Facing Emerging Risks in Carbon Sequestration Networks. A Comprehensive Source Modeling Approach.

Tackling risks in emerging infrastructures is a key point in making them acceptable and safer. Carbon Sequestration pipeline networks, as part of the Carbon Capture and Storage chains, are linked to the handling of large amounts of CO2 and may be subjected to failures and ruptures. This results in large pressurized and multiphase releases of CO2 that behaves as a denser-than-air and asphyxiant gas. The lack of a comprehensive modelling approach in this sense makes employed risk safety procedures often unreliable and lacking. In this work, a comprehensive modelling approach, based on self-collected experimental data, is proposed with the aim of filling existing gaps. Results well match experimental data and the modelling procedure allows for the estimation of characteristic parameters linked to heat transfer phenomena and the incidence of geometry and operative conditions on the release evolution. The occurrence of the solid phase and the applicability of the isothermal hypothesis is discussed showing that specific geometric and operative conditions are required

CCS and EOR hazard analysis. Experimental investigation and modeling of multiphase CO2 pressurized releases.

CO2 handling operations are gaining importance in the worldwide discussion mainly because of the large strategies that are currently being developed to govern the Global Warming. In this sense, the CO2 is considered one of the most important GHG (Greenhouse Gas) since it is also actually emitted in large quantities from anthropogenic sources. These emissions arise mainly from combustion of fossil fuels and biomass in power generation, gasification, industrial processes, natural gas processing, petroleum refining, building and transport sectors. The deployment of the Carbon Capture and Storage (CCS) technique is currently under analysis as a mean of limiting these emissions and so the atmospheric concentration of the CO2. The CCS chain is subdivided into three main systems: the system of capture and compression, the transport system and the storage system. This technology therefore involves the handling of the CO2 to store it in a reservoir, instead of allowing its release to the atmosphere, where it contributes to the Climate Change. Therefore, an essential element of the CCS chain is the transportation of large amounts of captured CO2 to the storage site. This is usually achieved by means of large infrastructures mainly consisting of pressurized pipelines that may typically be several hundred kilometers long. Given the significant amounts of CO2 involved and because of this substance at high concentrations is an asphyxiant, the safety of CO2 pipelines is of primarily importance to the public acceptance of CCS as viable means for tackling the impact of the Global Warming. This works moves therefore from the fact that central to QRA (Quantitative Risk Assessment) procedure of pressurized pipeline carrying CO2 is the accurate prediction of the flow parameters concerning an accidental release induced by a rupture. From this point of view, there is naturally the possibility of pipeline rupture that may be driven by many factors like human errors, component failures, corrosion, earthquakes and many others external interferences. In what concerning the CO2 releases modeling, it should be underlined the lack of a comprehensive model able to manage all phenomena that are expected to take place during a rapid depressurization. In the case of CO2 pipeline, the model must be capable of handling multiphase flows also at sonic conditions as well as the peculiar thermodynamic behavior that may invoke the occurrence of the solid phase. The main target is to have a comprehensive, reliable and easy applicable (from a QRA perspective) model to be used in assessing hazard profiles related to a CO2 pipeline rapid depressurization. In this sense, available models lack the whole dynamics and the formation and sublimation of solid CO2 expect for sophisticated and detailed CFD (Computational Fluid Dynamic) simulation that are substantially inappropriate to face the emergencies and the investigation of general scenarios. The model availability is also still limited by the lack of experimental data that are used to drive the model formulation and its validation. The few accessible experimental series give contradictory results in what concerning the peculiar CO2 behavior under transient pressure fields and in correspondence of choked flow conditions thus requiring further investigations. Moving from these considerations, the present study has the aim of covering the existing gaps in what concerning the availability of a descriptive model. The study is introduced by a detailed theoretical investigation of specific phenomena the CO2 undergoes when subjected to a rapid depressurization. Examples of these may include the occurrence of multiple choked flow states depending on the established thermodynamic equilibrium (liquid-vapor, solid-vapor) and the investigation of specific thermodynamic pathways that are linked to the solid phase appearance. A section pertaining to the experimental campaign follows. In this sense the data availability is enhanced by the collection of self-made data series especially linked to moderate pressures (up to 65-70 barg). The experimental arrangement allows for the investigation of different charging states, matching the operative CO2 conditions. Collected data are then used to support the model development in the assessment of specific discharge and thermodynamic parameters that are needed to close the mathematical structure. The proposed model, that is the main target of this investigation, is illustrated and discussed in a specific section with details on the adopted assumptions, the mathematical structure and the numerical approach. The structure covers all main mechanisms related to the rapid CO2 depressurization including phase change mechanisms (boiling, solidification and sublimation), heat transfer and friction effects as well as a reliable thermodynamic description of the expansion pathway to atmospheric conditions. Results are first checked against the collected laboratory scale experimental data especially in what concerning the prediction of the main depressurization variables requested by the QRA procedure (stagnation and orifice pressure and temperature profiles, mass flow rate evolution, total discharge time). A model extension oriented to large scale geometries and different orifice sizes and operative conditions is then proposed. Main discharge parameters are analyzed and their sensitivity to variations in the domain and orifice sizes is assessed with specific light on the relative amounts of dense phase produced and the total discharge time. The mathematical model is then supplemented of some features concerning non-equilibrium phenomena that do not allow for a mere thermodynamic description. Among these the behavior in the spinodal region, the structural entropy increase in the passage across the triple point and the irreversibilities in the phase change mechanisms are investigated. The target is to firstly check if the additional complication is reasonable from the QRA perspective to then move to variations in the release parameters that emerge because of this extended approach. A final section is dedicated to the model application to some real existing CCS and EOR (Ehnanced Oil Recovery) projects worldwide making available the main discharge parameters and profiles for different pipeline lengths and orifice sizes. A specific investigation on the solid CO2 is performed in addition to the collection of useful comprehensive parameters to be used in QRA studies

