that of vinasse by over 600 %, highlighting the relevance of anaerobic digestion as an efficient core processing step in the sucroenergetic industry. In particular, phase separation enhanced the total energy production by 13.1 % (604.30 vs. 683.76 MJ per ton of sugarcane) by maximizing the methane yield up to theoretical values.