Tackling the Methane Quandary: Curbing Emissions from Control Valves

In the wake of Eni's strategy to curb fugitive emissions - in particular methane – an innovative control valve (Clarke Shutter Valve) has been deployed and tested in an Italian Eni facility. This shutter type valve is capable of reducing the fugitive emissions by more than 90%, as well as greatly curbing purchase costs, thanks to an innovative design in bonnet and regulating mechanism. In order to assess the real potentiality of the innovation, four Fisher globe valves and one Fisher V-ball were substituted with the Shutter Valves on different hydrocarbon streams of the Trecate facility (Piedmont), in particular on streams containing oil, gas and corrosive fluids. The valves were monitored for more than a year and fugitive emissions tests have been performed to detect and estimate methane leak rates. Since this represented a first deployment of this technology in Europe, a thorough analysis and technology validation of the valves has been performed. A successful installation and start-up were performed in 3 days by Eni's staff at in February of 2020. The valves were fully operational after the installation and to date no issues have been reported. In order to monitor the valves performances of flow control, continuous data collection on each valve has been implemented, and the analysis performed showed that all valves behave correctly as to Eni's standards. A fugitive emission test that has been performed at the end of 2020 with a certified portable FID/PID analyzer displayed that no methane emissions were detected from the valves. Lastly the one year and half long technology validation concluded that the Shutter Valves are a valid technology for curbing methane emissions from the Oil and Gas plants, and that suggested to qualify the company as Eni partner for control valves. This deployment and field tests, as well as the technological assessment performed by Eni's professionals showed the potentiality of this new type of valves in reducing the methane emissions from the petroleum industry. Understanding the potentiality of intrinsically carbon neutral technology is a crucial step for the mitigation of greenhouse gases emissions and towards the creation of a more environmentally friendly industry.

Fugitive Emission Monitoring System Using Land-Based Sensors for Industrial Applications

Metal-oxide based emission detection sensors are typically used for point measurements of hydrocarbon emissions. They are low-cost sensors and can be used for continuous monitoring of emissions. This paper describes an analytical framework that uses time series data from a collection of such sensors deployed at a customer site, along with weather conditions, to detect anomalies in emission data, identify possible emission sources and estimate the leak rate from fugitive emissions. The analytical framework also comprises an optimization module that helps in determining the optimal number of sensors required and their potential location at a customer site. The paper discusses results of the different steps in the analytical framework obtained using concentration data generated using numerical simulations and obtained through controlled leak field tests.

VOCs Fugitive Emission Characteristics and Health Risk Assessment from Typical Plywood Industry in the Yangtze River Delta Region, China

Volatile organic compounds (VOCs) emissions from the plywood manufacturing industry in China have received concerns during recent years. A total of 115 VOCs were measured in the adhesive-making, adhesive-coating, and hot-pressing workshops of the plywood manufacturing industry to investigate fugitive emission characteristics of VOCs and assess their health risks to workers. The average concentration of total VOCs in workshops of the plywood manufacturing industry is 467 ± 359 μg/m3, whereas the value for ambient air is 81.4 μg/m3. For specific processes, the adhesive-coating and hot-pressing processes show higher VOCs concentrations (501 μg/m3–519 μg/m3) than the adhesive-making process (340 μg/m3). Formaldehyde, ethyl acetate, and dichloromethane are the three most abundant VOCs in workshops, with relative contributions to total VOCs of 55.9–63.1%, 4.3–11.0%, and 1.7–4.4%, respectively. For ozone formation potential (OFP) of VOCs, formaldehyde is the largest contributor (86.1%), followed by toluene, xylenes, and propanal. The non-cancer toxic risks (HI) and cancer risks of total VOCs (T-LCR) for three processes are calculated as 2.93–3.94 and 2.86–4.17 × 10−4 using the US EPA recommended methods, both significantly higher than threshold values (1.0 for HI and 10−4 for LCR), suggesting the highly toxic and cancer risks to workers. Formaldehyde contributes 68.1–78.2% and 91.4–93.9% of HI and T-LCR, respectively. The designed risk reduction scheme of VOCs based on air ventilation suggests that air ventilation rates of formaldehyde need to reach 4–5 times in 8 h in three processes to reduce T-LCR to 10−5. These results are useful for developing VOCs control measures and evaluating VOCs occupational health risk for workers in the plywood manufacturing industry.

