Mbinu mpya ya kukamata kaboni imebuniwa ili kunasa kaboni dioksidi kutoka kwa uzalishaji wa mafuta ya kisukuku
Uzalishaji wa hewa chafu ni mchangiaji mkubwa zaidi katika mabadiliko ya hali ya hewa. Uzalishaji wa gesi chafuzi muhimu ni matokeo ya ukuaji mkubwa wa viwanda na shughuli za binadamu. Uzalishaji mwingi wa chafu hizi ni za kaboni dioksidi (CO2) from burning of fossil fuels. The total concentration of CO2 in the atmosphere has increased by more than 40 percent ever since the era of industrialization started. This steady increase in greenhouse emissions is warming the sayari in what is termed as ‘ongezeko la joto duniani' kama uigaji wa kompyuta umeonyesha kuwa uzalishaji wa gesi chafu unawajibika kwa ongezeko la wastani wa joto la uso wa dunia baada ya muda kuonyesha 'mabadiliko ya hali ya hewa' kutokana na mabadiliko ya mifumo ya mvua, ukali wa dhoruba, viwango vya bahari n.k. Hivyo, kuendeleza njia zinazofaa za 'kunasa au kunasa. 'kaboni dioksidi kutoka kwa uzalishaji ni kipengele muhimu cha kukabiliana na mabadiliko ya hali ya hewa. Carbon teknolojia ya kukamata imekuwepo kwa miongo kadhaa lakini hivi karibuni imepata umakini zaidi kwa sababu ya maswala ya mazingira.
Mbinu mpya ya kukamata kaboni
Utaratibu wa kawaida wa kunasa kaboni unahusisha kutega na kutenganisha CO2 kutoka kwa mchanganyiko wa gesi, kisha kuisafirisha hadi kwenye hifadhi na kuihifadhi kwa mbali na angahewa kwa kawaida chini ya ardhi. Utaratibu huu ni wa nguvu sana, unahusisha masuala kadhaa ya kiufundi, hatari na mapungufu, kwa mfano, uwezekano mkubwa wa kuvuja kwenye tovuti ya kuhifadhi. Utafiti mpya uliochapishwa katika Chem inaelezea njia mbadala inayoahidi ya kunasa kaboni. Wanasayansi katika Idara ya Nishati Marekani wamebuni mbinu ya kipekee ya kuondoa CO2 kutoka kwa mitambo ya kuzalisha nishati ya makaa ya mawe na mchakato huu unahitaji nishati kidogo kwa asilimia 24 ikilinganishwa na vigezo ambavyo vinatumika kwa sasa katika sekta hii.
Researchers worked on naturally occurring kikaboni compounds called bis-iminoguanidines (BIGs) which have the ability to bind to negatively charged anions as seen inprevious studies. They thought that this particular property of BIGs should also be applicable to bicarbonate anions. So BIGs can act like a sorbent (a substance which collects other molecules) and convert CO2 into solid limestone (calcium carbonate). Soda lime is a mixture of calcium and sodium hydroxides used by scuba divers, submarines and other closed breathing environments to filter exhaled air and prevent any dangerous accumulation of CO2. The air can be then recycled multiple times. For example, rebreathers for scuba divers enables them to stay chini ya maji for long time which is otherwise impossible.
Njia ya kipekee ambayo inahitaji nishati kidogo
Based upon this understanding they developed a CO2 separation cycle which used an aqueous BIG solution. In this particular carbon-capture method they passed flue gas through the solution which caused CO2 molecules to bind to BIG sorbent and this binding would crystallize them into a solid type of kikaboni limestone. When these solids were heated to 120 degrees Celsius, bound CO2 would be released which could then be stored. Since this process occurs at relatively lower temperatures compared to existing carbon-capture methods, the energy required for the process is reduced. And, solid sorbent could be be dissolved again in maji and recycled for reuse.
Teknolojia za sasa za kunasa kaboni zina matatizo mengi kama vile tatizo la uhifadhi, gharama ya juu ya nishati n.k. Suala la msingi ni matumizi ya viyoyozi vya maji ambavyo huyeyuka au kuoza baada ya muda na pia huhitaji angalau asilimia 60 ya jumla ya nishati kwa ajili ya kuvipasha joto ambalo ni la juu sana. juu. Kioevu kigumu katika utafiti wa sasa kilishinda kikomo cha nishati kwa sababu CO2 inanaswa kutoka kwa chumvi iliyoangaziwa ya bicarbonate ambayo ilihitaji karibu asilimia 24 ya nishati kidogo. Pia hakukuwa na upotezaji wa sorbent hata baada ya mizunguko 10 mfululizo. Hitaji hili la chini la nishati linaweza kupunguza gharama za kunasa kaboni na tunapozingatia mabilioni ya tani za CO2, njia hii inaweza kuwa na athari kubwa kwa kufanya uzalishaji wa chafu kuwa mbaya kwa kukamata vya kutosha.
One limitation of this study is the relatively low CO2 capacity and absorption rate which is due to the limited solubility of BIG sorbent in maji. Researchers are looking at combining traditional solvents like amino acids to these BIG sorbents to address this limitation. The current experiment has been done on a small scale in which 99 percent CO2 was removed from exhaust gases. The process needs to be further optimized so that it can be scaled up to capture at least a ton of CO2 every day and from any different types of emissions. The method must be robust in handling contaminations in emissions.The ultimate goal of a carbon capture technology would be todirectly capture CO2 from the atmosphereby using an affordable and energy efficient method.
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Chanzo (s)
Williams N et al. 2019. Nasa CO2 kupitia Dimers za Bicarbonate za Hidrojeni za Fuwele. Chem.
https://doi.org/10.1016/j.chempr.2018.12.025
