A comprehensive approach to the design of ethanol supply chains including carbon trading effects

Towards facing uncertainties in biofuel supply chain networks: a systematic literature review

Biofuel supply chains (BSCs) face diverse uncertainties that pose serious challenges. This has led to an expanding body of research focused on studying these challenges. Hence, there is a growing need for a comprehensive review that summarizes the current studies, identifies their limitations, and provides essential advancements to support scholars in the field. To overcome these limitations, this research aims to provide insights into managing uncertainties in BSCs. The review utilizes the Systematic Reviews and Meta-Analyses (PRISMA) method, identifying 205 papers for analysis. This study encompasses three key tasks: first, it analyses the general information of the shortlisted papers. Second, it discusses existing methodologies and their limitations in addressing uncertainties. Lastly, it identifies critical research gaps and potential future directions. One notable gap involves the underutilization of machine learning techniques, which show potential for risk identification, resilient planning, demand prediction, and parameter estimations in BSCs but have received limited attention. Another area for investigation is the potential of agent-based simulation, which can contribute to analysing resilient policies, evaluating resilience, predicting parameters, and assessing the impact of emerging technologies on BSC resilience in the twenty-first century. Additionally, the study identifies the omission of various realistic assumptions, such as backward flow, lateral transshipments, and ripple effects in BSC. This study highlights the complexity of managing uncertainties in BSCs and emphasizes the need for further research and attention. It contributes to policymakers' understanding of uncertain sources and suitable approaches while inspiring researchers to address limitations and generate breakthrough ideas in managing BSC uncertainties.

Performance Measurement of the Sustainable Supply Chain During the COVID-19 Pandemic: A real-life case study

This paper aims to introduce a framework to measure the sustainable performance of the supply chain (SC) during the COVID-19 pandemic. The SC stakeholders in this investigation are Suppliers, Production / Remanufacturing / Refurbishing Centers (Factories), Collection / Distribution Centers, Recycling / Landfill Centers, and Customers. The suggested sustainable supply chain (SSC) performance measurement included three pillars with 23 indicators. To evaluate the overall sustainability of the SC understudy, a composite index has been developed that combines all the indicators to reflect the sustainability performance of the SC. Four steps are involved in creating a composite index:1) measuring the value of indicators, 2) weighing indicators, 3) Using the normalization technique, and 4) Evaluating the overall SSC indicator. The real case in Iran is selected as an illustrative case. Our research contributions are: We suggested a novelty indicator of SSC to better show the economic, environmental, and social tradeoffs during the COVID-19 pandemic and lockdowns. We have found and measured the negative and positive impacts of COVID-19 on aspects of sustainability in SC. Based on the achieved data of the real case study, a numerical example is represented to explain how to calculate the composite index. The main contribution of this paper is the development of SSC indicators during the COVID-19 epidemic.

The incorporated environmental policies and regulations into bioenergy supply chain management: A literature review

Bioenergy, a means to reach a sustainable economy, is being driven by governments by devising incremental regulations and more instrumental policies in parallel. These constant-changing regulations bring uncertainty to bioenergy supply chain optimization problems. An increasing number of recent studies on bioenergy supply chain optimization addressing environmental concerns have highlighted the need for an overview indispensable. The purpose of this paper is to present a review of the incorporated policies and regulations and to examine whether constraints or targets set by governments are fully met in optimizing of bioenergy supply chains. To this end, first, bioenergy policies and regulations enacted in the EU, the global leader in the energy transition, as a benchmark are reviewed based on the bioenergy supply chain steps. Then, the optimization problems employing policies and regulations are classified and discussed. The review reveals visible gaps between what policies demand and what is proposed in the literature, and underpin the regulations which need to be considered in future work. Examination of the literature also suggests that a globally drawn standard may lead to better bioenergy supply chain development considering other green energy developments. Our key finds are.

