ОңТҮстік қазақстан медицина академиясы, хабаршы №4 942, 2021 жыл, том 2
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| Hydrogen from Coal
: Coal contains hydrogen, and techniques are being developed to sequester hydrogen and carbon. Nevertheless, coal mining pollutes and despoils the landscape, and burning coal produces many harmful emissions. Bio-Hydrogen : Certain species of green algae produce hydrogen in the presence of sunlight. Researchers manipulated the photosynthetic process of spinach plants to produce hydrogen. But these biological means of hydrogen production, like the photoelectrolytic process described above, are known only as immature lab experiments. Intense research persists to better understand ways to improve these hydrogen production methods. Biohydrogen : Apart from the above mentioned technologies, the conversion route from biomass to hydrogen gains on interest, as it is a pathway based on renewable energy that can therefore contribute to the reduction of GHG. The conversion routes for hydrogen from biomass are therefore described below. There are currently two possible production routes for biohydrogen, the gasification of solid biomass and the digestion of (usually water rich) biomass, both with following purifying and reforming of the produced syngas to hydrogen. For both conversion routes there is a strong competition to the direct use of biomass. Using biomass gasification , hydrogen-rich biomass sources converts to synthesis gas when heated in a controlled atmosphere. This synthesis gas (see chapter 7.2.1) primarily consists of carbon monoxide (CO), carbon dioxide (CO 2 ), and hydrogen (H 2 ). It is often composed of several compounds from which the H 2 must be extracted afterwards. Gasification can be conducted using a variety of low, medium or high- temperature methods. These methods differ in several aspects, including required pre-treatment and post- gasification treatment. Gasification technology has been under intensive development in recent times. Large- scale demonstration facilities have been tested and commercial units are starting worldwide. Nevertheless, the barriers for biomass gasification have been economic rather than technical. If biomass gasification to hydrogen is combined with carbon sequestration, biomass could even serve as a measure for returning CO 2 from the atmosphere into the earth .The other method of gaining hydrogen from biomass is the жүктеу/скачать 3,39 Mb. Достарыңызбен бөлісу:
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