General Metal to Metal Static Seals Leak Tightness Overview - R&D Processes, FEA and Tests and Further Code Implementation

Latest development in oil and gas industry is focused on higher pressure and temperature. In addition, standard oil and gas components are more frequent adapted to the other applications like aerospace, food processing, renewable energy. For those conditions, tightness is even more critical than before. In the existing codes the requirements for different tightness classes can be find as well as detailed fugitive emission test descriptions. However, the complete design methodology for HPHT seal solution is still missing. There is no engineering procedure/methodology in the code which will link the design concept, R&D process to the prototype and real tests results. The method which will predict tightness for each size and each configuration/condition is not there. Therefore, there is an urgent need to understand the leakage phenomena and describe it by simplified and safe engineering method. Method, which will connect the design concept with real behavior and be in agreement (or conservative) with test results. By having such method, it will be possible to understand better the sealing mechanism in the existing solutions as well as designing new robust, simple, and cheap (optimized) solutions. There are some more or less accurate methods/rules which are already existing in the supplier companies. There is also more and more research about the continuum flow between two surfaces in contact. Based on those sources in this paper we will present the concept for metal to metal sealing solution designing methodology which can be implemented for future revision of the designing codes. The method which can be used simply and effectively and help to understand the current designs and further R&Ds. Presented here design concept, will be described based on example. The example will go through the process from design concept to the real component tightness test.

Characteristics of Volatile Organic Compound Leaks from Equipment Components: A Study of the Pharmaceutical Industry in China

Leak detection and repair (LDAR) plays an important role in controlling the fugitive emission of volatile organic compound (VOC) from chemical enterprises. At present, many policies and standards issued in China have set clear requirements for implementing LDAR in the pharmaceutical industry. In this study, the LDAR work of nine typical pharmaceutical enterprises was selected for analysis to allow investigation of the characteristics of VOC emissions from leaking equipment components. Some suggestions for controlling VOC are proposed to provide a reference for managing the fugitive emissions of VOC from pharmaceutical enterprises. The results showed that the number of equipment components used by the pharmaceutical enterprises ranged from several thousand to more than 20,000, which is lower than that in oil refining and coal chemical enterprises. The predominant leaky component was the flange, which accounted for 56.31% of the total, followed by connectors (21.51%) and valves (18.53%). Light liquid medium components accounted for the largest proportion of equipment (52.83%) on average, followed by gas medium components (45.52%, on average). Heavy liquid medium components, which are rarely used in pharmaceuticals, accounted for only 1.65%. The average leak ratio of the components in the pharmaceutical industry was approximately 0.99%. The leak ratio of the open-ended line was much higher than that of other types of components, reaching an average of 5.00%, while that value was only 0.92% for the flange, despite the numbers and proportion of them that were in use. The total annual VOC leakage from the nine pharmaceutical enterprises studied in this work was 20.11 tons, with an average of 2.23 tons per enterprise and an average of 0.22 kg/a per equipment component. Flanges, connectors, and valves were the top three contributors to leakage, generating 39.17%, 38.72%, and 16.79% of the total, respectively, and a total proportion of 94.68%. Although the number of pumps accounted for only 0.15% of the components, it generated 1.94% of the leakage. In terms of different production processes, the greatest unit product leakage came from the bulk production of chemicals used for pharmaceuticals, reaching 0.085 t/a. The production from traditional Chinese medicine enterprises was the lowest (0.011 t/a), which was only 12.80% of the leakage from the bulk production of chemicals for drugs. The leakage of VOC from the equipment components in the nine enterprises was reduced, to varying degrees, using LDAR. The overall reduction ratio was between 23.55% and 67.72%, with an average of 44.02%. The reduction in leakage was relatively significant after the implementation of LDAR; however, there is still room for improvement. Pharmaceutical enterprises should improve their implementation of LDAR and reduce VOC leakage by reducing the number of inaccessible components used and increasing the repair ratio of leaky components. Controlling the source of component leakage, which should be emphasized, can be realized by cutting down the number of components used, adopting low-leakage equipment, and putting anti-leakage measures in place.

Performance evaluation of two pot raised mud improved cookstove

Biomass cookstove is widely used in the rural areas of Nepal for cooking and space heating. Its thermal and emission performance keeps importance environmentally, economically and socially. Chimney operated two pot raised mud Improved Cookstove (ICS) is one of Nepal’s most promoted cookstoves. The goal of this study is to evaluate the thermal and emission performance. Thermal and emission performance has been obtained by water boiling test and emission parameters have been measured by using Laboratory Emissions Monitoring System (LEMS). The thermal efficiency of cookstove has been improved from 17.99% to 24.7 % i.e. Tier 1 to 2 with the fabrication of appropriate material and accessories. Similarly total emission performance has been found in Tier 1 and fugitive emission performance has been found in Tier 5. Experimental results of thermal efficiency and fugitive emission complied with the performance target of the cookstove.