Clean wa­ter for thirsty cities

MENA re­gion’s grow­ing need for de­sali­nated wa­ter must be met through use of re­new­able en­ergy forms, say ex­perts

Arab News - - Spotlight - Ju­mana Khamis Dubai

For all its hy­dro­car­bon wealth, the Mid­dle East and North Africa (MENA) re­gion suf­fers from a fun­da­men­tal scarcity, namely of un­der­ground re­new­able fresh­wa­ter re­sources.

The re­gion, one of the most wa­ter­scarce places on the planet, has some of the low­est wa­ter-avail­abil­ity lev­els on a per-capita ba­sis. De­sali­na­tion de­pen­dence in the re­gion is there­fore high, even though de­sali­na­tion pro­cesses have a di­rect im­pact on the is­sue of sus­tain­abil­ity and re­new­able-en­ergy port­fo­lios of these coun­tries.

Data from the In­ter­na­tional En­ergy Agency (IEA) shows that two-thirds of the wa­ter pro­duced from sea­wa­ter de­sali­na­tion in the re­gion is, at present, from fos­sil fuel-based ther­mal tech­nolo­gies. The rest is de­rived from mem­brane-based de­sali­na­tion, which re­lies heav­ily on elec­tric­ity pro­duced by burn­ing nat­u­ral gas. Cur­rently, the Mid­dle East ac­counts for roughly 90 per­cent of the ther­mal en­ergy used for de­sali­na­tion world­wide, with the UAE and Saudi Ara­bia at the helm. To sat­isfy the drink­ing-wa­ter re­quire­ments of the re­gion’s 400 mil­lion-plus peo­ple, a high reliance on non-con­ven­tional wa­ter re­sources such as de­sali­na­tion and the re­use of treated waste­water is “im­per­a­tive,” Waleed Zubari, co­or­di­na­tor of the Wa­ter Re­sources Man­age­ment Pro­gram at the Col­lege of Grad­u­ate Stud­ies in Manama, Bahrain, told Arab News.

In fact, de­sali­na­tion be­comes the only vi­able source for drink­ing wa­ter as the re­use of treated waste­water is in­creas­ingly be­ing used for agri­cul­ture and land­scap­ing, he said.

But the widely used de­sali­na­tion process based on fos­sil­fuel tech­nol­ogy is an eco­nomic and en­vi­ron­men­tal bur­den for coun­tries with a high reliance on hy­dro­car­bon rev­enues.

“Can we have sus­tain­able wa­ter sup­ply by de­sali­na­tion? Al­ter­na­tively, can we have sus­tain­able de­sali­na­tion?” asked Zubari. De­sali­na­tion, par­tic­u­larly co-pro­duc­tion tech­nolo­gies that pro­duce elec­tric­ity and wa­ter as by-prod­ucts, is an “en­ergy in­ten­sive” process that claims at “alarm­ing rates” a siz­able por­tion of the en­ergy re­sources in the Gulf Co­op­er­a­tion Coun­cil (GCC) coun­tries, he said.

De­spite a “tremen­dous de­crease” in the cost of de­sali­na­tion over the decades, the prac­tice is caus­ing the fast de­ple­tion of the re­gion’s en­ergy re­sources and threat­en­ing the very source of some coun­tries’ in­come, he added.

The way for­ward is to look beyond the de­ploy­ment of non-re­new­able re­sources such as fos­sil fu­els to pro­duce de­sali­nated wa­ter.

Ac­cord­ing to a spe­cial re­port in the World En­ergy Out­look se­ries, “Out­look for Pro­ducer Economies,” for re­source-rich economies “the high reliance on hy­dro­car­bon rev­enues, cou­pled with the risk of fluc­tu­a­tions in prices, cre­ates well­known pit­falls.”

