International Journal of Sustainable Energy and Environmental Research

Evaluation of olive stone for syngas production -integrated with CO2 capture by waste materials- and for amelioration of agricultural soil

Despina Vamvuka — 2026-03-30

A building waste material and an agro-industrial waste were investigated as CO₂ sorbents during the steam gasification of olive stone. Using a fixed-bed setup connected to a differential thermogravimetric–mass spectrometry system made it possible to determine key features, including the composition and energy content of the generated gas, as well as the yields of syngas and hydrogen. As an alternative application of the biochar, the possibility for soil amendment was examined by carrying out column leaching experiments. Upon steam gasification of the char, the building waste sorbent captured up to 94.1% of CO₂ emissions, whereas the olive stone ash sorbent captured up to 91.4% of CO₂. The building waste presented a higher overall performance, raising the mole fraction of H₂ to 73.3% at a Ca/C=2, the H₂/CO ratio to 3.35, the higher heating value of the generated gas to 13.4 MJ/m³, and the syngas yield to 1.74 m³/kg. Upon biochar leaching through the soil, the release of nitrates was quite low, whereas that of phosphates was considerable. Nutrient elements K, Na, and Mg were extracted in higher amounts from the biochar. The leachability of heavy metals was very low. Overall, the steam gasification of olive stone, integrated with CO₂ capture by waste materials, was very beneficial. An alternative application of biochar to the soil could improve the amendment when mixed with composts.

Climate-driven rainfall forecasting for small-scale hydropower potential in Dhaka using SARIMAX modeling

Ashif Imdad — 2026-03-31

Bangladesh is one of the most populous countries in the world and faces significant challenges in meeting its energy demands due to rapid population growth and economic development. Considering this, even a small amount of power can be significant in fulfilling part of the demands. The purpose of this paper was to investigate the feasibility of forecasting hydropower generation in Dhaka, Bangladesh, using predicted precipitation trends. Daily rainfall readings from 1981 to 2025 were accessed and used to determine monthly and annual forecasts for the period 2026-2045. The forecasting model (SARIMAX), which incorporates 2-meter air temperature and specific humidity as exogenous variables, was used, and its performance was compared with historical data. SARIMAX exhibited reliable data, closely matching the actual situation, especially regarding seasonal changes. This model can be suitable for Dhaka as a data-informed approach to renewable energy planning. The forecasted data indicates that Dhaka receives a substantial amount of rain annually, nearly 2,564 mm. The power generation results suggest that the yearly rainfall in Dhaka could generate approximately 0.117 MW, 0.234 MW, and 0.351 MW of continuous power under 1 m, 2 m, and 3 m head conditions, respectively, with an average runoff coefficient of 0.60 and 80% system efficiency. This highlights the importance of using climate forecasting in sustainable energy strategies, especially in rapidly urbanizing and climate-vulnerable regions like Dhaka.

Effect of gamma-irradiation of yam peel powder (Dioscorea rotundata l. Poir) on metal corrosion protection in sulphuric acid environment

Okomah Yvette Esama — 2026-04-01

The study assessed the influence of gamma irradiation at different temperatures and concentrations on the anticorrosion properties of yam peel. A mild steel surface was exposed to 0.5M H₂SO₄ at room temperature for five days. The highest inhibitor efficiency, exhibited by gamma-irradiated yam peel powder at 24 hours, was 98.76% at a concentration of 1.2 g/L, while the lowest at 120 hours was 40.03% at 0.2 g/L of Inh 2. The results revealed that increasing the inhibitor concentration from 0.2 g/L to 1.2 g/L enhanced inhibition efficiency. The highest efficiency was observed at 40°C, reaching 81.87% at 1.2 g/L of Inh 2, whereas the lowest was at 70°C, with 54.19% at 0.2 g/L of Inh 1. Inh 2 is irradiated yam peel powder, while Inh 1 is unirradiated yam peel powder. The efficiency depended on temperature, concentration, and time, with gamma-irradiated yam peel powder showing near-excellent inhibition efficiency compared to unirradiated yam peel powder, based on weight loss results. Surface analysis indicated that protection offered by gamma-irradiated yam peel powder was due to the extension of adsorbed molecules on the mild steel surface. The relationship between temperature and inhibition efficiency supported physical adsorption, and adsorption studies followed a Langmuir isotherm.