Mass Exchange Dynamics of Surface and Subsurface Oil in Shallow-Water Transport

We formulate a model for the mass exchange between oil at and below the sea surface. This is a particularly important aspect of modeling oil spills. Surface and subsurface oil have different chemical and transport characteristics and lumping them together would compromise the accuracy of the resulting model. Without observational or computational constraints, it is thus not possible to quantitatively predict oil spills based upon partial field observations of surface and/or sub-surface oil. The primary challenge in capturing the mass exchange is that the principal mechanisms are on the microscale. This is a serious barrier to developing practical models for oil spills that are capable of addressing questions regarding the fate of oil at the large spatio-temporal scales, as demanded by environmental questions. We use upscaling to propose an environmental-scale model which incorporates the mass exchange between surface and subsurface oil due to oil droplet dynamics, buoyancy effects, and sea surface and subsurface mechanics. While the mass exchange mechanism detailed here is generally applicable to oil transport models, it addresses the modeling needs of a particular to an oil spill model [1]. This transport model is designed to capture oil spills at very large spatio-temporal scales. It accomplishes this goal by specializing to shallow-water environments, in which depth averaging is a perfectly good approximation for the flow, while at the same time retaining mass conservation of oil over the whole oceanic domain.Comment: 18 pages, 6 figure

Air Pollution Simulation From Cirebon Power Plant Activity

Telah dilakukan penelitian simulasi sebaran polutan dari aktivitas PLTU Cirebon dengan menggunakan model gaussian plume. Persamaan gaussian plume digunakan untuk memprediksikan persebaran dan konsentrasi gas polutan di udara. Tujuan dari penelitian ini adalah untuk mengetahui konsentrasi polutan di udara ambien akibat dari aktivitas PLTU dan pemodelan dispersi polutan di udara yang berasal dari dua cerobong asap. Hasil penelitian menunjukkan bahwa konsentrasi maksimum untuk semua parameter masih berada di bawah baku mutu yang telah ditetapkan. Adapun konsentrasi maksimum untuk parameter SOx sebesar 36,89 µg/m3 sedangkan NOx adalah 31,25 µg/m3. Sedangkan simulasi dengan menggunakan dua cerobong asap konsentrasi maksimum SOx sebesar 52,95 µg/m3 dan NOx sebesar 44,86 µg/m3

An inverse Gaussian plume approach for estimating atmospheric pollutant emissions from multiple point sources

A method is developed for estimating the emission rates of contaminants into the atmosphere from multiple point sources using measurements of particulate material deposited at ground level. The approach is based on a Gaussian plume type solution for the advection-diffusion equation with ground-level deposition and given emission sources. This solution to the forward problem is incorporated into an inverse algorithm for estimating the emission rates by means of a linear least squares approach. The results are validated using measured deposition and meteorological data from a large lead-zinc smelting operation in Trail, British Columbia. The algorithm is demonstrated to be robust and capable of generating reasonably accurate estimates of total contaminant emissions over the relatively short distances of interest in this study

Emission inventories from Kuwait petroleum refineries and respective ground level concentration of pollutants in the neighboring residential area

The State of Kuwait has three large refineries, namely, Mina Al Ahmadi Refinery, Mina Abdullah Refinery and Shuaiba Refinery. These refineries process and refine Kuwait Crude Oil through different process units. There are many heaters, boilers and flares that form a part of the complicated equipment which enhance the different petroleum processes. Fuel gas is used as a firing fuel for those heaters and boilers. As a result, stack emissions like SO2, NOx, CO are predominantly present in the flue gases and this study focuses on those emissions and their impact on the surrounding residential area. The area of interest will be Umm Al-Hyman residential area. This study accumulates emission inventories from the three refineries and the respective ground level concentration of the pollutants in the neighboring residential area. It also focuses on the impact of emissions from the refinery operations on the ground level concentrations in the surrounding areas by using the inventory model and latest emission factors to provide accurate emission estimates. The models were developed and the results were verified with the actual data from the area of impact. As a result of the findings of the major pollutants, namely SO2, NOx & CO, it is found that SO2 and CO are not exceeding Kuwait EPA Ambient Air Quality Standards for Residential Areas normally. However, NOx is observed to exceed occasionally. Even though, NOx emissions from refineries sources represented by plume models were much less, there is a consistent increase in the measured NOx. Furthermore, in 2007, the measured hourly, daily and annual NOx concentration exceeded the international standard many times. The increasing trend in NOx is attributed to continuous increase in population and the number of motor vehicles. The study will go further step in recommending engineering solutions and best practices to reduce the pollutants concentrations which will help in the reduction of human health risks and protect the environment

Development and application of a comprehensive methodology for the analysis of global and local emissions of energy systems

