This paper aims at reviewing and analyzing the operation and design of a utility flare in an oilfield in the Iraq/Kurdistan region. The flare supports a gas separation unit that separates 100 MMSCFD of natural gas from other liquid compounds in petroleum refining. The actual flare dimensions are 50 m high and 0.6 m diameter and works in summer where the crosswind speed is 9 m/s and a flow of 1.2 MMSCFD of treated natural gas is flaring through it. At the beginning, the flare design was performed using the API-521 recommended approach based on full operating capacity of the unit and composition of the gas to be flared. The API-521 based design resulted in a flare with a 0.76 m diameter and 48.19 m height. The effects of stack height on heat radiation in case of full capacity firing showed that as the flare height increases from 42.34 m to 133.05 m, the heat radiation decreases from 15.8 kW/m^2 to 1.6 kW/m^2 within 45.7 m dimeter. Furthermore, the relation between stack height and heat radiation was studied for the actual firing rate 1.2MMSCFD using simulation, where the results showed that as the stack height increasing from 10 m to 50 m the heat radiation decreasing from over 1000 w/m^2 to around 150 W/m^2. In fact, CFD code C3d was used to analyze flare performance at normal firing condition during summer operation of 1.2 MMSCFD with a flare diameter and height of 50 m and 0.6 m, respectively. The code was able to predict the flame shape and size during actual flare operation. The results of the simulation demonstrated by defining four locations in the domain to measure the average temperatures and emissions, and to calculate the Combustion Efficiency (CE) and Destruction and Removal Efficiency (DRE). These points were 6 m, 8 m, 10 m, 12 m far from the tip on x-axis and at height of 52 m. The results showed that the average temperature at 6 m far from the flare is 658 K and it decreasing to 490 K at 12 m away from the tip. The CO and CO2 also decreased from 7.27E-5 and 0.033 mass% to 4.53E-6 and 0.027 mass%, respectively. Generally, soot formation was low but at points 8 m and 10 m from the tip the soot formation was considerably lower, respectively at 6.16E-5 and 8.71E-5 mass%. The emissions of C1, C2, C3 and C6+ were measured at 7.46E-9, 5.39E-9, 5.13E-9 and 4.35E-9 mass% at 6 m away from the tip. The emissions increased slightly at 8 m and 10 m from the tip but at 12 m they were observed to decrease. The flare CE and DRE were estimated to be 98% and 100%, respectively. Analysis results confirmed that the flare design was safe and the flare operation was highly efficient with very little smoke produced as indicated by the predicted CE and DRE.

Koya city, like any other city in the world, faces a critical environmental problem which is global warming and the increase in the rate of production of gaseous pollutants. This research is involved with the negative effects of private Electrical Power Generators (EPGs) on the environment in Koya City. The environmental pollutants resulted from EPGs were investigated by performing an actual study on land for the number of (EPGs), types, and distribution. Koya city is divided into 18 quarters. The investigation covers a period from 2009 to 2017, included. The production of power was increased due to the increase in the number of generators and supplying hours. The power production in 2009 was 23,850 megawatt (MW) whereas it was 49,635 MW in 2017. The amount of fuel consumed in 2009–2017 was relatively increased from 30,000 to 62,500 barrel/year. The total amount of pollutants was increased by about 108% during the period 2009–2017. The results showed that the most significant increase in pollutants was carbon dioxide (CO2). The annual amount of (CO2) emitted in 2009 was 6588 tons whereas it has increased in 2017–13710 tons. The conclusion of this study was that the highest pollution occurred in the center of Koya City in Nabeel quarter, which represented 22% of the whole pollutants.

Koya city like any other city in the world faces a critical environmental problem which is global warming and the increase in the rate of production of gaseous pollutants. This research is involved with the negative effects of private Electrical Power Generators (EPGs) on the environment in Koya City. The environmental pollutants resulted from EPGs was investigated by performing an actual study on land for a number of (EPGs) and its distribution all over Koya's City strips (total of 18 quarters) supported by statistical studies. The total amount of pollution (due to the annual increasing of power generation capacity) was increased by 130 % between 2009 and 2016, depending on data obtained from the Electricity Directorate in Koya City. The results showed that the most significant increase in pollutants was carbon Dioxide (CO₂). The conclusion of this study was that the highest rate of pollution occurred in the center of the Koya City in Nalee quarter, which represented 14 %, and in nine other quarters the rate of pollution was 7 %. While the lower pollution level occurred in eight other quarters, which represented 3 % of whole pollutants for each strip.

In Iraq, combined cycle gas turbine (CCGT) systems are the only and main process for power generation (electricity). Due to its importance and significance, accurate simulation is crucial for evaluating the process performance under different operation conditions. In this study, DWSIM software, open-source simulation tool, was used for modeling and assessing CCGT performance during part-load circumstances. This software used for its reliability in capturing operational behavior. The methodology consists of simulating CCGT response under the variation of the power by integrating part-load performance equations into DWSIM software. Generally, two cases included in this work; the first case covered a DWSIM simulation during part-load operation using data from previously published works that used Aspen HYSYS. On the other hand, the second case included performing a DWISM simulation using real filed data. The results gained were validated by comparing it with Aspen HYSYS simulation. The comparison between DWSIM and HYSYS showed a 3.8% variation in power generation, a close match in fuel flow, and a maximum variation of 4.36% in gas turbine efficiency. The findings of this work confirm that the DWSIM software is flexible, free, and reliable simulation tool for evaluating CCGT power plant’s performance and operation. In addition, this work presented that this software is suitable for use in both industrial and academic applications due to its performance compared to that of commercial simulators.

Recently, flares have been considered as a major source of air pollution from the petroleum refining industry. The United Nations has instigated an international effort related to the management of flare emissions to reduce the global warming impact related to flaring. Eliminating or removing the need for gas flares is difficult because these devices are generally used as safety devices to allow the combustion of flammable gases in a controlled fashion which supports safe operation. However, reducing flaring is generally possible using well-designed, efficiently operated flare equipment. In general, flare performance can be enhanced following the API-521 methodology and using assist-media including air and steam to achieve smokeless operation. This present work will discuss flare emissions in the petroleum refining industry and a method to manage flare emissions. Moreover, this work will discuss flare combustion efficiency (CE) and destruction and removal efficiency (DRE) in terms of efficient flare operation. This work uses actual operating flare data, published previously, which will be used in this work together with the CFD Code C3d. This code, developed at the USDOE Sandia National Laboratory, is based on a standard LES methodology to conduct transient flare analysis and is used to simulate flare operation to estimate flame shape and emissions produced. In this work, a new air-assisted flare tip design which uses the Coanda effect to improve flare operation was analyzed. This new flare design reduces the emission rate and demonstrates the design’s effectiveness. The analysis considers a flare 39″ high and 6″ diameter in the center of a 4m x 4m x 4m domain. Boundary conditions assume no cross wind and an ambient temperature of 300 K. The initial condition is a hydrostatic pressure profile across the computational domain. In the air-assist simulation, stoichiometric ratio will be a variable, and therefore, more than one case was considered.