Associations of clock genes polymorphisms with soft tissue sarcoma susceptibility and prognosis

BACKGROUND: Dysfunction of the circadian clock and polymorphisms of some circadian genes have been linked to cancer development and progression. We investigated the relationship between circadian genes germline variation and susceptibility or prognosis of patients with soft tissue sarcoma. PATIENTS AND METHODS: We considered the 14 single nucleotide polymorphisms (SNPs) of 6 core circadian genes that have a minor allele frequency >\u20095% and that are known to be associated with cancer risk or prognosis. Genotyping was performed by q-PCR. Peripheral blood and clinic-pathological data were available for 162 patients with liposarcoma or leiomyosarcoma and 610 healthy donors. Associations between the selected clock genes polymorphisms and sarcoma susceptibility or prognosis were tested assuming 3 models of inheritance: additive, recessive and dominant. Subgroup analysis based on sarcoma histotype was performed under the additive genetic model. Multivariate logistic regression and multivariate Cox proportional hazard regression analyses were utilized to assess the association between SNPs with patient susceptibility and survival, respectively. Pathway variation analysis was conducted employing the Adaptive Rank Truncated Product method. RESULTS: Six out of the 14 analyzed SNPs were statistically significantly associated with susceptibility or prognosis of soft tissue sarcoma (P <\u20090.05). The present analysis suggested that carriers of the minor allele of the CLOCK polymorphism rs1801260 (C) or of PER2 rs934945 (T) had a reduced predisposition to sarcoma (26% and 35% respectively with the additive model) and liposarcoma (33% and 41% respectively). The minor allele (A) of NPAS2 rs895520 was associated with an increased predisposition to sarcoma of 33% and leiomyosarcoma of 44%. RORA rs339972 C allele was associated with a decreased predisposition to develop sarcoma assuming an additive model (29%) and leiomyosarcoma (36%). PER1 rs3027178 was associated with a reduced predisposition only in liposarcoma subgroup (32%). rs7602358 located upstream PER2 was significantly associated with liposarcoma survival (HR: 1.98; 95% CI 1.02-3.85; P\u2009=\u20090.04). Germline genetic variation in the circadian pathway was associated with the risk of developing soft tissue sarcoma (P\u2009=\u20090.035). CONCLUSIONS: Genetic variation of circadian genes appears to play a role in the determinism of patient susceptibility and prognosis. These findings prompt further studies to fully dissect the molecular mechanisms

Interface fires in built-up areas. A real-case study on the risk assessment of fires interacting with urban domains.

