Emerging technologies of Industry 4.0 have introduced novel ways of perceiving maintenance management, which has developed from being perceived as a “necessary evil” to become proactive with a holistic focusing on entire systems rather than single machines from Maintenance 3.0. In this context, the industry has begun to really appreciate the unique opportunities followed by system dynamics and simulation tools capabilities of representing the real world. However, maintenance management and performance are complex aspects of asset’s operation that is difficult to justify because of its multiple inherent trade-offs. Although the majority are unanimous when it comes to the expected impact maintenance plays on company profitability, this is in most cases challenging to determine and quantify. Moreover, relevant literature is considered as limited, especially with regards to impact simulation of Maintenance 4.0. Therefore, this paper focuses on the supportive function system dynamics, and modeling and simulation tools can be of help to assess behavior and predicting the future outcome of Maintenance 4.0 in the era of Industry 4.0. This includes developing a conceptualized model that enables simulating the future expected behavior i.e. (un)availability and cost by implementing such maintenance system. In this context, a centrifugal compressor with the function of exporting gas to Europe is applied as a case study.
The highly energy requirement of rich amine solvent regeneration process is the biggest obstacle for the industrial application of amine-based CO2 capture technology. In this work, to reduce the heat duty of solvent regeneration, the novel composite materials zeolite Beta /SBA-15 (BS) with different zeolite Beta (β) content were synthesized by the hydrothermal method with β as the silicon source and were utilized to prepare Zr@BS and Fe-Zr@BS catalysts for amine regeneration. Experiments for CO2 stripping were performed using amines (monoethanolamine (MEA), Diethanolamine (DEA) and 2-(Diethylamino) ethanol (DEEA)) with an initial CO2 loading of 0.5 mol CO2/mol amine at 370.15 K. Additionally, various techniques including including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscopy (SEM), N2 adsorption–desorption experiment, ammonia and CO2 temperature programmed desorption (NH3/CO2-TPD), and pyridine-adsorption infrared spectroscopy (Py-IR) were adopted to characterize and estimate the prepared catalysts. Also, the catalytic CO2 desorption performances of seven different catalysts (β, SBA-15, three BS catalysts, Zr@BS and Fe-Zr@BS) were investigated in terms of the cyclic capacity, desorption rate and energy consumption. The experimental results showed that the catalytic performance of BS better than the individual catalysts, and that Fe-Zr@BS can enhance the desorption factor by 212% and reduce the energy consumption by 33% compared to the blank run. Furthermore, the Fe-Zr@BS catalysts have no influence on the amine absorption performance in terms of the absorption rate and have the advantages of good stability and easy regeneration. Based on the results of characterization and experiments, the possible catalytic mechanism for bifunctional Fe-Zr@BS catalysts catalyzed amine regeneration for CO2 stripping were proposed and the reusability of the catalysts were also investigated.
The characteristics of residential energy consumption and environmental emission in urban China was focused in this paper. For that, consumer expenditure items of urban residents (1997~2015) was reclassified into five categories i.e., Food, Residential energy use, Housing and household appliances, Transport and communication, Other goods and services. The expenditure consumer price indexes of new categories were calculated. We reclassified industrial sectors of Chinese environmentally extended input-output (CEEIO) accordingly. An Almost Ideal Demand System (AIDS) was employed to calculate price and expenditure elasticity of residential energy demand. The Economic Input-Output Environmental Life Cycle Assessment (EEIO-LCA) method was introduced to estimate cumulative energy consumption and environmental emissions per monetary unit considering the whole life cycle perspective. We found that during the period of 1997~2015, for each 1% increase in household income, there would be a 1.13% increase in energy use. The uncompensated demand price elasticity was -0.2096, while the compensated was -0.2565. The cumulative energy consumption and environmental emission intensities of each sectors show continued steady decline trends. Specifically, For each 10000 yuan of expenditures, energy consumption, CO2, nitrogen oxides, SO2, smoke and dust emission decreased from 2.9848tce, 26.2843t, 0.1005t, 0.0962t and 0.0677t in 1997 to 1.6161tce, 8.192t, 0.0182t, 0.0172t and 0.0087t in 2015 respectively, which declined at an average annual rate of 18.49%、32.2%、43.66%、43.42%、49.54% respectively. It means that the energy and environmental efficiency in Chinese urban residential sector has been improved dramatically for nearly two decades.
Considerable attention has been given to utilize the redundant renewable energy with its increasing penetration in the overall energy system. The corresponding concept of “power to gas” is actively investigated by changing the power into hydrogen for using it later. Because of its benefit of efficiency and environmentally friendliness, hydrogen is obviously a promising energy source. On the other hand, it costs a lot to store and transport it in practice. It is necessary to transform it into hydrogen-containing materials that is cheap to store and deliver. Alternatively, this paper investigates the case of using ammonia. While the ammonia production processes have been already developed, using it as an energy carrier is a different issue. It should be evaluated in terms of various measures such as economic feasibility, safety, etc. Particularly, this paper investigates the techno-economic feasibility of power to ammonia technology. The overall ammonia production cost is estimated based on the process simulation by using the surplus electricity price. There is much to be done in addition to the current work for the implementation of P2G in practice. The insight obtained in this paper can be a good indicator for the implementation.
This paper presents a techno-economic evaluation of the electricity generation options available to meet electricity demand in three remote areas not interconnected to the main power grid of the Kingdom of Saudi Arabia (KSA). It considers two main alternatives: 1) extension of the main grid and 2) development of new generation resources in the isolated local grids. In the analysis, the electricity transmitted by the main grid is generated by oil-fired (or natural gas) combined cycle power plants (90%) and from PV and wind (10%) -consistent with KSA’s plans for 2023- while the local isolated grids would include a combination of PV, wind, diesel, oil, HFO and li-ion batteries.
Results show that under most scenarios of capital costs, fuel prices, and costs of air pollution, developing the isolated grids is a better alternative than extending the main grid.
Since the first pilot test of CO2 waterless fracturing in 2014, a complete system, including equipment, operation and liquid, has been formed. Twenty-three field tests proved the functions of CO2 waterless fracturing on reservoir energy storage, artificial fracture network and mixed-phase production increase. The effects lead to great water saving and CO2 storage. A unit volume of CO2 has the equivalent effect with 2.4 unit volumes of water-based fracturing liquid on oil production. The final storage rate of CO2 is 76.46%, 30% higher than that of CO2-EOR technology.