Economic optimization for a dual-feedstock lignocellulosic-based sustainable biofuel supply chain considering greenhouse gas emission and soil carbon stock

Environmental factors, including greenhouse gas (GHG) emissions and soil organic carbon (SOC), should be considered when building a sustainable biofuel supply chain. This work developed a three-step optimization approach integrating a geographical information system-based mixed-integer linear programming model to economically optimize the biofuel supply chain on the premise of meeting certain GHG emission criteria. The biomass supply grid cell was considered first, based on a maximum level of GHG emissions, prior to economic optimization. The optimization simultaneously considered dual-feedstock sourcing, selection between distributed and centralized configurations, and the impact of maintaining SOC balance in agricultural soil on biomass availability. The applicability of the modeling approach was demonstrated through a case study that optimized a dual-feedstock renewable jet fuel supply chain via a gasification-Fischer–Tropsch (gasification-FT) conversion pathway in 2050 under three biomass availability scenarios. The case study results show that the differences in procurement costs and GHG emissions between energy crops and agricultural residues have a large impact on the layout of the supply chain. The supply-chain configuration tends to be more centralized with large-scale biorefineries when a supply region has an intensive and centralized distribution of biomass resources. The cost-supply curves demonstrated the technical potential of biofuels that could be obtained at a certain level of cost. Additionally, sensitivity analysis shows that the GHG emission credit from producing extra electricity during the gasification-FT process will be significantly reduced with a rising share of renewable electricity generation in the future

Optimization of Electric Ethylene Production:Exploring the Role of Cracker Flexibility, Batteries, and Renewable Energy Integration

The electrification of naphtha cracking for ethylene production could reduce the associated CO2 emissions but would require significantly larger electricity consumption. Within this context, the flexible operation of electric crackers opens opportunities for improved integration with the future electricity system. In this work, we developed a computationally efficient mixed-integer linear programming model to investigate flexibility in electric crackers, exploring the effect of operational parameters, such as operating envelope, ramping time, and start-up/shut-down time, on costs and emissions. We optimized three electric cracker systems: two with grid electricity consumption (with/without batteries) and one with electricity supply from dedicated renewable technologies. We find that the operating envelope of the cracker has the strongest impact on cost savings, enabling up to 5.5% reduction when using flexible electricity from the grid and 58% for systems with direct coupling to renewables. Moreover, the flexible operation of electric crackers relying on the electricity grid enhances the CO2 emission savings, achieving a 90.4% emission reduction against 54.6% of the constant operation case. Finally, we find that for direct coupling with renewables, electric crackers need to be flexible to avoid suboptimal oversizing of renewable technologies and especially unrealistic battery capacities.</p

Economic optimization for a dual-feedstock lignocellulosic-based sustainable biofuel supply chain considering greenhouse gas emission and soil carbon stock

Environmental factors, including greenhouse gas (GHG) emissions and soil organic carbon (SOC), should be considered when building a sustainable biofuel supply chain. This work developed a three-step optimization approach integrating a geographical information system-based mixed-integer linear programming model to economically optimize the biofuel supply chain on the premise of meeting certain GHG emission criteria. The biomass supply grid cell was considered first, based on a maximum level of GHG emissions, prior to economic optimization. The optimization simultaneously considered dual-feedstock sourcing, selection between distributed and centralized configurations, and the impact of maintaining SOC balance in agricultural soil on biomass availability. The applicability of the modeling approach was demonstrated through a case study that optimized a dual-feedstock renewable jet fuel supply chain via a gasification-Fischer–Tropsch (gasification-FT) conversion pathway in 2050 under three biomass availability scenarios. The case study results show that the differences in procurement costs and GHG emissions between energy crops and agricultural residues have a large impact on the layout of the supply chain. The supply-chain configuration tends to be more centralized with large-scale biorefineries when a supply region has an intensive and centralized distribution of biomass resources. The cost-supply curves demonstrated the technical potential of biofuels that could be obtained at a certain level of cost. Additionally, sensitivity analysis shows that the GHG emission credit from producing extra electricity during the gasification-FT process will be significantly reduced with a rising share of renewable electricity generation in the future

Comprehensive characterisation and analysis of PV module performance under real operating conditions

The specifications of photovoltaic modules show performance under standard testing conditions (STC), but only limited information relating to performance at non-STC conditions. While performance is affected by irradiance, temperature, spectral composition of irradiance, angle-of-incidence of the irradiance and other parameters, specifications only partly give detail to consumers or retailers about the effect of irradiance and temperature. In this study, we characterise and analyse the performance of eight different, commercially available photovoltaic modules. We establish the effect of four different parameters on module performance: irradiance, temperature, spectral composition of irradiance (via the parameter average photon energy) and angle-of-incidence, by performing linear and nonlinear optimisation of physical or empirical models. Furthermore, we characterise the operating conditions and analyse the seasonal and annual development and contribution of the four parameters to energy losses or gains relative to STC operating conditions. We show a comprehensive way of presenting the deviation of performance from STC, combining the variation in operating conditions and the resulting variation in performance. Our results show that some effects on performance are attributable to the semiconductor material used in the modules (spectral composition and temperature), while especially angle-of-incidence effects seem more related to the type of glass used on as the front cover of the module. Variation in irradiance and module temperature generally affect performance the strongest, resulting in a performance effect ranging from + 2.8% to − 3.2% and − 0.5% to − 2.2%, respectively. The combined effect of all parameters results in an annual yield deviation ranging from + 1.2% to − 5.9%

