{"id":5574,"date":"2018-12-14T12:12:14","date_gmt":"2018-12-14T12:12:14","guid":{"rendered":"http:\/\/ecm.eng.auburn.edu\/wp\/emag\/?p=5574"},"modified":"2018-12-18T20:28:33","modified_gmt":"2018-12-18T20:28:33","slug":"sour-power","status":"publish","type":"post","link":"https:\/\/ecm.eng.auburn.edu\/wp\/emag\/?p=5574","title":{"rendered":"Sour Power"},"content":{"rendered":"
\"Sourcat<\/a>
Traditional methods of desulfurization generally cost significantly more than a dollar per thousand cubic feet of natural gas. The approach that Tatarchuk\u2019s group is developing cleans the gas up for 13-17 cents per thousand cubic feet.<\/figcaption><\/figure>\n

Bruce Tatarchuk, who has long been recognized for his work in catalysis and microfiber technologies, is taking a new direction in his research that looks to bold frontiers in energy. His latest effort is literally taking place at the end of a long road \u2013 in the scrublands of Texas where oil and gas fields reign supreme.<\/p>\n

It\u2019s where Tatarchuk and his team are running a pilot project that aims to reclaim natural gas that would otherwise go unused because it is \u2018sour\u2019 in the vernacular of the industry. Too high in sulfur content, it is either flared, vented or capped at the well, a shutting-in process that generally costs more than $500,000 per well after $2 million is spent drilling it.<\/p>\n

\u201cThe presence of hydrogen sulfide or mercaptans (organic sulfur compounds) in natural gas is what causes the problem here,\u201d Tatarchuk explained. \u201cWe remove the sulfur in a way that is much more efficient than traditional approaches, by using a patented selective oxidative catalyst that directly transforms 97 percent of sulfur contaminants into elemental sulfur.\u201d<\/p>\n

Tatarchuk notes that traditional methods of desulfurization generally cost significantly more than a dollar per thousand cubic feet of natural gas. The approach that his group is developing cleans the gas up for 13-17 cents per thousand cubic feet.<\/p>\n

At the heart of the process is a skid-mounted pilot unit that the Auburn team installed about an hour from San Antonio, Texas, in the Eagle Ford Shale gas and oil field. Called the Sourcat 100 MSCFD System, it was demonstrated for a 540-hour run that culminated in October. Its oxidative sulfur removal process converted up to 97 percent of the hydrogen sulfide in the gas stream into elemental sulfur.<\/p>\n

\u201cThis process resulted in the production of pipeline-spec natural gas,\u201d Tatarchuk said. \u201cWe pulled in gas with sulfur concentrations ranging from 125 ppm (parts per million) to 2,000 ppm and successfully treated it to an outlet gas sulfur level of less than 4 ppm. It works even when the level of sulfur in the gas varied widely, which is often not the case with other technologies.\u201d<\/p>\n

\"Bruce<\/a>
Bruce Tatarchuk, center, discusses the technology surrounding a demonstration site located in Texas about an hour out of San Anto- nio in the Eagle Ford shale formation. Pictured from left are Mario Eden, chair of the Department of Chemical Engineering; resident engineer Kylie Webb; Brian Wright, director of commercialization in Auburn\u2019s Office of Innovation Advancement and Commercialization; Tatarchuk; Steve Taylor, associate dean of research in the College of Engineering, and resident engineer Harrison Wright.<\/figcaption><\/figure>\n

Tatarchuk, who is widely recognized for his career-long work in catalysis, also noted that the catalyst used in the process is cost-effective, and robust, showing no signs of deactivation when it experiences feeds with high levels of condensable hydrocarbons.<\/p>\n

\u201cWe also gave it real-world testing involving multiple shutdowns that are caused by external events,\u201d Tatarchuk added. \u201cThese kinds of stop-and-go cold starts are a true test of the efficacy of the system, and even under these conditions we experienced up to 97 percent removal of H2S (hydrogen sulfide).<\/p>\n

Tatarchuk points as well to the flexibility of the system, which can be placed at gathering points, compressor stations, sales points and even directly at the well head. It also offers remote monitoring capabilities and emergency shutdowns with alarm notifications.<\/p>\n

\u201cWe have two to three Auburn engineers on site at the pilot plant that is staffed 24\/7, but I always like to point out that what they are monitoring can be done off-site as well, and will be in the future,\u201d Tatarchuk said. \u201cI always like to say that one of our co-op students can literally monitor the process from his dorm room.\u201d<\/p>\n

The pilot site is essentially a tenth-scale rendition that has proven the success of the process.<\/p>\n

\u201cWhen we scale this to a commercial level we will be able to produce gas at a far lower cost, and in smaller volumes, than competing processes, so it means that shut-in, flared, vented or unproduced gas can be brought to market,\u201d Tatarchuk explained. \u201cThis represents as much as 30 percent of the gas associated with the Eagle Ford and Bakken formations.\u201d<\/p>\n

To put it in perspective, he noted that a city the size of the Washington, D.C., metro area could \u201crun off of that amount of gas ten times over.\u201d<\/p>\n

In addition to the jobs and energy security that would be a part of the economic potential, Tatarchuk points to environmental benefits as well.<\/p>\n

\"<\/a>
Resident engineers Harrison Wright and Kylie Webb, both \u201915 graduates in chemical engineering, monitor the pilot plant\u2019s technology from an on-site trailer that contains both office space and living quarters.The technology can also be monitored and adjusted off-site.<\/figcaption><\/figure>\n

In terms of global warming, vented methane absorbs infrared radiation at night 20 times more strongly than CO2, he points out. But the primary benefits will be economic in nature, with new electric generation capacity generally moving to gas from coal and nuclear.<\/p>\n

\u201cThe challenge in this scenario is cleaning up \u2018sour\u2019 gas to the point that it can be produced and moved,\u201d Tatarchuk said. \u201cAnd to do so economically, which is where we come in. We are looking beyond the current technology of $25 million scrubbers, and we are not using large-scale plants and chemical scavengers with our process. We can make pipeline-spec gas in a single pass, using a robust catalyst.\u201d He adds that the Sourcat system is modular and more easily moved from site to site as wells move through their production cycles.<\/p>\n

\u201cIt means better access to what the industry calls stranded or remote wells, because their output level doesn\u2019t justify building pipelines that can handle the corrosive nature of gas with either low or high sulfur content. I like to call them \u2018hindered\u2019 wells, however, because there is a fix to this situation that our technology addresses.\u201d<\/p>\n

Finally, Tatarchuk noted, that in addition to economic and environmental factors, this new process would bring added stability to the natural gas grid, which is only a step away from the electric grid.<\/p>\n

\u201cUnlike liquid fuels, natural gas cannot be stored, so this technology provides a new technology that can assist the energy grid through a higher level of efficiency at a lower cost,\u201d he concludes. \u201cIt\u2019s a win-win situation for all involved.\u201d<\/p>\n