How­ever, the re­port noted, in re­sponse to chang­ing con­di­tions and the grow­ing em­pha­sis on re­new­ables, “many ma­jor pro­duc­ers are dis­play­ing a re­newed com­mit­ment to re­form and eco­nomic di­ver­si­fi­ca­tion.” The World En­ergy Out­look se­ries ex­am­ined six re­sourcede­pen­dent economies that are pil­lars of global en­ergy sup­ply: Iraq, Nige­ria, Rus­sia, Saudi Ara­bia, the UAE and Venezuela. It as­sessed how the prospects for these ma­jor oil- and gas-pro­duc­ing economies will evolve in var­i­ous sce­nar­ios by 2040.

The pro­duc­tion of de­sali­nated sea­wa­ter in the Mid­dle East, the re­port said, is pro­jected to in­crease al­most 14-fold dur­ing this pe­riod.

Glob­ally, too, wa­ter de­sali­na­tion as a source of fresh­wa­ter sup­ply has be­come a ma­jor pri­or­ity due to rapid pop­u­la­tion growth, poor wa­ter-man­age­ment prac­tices and global warm­ing. The lat­ter is be­lieved to be de­creas­ing an­nual rain­fall by 20-40 cm.

To meet these chal­lenges, there is “a con­certed shift to­wards mem­brane-based de­sali­na­tion,” the re­port said.

Mem­brane-based tech­nolo­gies use elec­tric­ity as the driver

Sorek

Ras Al Khair

Tawee­lah for de­sali­na­tion. For ex­am­ple, “re­verse os­mo­sis (RO) tech­nolo­gies” in mem­brane-based pro­cesses ac­count for 60 per­cent of the ca­pac­ity in Oman and roughly half the ca­pac­ity in Saudi Ara­bia.

The Saudi state-owned Wa­ter and Elec­tric­ity Co. is cur­rently devel­op­ing the Rabigh 3 project, which is ex­pected to come on stream in 2021, with the po­ten­tial to be­come one of the largest mem­brane-based sea­wa­ter-de­sali­na­tion plants in the world.

The need of the hour, ac­cord­ing to Zubari, is to achieve a de­gree of sus­tain­abil­ity for de­sali­na­tion, which he said de­pends on coun­tries “min­i­miz­ing associated costs and max­i­miz­ing de­sali­na­tion’s added value in the re­gion.” He be­lieves this can be done through in­vest­ment and own­er­ship of de­sali­na­tion tech­nolo­gies, and urges gov­ern­ments to in­crease wa­ter con­ser­va­tion and de­crease wa­ter waste and loss.

“One of the main op­tions is the devel­op­ment of re­new­able en­er­gies to power de­sali­na­tion plants, par­tic­u­larly so­lar en­ergy, in which the GCC coun­tries have a com­par­a­tive ad­van­tage,” Zubari said.

His view is sec­onded by Dr. Emad Yousef Alh­seinat, as­sis­tant pro­fes­sor of chem­i­cal en­gi­neer­ing at the UAE’s Khal­ifa Univer­sity. En­ergy sus­tain­abil­ity is key to achiev­ing sus­tain­able de­sali­na­tion, said Alh­seinat, adding that to achieve this ob­jec­tive, GCC coun­tries have to di­ver­sity their en­ergy sources to in­clude re­new­able forms such as so­lar, wind and wave.

“And to get sus­tain­able de­sali­na­tion pro­cesses, we need to in­vest in devel­op­ing de­sali­na­tion tech­nolo­gies that are com­pat­i­ble with re­new­able en­ergy,” he said. Ac­cord­ing to Alh­seinat, de­sali­na­tion pro­cesses, whether clas­si­fied as ther­mal or mem­brane-based, re­quire large amounts of en­ergy to pro­duce fresh wa­ter.

For ex­am­ple, “in RO pro­cesses, there is a need to reach a pres­sure of 50-80 bar to de­sali­nate salty wa­ter,” he said, adding that this “high pres­sure” re­quires big pumps of wa­ter that con­sume large amounts of en­ergy.