Scaling up the electricity access and addressing best strategies for a sustainable operation of an existing solar PV mini-grid: A case study of Mavumira village in Mozambique

Access to electricity in a sustainable, affordable, and reliable manner is still a challenge, especially for rural communities in developing regions. In this study, we applied the HOMER Pro software for scaling up electricity and finding the optimum system that can satisfy the future electricity demand cost-effectively. Additionally, we analyzed the aspects that could influence the sustainability of the project, based on selected indicators, to address the best strategies for future improvements in the system performance. The main source of information for this research was the data collection in the study area through interviews with 35 individuals, including the owners of households, revenue collectors, and local governance selected based on their level of involvement and also their knowledge about the project. We focused on the solar PV mini-grid system installed in Mavumira village in Mozambique. Our results showed that among various configurations analyzed, hybrid solar PV/diesel/battery is the most appropriate system, as it presents the lowest cost of electricity (LCOE) of 0.47 $/kWh compared to other solutions, such as diesel-only with 0.63$/kWh. Moreover, we found that in the future, the system will require less government subsidy than today's case, as the optimized future system is 1.3 times more expensive than the expected future tariff (0.37 $/kWh). By investigating the sustainability of the project, we found that, on a scale from 1 to 5, the economic and social indicators like economic activities and safety scored high (5 and 4, respectively), meaning that they are likely to ensure the project's performance over its lifetime, compared to the technical and institutional indicators like the reliability of power supply and effectiveness of local governance, which were attributed low-performance scores (1 and 2, respectively). These last aspects need to be adequately addressed, through local skills for operation and maintenance, to avoid failure in the system

GHG Balance of Agricultural Intensification &amp; Bioenergy Production in the Orinoquia Region, Colombia

Energy crop expansion can increase land demand and generate displacement of food crops, which impacts greenhouse gas (GHG) emissions mainly through land-use change (LUC). Increased agricultural productivity could compensate for this. Our study aims to evaluate the regional combined GHG emissions of increasing agricultural yields for food crop and beef production and using the generated surplus land for biomass production to replace fossil fuels in the Orinoquia region of Colombia until 2030. The results show that surplus land for biomass production is obtained only when strong measures are applied to increase agricultural productivity. In the medium and high scenario, a land surplus of 0.6 and 2.4 Mha, respectively, could be generated. Such intensification results in up to 83% emission reduction in Orinoquia’s agricultural sector, largely coming from increasing productivity of cattle production and improving degraded pastures. Biofuel potential from the surplus land is projected at 36 to 368 PJ per year, with a low risk of causing indirect LUC, and results in GHG emission reductions of more than 100% compared to its fossil fuel equivalent. An integrated perspective of the agricultural land use enables sustainable production of both food and bioenergy

The GHG emissions and economic performance of the Colombian palm oil sector; current status and long-term perspectives

Increasing oil palm plantations, both for obtaining crude palm oil (CPO) and for the production of biobased products, have generated growing concern about the impact of greenhouse gas (GHG) emissions on the environment. Colombia has the potential to produce sustainable biobased products from oil palm. Nevertheless, national GHG emissions have not yet been reported by this sector. Achieving the collection of the total primary data from the oil palm sector, in Colombia, entails a tremendous challenge. Notwithstanding, for this study, the data collection of 70% of the production of fresh fruit bunches (FFB) was achieved. Therefore, current situation of CPO production in Colombia is analyzed, including 1) GHG emissions calculation, 2) net energy ratio (NER), and 3) economic performance. Moreover, the analysis includes two future scenarios, where the CPO production chain is optimized to reduce GHG emissions. Future scenario A produces biodiesel (BD), biogas, cogeneration, and compost; while future scenario B produces BD, biogas, cogeneration, and pellets. The methodology, for all the scenarios, includes life-cycle assessment and economic analysis evaluation. The results show a significant potential for improving the current palm oil production, including a 55% reduction in GHG emissions. The impact of land-use change must be mitigated to reduce GHG emissions. Therefore, a sustainable oil palm expansion should be in areas with low carbon stock or areas suitable/available to the crop (e.g., cropland, pastureland). Avoiding the deforestation of natural forests is required. Besides, crop yield should be increased to minimize the land use, using biomass to produce biobased products, and capture biogas to reduce methane emissions. In the biodiesel production life-cycle, the NER analysis shows the fossil energy consumed is lower than the renewable energy produced. Regarding the economic performance, it shows that in an optimized production chain, the capital expenditure and operational expenditure will decrease by approximately 20%