The Design of Green Supply Chains under Carbon Policies: A Literature Review of Quantitative Models

Carbon footprinting of products and services is getting increasing attention due to the growing emphasis on carbon related policies in many countries. As a result, many enterprises are focusing on the design of green supply chains (GSCs) with research on supply chains (SCs) focused not only on cost efficiency, but also on its environmental consequences. The review presented in this paper focuses on the implications of carbon policies on SCs. The concept of content analysis is used to retrieve and analyze the information regarding drivers (carbon policies), actors (for example, manufacturers and retailers), methodologies (mathematical modeling techniques), decision-making contexts (such as, facility location and order quantity), and emission reduction opportunities. The review shows a lack of emissions analysis of SCs that face carbon policies in different countries. The research also focuses on the design of carbon policies for emissions reduction in different operating situations. Some possible research directions are also discussed at the end of this review.

Carbon Emissions Cost Analysis with Activity-Based Costing

Due to growing awareness about environmental issues, consumers are becoming more likely to purchase environmentally friendly products that involve lower carbon emissions (CE). Environmental regulations are being enforced and lower-carbon products are being produced in order to maintain competitiveness when complying with such regulations. This paper aims to explore the effect of CE on profit through three kinds of models using the activity-based costing (ABC) approach. The results indicate that governmental policy makers can effectively decrease CE by Total Quantity Control (TQC) to resolve problems of environmental degradation. Governmental policy makers can control CE by limiting the quantities of CE, thereby forcing manufacturers to decrease CE during production. Furthermore, policy makers can set up regulations on CE quotas to control CE well instead of imposing carbon taxes. Therefore, manufacturers will try their best to find methods of improving production processes, equipment, and/or materials to decrease the CE quantity and achieve maximum profit under the restricted carbon emissions quotas.

A generalized disjunctive programming framework for the optimal synthesis and analysis of processes for ethanol production from corn stover

The aim of this study is to analyze the techno-economic performance of process configurations for ethanol production involving solid-liquid separators and reactors in the saccharification and fermentation stage, a family of process configurations where few alternatives have been proposed. Since including these process alternatives creates a large number of possible process configurations, a framework for process synthesis and optimization is proposed. This approach is supported on kinetic models fed with experimental data and a plant-wide techno-economic model. Among 150 process configurations, 40 show an improved MESP compared to a well-documented base case (BC), almost all include solid separators and some show energy retrieved in products 32% higher compared to the BC. Moreover, 16 of them also show a lower capital investment per unit of ethanol produced per year. Several of the process configurations found in this work have not been reported in the literature.

Robust optimization on sustainable biodiesel supply chain produced from waste cooking oil under price uncertainty

Waste cooking oil (WCO)-for-biodiesel conversion is regarded as the "waste-to-wealthy" industry. This paper addresses the design of a WCO-for-biodiesel supply chain at both strategic and tactical levels. The supply chain of this problem is studied, which is based on a typical mode of the waste collection (from restaurants' kitchen) and conversion in the cities. The supply chain comprises three stakeholders: WCO supplier, integrated bio-refinery and demand zone. Three key problems should be addressed for the optimal design of the supply chain: (1) the number, sizes and locations of bio-refinery; (2) the sites and amount of WCO collected; (3) the transportation plans of WCO and biodiesel. A robust mixed integer linear model with muti-objective (economic, environmental and social objectives) is proposed for these problems. Finally, a large-scale practical case study is adopted based on Suzhou, a city in the east of China, to verify the proposed models.

Energy efficiency and environmental performance of bioethanol production from sweet sorghum stem based on life cycle analysis

Life cycle analysis method was used to evaluate the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem in China. The scope covers three units, including plant cultivation, feedstock transport, and bioethanol conversion. Results show that the net energy ratio was 1.56 and the net energy gain was 8.37 MJ/L. Human toxicity was identified as the most significant negative environmental impact, followed by eutrophication and acidification. Steam generation in the bioethanol conversion unit contributed 82.28% and 48.26% to total human toxicity and acidification potential, respectively. Fertilizers loss from farmland represented 67.23% of total eutrophication potential. The results were significantly affected by the inventory allocation methods, vinasse reusing approaches, and feedstock yields. Reusing vinasse as fuel for steam generation and better cultivation practice to control fertilizer loss could significantly contribute to enhance the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem.

