Clean Technologies

A system dynamics approach is described to explore the path of Carbon Capture diffusion. The proposed model, in principle, follows the Bass diffusion of innovation theory and includes all major influencing factors. The primary contribution of this paper is the modification of Bass’s model to reflect parameters affecting the adoption of Carbon capture and storage technology. Consequently, it differs from other extensions to Bass’s model. The underpinning of this work is the system dynamics (SD) approach, which can open a pathway for further research into CCS acceptance. The proposed model’s behaviour is illustrated for various transition pathways of the technology, for different regimes. By modifying the proposed model, the paper also allows consideration of various capturing technologies on their merit. The proposed framework enables the examination of the impact of intervention policies on the adoption of CCS by individual investors. The purpose is to identify the parameters of these policies to support the under-resourced CCS technology and reduce the need for government participation. It is worth noting that the SD is primarily a descriptive method used for scenario analysis to illustrate what the future would look like.

The Arctic is warming three to four times faster than the global average. This is transforming global maritime routes, thereby increasing shipping and resource extraction in Alaska. This surge requires sustainable energy solutions as policy trends towards stricter emissions standards. This article assesses the potential of Geothermal-to-X (GtX) technologies in establishing clean refueling infrastructure across Alaska, using its untapped geothermal resources. GtX uses electrolysis to split water into hydrogen and oxygen, a process powered by geothermal energy. Hydrogen and its X products, such as green methane or green ammonia, can be stored as fuels and are largely recognized as the key to a carbon-free future to address the growing energy demand. This study assesses the technical, economic, strategic, and geological feasibility of GtX refueling hubs in Alaska. Five locations were denoted as potential candidates and beckon future research. This study concludes that Unalaska is the most viable initial GtX hub given the highest Multi Criteria Decision Analysis (MCDA) score from its combination of a high-quality geothermal resource, an existing and accessible deepwater port, and a sizable local energy demand. The goal of this study is to provide an accessible and comprehensive resource for stakeholders and policymakers, outlining an energy future with sustainable maritime development, powered by affordable and secure energy.

Soil contamination by petroleum hydrocarbons represents a significant environmental challenge, especially in industrial and urban areas. This study evaluates the use of three industrial liquid by-products—sludge dewatering sidestream (SD), leftover yeast (LY), and secondary clarifier effluent (SC)—as biostimulant agents for the bioremediation of soils contaminated with gasoline and diesel mixtures. The novelty lies in applying these waste streams within a circular economy framework, with the added advantage that they can be injected directly into the subsurface. Microcosm tests were conducted over 20 weeks, analyzing the degradation of total petroleum hydrocarbons (TPHs) and their aliphatic and aromatic fractions using gas chromatography. The results show that all by-products improved biodegradation compared to natural attenuation. LY was the most effective, achieving 73.2% TPH removal, followed by SD (70.6%) and SC (65.4%). The greatest degradation was observed in short-chain hydrocarbons (C6–C16), while compounds with higher molecular weight (C21–C35) were more recalcitrant. In addition, aliphatic hydrocarbons showed greater degradability than aromatics in heavy fractions. Kinetic analysis revealed that the second-order model best fitted the experimental data, with higher correlation coefficients (R²) and more representative half-lives. Catalase enzyme activity also increased in soils treated with LY and SD, indicating higher microbial activity.