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The cement industry is highly energy-intensive, consuming approximately 7% of global industrial energy consumption each year. Improving production technology is a good strategy to reduce the energy needs of a cement plant. The market offers a wide variety of alternative solutions; besides, the literature already provides reviews of opportunities to improve energy efficiency in a cement plant. However, the technology is constantly developing, so the available alternatives may change within a few years. To keep the knowledge updated, investigating the current attractiveness of each solution is pivotal to analyze real companies. This article aims at describing the recent application in the Italian cement industry and the future perspectives of technologies. A sample of plant was investigated through the analysis of mandatory energy audit considering the type of interventions they have recently implemented, or they intend to implement. The outcome is a descriptive analysis, useful for companies willing to improve their sustainability. Results prove that solutions to reduce the energy consumption of auxiliary systems such as compressors, engines, and pumps are currently the most attractive opportunities. Moreover, the results prove that consulting sector experts enables the collection of updated ideas for improving technologies, thus giving valuable inputs to the scientific research.

Geosynthetics are extensively utilized to improve the stability of geotechnical structures and slopes in urban areas. Among all existing geosynthetics, geotextiles are widely used to reinforce unstable slopes due to their capabilities in facilitating reinforcement and drainage. To reduce settlement and increase the bearing capacity and slope stability, the classical use of geotextiles in embankments has been suggested. However, several catastrophic events have been reported, including failures in slopes in the absence of geotextiles. Many researchers have studied the stability of geotextile-reinforced slopes (GRSs) by employing different methods (analytical models, numerical simulation, etc.). The presence of source-to-source uncertainty in the gathered data increases the complexity of evaluating the failure risk in GRSs since the uncertainty varies among them. Consequently, developing a sound methodology is necessary to alleviate the risk complexity. Our study sought to develop an advanced risk-based maintenance (RBM) methodology for prioritizing maintenance operations by addressing fluctuations that accompany event data. For this purpose, a hierarchical Bayesian approach (HBA) was applied to estimate the failure probabilities of GRSs. Using Markov chain Monte Carlo simulations of likelihood function and prior distribution, the HBA can incorporate the aforementioned uncertainties. The proposed method can be exploited by urban designers, asset managers, and policymakers to predict the mean time to failures, thus directly avoiding unnecessary maintenance and safety consequences. To demonstrate the application of the proposed methodology, the performance of nine reinforced slopes was considered. The results indicate that the average failure probability of the system in an hour is 2.8×10−5 during its lifespan, which shows that the proposed evaluation method is more realistic than the traditional methods.

The integrity of the gas distribution network is crucial to guarantee the safety of human beings and the environment, while avoiding significant financial outlay. Since gas plants are progressively increasing near urban areas, a comprehensive tool to conduct maintenance and reduce the risk arising from the operations is required. To this end risk mitigation strategies have played a pivotal role during the last decades. In this paper, a comparison of three Risk-Based Maintenance (RBM) methodologies able to point out the most critical components, is presented. The first developed technique is a four stages Probabilistic Risk Assessment (PRA), characterized by a Hierarchical Bayesian Network (HBN) to perform the occurrence analysis and a Failure Modes, Effects and Criticality Analysis (FMECA) to assess the magnitude of the adverse outcomes. The HBN is adopted to overcome the limitations of traditional probability analysis approaches such as Fault Tree (FT), Event Tree (ET) or Bow-Tie (BT). To define a risk metric the total cost of failure is estimated and subsequently the Cost Risk Priority Number (CRPN) is calculated for each equipment. The second approach is a Quantitative Risk Analysis (QRA) carried out via a software named Safeti (by Den Norske Veritas -German Lloyds DNV-GL). By exploiting standard frequencies and modelling the losses of containment through Safeti, the most compelling devices are determined based on their estimated risk integral percentage. At last, Synergi Plant (another software developed by DNV-GL) is adopted for the third methodology. The software provides a Risk-Based Inspection (RBI) plan, through which the components are ranked. The proposed study can provide asset manager a concrete aid to focus maintenance efforts on priority apparatus, while assisting them in adopting the most appropriate methodology to their context. To demonstrate the applicability of the approaches and compare the obtained rankings, a Natural Gas Regulating and Measuring Station (NGRMS) is considered as case of study. The results proofed that all the proposed approaches can be implemented for practical application and the choice of the method strongly depends on the available data.

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