A conceptual design of an industrial production plant for activated carbon was developed to process 31.25 tons/day of industrial waste nutshells as the raw material and produce 6.6 ton/day of activated carbon using steam as an activation agent. The design considered the cost of the main equipment, the purchase price of the nutshells, basic services, and operation. A sensitivity analysis was developed, considering the price of the finished product and the volume of raw material processing varied up to ±25%. Furthermore, the total annual cost of the product was determined based on the production of 2100 tons/year of activated carbon. Two cash flows were developed and projected to periods of 10 years and 15 years of production, using a tax rate of 27%, a low discount rate (LDR) of 10% per year, and without external financing. For a 10-year production project, the net present value (NPV) was USD 2,785,624, the internal return rate (IRR) 21%, the return on investment (ROI) 25%, and the discounted payback period (DPP) after the fifth year. Considering a project with 15 years of production, the NPV was USD 4,519,482, the IRR at 23%, the ROI 24%, and the DPP after the fifth year of production.

In this study, we present a pre-feasibility analysis that examines the viability of implementing autonomous green hydrogen production plants in two strategic regions of Chile. With abundant renewable energy resources and growing interest in decarbonization in Chile, this study aims to provide a comprehensive financial analysis from the perspective of project initiators. The assessment includes determining the optimal sizing of an alkaline electrolyzer stack, seawater desalination system, and solar and wind renewable energy farms and the focus is on conducting a comprehensive financial analysis from the perspective of project initiators to assess project profitability using key economic indicators such as net present value (NPV). The analyses involve determining appropriate sizing of an alkaline electrolyzer stack, a seawater desalination system, and solar and wind renewable energy farms. Assuming a base case production of 1 kiloton per year of hydrogen, the capital expenditures (CAPEX) and operating expenses (OPEX) are determined. Then, the manufacturing and production costs per kilogram of green hydrogen are calculated, resulting in values of USD 3.53 kg⁻¹ (utilizing wind energy) and USD 5.29 kg⁻¹ (utilizing photovoltaic solar energy). Cash flows are established by adjusting the sale price of hydrogen to achieve a minimum expected return on investment of 4% per year, yielding minimum prices of USD 7.84 kg⁻¹ (with wind energy) and USD 11.10 kg⁻¹ (with photovoltaic solar energy). Additionally, a sensitivity analysis is conducted to assess the impact of variations in investment and operational costs. This research provides valuable insights into the financial feasibility of green hydrogen production in Chile, contributing to understanding renewable energy-based hydrogen projects and their potential economic benefits. These results can provide a reference for future investment decisions and the global development of green hydrogen production plants.

The effect of magnesium chloride as an additive of hydrothermal carbonization (HTC) of lignocellulosic biomass (Pinus radiata sawdust) was studied. The HTC tests were carried out at fixed conditions of temperature and residence time of 220 °C and 1 h, respectively, and varying the dose of magnesium chloride in the range 0.0–1.0 g MgCl₂/g biomass. The carbonized product (hydrochar) was tested in order to determine its calorific value (HHV) while using PARR 6100 calorimeter, mass yield by gravimetry, elemental analysis using a LECO TruSpec elemental analyzer, volatile matter content, and ash content were obtained by standardized procedures using suitable ovens for it. The results show that using a dose of 0.75 g MgCl₂/g biomass results in an impact on the mass yield that was almost equal to change operating conditions from 220 to 270 °C and from 0.5 to 1 h, without additive. Likewise, the calorific value increases by 33% for this additive dose, resulting in an energy yield of 68%, thus generating a solid fuel of prominent characteristics.

Hydrothermal carbonization makes it possible to transform lignocellulosic biomass into hydrochar, a carbon-rich material that can be used as fuel. Hydrochar has less calorific value than standard coal but generates less ashes during combustion. This study is a pre-feasibility analysis carried out to evaluate technically-economically and environmentally the use of hydrochar as fuel or co-fuel in thermal power plants in Chile. Until now there are no reports about it. The proposal of this work was to study the replacement of coal with a fuel that uses the same equipment and processes in power generation but with less air emission and with an economically profitable change. The results suggest that a plant with a supply of 104 t/h of bituminous coal could be replaced between 18 and 37 t/h of hydrochar, with a reduction of 8 and 27% in NO_x and SO₂ emissions, a reduction in 7 to 24% in ashes and a marginal increase in CO₂ emission. The proposed use of hydrochar was economically profitable, with internal rates of return of up to 40% and with cash flows that reached USD 22 million.

In the search for safe and effective natural antioxidants, this study investigates the antioxidant and cytotoxic properties of aqueous extracts obtained from three fungi of the family Hymenochaetaceae: Inonotus sp., Fulvifomes sp., and Phylloporia boldo, all associated with endemic trees of the Chilean sclerophyll forest. Antioxidant capacity was assessed through DPPH, ABTS, and hydroxyl radical scavenging assays. Fulvifomes sp. exhibited the highest antioxidant activity across all methods, which was consistent with its elevated polyphenol content. P. boldo, on the other hand, had the highest protein concentration but comparatively lower antioxidant activity. Cytotoxicity was evaluated using the WST-1 assay in the RTgill-W1 salmonid cell line, revealing that Inonotus sp. displayed the lowest cytotoxicity at both tested concentrations, suggesting it may be suitable for bioactive applications in aquaculture. In contrast, Fulvifomes sp. and P. boldo showed significant cytotoxic effects at higher concentrations. These findings highlight the potential of Inonotus sp. as a natural antioxidant with low cytotoxicity and encourages further exploration of native forest fungi as sources of functional bioactive compounds for food, nutraceutical, or aquaculture applications.

Selecting physics parameterizations for meteorological simulations is typically guided by univariate metrics, which are computed separately for each variable and station and frequently yield contradictory rankings and force subjective decisions. Although the Mahalanobis distance (MD) has previously been used for multivariate analysis, to the best of our knowledge, it has not previously been used as a decision criterion for selecting physics parameterizations in meteorological simulations. This study proposes the MD as a single multivariate performance metric that is dimensionless, invariant to measurement scales, and corrects for inter-variable correlations. The framework was demonstrated using 40 meteorological simulations combining microphysics, radiation, surface-layer, planetary boundary layer, and cumulus schemes, evaluated against hourly observations of temperature, relative humidity, and wind at surface stations in the Biobío region, south-central Chile. The traditional univariate metrics nominated different optimal configurations depending on the variable and station. In contrast, the MD identified a single configuration attaining the minimum distance at three of the four stations and the minimum cross-station mean, and revealed that performance was governed primarily by the surface-layer/PBL pairing rather than by microphysics or radiation choices. The MD thus provides an objective, reproducible, and easily interpretable criterion for parameterization selection, directly applicable to meteorological inputs for air quality modeling.