Recovery Hydrogen sulphide from Oil Refinery an enviroeconomic study Essay

Recovery Hydrogen sulphide from Oil Refinery an enviroeconomic study - Essay Example Additionally, the iron sulfide can cause upsets in treating systems and plugging in disposal wells. Aside from its corrosive nature, H2S is also a very toxic and very flammable gas. At low levels, H2S has a "rotten egg" smell. At levels of 100 ppm, H2S will paralyze the olfactory system, making it appear odorless. At levels above 700 ppm, H2S can kill instantly. To add to the threat this creates, H2S is heavier than air, allowing it to creep along the surface where it becomes a potentially life threatening, explosive hazard. Therefore it is extremely important to extract this compound from refineries for safety of humans and expensive machinery. However, Hydrogen Sulphide also has some significant uses. The most important industrial use of hydrogen sulfide is as a source of about 25% of the world production of elemental sulphur. The manufacturing process is based on burning about 1/3 of hydrogen sulfide to sulphur dioxide, then letting the resulting SO2 react with H2S. Other uses are in metallurgy for the preparation of metallic sulfides. It also finds use in preparation of phosphors and oil additives, in separation of metals, removal of metallic impurities, and in organic chemical synthesis. Hydrogen sulfide is also used in nuclear engineering, in the Girdler Sulfide process of manufacturing heavy water. The primary source of H2S is the Desulfovibrio sulfide reducing bacteria (SRB). SRBs reduce naturally occurring sulfate found in oilfield waters to hydrogen sulfide, which in turn reacts with iron to form iron sulfide. They are especially efficient in low-oxygen environments, such as in swamps and standing waters. Some other anaerobic bacteria liberate hydrogen sulfide when they digest sulfur-containing amino acids. Hydrogen Sulphide can be created anywhere where sulphur comes in contact with organic material at high temperatures. Processes for Hydrogen Sulphide recovery The most obvious method to avoid creation of Hydrogen Sulphide is to eliminate the sulphate from water prior to its injection. This can be done by using a nanofiltration membrane which removes all particles greater than one one-thousands of a micron resulting in high quality injection water free of silica and bacterial materials thereby insuring continued injection rates reflective of initial reservoir conditions.This process is very cost effective because it reduces the cost related to sour gas and oil treatment or dedicated "sour safe" pipelines and allows use of less costly metallurgy for the operation due to reduced stress cracking and corrosion. It also reduces the potential for necessary addition equipment on a platform with limited space and weight capacities. Another method for removing Hydrogen Sulphide is by caustic washing. Caustic treating (sweetening) removes all the hydrogen sulphide and convert most of the mercaptans to disulphides. Chlorine is also used to control odor and for H2S control. Continuous chlorination is a widely used and effective method for oxidizing hydrogen sulfide, especially if the water pH is 6.0-8.0. Chlorine is usually administered as sodium hypochlorite, which reacts with sulfide, hydrogen sulfide, and bisulfates to form compounds that do not cause foul taste or odors. Other oxidizing agents besides chlorine can be added to the water to oxidize H2S. These include hydrogen peroxide, potassium

Distance Education Research Paper Example | Topics and Well Written Essays - 1250 words

Distance Education - Research Paper Example It is therefore a vital concept that serves the interest of the people of all categories, both full time and part time students, who may also be engaged in other aspects of life such as working, or even domestic responsibilities, thus they may not be able to attend to a classroom setting. The change in the social, economic and technological conditions have brought about the need for educational advancement, considering that the more the society advances in the technological, social and economic spheres, the higher the demand for educational attainment and advancement. Therefore, the concept â€Å"is emerging as an increasingly important component of higher education† (Bradford, 1999). It has opened an opportunity that can be exploited by those who have always had the desire to advance their education, but were limited by the traditional concept of attending classrooms. This opportunity is even more crucial to the disabled people, who are well served through Distance Education, as opposed to attending physical classrooms, which proves a great challenge for them (Barnard-Brak, Paton, & Sulak, n.d.). Additionally, Distance Education has made it possible for â€Å"Adults who work full time, family people, and people from remote countries all over the world† to access education, while they â€Å"would otherwise never even dream of it† (Bozorgmanesh, 2011). Despite all these benefits as provided by Distance Education, there are numerous challenges that are associated with this modern concept. Therefore, this discussion seeks to critically assess the concept of Distance Education, with a focus on advancing the argument that Distance Education is not an effective mode of Education acquisition. Discussion First, the mode of offering instructions highly determines how effective learning will be for students. Therefore, it is highly unlikely that technology, the means through which Distance Education is offered, can replace the instructional offering made by the teachers in a classroom setting. For example, the stakeholders and the teachers of Eagle County, CO, school district opposed â€Å"replacing face-to-face instructors with a digital option they argued would not be as rich or as meaningful† (Quillen, 2012). It is easier for teachers issuing direct instructions to the students, to assess whether students are clearly understanding the instructions given, since the absorption of instructions is not only assessable through the performance of a student in a test, but also through the observable behavior of such a student. While learning in a classroom setting offers an opportunity for the teacher to assess how well the students have internalized the instructions, the concept of Distance Education does not provide such a valuable opportunity, since the instructional offering through Distance Education is limited to online communications and conversations, which are not as effective and convenient as face-to-face instructi ons (Bradford, 1999). Distance Education could be beneficial due to its budget efficiency possibilities, where an institution can effectively reduce the number of staff and still reach the same number of students as would happen with a large number of teachers in a classroom setting (Mayadas, Bourne, & Bacsich, 2009). However, the issue is that the quality of the education obtained by the large number of studen