Designing an olive tree pruning biorefinery for the production of bioethanol, xylitol and antioxidants: a techno-economic assessment

Holzforschung ◽  
2018 ◽  
Vol 73 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Ana Susmozas ◽  
Antonio D. Moreno ◽  
Juan M. Romero-García ◽  
Paloma Manzanares ◽  
Mercedes Ballesteros

Abstract Olive tree crops, extensively cultivated in Southern European countries, yield large amounts of olive tree pruning (OTP) biomass. This could be used within the framework of a bio-based economy that maximizes the utilization of biomass resources in a sustainable way. In the present work, the techno-economic feasibility of an OTP-based integrated biorefinery is evaluated by the process simulation software Aspen Plus, while the process is aimed at the production of ethanol, xylitol, antioxidants and electricity. Overall, the proposed plant could perform economically, and it is self-sufficient from an energy resource point of view. The plant as designed yields around 109 l of ethanol, 27 kg of xylitol and 43 kg of antioxidants per ton of OTP biomass, with an estimated production cost of 0.24 € l−1, 1.48 € kg−1 and 5.12 € kg−1, respectively. In a 10-year period, the economic profitability of the biorefinery plant is within a positive investment balance, with a net present value (NPV) of 32.1 M€ and a payback period of 5–6 years. These figures point out the opportunities for placing in the market several OTP-based products. Based on these data, the construction of small-scale OTP-based lignocellulosic biorefineries seems to be a realistic scenario.

2018 ◽  
Vol 31 (1) ◽  
pp. 60-76 ◽  
Author(s):  
Mattia De Rosa

Biogas is a promising renewable energy resource produced by using anaerobic digestion of organic substrates and it is mainly used to generate electricity by means of biogas engines. Other potential utilisations are growing, e.g. grid injection and biofuels production but, generally, a treatment aimed to increase its quality is mandatory and greater investments are generally required to produce upgraded biogas (biomethane). Despite the increasing of interest on these applications, a lack of information is still present from an economic point of view. The present paper performs an extended economic assessment of upgrading and selling biogas starting from a typical farm-based anaerobic digestion plant in Northern Ireland assumed as reference. Several economic indexes have been considered to assess the economic performance of the upgraded anaerobic digestion plant, namely net present value, pay-back period, profitability index and internal rate of return. Moreover, different scenarios in terms of fossil fuel prices have been analysed. The results show that producing and selling biomethane can be economically feasible if an adequate market is fostered. Optimum anaerobic digestion sizes between 26.9 and 64.4 tonne/y have been found, with correspondent net present value and pay-back period values in the range of £6.7–64.4M and 2.8–7.5 years, respectively, depending on the price scenarios analysed and the economic index chosen. Generally, adopting the net present value as objective function of the optimisation leads to greater anaerobic digestion size than the other indexes for any price scenarios considered. Finally, tougher market conditions (i.e. higher fossil fuel prices) lead to better economic performances of the upgraded anaerobic digestion configuration.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ramhari Poudyal ◽  
Pavel Loskot ◽  
Ranjan Parajuli

AbstractThis study investigates the techno-economic feasibility of installing a 3-kilowatt-peak (kWp) photovoltaic (PV) system in Kathmandu, Nepal. The study also analyses the importance of scaling up the share of solar energy to contribute to the country's overall energy generation mix. The technical viability of the designed PV system is assessed using PVsyst and Meteonorm simulation software. The performance indicators adopted in our study are the electric energy output, performance ratio, and the economic returns including the levelised cost and the net present value of energy production. The key parameters used in simulations are site-specific meteorological data, solar irradiance, PV capacity factor, and the price of electricity. The achieved PV system efficiency and the performance ratio are 17% and 84%, respectively. The demand–supply gap has been estimated assuming the load profile of a typical household in Kathmandu under the enhanced use of electric appliances. Our results show that the 3-kWp PV system can generate 100% of electricity consumed by a typical residential household in Kathmandu. The calculated levelised cost of energy for the PV system considered is 0.06 $/kWh, and the corresponding rate of investment is 87%. The payback period is estimated to be 8.6 years. The installation of the designed solar PV system could save 10.33 tons of CO2 emission over its lifetime. Overall, the PV systems with 3 kWp capacity appear to be a viable solution to secure a sufficient amount of electricity for most households in Kathmandu city.


2021 ◽  
Vol 13 (22) ◽  
pp. 12720
Author(s):  
Duong Minh Ngoc ◽  
Kuaanan Techato ◽  
Le Duc Niem ◽  
Nguyen Thi Hai Yen ◽  
Nguyen Van Dat ◽  
...  