Energy Supply Chain Optimization of Hybrid Feedstock Processes: A Review

The economic, environmental, and social performances of energy systems depend on their geographical locations and the surrounding market infrastructure for feedstocks and energy products. Strategic decisions to locate energy conversion facilities must take all upstream and downstream operations into account, prompting the development of supply chain modeling and optimization methods. This article reviews the contributions of energy supply chain studies that include heat, power, and liquid fuels production. Studies are categorized based on specific features of the mathematical model, highlighting those that address energy supply chain models with and without considerations of multiperiod decisions. Studies that incorporate uncertainties are discussed, and opportunities for future research developments are outlined.

Biomass supply chain optimisation for Organosolv-based biorefineries

This work aims at providing a Mixed Integer Linear Programming modelling framework to help define planning strategies for the development of sustainable biorefineries. The up-scaling of an Organosolv biorefinery was addressed via optimisation of the whole system economics. Three real world case studies were addressed to show the high-level flexibility and wide applicability of the tool to model different biomass typologies (i.e. forest fellings, cereal residues and energy crops) and supply strategies. Model outcomes have revealed how supply chain optimisation techniques could help shed light on the development of sustainable biorefineries. Feedstock quality, quantity, temporal and geographical availability are crucial to determine biorefinery location and the cost-efficient way to supply the feedstock to the plant. Storage costs are relevant for biorefineries based on cereal stubble, while wood supply chains present dominant pretreatment operations costs.

Integrated supply chain design for commodity chemicals production via woody biomass fast pyrolysis and upgrading

This study investigates the optimal supply chain design for commodity chemicals (BTX, etc.) production via woody biomass fast pyrolysis and hydroprocessing pathway. The locations and capacities of distributed preprocessing hubs and integrated biorefinery facilities are optimized with a mixed integer linear programming model. In this integrated supply chain system, decisions on the biomass chipping methods (roadside chipping vs. facility chipping) are also explored. The economic objective of the supply chain model is to maximize the profit for a 20-year chemicals production system. In addition to the economic objective, the model also incorporates an environmental objective of minimizing life cycle greenhouse gas emissions, analyzing the trade-off between the economic and environmental considerations. The capital cost, operating cost, and revenues for the biorefinery facilities are based on techno-economic analysis, and the proposed approach is illustrated through a case study of Minnesota, with Minneapolis-St. Paul serving as the chemicals distribution hub.

Scenario optimization modeling approach for design and management of biomass-to-biorefinery supply chain system

The aim of this study was to develop a scenario optimization model to address weather uncertainty in the Biomass Supply Chain (BSC). The modeling objective was to minimize the cost of biomass supply to biorefineries over a one-year planning period using monthly time intervals under different weather scenarios. The model is capable of making strategic, tactical and operational decisions related to BSC system. The performance of the model was demonstrated through a case study developed for Abengoa biorefinery in Kansas. Sensitivity analysis was done to demonstrate the effect of input uncertainty in yield, land rent and storage dry matter loss on the model outputs. The model results show that available harvest work hours influence major cost-related decisions in the BSC.

Energy intensity, life-cycle greenhouse gas emissions, and economic assessment of liquid biofuel pipelines

Petroleum fuels are predominantly transported domestically by pipelines, whereas biofuels are almost exclusively transported by rail, barge, and truck. As biofuel production increases, new pipelines may become economically attractive. Location-specific variables impacting pipeline viability include construction costs, availability and costs of alternative transportation modes, electricity prices and emissions (if priced), throughput, and subsurface temperature. When transporting alcohol or diesel-like fuels, pipelines have a lower direct energy intensity than rail, barge, and trucks if fluid velocity is under 1 m/s for 4-inch diameter pipelines and 2 m/s for 8-inch or larger pipelines. Across multiple hypothetical state-specific scenarios, profit-maximizing design velocities range from 1.2 to 1.9 m/s. In costs and GHG emissions, optimized pipelines outperform trucks in each state and rail and barge in most states, if projected throughput exceeds four billion liters/year. If emissions are priced, optimum design diameters typically increase to reduce pumping energy demands, increasing the cost-effectiveness of pipeline projects.