Fire scenarios may pose serious risks and induce severe damages to anthropic structures, activities and business. These can be represented by typical fires in industrial facilities or also atypical scenarios involving differentiated targets as in the case of interface fires. The occasion of the collaboration between our two departments arouse from the EU Interreg Progect CROSSIT SAFER, intended to enhance collaboration between actors and institutions of the Civil Protection for the management of natural disasters in the Italia-Slovenija cross border area. Risk assessment of atypical scenarios requires improved approaches since a multi-risk framework can arise including the interactions between the fire and surrounding domains. An effective hazard investigation and management should therefore include estimations of consequences based on the results of models\u2019 simulation. The present study deals with a preliminary risk assessment methodology applied to fires interacting with an existing urban area. The fire spread is approached through a dedicated tool and a GIS-based system is used to spatially map expected consequences. Starting from these data, a preliminary risk estimation is proposed with the aim of mapping hazardous areas. In this sense, a combined approach based on fire simulation tools and exposure functions is employed. Major risk areas are identified and expected results can be used to support land planning and emergency-related operations

On the effectiveness of mitigation strategies for cryogenic applications

The need for sustainable energy sources, as well as the current energetic crisis involving the majority of markets, has promoted the use of cryogenic liquefaction for the transportation and storage of natural gas (i.e., LNG). To guarantee the development of a robust and safe infrastructure, a complete understanding of the main phenomena occurring at low temperatures is paramount. In this sense, the largest grey areas are the characterization of the combustion at low-initial temperature and the interactions between water and cryogenic liquid. For these reasons, this work presents an experimental campaign on the possible mitigation strategies for the mitigation of consequences related to the accidental release of LNG. Particular emphasis was posed on the direct and indirect effects of water on cryogenic pool fire. The former resulted in a significant increase in the dimensions of fire (∼+50%) and burning rate (∼300%) with respect to the case with no direct contact between water and LNG, whereas the latter generated an abrupt decrease in the measured temperatures (&lt;100 °C). The use of an emergency flare to empty an LNG tank was tested, as well. The spatial distribution of temperature was monitored along with the time to guarantee the safe operability of this equipment in the case of LNG combustion. The explanations for the observed phenomena and trends were provided, allowing for the development of safe procedures for the emergency response related to cryogenic fuels

Integrating the Benefits of Turquoise Hydrogen to Decarbonise High-emission Industry

Total indirect greenhouse gas (GHG) emissions from oil and gas operations today are around 5,200 Mt of carbon dioxide equivalent (CO2-eq) yearly, 15% of total energy sector GHG emissions. Most of these emissions occur due to natural gas leaks. Methane, a much more potent GHG than CO2, is the most significant single component of natural gas and, therefore, of these emissions. Part of these emissions results from routine operations such as flaring and venting, representing both an economic and an environmental issue. Many solutions have been developed to recover and use this natural gas instead of venting and flaring it. Three possibilities were simulated with AVEVA PRO/II, and a preliminary economic assessment was carried out with Guthrie’s method. 30 kmol/hr of natural gas fed was assumed, according to average site data, therefore, small-scale plants are suitable. A first solution based on compression, though requiring high OPEX (> 280 k$/y), produces very low emissions yearly (1,140 t CO2-eq/y). Another possibility is to couple flaring to a microturbine for energy generation, but this solution is both uneconomical and has a high environmental impact (> 10,000 t CO2-eq/y). The last technology analysed is thermal methane pyrolysis. This possibility, often disregarded in environmental studies, involves the production of turquoise hydrogen and carbon black. Although characterised by high capital costs (almost 3 M$), it can reduce gaseous emissions since it stores the carbon part of hydrocarbons in the solid matrix that is formed

Hydrogen Refueling Stations: Prevention and Scenario Management. Large Scale Experimental Investigation of Hydrogen Jet-Fires