A novel, small-scale vertical axis wind turbine tree was designed using turbines combining both Darrieus and Savonius blades. We tested for economic viability using wind data collected at a site in Surat Thani, Thailand. The Weibull distribution and Monte Carlo modeling with financial indices (Levelized Cost of Electricity (LCOE), Net Present Value (NPV), Internal Rate of Return (IRR), and Simple Payback Period (SPP)) were used to analyze data. We found that monthly mean wind speeds varied from 2.35 m/s in October to 2.84 m/s in February, corresponding to a wind power of 28.43 W/m2 and 42.68 W/m2. The average annual power output was 1446.1 kWh for May 2019 to April 2021. Results show that for turbine cut-in to cut-out speeds (2 m/s to 15 m/s), the prototype has potential economic feasibility (NPV > 0 for 64.93%), although the small capacity of the wind tree, in combination with the low average wind speed at the Surat Thani test site, showed a lack of economic viability at this specific location (NPV = USD − 20,946.29). A higher-wind-speed location (Chiang Mai) showed viability, especially at a 10 m height (NPV > 0 for 84.83%). We discuss potential conditions that would make broader use of the prototype feasible.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3637
Author(s):  
Eduardo Leiva ◽  
Carolina Rodríguez ◽  
Rafael Sánchez ◽  
Jennyfer Serrano

Water scarcity is causing a great impact on the population. Rural areas are most affected by often lacking a stable water supply, being more susceptible to the impact of drought events, and with greater risk of contamination due to the lack of appropriate water treatment systems. Decentralized greywater treatment systems for water reuse in rural areas can be a powerful alternative to alleviate these impacts. However, the economic feasibility of these systems must be thoroughly evaluated. This study reports an economic analysis carried out on the viability of greywater reuse considering scenarios with light greywater or dark greywater to be treated. For this, data obtained from the assembly and monitoring of greywater treatment systems located in the north-central zone of Chile, supplemented with data obtained from the literature were used. The results showed that both scenarios are not economically viable, since the investment and operating costs are not amortized by the savings in water. In both evaluated cases (public schools), the economic indicators were less negative when treating light greywater compared with the sum of light greywater and dark greywater as the inlet water to be treated. The investment and operating costs restrict the implementation of these water reuse systems, since in the evaluation period (20 years) a return on the initial investment is not achieved. Even so, our results suggest that the best alternative to reuse greywater in small-scale decentralized systems is to treat light greywater, but it is necessary to consider a state subsidy that not only supports capital costs but also reduces operating and maintenance costs. These findings support the idea that the type of water to be treated is a factor to consider in the implementation of decentralized greywater treatment systems for the reuse of water in rural areas and can help decision-making on the design and configuration of these systems.


Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 806 ◽  
Author(s):  
Laura Castro-Santos ◽  
Ana Bento ◽  
Carlos Guedes Soares

A technique to analyse the economic viability of offshore farms composed of wave energy converters is proposed. Firstly, the inputs, whose value will be considered afterwards in the economic step, was calculated using geographic information software. Secondly, the energy produced by each wave converter was calculated. Then the economic factors were computed. Finally, the restriction that considers the depth of the region (bathymetry) was put together with the economic outputs, whose value depends on the floating Wave Energy Converter (WEC). The method proposed was applied to the Cantabric and Atlantic coasts in the north of Spain, a region with a good offshore wave energy resource. In addition, three representative WECs were studied: Pelamis, AquaBuoy and Wave Dragon; and five options for electric tariffs were analysed. Results show the Wave Energy Converter that has the best results regarding its LCOE (Levelized Cost of Energy), IRR (Internal Rate of Return) and NPV (Net Present Value), and which area is best for the development of a wave farm.


Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2397
Author(s):  
Antonio Zuorro ◽  
Kariana Andrea Moreno-Sader ◽  
Ángel Darío González-Delgado

The high freshwater consumption requirements in shrimp biorefinery approaches represents one of the major drawbacks of implementing these technologies within the shrimp processing industry. This also affects the costs associated with the plant operation, and consequently, the overall economic performance of the project. The application of mass integration tools such as water pinch analysis can reduce frewshwater consumption by up to 80%, contributing to shrimp biorefinery sustainability. In this work, the economic evaluation and the techno-economic sensitivity analysis for a mass integrated approach for shrimp biorefinery were performed to determine the economic feasibility of the project when located in the North-Colombia region and to identify the critical techno-economic variables affecting the profitability of the process. The integrated approach designed to process 4113.09 tons of fresh shrimp in Colombia reaches a return on investment (%ROI) at 65.88% and a net present value (NPV) at 10.40 MM USD. The process supports decreases of up to 28% in capacity of production and increases of 12% and 11% in the cost of raw materials and variable operating costs without incurring losses, respectively. These findings suggest that the proposed design of the water recycling network coupled to a shrimp biorefinery approach is attractive from an economic point of view.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3097 ◽  
Author(s):  
J. R. Copa ◽  
C. E. Tuna ◽  
J. L. Silveira ◽  
R. A. M. Boloy ◽  
P. Brito ◽  
...  

