With the world’s energy needs projected to rise by 48 percent by 2040 – with natural gas expected to make up for the largest increase from 120 trillion cubic feet (TCF) in 2012 to 203 TCF in 2040 – it seems that a new invention by two United Arab Emirates University (UAEU) professors is more timely than ever.
The world's gas fields are mostly contaminated with carbon dioxide (CO2), hydrogen sulfide (H2S) and other impurities. Current treatment technology for removing the sour toxic compounds, however, mainly relies on large and energy intensive sweetening units to treat the gas to ensure that it meets market standards.
Such a method got Mohamed Al-Marzouqi, Professor of Chemical Engineering at UAEU and director of the University’s Emirates Center for Energy and Environment Research, and Sayed Marzouk, Professor of Chemistry at UAEU, thinking. Together, the duo started exploring alternative membrane-based treatment method.
Al-Marzouqi explains. “We developed a new membrane-based technology to capture carbon dioxide from natural gas which currently is done – or at least mostly done – by what they call a sweetening unit. In one unit, sour gases are captured using some kind of solvent; and in the other unit, the solvent is regenerated for reuse. Now, we use the same technology but instead of using large sweetening units we use a small membrane based treatment to provide an alternative compact technology making it ideal for offshore plants.”
Furthermore, Al-Marzouqi says: “Sweetening units use lots of energy – in fact most of the energy consumption is used for the regeneration of these solvents. Our technology – which relies on large number of small porous polymeric tubes – uses much less solvent, ultimately reducing the amount of energy needed in the regeneration part of the process.”
Reflecting on the project to date, and the professor says the work involved was extensive. Ten years, in fact. “This project started in UAEU with the collaboration of ADGAS and support from Japan Cooperation Center, Petroleum (JCCP).
“In the lab we developed conditions that were similar to what they have in the field – in terms of high temperatures and pressures. A lot of work went into making sure that we not only met the target using a different technology but that we were working in the same conditions.”
“We tried to reduce the solvent usage because our target was not only to see if we could meet the target but to determine how much less solvent we could use. Based on this we could calculate how much energy we could save. Once we were able to get these conditions right, and these were very severe conditions that don’t usually work together – very high temperatures, high pressure and toxic gases – we knew we could take it further.”
It doesn't stop there. While the professors were working on the membrane-based treatment, they noted the high capital and maintenance cost of the commercial hydrogen sulfide and carbon dioxide analyzers.
“Currently the available devices to measure CO2 and H2S are very expensive,” adds Al-Marzouqi who, together with Professor Marzouk, started developing analyzers for measuring the concentrations of both compounds. After several years of intensive research, the duo’s Aha! moment finally came.
“This is smaller, lighter and cheaper to manufacture,” explains Al-Marzouqi. “With this, you can have an analyzer based on a miniature sensor for a fraction of that budget. You just supply the gas stream and measure the concentration.”
The CO2 analyzer is now patented by the Japan Patent Office, while the H2S analyzer is patented by both Japan and the United States Patent Offices.
“We call the analyzer a by-product of the main project but it turned out to be a very sweet by-product,” laughs Al-Marzouqi, who is hoping to bring the analyzer to market soon with support from UAEU.
“UAEU has made innovation a strategic priority and seeks to encourage creativity and innovation that can contribute to strengthening sustainable development and the development of a knowledge economy at local and international levels,” adds Professor Mohamed Albaili, Vice Chancellor at UAEU. “Through promoting innovation the university has established a competitive spirit throughout the scientific research community – and this is not only in line with UAEU’s goals, but in line with the national leadership’s vision of striving for continued excellence and leadership.”
Looking ahead, and Al-Marzouqi says: “I’m continuing on the same project, we are modifying it to make it better. The Emirates Center for Energy and Environment Research itself is working with 20 running projects. Alternative and renewable energy is a very active unit, and this is one of the priorities of the country. We expect the number of running projects in this area to increase.”