Hydrogen is becoming an attractive alternative for energy storage and transportation, because of the elevated energy content per unit of mass and possibility to have zero carbon-emission vehicles. For these reasons, hydrogen's share in global market is expected to grow substantially in the coming years. Today, hydrogen-fueled buses and cars are already available, and several refueling stations are operating in different countries around the world. A key role of the deployment of hydrogen fueled-vehicles is the presence of a widespread network of refueling stations, especially close to residential and industrial areas. This fact poses attention to the safety aspects related to hydrogen, with particular interest to its high flammability that can lead to catastrophic consequences for personnel and equipment. As a matter of fact, hydrogen is a comparatively less safe fuel compared to conventional fuels such as gasoline and diesel. Hydrogen infrastructures are characterized by operating pressure up to 1000 bar that, in case of an unintended loss of containments, produce a highly under expanded turbulent jet. If ignited, this hydrogen jet may give rise to very severe scenarios, mainly related to high temperatures and the oriented flows. As recently suggested by Moradi and Groth (Moradi and Groth, 2019), there is a lack of experimental and on-site data for almost all of the storage and delivery technologies relevant to the hydrogen infrastructures. Experimental data is vital to support model validation, especially in the case of the very peculiar combustion process of hydrogen. In this way, a real-scale experimental campaign is proposed to investigate the main characteristic of the hydrogen jet fire resulting from its rapid fired depressurizations. Focus of the experimental campaign is evaluation of safety distance for person and device (i.e. pressurized tanks) in order to avoid critical conditions and domino effects in real refueling station. Different initial conditions, i.e., storage pressures, are exploited, and the resulting jet across specified orifice is investigated. More specifically, temperatures at various locations are measured through an arrangement of thermocouples. Values up to 1200 °C were obtained in the core of the jet. Moreover, it was found that the recorded temperatures, especially those at the outer portion of the jet, are very sensitive to the initial conditions

Forequarter amputation for local recurrence of sarcoma after previous amputation through the shoulder in a female patient – A case report

Abstract Forequarter amputation is a very demolitive surgical procedure that affects the quality of life and it is performed when the tumour involves the proximal end of homerus and the shoulder. We describe here the case of a female patient with a recurrent dedifferentiated liposarcoma of the upper limb already treated with tumour asportation, isolated limb perfusion and upper limb amputation through the shoulder, who returned to our attention for a recurrence of the sarcoma in the stump. We then performed a forequarter amputation in a previous amputated limb. Since the patient underwent numerous surgical procedures, our last surgical approach was a quite challenging one. To our knowledge, it is the first described case of an interscapular-thoracic disarticulation after a previous amputation to the shoulder

A Therapeutic and Diagnostic Multidisciplinary Pathway for Merkel Cell Carcinoma Patients

Merkel Cell Carcinoma (MCC) is a highly aggressive neuroendocrine neoplasm of the skin. Due to its rarity, the management of MCC is not standardized across centers. In this article, we present the experience of the Veneto region in the North-East of Italy, where a committee of skin cancer experts has proposed a clinical pathway for the diagnosis and treatment of MCC. Putting together the evidence available in the international literature, we outlined the best approach to the management of patients affected with this malignancy step- by- step for each possible clinical situation. Crucial in this pathway is the role of the multidisciplinary team to deal with the lack of robust information on each aspect of the management of this disease

The surgical treatment of non-metastatic melanoma in a Clinical National Melanoma Registry Study Group (CNMR): a retrospective cohort quality improvement study to reduce the morbidity rates

Background: Reproducible, high-quality surgery is a key point in the management of cancer patients. Quality indicators for surgical treatment of melanoma has been presented with benchmarks but data on morbidity are still limited. This study presents the quality indicators on morbidity after surgical treatment for non-metastatic skin melanoma in an Italian registry. Methods: Data were extracted from the Central National Melanoma Registry (CNMR) promoted by the Italian Melanoma Intergroup (IMI). All surgical procedures (WE, SNLB or LFND) for non-metastatic skin melanoma between January 2011 and February 2017 were evaluated for inclusion in the study. Only centers with adequate completeness of information (&gt; 80%) were included in the study. Short-term complications (wound infection, dehiscence, skin graft failure and seroma) were investigated. Results: Wound infection rate was 1.1% (0.4 to 2.7%) in WE, 1.3% (0.7 to 2.5%) in SLNB and 4.1% (2.1 to 8.0%) in LFND. Wound dehiscence rate was 2.0% (0.8 to 5.1%) in WE, 0.9% (0.2 to 3.0%) in SLNB and 2.8% (0.9 to 8.6%) in LFND. Seroma rate was 4.2% (1.5 to 11.1%) in SLNB and 15.1% (4.6 to 39.9%) in LFND. Unreliable information was found on skin graft failure. Conclusions: Our findings contribute to available literature in setting up the recommended standards for melanoma centers, thus improving the quality of surgery offered to patients. A consensus on the core issues around surgical morbidity is needed to provide practical guidance on morbidity prevention and management