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Pit J is a new pit at Binungan 8 that will be developed to the west in 2024 and has a mine life of 9 years. The initial plan was to develop Pit J, which produced around 23 million tons of coal. However, there is a second alternative that can increase Pit J production to 28 million tons. Therefore, a project investment analysis of these two alternatives was conducted to determine which mining scheme to take and which is more profitable. This research uses a method of conducting investment valuation of the Pit J mine project, namely discounted cash flow (DCF). A deterministic approach using DCF was first conducted to determine the value of economic feasibility parameters, including net present value (NPV), internal rate of return (IRR), and payback period. This was followed by the identification of variables that most affect the NPV value through sensitivity analysis. Based on the research, both mining alternatives were declared financially feasible through the discounted cash flow method, with the first alternative having an NPV of 65.8 million USD, IRR of 60%, and a payback period of 4.77 years, while the second alternative resulted in an NPV of 88.4 million USD, IRR of 65%, and payback period 4.55 years. Sensitivity analysis shows that the variable change in Coal price is the most sensitive variable to the valuation of Pit J. Therefore, the second alternative is chosen as the best alternative to run. [ABSTRACT FROM AUTHOR]

During the COVID-19 pandemic, more than 24 billion pieces of surgical mask waste (WM) were generated in the EU region, with an acute shortage of their management and recycling. Pyrolysis and gasification are among the most promising treatments that were proposed to dispose of WMs and convert them into pyrolysis oil and hydrogen-rich syngas. This work aimed to investigate the techno-economic analysis (TEA) of both treatments in order to assess the feasibility of scaling up. The TEA was carried out using a discounted cash flow model and its data were collected from practical experiments conducted using a fluidised bed pyrolysis reactor and bubbling fluidised bed gasifier system with a capacity of 0.2 kg/h and 1 kg/h, respectively, then upscaling to one tonne/h. The technological evaluation was made based on the optimal conditions that could produce the maximum amount of pyrolysis oil (42.3%) and hydrogen-rich syngas (89.7%). These treatments were also compared to the incineration of WMs as a commercial solution. The discounted payback, simple payback, net present value (NPV), production cost, and internal rate of return (IRR) were the main indicators used in the economic feasibility analysis. Sensitivity analysis was performed using SimLab software with the help of Monte Carlo simulations. The results showed that the production cost of the main variables was estimated at 45.4 EUR/t (gate fee), 71.7 EUR/MWh (electricity), 30.5 EUR/MWh (heat), 356 EUR/t (oil), 221 EUR/t (gaseous), 237 EUR/t (char), and 257 EUR/t (syngas). Meanwhile, the IRR results showed that gasification (12.51%) and incineration (7.56%) have better economic performance, while pyrolysis can produce less revenue (1.73%). Based on the TEA results, it is highly recommended to use the gasification process to treat WMs, yielding higher revenue. [ABSTRACT FROM AUTHOR]

An economic feasibility study must consider the uncertainties inherent to a mining project, whose risks must be quantified properly to enable accurate decisionmaking. Studies previously carried out through the Discounted Cash Flow (DCF) methodology in the project evaluated here - a quarry whose operations are currently interrupted, located in Pernambuco, Brazil, formerly taxed under the presumed profit regime - indicated a positive Net Present Value (NPV) in the deterministic scenario, therefore projecting a profitable project. However, a probabilistic analysis using Monte Carlo simulations indicated only a 49.98% occurrence probability for this NPV. An assessment focused on the company's taxation was never carried out, which is a gap that the present study intends to fill, in addition to evaluating the feasibility of immediate investment in this project. Furthermore, this is a gap in Brazilian literature in general, which does not take into account the taxation system in their economic assessments. In this context, considering scenarios whose taxation was based on real and presumed profit regimes, we reassessed the cash flows of this quarry and performed deterministic and probabilistic economic analyses, and compared the results of both scenarios. The sensitivity analysis indicated that the production rate would be the most impactful variable in the project's NPV, considering the six variables assessed. Hence, it was verified in both deterministic and probabilistic analyses that taxation under real profit, results in a higher economic return with a 56.08% probability of the NPV being positive and with the Internal Rate of Return (IRR) higher than inflation (SELIC rate) at 4.81%; the taxation under the presumed profit, on the other hand, obtained respective probabilities of 46.54% and 3.23%. However, with the chances of obtaining some profit (NPV greater than zero) at the order of 50% and a minimal chance of the IRR being greater than the SELIC rate adopted at the time of this study, we would advise against investing in this venture. Moreover, even if the current moment is not the most suitable for investment in this sector, regardless of the production rate assessed in the probabilistic analysis, taxation on the real profit regime presented a greater economic return than taxation on the presumed profit regime., indicating that, for the parameters considered in this study, the first would be the most appropriate choice of tax system for this type of enterprise in Brazil. [ABSTRACT FROM AUTHOR]

