Implementation of the energy efficiency existing ship index and carbon intensity indicator on domestic ship for marine environmental protection

Energy efficiency research of propulsion system for series-parallel hybridization of amphibious vehicles

The series-parallel hybrid system has attracted much attention from scholars for its effective integration of the power advantages and operating characteristics of different power sources, which is influenced by international emission regulations, energy-saving and emission reduction policies. As such, a series-parallel hybrid powertrain is introduced to the amphibious vehicle, and an innovative powertrain topology architecture is proposed. Meanwhile, the operation mode and energy efficiency characteristics are investigated during the working process. Firstly, the energy flow simulation model of a series-parallel gas-electric hybrid propulsion system is constructed using a modular modeling approach. Secondly, four operating modes, namely mechanical propulsion, electric propulsion, hybrid propulsion and charging mode, were formulated due to the fact that the propulsion system has multiple forms of power sources in the form of natural gas engine and reversible motor. Meanwhile, the energy flow states were investigated under different operating modes. Meanwhile, a comprehensive investigation of the energy efficiency associated with propulsion, storage and start-up energy was conducted for each specific mode. The results of the research indicated that the energy efficiency of the electric propulsion mode can reach up to 35.15 %, which is the gain from the wide operating range of the motor's high efficiency. The hybrid propulsion mode can obtain the highest energy efficiency of 35.88 %, which fully demonstrates the advantages of coordinating and complementing the two power sources, the natural gas engine and the reversible electric motor. This investigation also provides theoretical and empirical support for optimizing energy matching and formulating energy management strategies.

Decarbonising ASEAN coastal shipping: Addressing climate change and coastal ecosystem issues through sustainable carbon neutrality strategies

This study analyzes the impact of ASEAN's goal of achieving carbon neutrality by 2050 on climate change and coastal ecosystems by examining carbon emissions and energy usage from 2019 to 2050 using different scenarios to reduce emissions and meet global temperature goals. This research proposes strategies to reduce carbon emissions and mitigate climate change effects on coastal ecosystems, focusing on evaluating CO2 emissions from ASEAN's coastal shipping sector. Geospatial data was used to analyze ship activity and develop carbon neutrality strategies. Various sources are used to gather data, including the Maritime Portal, exact Earth AIS, FASA and GFW. This study finds that container ships emitted 13.7 × 106 t of CO2 in 2019, with the transportation sector contributing 3.8% of the total greenhouse gas in 2020. Without regulations, CO2 emissions could increase fourfold by 2050. The study recommends implementing policies such as adopting clean fuels, energy efficiency standards and fuel-related regulations to reduce CO2 emissions by 65-80% by 2050. It also emphasizes the importance of cleaner technologies, regulatory considerations and collaboration, which would have positive implications for coastal ecosystems. This study is beneficial to professionals in the maritime and shipping industries, policy makers, environmental consultants, sustainability specialists, and international organizations.

Enhancing chemical phosphorus precipitation from tapioca starch anaerobic digestion effluent in a modified pilot-scale fluidized bed reactor

This study aimed to evaluate the possibility of P precipitation as struvite from real anaerobic digestion (AD) effluent of tapioca starch processing. The results showed that at a pH of 9, and without Mg:P molar adjustment, P recovery was at 85%. The percentage of P recovery was increased to 90% and P contained in precipitates was at 11.80-14.70 wt% P, which is higher than commercial single superphosphate fertilizer (SSP, 18-22 wt% P2O5). This was achieved by controlling mixing at 200-400 rpm and upflow velocity at 50-200 cm min-1 inside a fluidized bed reactor (FBR). Based on SEM-EDX, powder XRD, phase identification by profile matching, and FT-IR analysis, the results demonstrated that recovered precipitates formed struvite predominantly. In addition, results of the woodchip ash additions and the one-way ANOVA based-RSM analysis revealed that mixing, the solution pH, and the woodchip ash intensely affected P recovery with the optimum condition found at 400 rpm, pH9, 4 g L-1, respectively. Ash addition enhanced P recovery efficiency but decreased the product's purity. Total costs of P recovery varied considerably from 0.28 to 7.82 USD∙(kg P)-1 depending on chemical consumption and %P content in recovered products. Moreover, the total cost was reduced by 57% from 7.82 USD∙(kg P)-1 (profit margin: -4.30 to -2.82) by a single mixing operation to 3.35 USD∙(kg P)-1 (profit margin: +0.17 to +1.65) employing coupling effect of mixing and Vup. The results indicate that P recovery from tapioca starch AD effluent not only provides a good-quality alternative slow-release P fertilizer, but also helps to curtail environmental problems due to excessive P and nitrogen discharge. These findings also demonstrate the ways of recovering nutrients from an abundant renewable resource that are relevant to simultaneous waste utilization during pollution controls.

