Cost minimization of supplying biomass for ethanol biorefineries

A major hurdle facing commercial biofuel production is the cost of producing the feedstock. Since biofuel feedstock is bulky in nature, a large proportion of cost needed to be allocated for harvesting and transportation of feedstock. Economic viability of ethanol production from cellulosic feedstock depends in part of the cost to produce, harvest and deliver feedstock to the ethanol production facilities. A well-developed harvesting and transportation system does not exist for most feedstock. Hence to determine accurate estimation of the harvest, transportation and storage costs is important in ethanol production. The objectives of the study are to determine the optimal harvesting unit for ethanol biorefinery and estimate harvesting, storage and transportation costs of switchgrass under various harvesting schedules. A biorefinery with the annual capacity of processing 4.16 million gallons of ethanol was considered. Based on average dry matter yield, total production area needed for annual harvesting was estimated. The harvesting units needed for the continuous harvest and supply of biomass were estimated based on information on the capacity of machineries etc. Accordingly various costs associated with operating and maintaining harvesting unit were estimated. Transportation units needed were estimated for continuous supply of feedstock to the refinery and the associated costs were calculated. The number of machinery needed for a harvesting unit for the 90 day harvesting schedule are the most while year round harvesting schedules needs lesser number of machinery for a harvesting unit. Harvesting switchgrass in 90 day schedule is the most expensive scenario with all harvesting, hauling and storage costs added together. Year round harvesting schedule occurs as the least costly scenario. Sensitivity analysis shows the positive trend for harvesting and hauling costs to biomass yield, ethanol conversion technology, distance and decreasing trend for the range of truck speed considered. The results generated in this study will be useful in designing optimal harvest schedule of biomass for ethanol biorefinery

Modeling net energy balance of ethanol production from native warm season grasses

There has been an increasing interest in the use of perennial grasses as potential feedstock for ethanol production. The characteristics which make perennial grasses attractive for bioenergy feedstock development initiative are their high yield potential and the high contents of lignin and cellulose. The objective of the study is to model energy input and output and simulate Net Energy Value (NEV) of producing ethanol from native warm season grasses. According to simulated results, the mean NEV of ethanol production from native warm season grasses considered in the analysis was positive. Mean NEV for switchgrass and eastern gammagrass was higher compared to Indiangrass and big bluestem. Although the probability of having positive NEV is high, there is a risk of having negative energy balance under low output scenarios

Designing Harvesting and Hauling Cost Models for Energy Cane Production for Biorefineries

The harvesting and hauling operations of bioenergy feedstock is an important area in biofuel production. Production costs can be minimized by maintaining optimal machinery units for these operations. The objective of this study is to design an optimal harvesting unit for bioenergy refinery and estimate harvesting and hauling costs of energy cane. A biorefinery with the annual capacity of processing twenty-five million imp. gallons of ethanol were considered. Given the efficiency of harvesting, a two-row soldier system was considered. Considering the year-round supply of energy cane to the refinery, the optimal machinery unit was designed, and the combined operation costs were derived. The average estimated ownership, repair, labor and fuel and lubricant costs of biomass harvest unit were calculated to be $0.50,$0.54, $1.78 and$1.51/mt, respectively. The costs distribution generated showed harvesting and hauling costs could range between $5.47–$9.23/mt of energy cane. The methodology and the research output will provide guidelines for investors in designing harvesting and hauling units and estimating costs for different scales of operation

Optimal design and planning multi resource-based energy integration in process industries

Recently, process industries have experienced a significant pressure to shift from centralized energy supplying systems to the in-situ exploitation of renewable resources. Special attention has been paid to multi resource-based energy systems, a particular case of distributed generation where processing nodes include energy generation and can operate either grid-connected or isolated. This work proposes a general model to determine the optimal retrofitting of a supply chain integrating renewable energy sources under uncertain conditions and to analyze the effect of different planning horizons in the solution. The proposed mixed integer linear programming (MILP) formulation allows determining the best combination of available technologies that satisfies the internal energy demand of a given set of scenarios while addressing total expected cost and expected environmental impact minimization. The potential of the approach is illustrated through a case study from the sugar cane industry proposed by Mele et al. (2011).Peer ReviewedPostprint (author's final draft