The focus of this study is to provide a comparative techno-economic analysis concerning the deployment of small-scale gasification systems in dealing with various fuels from two countries, Portugal and Brazil, for electricity generation in a 15 kWe downdraft gasifier. To quantify this, a mathematical model was implemented and validated against experimental runs gathered from the downdraft reactor. Further, a spreadsheet economic model was developed combining the net present value (NPV), internal rate of return (IRR) and the payback period (PBP) over the project’s lifetime set to 25 years. Cost factors included expenses related to electricity generation, initial investment, operation and maintenance and fuel costs. Revenues were estimated from the electricity sales to the grid. A Monte Carlo sensitivity analysis was used to measure the performance of the economic model and determine the investment risk. The analysis showed an electricity production between 11.6 to 15 kW, with a general system efficiency of approximately 13.5%. The viability of the projects was predicted for an NPV set between 18.99 to 31.65 k€, an IRR between 16.88 to 20.09% and a PBP between 8.67 to 12.61 years. The risk assessment yielded favorable investment projections with greater risk of investment loss in the NPV and the lowest for IRR. Despite the feasibility of the project, the economic performance proved to be highly reliant on the electricity sales prices subdue of energy market uncertainties. Also, regardless of the broad benefits delivered by these systems, their viability is still strikingly influenced by governmental decisions, subsidiary support and favorable electricity sales prices. Overall, this study highlights the empowering effect of small-scale gasification systems settled in decentralized communities for electric power generation.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
José A. León ◽  
Gisela Montero ◽  
Marcos A. Coronado ◽  
Conrado García ◽  
Héctor E. Campbell ◽  
...  

In recent years, research on noncatalytic methods for biodiesel production has increased, mainly processes under supercritical conditions that allow the processing of waste vegetable oils (WVO) without the need to use catalysts, where the absence of catalyst simplifies the processes of purification of biodiesel. The high consumption of alcohol and energy to maintain the appropriate conditions of pressure and temperature of the reaction has turned the processes of supercritical conditions into an unfeasible method. However, the stages of biodiesel purification and methanol recovery are more straightforward, allowing the reduction of the total energy consumption by 25% compared to alkaline methods. Therefore, the present work describes a study through Aspen Plus® of the production of biodiesel by a process in supercritical conditions with WVO as raw material. Also, a solar collector arrangement was structured using the TRNSYS® simulator to supply energy to the process. To evaluate the economic feasibility of the proposed process, the installation of a pilot plant in Mexicali, Baja California, was considered. The internal rate of return (IRR) and the net present value (NPV) were determined for ten-year period. The planned system allows supplying solar energy, 69.5% of the energy required by the process, thus reducing the burning of fossil fuels and the operation cost. Despite the additional investment cost, for the solar collectors, the process manages to maintain a competitive production cost of USD 0.778/l of biodiesel. With an IRR of 31.7%, the investment is recovered before the fifth year of operation. The integration and implementation of clean technologies are vital in the development of the biofuels.


2021 ◽  
Vol 14 (5) ◽  
pp. 44
Author(s):  
Suraya Akter ◽  
Humayun Kabir ◽  
Shamima Akhter ◽  
Md. Mehedi Hasan

The study investigated the distinct environmental impacts and economic viability of domestic biogas technology in the countryside of Bangladesh. The study was carried out by a survey through personal interviews with biogas users. Seventy households were selected purposively and interviews were conducted through semi-structured questionnaires. The study mainly highlighted the potential reduction of greenhouse gas (GHG) emission and economic benefits of biogas utilization which were evaluated considering the substitution of traditional biomass fuels, by saving Liquefied Petroleum Gas (LPG) and cost of chemical fertilizer, and carbon trading. The economic benefits are addressed using some well-known economic indicators like Net Present Value (NPV), Payback Period (PBP), and Benefit-Cost Ratio (BCR). The results of the study revealed that a small-scale household anaerobic cow dung biogas digester not only exhibited the potential to cut carbon emissions on average by about 7.8 tons of CO2 equivalents yearly, but it also demonstrated the economic feasibility of doing so as the value of NPV and BCR was positive. This study recommends that the government approach, awareness program, and continuous and proper performing of the biogas technology are needed to intensify the multiples environmental benefits of the technology.


Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 180 ◽  
Author(s):  
Liqin Zhu ◽  
Congguang Zhang

The principle of sustainable development is becoming more and more prominent in various schools, and the eco-campus in rural areas often has more room for display. The identification and assessment of cost-effective biomass resources appropriate for recycling represent an opportunity that may significantly improve the comprehensive efficiency of an eco-campus system, resulting in remarkable investment savings, pollution reduction, as well as reducing energy consumption and resources waste. The economic feasibility of two biogas-linked rural campus systems (Fanjiazhai Middle School, FJZ and Xidazhai Middle School, XDZ, Yangling, China), as well as their key technologies, is investigated, the two systems respectively represent two biobased agricultural production modes. It is found that the initial investment, operating investment, and total revenue of FJZ system is 1.37 times, 2.39 times, and 1.71 times of XDZ system respectively, thus indicating that FJZ campus is proved to be a “larger” system compared to the other one. The operating costs show that reasonable control of labor and transportation costs should be carried out to optimize the economic feasibility of the system. After considering the system’s economic credits obtained from using biogas slurry flushing system and avoiding waste management, the net present value of XDZ system had increased to its 1.5 times, while the FJZ system had increased to its 135%. From the perspective of revenue to investment ratio, XDZ system has a better profit earning efficiency compared to FJZ system. The sensitivity analysis indicates that biogas price, fruit yield, labor use are main factors that have the greatest impacts on the economic performance of these eco-campuses.


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