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The adoption of renewable energy resources is in the core of energy transition. However, its implementation can be highly impacted by country policies. A limited number of researches investigated solar photovoltaic investments, comparing net-metering rules for distinctive energy consumption levels and different discounted rates, from the investors' point of view. This paper analyzes the impact of Brazilian net-metering rules on solar photovoltaic investments, considering residential scale. The methodology contemplates the development of a Discounted Cash Flow model to calculate Discounted Payback (DP), Net Present Value (NPV), Internal Rate of Return (IRR), and Levelized Cost of Electricity (LCOE) of projects. The case studies consider the impact of Brazilian regulation from net-metering rules (previous, considered, and current), energy consumption levels (Low, Middle, and High), and discount rates (5 %, 10 %, 15 %, and 20 %). The results show that from the previous to current rule the return for investor, on average, decreased 5.77 %. However, this reduction would be of 12.81 % if considered rule was adopted. For the 36 studies carried out, even in the worst case the investments remain viable. Therefore, the existing policy is suitable for the current stage of sector development; minimizing the impacts for energy tariff, distribution companies, consumers, and prosumers. [ABSTRACT FROM AUTHOR]

Hydrogen is a prominent clean fuel option for combatting global warming and producing low-emission, ecologically friendly electricity. Consequently, the proton exchange membrane water electrolysis (PEMWE) hydrogen refueling station has undergone thorough economic and environmental analysis. This work intends to fill the gap by presenting the influence of various operating circumstances and design parameters on the economic and environmental aspects of PEMWE based on various behaviors and features (I–V curve) under various scenarios. Profitability analysis (PA) is performed in terms of the net present value (NPV), discounted payback period (DPBP), benefit-cost ratio (BCR), and internal rate of return (IRR) from cumulative discounted cash flow diagrams (CFD). Also, sensitivity analysis (SA) is conducted to assess the impact of different economic factors, while simultaneously establishing CO 2 footprint guidelines for optimal operating and design conditions. The findings highlight that enhancing economic feasibility and reducing environmental concerns are simultaneously achievable by increasing cathode pressure, operating temperature, and decreasing membrane thickness. At membrane thicknesses over 100 μm, the project becomes unprofitable and inefficient at 1.85 V. PEMWE becomes more valuable and sustainable with a current density of 12,000 A/m2 or higher, but it releases more CO 2 emissions. Hence, utilizing excess renewable electricity in PEMWE addresses environmental concerns and enhances the overall ecological sustainability of hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Design of an integrated catalytic deoxygenation and hydrothermal gasification was performed. • Using experimental data, a high-fidelity process model was created with Aspen Plus. • Exergy analysis results showed that the deoxygenation reactor's exergy efficiencies are superior. • Equipment and raw material costs have superior effect influences on economic viability. Several technologies have been developed to produce sustainable aviation fuel (SAF), the hydroprocessing of esters and fatty acids (HEFA) representing one of the most mature pathways. Although HEFA has been widely adopted by industry, this pathway is mainly reliant on the hydrodeoxygenation (HDO) reaction, which requires large amounts and high pressures of hydrogen gas that reduces the cost-effectiveness of the process. In this study, the economic, environmental, and exergy analyses of two alternative scenarios for the catalytic production of SAF were considered. In both scenarios, SAF is produced through the catalytic deoxygenation of tall oil fatty acid (TOFA) via decarboxylation/decarbonylation (deCO x) – an approach requiring smaller amounts and lower pressures of hydrogen, feedstocks of lower purity and cost, and simpler supported metal catalysts relative to HDO. The material and energy balance was calculated using Aspen Plus process simulation software. Scenario 1 comprises a plant in which the catalytic deoxygenation of TOFA via deCO x is performed using hydrogen gas obtained commercially, while scenario 2 integrates catalytic deoxygenation with a plant that produces hydrogen gas via hydrothermal gasification. The study revealed that both scenarios were economically feasible relative to other pathways for SAF production, with the minimum fuel selling price (MFSP) of scenario 2 (USD$ 0.39/L) being lower than that of scenario 1 (USD$ 0.62/L). In addition to being the most economically viable, scenario 2 was also found to be preferable from an environmental standpoint since it also shows a lower global warming potential (GWP). Discounted cash flow analysis (DCFA) was used to determine other economic indicators such as net present value (NPV), internal rate of return (IRR), net rate of return (NRR) and payback period (PBP), which was estimated to be approximately 3 years for both scenarios. Finally, sensitivity analysis confirms that the raw materials and equipment purchase costs have the greatest impact on the MFSP. [ABSTRACT FROM AUTHOR]