Waste newspaper driven activated carbon to remove polycyclic aromatic hydrocarbon from wastewater

In this study, a carbon-based adsorbent was developed from waste newspaper through pyrolysis at 800 °C to evaluate the removal efficiency of polycyclic aromatic hydrocarbons (Benzo[ghi]perylene (BghiP) and Indeno [1,2,3-cd] pyrene (IP)) from wastewater. The surface area of the developed adsorbent was estimated at 509.247m²g^-1 which allowed the adsorption of the PAHs from wastewater. The maximum adsorption capacity was estimated at 138.436 μg g^-1 and 228.705 μg g^-1 for BghiP and IP, respectively and the highest removal efficiency was observed at pH 2. Around 91% removal efficiency was observed at pH 7 for both pollutants. Experimental adsorption data were fit for pseudo-second-order kinetics and Langmuir isotherm models, which demonstrate electrostatic interaction, monolayered deposition, hydrogen bonding, and π-π interaction between adsorbate and adsorbent which play a significant role in adsorption. The regeneration study described that the developed adsorbent could be able to intake 52.75% BghiP and 48.073% IP until the 8th and 6th cycles, respectively. The removal efficiency of the adsorbent in the real sample was also evaluated. This study will provide a method to convert waste material into adsorbent and will remove PAHs from wastewater as a function of pollutant mitigation and waste management.

Numerical Calculation of High-Strength-Steel Saddle Plate Forming Suitable for Lightweight Construction of Ships

With the demand for construction of lightweight ships and polar ships, high-strength steel is increasingly applied in shipbuilding. There are a large number of complex curved plates to be processed in ship construction. The main method for forming a complex curved plate is line heating. A saddle plate is an important type of double-curved plate, which affects the resistance performance of the ship. The existing research on high-strength-steel saddle plates is lacking. To solve the problem of forming for high-strength-steel saddle plates, the numerical calculation of line heating for a EH36 steel saddle plate was studied. By combining it with a line heating experiment of low-carbon-steel saddle plates, the feasibility of numerical calculation based on the thermal elastic-plastic theory for high-strength-steel saddle plates was verified. Under the premise that the processing conditions such as the material parameters, heat transfer parameters, and the constraint mode of the plate were correctly designed, the effects of the influencing factors on deformation of the saddle plate could be studied by the numerical calculation method. The numerical calculation model of line heating for high-strength-steel saddle plates was established, and the effects of geometric parameters and forming parameters on shrinkage and deflection were studied. This research can provide ideas for the lightweight construction of ships and provide data support for automatic processing of curved plates. It can also provide inspiration for curved plate forming in fields such as aerospace manufacturing, the automotive industry, and architecture.

Performance evaluation of phosphonium based deep eutectic solvents coated cerium oxide nanoparticles for CO2 capture

The critical challenge being faced by our current modern society on a global scale is to reduce the surging effects of climate change and global warming, being caused by anthropogenic emissions of CO₂ in the environment. Present study reports the surface driven adsorption potential of deep eutectic solvents (DESs) surface functionalized cerium oxide nanoparticles (CeNPs) for low pressure CO₂ separation. The phosphonium based DESs were prepared using tetra butyl phosphoniumbromide as hydrogen bond acceptor (HBA) and 6 acids as hydrogen bond donors (HBDs). The as-developed DESs were characterized and employed for the surface functionalization of CeNPs with their subsequent utilization in adsorption-based CO₂ adsorption. The synthesis of as-prepared DESs was confirmed through FTIR measurements and absence of precipitates, revealed through visual observations. It was found that DES6 surface functionalized CeNPs demonstrated 27% higher adsorption performance for CO₂ capturing. On the contrary, DES3 coated CeNPs exhibited the least adsorption progress for CO₂ separation. The higher adsorption performance associated with DES6 coated CeNPs was due to enhanced surface affinity with CO₂ molecules that must have facilitated the mass transport characteristics and resulted an enhancement in CO₂ adsorption performance. Carboxylic groups could have generated an electric field inside the pores to attract more polarizable adsorbates including CO₂, are responsible for the relatively high values of CO2 adsorption. The quadruple movement of the CO₂ molecules with the electron-deficient and pluralizable nature led to the enhancement of the interactive forces between the CO₂ molecules and the CeNPs decorated with the carboxylic group hydrogen bond donor rich DES. The current findings may disclose the new research horizons and theoretical guidance for reduction in the environmental effects associated with uncontrolled CO₂ emission via employing DES surface coated potential CeNPs.