Organic and conventional sweetpotato production in the Southeastern of United States: a comparative analysis

Background There has been a piqued interest in alternative agricultural production systems that are environmentally friendly due to concerns on how sustainable it is to grow conventionally. However, in the producer’s point of view, economic returns are an important issue in decision-making in adaptation. The purpose of this study is to assess the economic risk of conventional and organic sweetpotato production in the Southeastern US. The primary and secondary data were used for the analysis. We identified risk variables in stochastic profit function and performed Monte Carlo simulation in analyzing profitability and economic risk of conventional and organic production systems. Results Findings from the meta-analysis suggest lower sweetpotato yields and higher selling prices, are to be expected in the organic sweetpotato production systems compared with the conventional. A higher probability of having positive net return from organically grown sweetpotato compared to conventional production systems was observed. Conclusions Increase in unit cost leads to a decrease in net profit in both conventional and organic production systems. Sweetpotato price has more effect on net return compared to its yield in conventional production systems. The higher selling price, lower yield and lower unit costs provide a higher net profit return for the organic sweetpotato production systems. Unit cost in conventional production was noted to be higher in general, inferring conventional sweetpotato production could potentially experience a higher variability in net farm income. Despite the high production cost, however, farmers are encouraged to go into sweetpotato production as it appears to be profitable. Further studies should be conducted on conventional treatments without synthetic pesticides and fertilizers as these systems perhaps, may display lower external input costs that might make them more profitable similar to organic systems

Meeting Stakeholder Energy Technology Education Needs Using a Mobile Demonstration

Understanding the impact of workshops that include mobile demonstrations for describing technical applications can be useful when planning an Extension program on new energy technologies. We used a mobile demonstration in a workshop that provided information on small-scale on-farm biodiesel production. Evaluation of the workshop outcomes identified significant increases in attendees\u27 perceptions, awareness, interest, and knowledge related to the topic. On the basis of our process for planning and conducting the workshop and the results of the evaluation, we recommend implementing a well-distributed needs assessment and using a mobile demonstration to present technology that is economically feasible to use. The workshop we describe can be used as a model for other Extension programs

Education can improve the negative perception of a threatened long-lived scavenging bird, the Andean condor

Human-wildlife conflicts currently represent one of the main conservation problems for wildlife species around the world. Vultures have serious conservation concerns, many of which are related to people's adverse perception about them due to the belief that they prey on livestock. Our aim was to assess local perception and the factors influencing people's perception of the largest scavenging bird in South America, the Andean condor. For this, we interviewed 112 people from Valle Fértil, San Juan province, a rural area of central west Argentina. Overall, people in the area mostly have an elementary education, and their most important activity is livestock rearing. The results showed that, in general, most people perceive the Andean condor as an injurious species and, in fact, some people recognize that they still kill condors. We identified two major factors that affect this perception, the education level of villagers and their relationship with livestock ranching. Our study suggests that conservation of condors and other similar scavengers depends on education programs designed to change the negative perception people have about them. Such programs should be particularly focused on ranchers since they are the ones who have the worst perception of these scavengers. We suggest that highlighting the central ecological role of scavengers and recovering their cultural value would be fundamental to reverse their persecution and their negative perception by people.Fil: Cailly Arnulphi, Verónica Beatríz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Lambertucci, Sergio Agustin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Borghi, Carlos Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; Argentin

Farming Vs Forests: An Investigation from Sri Langka

Across Southeast Asia, tropical forests act as an important source of food, fuel and other vital products. Many people living near forests depend on them for their subsistence needs, especially during times of hardship. But growing populations have put increasing pressure on this resource, which is now threatened by over-use. Sri Langka is one country where this situation has reached a crisis point. One possible way forward is to improve the technical efficiency of agriculture in the land bordering forests - in other words, to boost the amount of income, food and other resources forest gatherers produce on their farms, so they do not need to use forest resources as much. This can he done in a number of ways, by, for example, improving technical expertise and capitalizing on any economies of scale.Farming, forest, Sri Lanka