Selection of process alternatives for lignocellulosic bioethanol production using a MILP approach

This work proposes a decision-making framework for the selection of processes and unit operations for lignocellulosic bioethanol production. Process alternatives are described by its capital and operating expenditures, its contribution to process yield and technological availability information. A case study in second generation ethanol production using Eucalyptus globulus as raw material is presented to test the developed process synthesis tool. Results indicate that production cost does not necessarily decrease when yield increases. Hence, optimal processes can be found at the inflexion point of total costs and yield. The developed process synthesis tool provides results with an affordable computational cost, existing optimization tools and an easy-to-upgrade description of the process alternatives. These features made this tool suitable for process screening when incomplete information regarding process alternatives is available.

Integrating multimodal transport into cellulosic biofuel supply chain design under feedstock seasonality with a case study based on California

A multistage, mixed integer programing model was developed that fully integrates multimodal transport into the cellulosic biofuel supply chain design under feedstock seasonality. Three transport modes are considered: truck, single railcar, and unit train. The goal is to minimize the total cost for infrastructure, feedstock harvesting, biofuel production, and transportation. Strategic decisions including the locations and capacities of transshipment hubs, biorefineries, and terminals and tactical decisions on system operations are optimized in an integrated manner. When the model was implemented to a case study of cellulosic ethanol production in California, it was found that trucks are convenient for short-haul deliveries while rails are more effective for long-haul transportation. Taking the advantage of these benefits, the multimodal transport provides more cost effective solutions than the single-mode transport (truck).

Design and modeling of sustainable bioethanol supply chain by minimizing the total ecological footprint in life cycle perspective

The purpose of this paper is to develop a model for designing the most sustainable bioethanol supply chain. Taking into consideration of the possibility of multiple-feedstock, multiple transportation modes, multiple alternative technologies, multiple transport patterns and multiple waste disposal manners in bioethanol systems, this study developed a model for designing the most sustainable bioethanol supply chain by minimizing the total ecological footprint under some prerequisite constraints including satisfying the goal of the stakeholders', the limitation of resources and energy, the capacity of warehouses, the market demand and some technological constraints. And an illustrative case of multiple-feedstock bioethanol system has been studied by the proposed method, and a global best solution by which the total ecological footprint is the minimal has been obtained.

Optimal design of ethanol supply chains considering carbon trading effects and multiple technologies for side-product exploitation

This work proposes a spatially explicit mixed integer linear programming modelling framework representing the dynamic evolution of a bioethanol supply chain (SC) under increasing biofuel demand and greenhouse gas (GHG) emission savings over time. Key features of the proposed framework comprise: (i) the incorporation of available set-aside rural surfaces for energy crop cultivation; (ii) the acknowledgement ofan economic value to the overall GHG emissions through the introduction of an Emission Trading System. Multiple technological options are assessed to exploit the co-product Distiller's Dried Grains with Solubles either as animal fodder (standard usage) or as fuel for heat and power generation or as raw material for biogas production (and hence heat and power). Bioethanol production in Northern Italy is chosen as a demonstrative case study.

Life-cycle energy efficiency and environmental impacts of bioethanol production from sweet potato

Life-cycle assessment (LCA) was used to evaluate the energy efficiency and environmental impacts of sweet potato-based bioethanol production. The scope covered all stages in the life cycle of bioethanol production, including the cultivation and treatment, transport, as well as bioethanol conversion of sweet potato. Results show that the net energy ratio of sweet potato-based bioethanol is 1.48 and the net energy gain is 6.55 MJ/L. Eutrophication is identified as the most significant environmental impact category, followed by acidification, global warming, human toxicity, and photochemical oxidation. Sensitivity analysis reveals that steam consumption during bioethanol conversion exerts the most effect on the results, followed by sweet potato yields and fertilizers input. It is suggested that substituting coal with cleaner energy for steam generation in bioethanol conversion stage and promotion of better management practices in sweet potato cultivation stage could lead to a significant improvement of energy and environmental performance.