The financial evaluation of renewable energy sources (RES) projects is well explored in the literature, but many different methods have been followed by different authors. Then, it is important to understand if and how these methods have been changing and what factors may have driven new approaches. Therefore, this article aims to explore the publications on the financial evaluation of RES projects from 2011 to 2020 and to present a critical analysis of the reviewed literature. The methods for evaluating RES projects were grouped into four categories: (i) traditional metrics based on net present value, internal rate of return, and payback period; (ii) levelized cost of electricity; (iii) return on investment approach; and (iv) real options analysis. A quantitative analysis was carried out considering aspects related to the relevance of the authors, productivity by country, and the most relevant journals for each of these groups. Then, a qualitative analysis of the main characteristics of the five most cited articles in each group was conducted. The results show that the more traditional methods are still widely used for the financial evaluation of RES projects. However, approaches based on the levelized cost and real options have been growing in importance to tackle the complex features of financial evaluation and comparison of RES projects. [ABSTRACT FROM AUTHOR]

• The state of São Paulo offers ten potential scenarios for the establishment of biorefineries. • Eucalyptus residues are a promising feedstock that produces 71,000 tons of bio-oil/year. • The minimum selling price of bio-oil varies according to plant capacities between from $11.6 to 19.3/GJ. • The minimum selling price of bio-oil is particularly sensitive to plant capacity and yield. • Co-processing bio-oil with vacuum gasoil can contribute 3.4 % of total "green fuel" in Brazil. Forestry residue is potentially useful for obtaining bio-oil and its by-products (biochar, syngas, and acid-rich aqueous extract) via fast pyrolysis. As such, we carried out a techno-economic analysis of both the production of bio-oil from Eucalyptus grandis residues (ER) and their availability in the state of São Paulo, Brazil. Discounted cash flow was used to calculate the minimum selling price (MSP) of bio-oil. Georeferencing identified the location of 20 Eucalyptus plantations, ten of which were selected due to their better economic performance. These ten plantations were potentially able to produce 59 million L/year of bio-oil. The economic analysis of the future biorefineries showed that an MSP of 11.6–19.3 $ (US)/GJ could support the processing of 60,000–5,000 tons/year of ER. A simulation of a large biorefinery revealed a capital investment (CAPEX) of around 6 M$ (US), reaching an operating expenditure peak of approximately 3 M$/year. The sensitivity analysis identified that plant capacity had the most significant impact on MSP, while the by-products (acid extract and biochar) lowered this by 22 %. The large biorefinery simulated using the Monte Carlo method had an 80 % chance of reaching a net present value (NPV) > 0, and an 80 % probability of reaching an internal rate of return (IRR) > 10 %. This study demonstrated that the production of bio-oils by the ten simulated centralized biorefineries is economically viable based on the NPV and IRR indicators. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrothermal carbonization can readily convert paunch waste to value-added products. • Process modelling indicates that pre-heater and dryer are the main energy consumer. • Hydrothermal carbonization technology development is challenged by reactor high cost. • Treating dewatered paunch waste is more commercially viable despite lower conversion. • Economic viability is highly sensitive to LHSV of reactor and economic assumptions. In this study, dewatered and raw paunch waste, with 15 and 3 wt% total solids respectively, generated at abattoirs was hydrothermally carbonised under subcritical water conditions. Higher solids content was found to produce higher hydrochar yield (i.e. 53% for 15 wt% compared to 33.5% for 3 wt%) at similar operating conditions of 10 bar and 240 °C for 5 min. The morphological differences were noted via Scanning Electron Microscopy (SEM) in the hydrochar samples, and the surface area for processing raw paunch waste was found to be 68.1 m2 g−1 compared to 10.8 m2 g−1 in case of dewatered paunch waste. The light bio-oil was mostly composed of phenolic compounds while the heavy bio-oil mainly contained long chain fatty acids and their esters. Following the experimental work, a full-scale ASPEN Plus process model was developed for a typical abattoir generating 27 tonne dry paunch waste per day. Pre-heater and hydrochar dryer contributed to 73% and 57% of the total energy for processing raw and dewatered paunch waste, respectively, because of the high moisture content of the feedstock and hydrochar. After the equipment sizing and estimation of capital and operating costs, the discounted cash flow analysis was performed using the Nth-Plant financing assumptions. It was concluded that treating dewatered paunch waste is preferable as it: needed a smaller reactor i.e. lower overall initial investment, was less sensitive to bio-oil price, and improved the net present value over a period of 30 years to $2.8 MM. Besides the liquid hourly speed velocity, its commercial viability is highly sensitive to internal rate of return and existence of hydrochar dryer. [ABSTRACT FROM AUTHOR]