The energy sector is a source of economic and social progress, but it is also the main responsible of air pollution resulting from human activity, mainly from the combustion of fossil fuels and bioenergy. The impacts on atmosphere may be divided into global effects, due to change in concentration of greenhouse gases, and regional/local effects, due to the dispersion of SO2, NOx, particulates and other gases. The aim of this thesis is the development and application of a methodology for calculating the emissions in atmosphere associated with energy management interventions. The methodology aims to characterize and quantify the environmental impacts affecting both the local and global scale. The pollutants involving local effects considered in this study are nitrogen oxides and particulate matter. Globally, the emission of greenhouse gases is considered, by quantifying the equivalent CO2 (CO2eq) emitted. The environmental impact of an energy option is quantified in terms of its emission balance, i.e. by comparing the present situation with one (or more) future scenarios. The study at the local scale also considers the dispersion of pollutants using modelling tools. The methodology is applied to two case studies located in the Italian Metropolitan City of Turin, characterized by different application contexts and different scales of operation. The first case study is represented by a system for the production and conversion of biogas and biomethane. The analysis of global emissions considers four different operating scenarios. The results show a CO2 reduction of 1426 t/y for biogas combustion in full cogeneration mode (generation of both heat and electricity). Biomethane for transports scenario provides a similar result (1379 t/y). If biogas combustion with partial cogeneration is considered (generation of electricity only), the CO2 balance approaches to zero. The evaluation of local impacts is made with two different dispersion models. The application of an Octave-based Gaussian model provides an average increase of concentration both for NOx and TSP, in the order of units of g/m3. The results of CALPUFF model simulations show a slight decrease of concentration in the order of 10-2 g/m3. The second case study consists of a potential extension of the district heating network in the urban area of Turin. The production of local emissions is calculated considering the operation of the main power plants in response to the estimated heat demand. Avoided emissions are calculated simulating the heat production of centralized residential heaters. The results of CALPUFF model simulations show a potential reduction of NOx average concentration between 1 and 6 g/m3. The results of global emissions show an unfavorable balance in the order of 104 t/y of CO2, that varies depending on the assumptions on the emission factors of the power units. A comprehensive final discussion is reported after the analysis of the two case studies. The calculation of two indicators (the “thermal benefit vs. local emission indicator” and the “local to global emission ratio”) is also included to discuss a possible standardization of the proposed methodology. This study provides important information on the effects on air quality resulting from the modification of the energetic management of an area or settlement. The employed methodology is consistent and comprehensive in identifying the potential optimal solutions for energy production and management, as well as identifying the consequences to a given scenario under an environmental point of view

Atmospheric emissions of one pulp and paper mill. Contribution to the air quality of Viana do Castelo

One of the most sensitive environmental impact of the pulp and paper mills is associated with the atmospheric pollution namely with sulphur compounds, particulate matter and nitrogen oxides. The study undertaken aimed to evaluate the influence of one pulp and paper mill to the air quality of a Portuguese city located in the vicinity. A range of numerical models were used to produce the concentration maps: the ADMS- Urban model for the pollutants dispersion; the Hills model to calculate air flow and turbulence over complex terrain, including the effects of variable surface roughness and EPER data (The European Pollutant Emission Register) to estimate the emissions factors

Location Optimization of a Coal Power Plant to Balance Coal Supply and Electric Transmission Costs Against Plant’s Emission Exposure

This research is focused on developing a location analysis methodology that can minimize the pollutant exposure to the public while ensuring that the combined costs of electric transmission losses and coal logistics are minimized. Coal power plants will provide a critical contribution towards meeting electricity demands for various nations in the foreseeable future. The site selection for a new coal power plant is extremely important from an investment point of view. The operational costs for running a coal power plant can be minimized by a combined emphasis on placing a coal power plant near coal mines as well as customers. However, this business strategy has produced a detrimental effect on the environment in various nations around the globe. In this new era of rapid urbanization, increased electric utility demand and environmental consciousness; the location analysis for a new coal power plant needs to include both the investment and environmental considerations. To provide a general background of the issue, a detailed literature review was conducted on the topics of Environmental Protection Agency (EPA) pollutant dispersion models, health effects due to exposure to pollutants, coal logistics, electric transmission technical losses, and location analysis models. Next, a methodology, based on dynamic programming, was formulated by combing the EPA’s pollutant dispersion models with the minimum spanning tree algorithm to calculate the combined costs of coal logistics and electric transmission losses for a given set of coal mines and customers present on a network. The subsequent simulation was developed based on the proposed methodology. The simulation successful ly proved that the selection of a site on a grid map provided the minimum of the combined cost of electric line losses and coal transportation, and no customers were exposed to pollutant concentration above the declared threshold for that pollutant. The resultant emission’s data were validated via comparing against the EPA Screen3 and Japanese Ministry of Economy, Trade, and Industry (METI-LIS) models. The minimum spanning tree for electric transmission lines and coal transportation were validated using R-software

Total flare emission inventories of crude oil production operations from Kuwait oilfields

The State of Kuwait is one of the major oil-producing countries with its economy solely and directly dependent on export of crude oil and its refined products. Kuwait Oil Company (KOC) is responsible for the exploration, development and production of marketable quality hydrocarbon, Although KOC has a very strict flaring policy and practices, emission of some gaseous pollutants to the atmosphere; particularly from the flaring of normally undesirable effluent streams and excess gases. This study provides a comprehensive account and estimates of all emissions of primary pollutants associated with flaring activities from Kuwait Oilfields. This inventory provides the monthly emissions for a decade starting for year 1997 of air pollutants: NOx, SO2, CO, CO2, methane and non-methane hydrocarbons. The emissions are generated from various point sources and aggregated to obtain total pollutants load of ambient air in and around oilfields. The emissions of pollutants from the flaring associated with all types of operations in the oilfields, gathering centres (GC), booster stations (BS), tank areas and other oil production related emission activities. [Continues.

Impact of emissions results from power generation on the air quality of selected urban areas in Kuwait

Air pollution in urban areas is a problem affecting many countries in the world and has important implications for health and environmental management. However, air quality prediction plays an important role in the controlling air pollution problem. Air-quality models are also extensively used in all aspects of air pollution control and to predict spatial and temporal dispersion of pollutants in the atmosphere. The main objectives of this work are to provide an overview of the pollutant levels and their trends in the study area (Rabia) and to predict the ground level concentrations of sulphur dioxide (SO2) and nitrogen oxide (NOx) mainly emitted from power generation stations by using Source Complex model for Short-term Dispersion (ISCST 4.5) for years 2001 and 2004. The hourly air pollutants concentrations were measured continuously by fixed ambient air stations located over the polyclinics in Rabia area in Capital Governorate in the State of Kuwait. [Continues.