Energy transition is crucial for climate change mitigation and Sustainable Development Goals (SDGs), and has been a key government focus in Colombia since 2022, which must carefully consider its energy roadmap. This study evaluates three potential scenarios for achieving nearly 100% renewable energy by 2035: replacing fossil fuels with biofuels, using hydrogen for transport and industrial heat, and relying entirely on renewable electricity. This paper discusses these scenarios’ technical, economic, and social challenges, including the need for substantial investments in renewable energy technologies and energy storage systems to replace fossil fuels. The discussion highlights the importance of balancing energy security, environmental concerns, and economic growth while addressing social priorities such as poverty eradication and access to healthcare and education. The results show that while the Colombian government’s energy transition goals are commendable, a rapid energy transition requires 4 to 8 times the government’s projected 34 billion USD investment, making it economically unfeasible. Notably, focusing on wind, photovoltaic, and green hydrogen systems, which need storage, is too costly. Furthermore, replacing fossil fuels in transport is impractical, though increasing biofuel production could partially substitute fossil fuels. Less energy-intensive alternatives like trains and waterway transport should be considered to reduce energy demand and carbon footprint.

This study aimed to assess the physical, chemical, and combustion properties of pellets made from corncob and rice husk residues sourced in Sucre, Colombia, and to evaluate the performance of different blending ratios. Before pelletization, the residues were ground and processed using a small-scale flat die pellet mill equipped with a 6 mm die. Physical properties were evaluated according to ISO standards for particle density, bulk density, and impact resistance assessment. Proximate and ultimate analyses, as well as heating values, were determined and compared against the ISO 17225-6:2021 classification for herbaceous biomass. The 70:30 corncob-to-rice husk blend (CC70:RH30) showed good quality, with 7.23% ash, 9.18% moisture, and an LHV of 15.19 MJ/kg, meeting the criteria for Class B pellets. Combustion performance was assessed using a custom-designed macro-TGA, revealing that co-pelletized blends exhibited improved ignition temperatures and comprehensive combustion indices compared to the individual feedstocks. Additionally, calorific values were proportional to the blending ratios. In summary, controlling the blending ratio of corncob and rice husk residues during pellet production allows modulation of both the total ash content and the lower heating value of the resulting solid biofuels, making them more suitable for thermochemical conversion routes such as combustion and/or gasification.

Whether economic growth decouples from municipal solid waste (MSW) generation in upper–middle-income economies remains contested. We test the Waste Kuznets Curve and a disposal-to-recovery substitution effect using a 13-year panel of 1101 Colombian municipalities, combining step-wise fixed-effects models with a non-parametric generalized additive model (GAM), a family of spatial specifications, and a selection-aware recovery model. We find no evidence of income-driven decoupling in landfilling. Once the urban density and demographic structure are controlled, the income terms lose significance, the non-parametric estimate is predominantly monotonic, and density emerges as the main structural driver. Material recovery grows faster than disposal with income (relative substitution), but this signal is concentrated where recovery is measured—only 27% of municipalities report it, and coverage falls from every metropolitan municipality to one in five in the rural periphery, and the income terms are stable across every spatial representation—so that once selection is corrected the recovery elasticity falls from about 5.9 to a non-significant 1.3. Rather than spontaneous decoupling, Colombia exhibits persistent coupling alongside an institutionally engineered, spatially unequal recovery capacity. Achieving SDG 12 therefore requires stratified policies that mandate consumption reduction in mature urban economies while subsidizing shared circular infrastructure for historically neglected rural jurisdictions.