Repairing What Policy Is Missing Out on: A Constructive View on Prospects and Preconditions for Sustainable Biobased Economy Options to Mitigate and Adapt to Climate Change

Biomass use for energy and materials is, on the one hand, one of the key mitigation options to reach the 1.5 °C GMT target set in the Paris Agreement, as highlighted by the IPCC and many other key analyses. On the other hand, particularly in parts of the EU, a strong negative connotation has emerged in public debate and EC policy, with a particular emphasis on the (presumed) displacement effect in markets and land use. This is a remarkable contrast because the reasons to use sustainable biomass, on the one hand, and the possibilities and synergies for supplying sustainable biomass, on the other, are underpinned with strong evidence, also providing insights on how displacement issues can be avoided. Sustainable biomass supplies can contribute 20–30% of the future global and European energy supply, leading to reduced overall mitigation costs, including realizing the net CO2 removal from the atmosphere using BECCS concepts. This paper highlights which options, pathways and preconditions are key to achieving such a substantial contribution of sustainable biomass in future (2050) energy and material supply (with a focus on the European setting). By pinpointing how “biomass can be done right” and how important synergies can be achieved via better agricultural methods, the restoration of marginal and degraded lands and the adaptation of climate change, a different policy agenda emerges in sharp contrast to how a biobased economy has been framed in recent years. It is recommended that future policy priorities, particularly at the EU level, take a more integral view on the synergy between the role of biomass in the energy transition, climate adaptation and mitigation, better agriculture and the better use of land in general. Strategies to achieve such positive results typically require an alignment between renewable energy, and agricultural, environmental, mitigation and adaptation policies, which is a largely missing nexus in different policy arenas. Resolving this lack of alignment offers a major opportunity, globally, to contribute to the European Green deal and improve energy security

Fuels and plastics from lignocellulosic biomass via the furan pathway: an economic analysis

Furan compounds represent a class of chemicals that have the potential to become platform chemicals due to their attractive properties thanks to their structure. In a previous publication, three biorefi nery cases were presented that convert wheat straw into polyethylene furanoate (PEF) and furfuryl ethyl ether (FEE) and analyzed from a technical point of view. In this paper, the production costs were calculated using the net present value methodology, including a sensitivity analysis to determine the effects for changes in fi nancial parameters, feedstock, chemicals, and market prices. In order to compete with petrochemical polymers, the production costs of PEF has to be around 1500 $/tonne. For the base case, all three cases approach this level of 1500$/tonne; the production costs for Case I are 1495 $/tonne PEF and Case II at 1555$/tonne PEF. For Case III, the costs are calculated to be negative (at −131) $/tonne. This is because PEF is not the main product within Case III, as dimethyl ether (DME) and methyl levulinate (ML) account for 75$/tonne. Considering also the improved material performance of PEF and a potentially more favorable greenhouse gas (GHG) footprint, PEF produced from biomass may become a superior plastic to PET produced from petrochemical feedstocks. © 2015 Society of Chemical Industry and John Wiley & Sons, Lt

The economical and environmental performance of miscanthus and switchgrass production and supply chains in a European setting

The purpose of this study is to analyse the economical and environmental performance of switchgrass and miscanthus production and supply chains in the European Union (EU25), for the years 2004 and 2030. The environmental performance refers to the greenhouse gas (GHG) emissions, the primary fossil energy use and to the impact on fresh water reserves, soil erosion and biodiversity. Analyses are carried out for regions in five countries. The lowest costs of producing (including storing and transporting across 100 km) in the year 2004 are calculated for Poland, Hungary and Lithuania at 43-64 [euro] per oven dry tonne (odt) or 2.4-3.6 [euro] GJ-1 higher heating value. This cost level is roughly equivalent to the price of natural gas (3.1 [euro] GJ-1) and lower than the price of crude oil (4.6 [euro] GJ-1) in 2004, but higher than the price of coal (1.7 [euro] GJ-1) in 2004. The costs of biomass in Italy and the United Kingdom are somewhat higher (65-105 [euro] odt-1 or 3.6-5.8 [euro] GJ-1). The doubling of the price of crude oil and natural gas that is projected for the period 2004-2030, combined with nearly stable biomass production costs, makes the production of perennial grasses competitive with natural gas and fossil oil. The results also show that the substitution of fossil fuels by biomass from perennial grasses is a robust strategy to reduce fossil energy use and curb GHG emissions, provided that perennial grasses are grown on agricultural land (cropland or pastures). However, in such case deep percolation and runoff of water are reduced, which can lead to overexploitation of fresh water reservoirs. This can be avoided by selecting suitable locations (away from direct accessible fresh water reservoirs) and by limiting the size of the plantations. The impacts on biodiversity are generally favourable compared to conventional crops, but the location of the plantation compared to other vegetation types and the size and harvesting regime of the plantation are important variables.Miscanthus Switchgrass Costs Soil erosion Biodiversity Water Greenhouse gas emissions Primary energy use