In short, he said, this process is “en­ergy in­ten­sive, mean­ing high­cost, low-eco­nomic im­pact and high-car­bon foot­print.”

An­other way to im­prove de­sali­na­tion in the re­gion, added Alh­seinat, is to al­lo­cate more in­vest­ments to re­search and devel­op­ment in or­der to en­hance the ef­fi­ciency of cur­rent de­sali­na­tion plants.

“This can be done through adopt­ing state-of-the-art op­ti­miza­tion tools such as data min­ing and ma­chine learn­ing,” he said. Ap­ply­ing ar­ti­fi­cial in­tel­li­gence to an­a­lyze de­sali­na­tion data could also be a promis­ing ap­proach, ac­cord­ing to Alh­seinat.

An­other im­por­tant as­pect of the de­sali­na­tion de­bate is its im­pact on the ecosys­tem. In­ject­ing the hy­per­saline brine, or the waste stream of de­sali­na­tion plants, into the ground is harm­ful to the marine en­vi­ron­ment, par­tic­u­larly in the Ara­bian Gulf, said Alh­seinat. He be­lieves a “zero-liq­uid dis­charge ap­proach” could be de­vel­oped to re­duce the en­vi­ron­men­tal im­pact.

High­light­ing the de­pen­dence of the Mid­dle East, in­deed the world, on de­sali­na­tion tech­nolo­gies is the fact that there ex­ist ap­prox­i­mately 18,000 com­mer­cial de­sali­na­tion plants in op­er­a­tion in­ter­na­tion­ally, with to­tal in­stalled pro­duc­tion ca­pac­ity of 86.55 mil­lion cu­bic me­ters per day (m3/day) or 2,870 mil­lion gal­lons per day (MGD). “About 44 per­cent of this ca­pac­ity (37 mil­lion m3/day) or 9,860 MGD is lo­cated in the Mid­dle East and North Africa. De­sali­na­tion in this re­gion is pro­jected to grow at a rate of 7-9 per­cent per year,” Alh­seinat said.

While it may be the so­lu­tion to fresh­wa­ter short­age in the re­gion, “so far there is no ex­pec­ta­tion of a di­rect eco­nomic value from it,” he added.

“De­sali­na­tion in the GCC is con­tribut­ing in­di­rectly to the eco­nomic growth of the re­gion even though it is con­sid­ered as a cost in the coun­tries’ en­ergy bill.” At the end of the day, Alh­seinat said, as­sur­ing the avail­abil­ity of fresh­wa­ter is a must for any coun­try to have sus­tain­able eco­nomic growth.

AFP

A de­sali­na­tion plant in the Omani port city of Sur, south of the cap­i­tal Mus­cat. Wa­ter for res­i­dents and busi­nesses from the plant im­proves the qual­ity of life for some 600,000 peo­ple.

AFP

(232.4MGD) Shuaiba 3, Saudi Ara­bia: (158.5MGD) Rabigh 3 IWP, Saudi Ara­bia: (156.1MGD) Fu­jairah 2, UAE: De­sali­na­tion, par­tic­u­larly co-pro­duc­tion tech­nolo­gies that pro­duce elec­tric­ity and wa­ter as by-prod­ucts, is an en­ergy in­ten­sive process. (240.1MGD) Tawee­lah, UAE:

Can we have sus­tain­able wa­ter sup­ply by de­sali­na­tion? Al­ter­na­tively, can we have sus­tain­able de­sali­na­tion? Waleed Zubari Co­or­di­na­tor, Wa­ter Re­sources Man­age­ment Pro­gram, Col­lege of Grad­u­ate Stud­ies in Manama, Bahrain

De­sali­nated wa­ter pro­duc­tion in the Mid­dle East is ex­pected to grow al­most 14-fold by 2040. World En­ergy Out­look

(164.8MGD) Sorek, Is­rael: (273.7MGD) Ras Al Khair, Saudi Ara­bia:

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