The transition to a circular bioeconomy in developing economies is frequently hindered by the operational failure of biogas facilities due to feedstock supply discontinuity. Whilst biochemical potential is traditionally the primary selection criterion, this study postulates that logistic reliability serves as the governing constraint for sustainable implementation. To validate this paradigm shift, a spatially explicit decision-making framework integrating Shannon Entropy and TOPSIS was developed and applied to a representative tropical agro-industrial region. By evaluating conflicting criteria covering logistic availability, technical efficiency, and biochemical stability, the model identified Annual Residue Production as the dominant weighting factor. Results established Cattle Manure as the universal baseload substrate essential for mitigating seasonality risks, outweighing higher-yielding but intermittent agricultural residues. Spatial analysis further revealed distinct bioenergy clusters dictating tailored technological strategies: a high-potential Rice-Livestock cluster suitable for centralised industrial plants overseeing recalcitrant biomass, and a Cassava-Livestock cluster favourable for decentralised, low-tech digestion. This data-driven approach demonstrates that successful substrate selection must transcend theoretical yield maximisation to prioritise supply chain reliability, providing a robust roadmap for de-risking bioenergy investments in tropical regions.

The transition towards a circular bioeconomy in developing regions is frequently hindered by operational failures caused by feedstock discontinuity. Whilst biochemical potential is traditionally the primary selection criterion, this study postulates that logistic reliability serves as the governing constraint. To validate this strategic reorientation, a decision-making framework was developed and applied to a representative tropical agro-industrial region. A sensitivity analysis comparing objective, subjective and neutral weighting scenarios identified annual residue production as the dominant factor. Results established cattle manure as the universal baseload substrate essential for mitigating seasonality, outweighing higher-yielding but intermittent agricultural residues. Spatial analysis revealed distinct territorial vocations, identifying a high-availability rice–livestock cluster in the south suitable for centralised industrial plants and dispersed cassava–livestock nodes in the centre favourable for decentralised digestion. Furthermore, the assessment of energy autonomy demonstrated that the prioritised co-digestion scenarios could cover local residential electricity demand between 1.5 times and 81 times. Crucially, residues favoured by expert judgement proved logistically unfeasible despite superior theoretical yields. This data-driven approach demonstrates that successful substrate selection must transcend theoretical yield maximisation to prioritise supply chain reliability, providing a robust roadmap for de-risking bioenergy investments and ensuring regional energy autonomy.

Landfills emit biogenic CH4 with which green H2 can be produced. However, in developing countries, its territorial potential is unknown. This study presents the first site-resolved national assessment of that potential, with cost and carbon intensity, for the 248 disposal sites active in Colombia in 2024. The CH4 generation was estimated with a first-order decay model following the recommendations of the Intergovernmental Panel on Climate Change (IPCC) and the United States Environmental Protection Agency (US EPA). Catalytic reforming and electrolysis projects were evaluated, with Monte Carlo propagation. As a mean over 2026–2040, reforming would produce 74$\mathrm{k}$$\mathrm{t}$H2/$\mathrm{yr}$ if these sites keep receiving waste, 45$\mathrm{k}$$\mathrm{t}$H2/$\mathrm{yr}$ if they close when the current licenses expire, and 42$\mathrm{k}$$\mathrm{t}$H2/$\mathrm{yr}$ in the first case with a conservative reformer efficiency. Electrolysis would yield up to 23$\mathrm{k}$$\mathrm{t}$H2/$\mathrm{yr}$. Thirty landfills concentrated 91$\mathrm{bad}\mathrm{hbox}$ of the national potential, and 58$\mathrm{bad}\mathrm{hbox}$ of the H2 via reforming (085$\mathrm{bad}\mathrm{hbox}$) cost less than 3$\mathrm{USD}$/$\mathrm{k}$$\mathrm{g}$H2. The CH4 slip proved decisive for the carbon intensity, which reached 0.88$\mathrm{k}$$\mathrm{g}$CO2e/$\mathrm{k}$$\mathrm{g}$H2 for reforming and 2.9$\mathrm{k}$$\mathrm{g}$CO2e/$\mathrm{k}$$\mathrm{g}$H2 for electrolysis. Capturing the biogenic CO2 generated in reforming would reduce its carbon intensity to -4.7$\mathrm{k}$$\mathrm{g}$CO2e/$\mathrm{k}$$\mathrm{g}$H2, provided that CO2 transport and storage exist.