Scenario-Based Techno-Economic Analysis of Steam Methane Reforming Process for Hydrogen Production

Steam methane reforming (SMR) process is regarded as a viable option to satisfy the growing demand for hydrogen, mainly because of its capability for the mass production of hydrogen and the maturity of the technology. In this study, an economically optimal process configuration of SMR is proposed by investigating six scenarios with different design and operating conditions, including CO2 emission permits and CO2 capture and sale. Of the six scenarios, the process configuration involving CO2 capture and sale is the most economical, with an H-2 production cost of $1.80/kg-H-2. A wide range of economic analyses is performed to identify the tradeoffs and cost drivers of the SMR process in the economically optimal scenario. Depending on the CO2 selling price and the CO2 capture cost, the economic feasibility of the SMR-based H-2 production process can be further improved

Pullout Resistance Of Geogrid Reinforcement With In-Plane Drainage Capacity In Cohesive Soil

This study presents the results of geogrid pullout tests conducted in wet and fine-grained soils. Failures of reinforced soil structures have often involved inadequate drainage due to the use of fine-grained soils, which has led to stringent specifications for backfill material in such structures although there are significant economic reasons for relieving the specifications. One approach to improve the issue is to reinforce fine-grained soils with geosynthetic providing both reinforcement and lateral drainage. Although using reinforcement with in-plane drainage capability is conceptually promising, transmissivity requirements for this application have not been properly evaluated. Pullout tests were conducted on cohesive soils using geogrids with the same tensile strength but with and without in-plane drainage channels. The results indicate that geogrids with in-plane drainage layers show higher pullout resistance than conventional geogrids. The finding contributes to promoting the use of poorly draining soils as backfill material

Long-Term Performance Of Recycled Concrete Aggregate For Subsurface Drainage

Recycled concrete aggregate (RCA) is one of many sustainable construction materials, and its use in drainage systems by replacing virgin aggregate is beneficial from both economic and environmental perspectives. However, the use of RCA as pipe backfill material may cause a long-term performance issue such as clogging due to fine accumulation and calcite precipitation on filter fabric. Therefore, this study investigated long-term performance of RCA regarding flow rate and calcite precipitation. Long-term permeability testing was conducted to measure the reduction of flow rate with time, and the effect of filter fabric\u27s opening size on the flow was also evaluated. Additionally, an accelerated calcite precipitation (ACP) procedure was devised and used to estimate lifetime calcite precipitation of RCA. Two key findings are: (1) excessive RCA fine accumulation can cause significant reduction in RCA\u27s drainage performance; and (2) the clogging due to calcite precipitation of RCA may not be as significant as the existing and/or accumulated RCA fine

Promoting effective modes of the university-industry interaction and their evolution for economic catch-up in Asia

The project identified the drivers of, and barriers to university-industry relations (UIR) and collaboration in Asia. A survey and case studies were conducted to examine capacities and limitations of the universities and the industrial firms, legal and market institutions including intellectual property rights (IPRs) arrangements, and any historical legacies and cultural factors. One finding from the Malaysian team is that contrary to most of past findings, medium firms rather than large firms are more likely to collaborate with universities. The project also produced final reports by five country teams explaining the determinants of current UIR in each country

Impact of Soil Moisture Data Assimilation on Analysis and Medium-Range Forecasts in an Operational Global Data Assimilation and Prediction System

Accurate initial soil moisture conditions are essential for numerical weather prediction models, because they play a major role in land–atmosphere interactions. This study constructed a soil moisture data assimilation system and evaluated its impacts on the Global Data Assimilation and Prediction System based on the Korea Integrated Model (GDAPS-KIM) to improve its weather forecast skill. Soil moisture data retrieved from the Advanced Scatterometer (ASCAT) onboard the Meteorological Operational Satellite was assimilated into GDAPS-KIM using the ensemble Kalman filter method, and its impacts were evaluated for the 2019 boreal summer period. Our results indicated that the soil moisture data assimilation improved the agreement of the observations with the initial conditions of GDAPS-KIM. This led to a statistically significant improvement in the accuracy of the initial fields. A comparison of a five-day forecast against an ERA5 reanalysis and in situ observations revealed a reduction in the dry and warm biases of GDAPS-KIM over the surface and in the lower- and mid-level atmospheres. The temperature bias correction through the initialization of the soil moisture estimates from the data assimilation system was shown in the five-day weather forecast (root mean squared errors reduction of the temperature at 850 hPa by approximately 5% in East Asia)

Representation of the 2016 Korean Heatwave in the Unified Model Global NWP Forecasts: The Impact of Remotely Forced Model Errors and Atmosphere-Ocean Coupling

This study investigates the effects of atmosphere-ocean coupling for medium-range forecasts by using coupled numerical weather prediction (NWP) experiments based on the unified model (UM) on a case study of the 2016 heatwave over the Korean Peninsula. Atmospheric nudging experiments were carried out to determine the key regions which may have large impacts on the forecasts of the heat wave. The results of the nudging experiments suggest that key forcing from the Mongolia region gives the largest impact to this case by causing a transport of warm air from the northwest part of Korea. Moreover, the Pacific region shows an important role in the global circulation in nudging experiments. Results from the atmosphere-ocean coupled model show no clear benefit for the extreme heat wave temperatures in this case. In addition, more model development seems to be needed to improve the representation of sea surface temperature (SST) in some key areas. Nevertheless, it is confirmed that the atmosphere-ocean coupled simulation produces a better representation of aspects of the large-scale flow such as the blocking high over the Kamchatka Peninsula, the high pressure system in the northwest Pacific and Hadley circulation. The results presented in this study show that atmosphere-ocean coupling can be an important way to improve the deterministic model forecasts as the lead time increases beyond a few days

MORPHOLOGY, THERMAL STABILITY, AND SOLDERABILITY OF ELECTROLESS NICKEL–PHOSPHORUS PLATING LAYER

We studied the growth kinetics and characteristics of electroless nickel–phosphorus (EN–P) deposition layer on Cu substrate in an acid plating bath with sodium hypophosphite as the reducing agent. The individual nodules of the EN–P layer increased in size but decreased in number with increasing plating time and pH, i.e. the root-mean-square (RMS) roughness of the EN deposit decreased. In addition, the plating rate of the EN layer increased with increasing plating bath pH. X-ray diffraction (XRD) analyses revealed that the as-plated deposit was in an amorphous phase, while the heat-treated layer was composed of crystallized Ni and Ni3P compound. The solderability of the EN layer increased with decreasing P content. In addition, the wetting force increased with increasing surface roughness. The present study clearly showed that the solderability behavior of the EN layer is affected by both surface composition (P content) and morphology.Electroless nickel-phosphorus plating, surface morphology, solderability