Optimization of an ion transport membrane reactor system for syngas production
Abstract Ion transport membrane (ITM) reactor has been regarded as a promising novel technology for syngas production. To commercialize this technology, overall system designs and operating conditions should be optimized. In this study, a mathematical analysis of the ITM reactor system has been performed using Aspen Plus® to optimize its operations. Two-dimensional ITM reactor model developed in our […]
Energy, economic and environmental analysis of a BOG re-liquefaction process for an LNG carrier
Abstract Due to tighter environmental regulations, newly built liquefied natural gas (LNG) carriers are equipped with a re-liquefaction system to minimize combustion of surplus boil-off-gas (BOG). Thus, this paper comparatively analyzes the re-liquefaction system for a low-pressure gas injection engine according to the refrigerant (no external refrigerant or single mixed refrigerant) with three key performance indicators: energy, economic, […]
Novel approach to integrate CO2 utilization coupled with direct methane conversion to C2 products using solid oxide electrolysis cell
Abstract Solid oxide electrolysis cells (SOECs) based on oxygen ion-conducting electrolytes driven at high temperatures have been considered promising candidates for CO2 utilization and energy storage to mitigate environmental problems because of their high current density and efficiency. Additionally, SOECs have potential to integrate with processes that require high-temperature pure oxygen produced at anode and CO2 utilization […]
Study on cyclic plastic behaviour of sandwich pipelines subjected to cyclic thermo-mechanical loads
Abstract Subsea pipelines are generally used to transfer hydrocarbons from ultra-deep seawater to facilities on the shore. Typically, sandwich pipelines are filled with polymeric cores for thermal insulation, with structural reinforcements also used as a deep-water application. Sandwich pipelines are subjected to either monotonic or cyclic loads, such as bending moment, buckling, internal and external pressures during […]
Distributional reinforcement learning with the independent learners for flexible job shop scheduling problem with high variability
Abstract Multi-agent scheduling algorithm is a useful method for the flexible job shop scheduling problem (FJSP). Also, the variability of the target system has to be considered in the scheduling problem that includes the machine failure, the setup change, etc. This study proposes the scheduling method that combines the independent learners with the implicit quantile […]
Analysis of the effect of vortex reduction structures on submarine tonal noise via frequency-domain method employing thickness noise source
Abstract In this study, the acoustic effect of unfavorable flow, such as horseshoe vortex (HSV) generated around the appendages, on propeller radiated noise was analyzed. To analyze this, a frequency-domain noise model is developed, which can predict the noise of an underwater propeller placed in a non-uniform wake. To clearly analyze the acoustic effects of HSV around appendages, vortex reduction […]
Estimation of ice loads on offshore structures using simulations of level ice-structure collisions with an influence coefficient method
Abstract During their service, ice-class vessels are exposed to ice collision loads. Precise estimation of such ice loads is essential to the design of ice-class vessels. Due to difficulties encountered in real measurement of ice loads, a simple yet logically straightforward method, namely the influence coefficient method (ICM), has been widely employed to convert strain […]
Experimental investigation on speed excursion of PIG due to friction variation in natural gas pipeline
Abstract Natural gas pipeline pigging with speed excursions may lead to potential loss of inspection data and possible dangers due to high acceleration; however, the operation relies heavily on a rule of thumb. Most pigging operations in gas pipelines are performed at normal operating pressures with regular flow rates, and the PIG velocity is generally in the range of 2–5 m/s. […]
Dynamic bending of an ice wedge resting on a winkler-type elastic foundation
Abstract For most ice – sloping structure interactions, the incoming ice floes' failures are determined by the formation of circumferential cracks. This physical process can be simplified as analyzing the bending failure of an ice wedges resting on a fluid foundation. In history, closed-form analytical/empirical solutions have been developed for the static bending problem; and […]
Techno-economic analysis and Monte Carlo simulation for green hydrogen production using offshore wind power plant
Abstract With the growth of marine energy such as offshore wind power, hydrogen is a promising solution for the intermittence of renewable energy sources and long-distance transmission. Some demonstration projects of offshore hydrogen production are underway using wind power. However, comparative studies on novel options such as individual hydrogen production and transport to land from […]
