What is Nitrogen Fixation? What is artificial nitrogen fixation? Here s an example.

Definition: The process in which molecular nitrogen is catalyzed into ammonia by nitrogen-fixing organisms (such as various nitrogen-fixing bacteria) nitrogen-fixing organisms in nature. Artificial nitrogen fixation is usually used in the industry to synthesize ammonia with H2 and N2 under catalyst, high temperature and high pressure Chemical Equation:

N2 + 3H2 = (HPHT catalyst) 2NH3 Recently, two Greek chemists, George Marnellos and Michael Chaelstoukides of the Aristotel University in Thessaloniki, have invented a new method for the synthesis of ammonia (Science, 2OCT 1998, p98). At atmospheric pressure, hydrogen and nitrogen diluted with helium are respectively passed into an electrolytic cell heated to 570 with strontium-cerium-yttrium-perovskite porous ceramics (SCY) as solid electrolytes, and are converted into ammonia by catalysis of porous palladium polycrystalline films covering the inner and outer surfaces of the solid electrolyte, with a conversion rate of 78. Comparison: Nearly a century of Haber ammonia synthesis process typically has a conversion rate of 10 to 15 !

They used ** gas chromatography to detect the gas entering and leaving the electrolytic cell, and estimated the yield of ammonia by using the pH change caused by HCl absorption, which confirmed that increasing the partial pressure of nitrogen was ineffective in improving the conversion rate; Although increasing the current and temperature increases the transfer speed of protons in SCY, the conductivity of SCY is limited by temperature, and the temperature increase accelerates the decomposition of ammonia.

The process of converting free nitrogen in the air into nitrogen-containing compounds is called nitrogen fixation.

The process of converting free nitrogen in the air into nitrogen-containing compounds is called nitrogen fixation. Biological nitrogen fixation is a special physiological function of nitrogen-fixing microorganisms, and there are nearly 50 genera of microorganisms known to have nitrogen-fixing effects, including bacteria, actinomycetes and cyanobacteria (i.e., cyanobacteria).

They differ greatly in their lifestyles and types of nitrogen fixation, but they all have nitrogenase enzymes in their cells. The nitrogenases of different nitrogen-fixing microorganisms are composed of molybdenum ferritin and ferritin. Nitrogenase must catalyze the reaction under anaerobic conditions, i.e. at low redox conditions.

Biological nitrogen fixation:

The process of nitrogen fixation is complex and not fully understood. The total reaction of nitrogen-fixing microorganisms can be expressed in the following short formula:

According to the relationship between nitrogen-fixing microorganisms and higher plants, they can be divided into autogenous nitrogen-fixing bacteria, symbiotic nitrogen-fixing bacteria and combined nitrogen-fixing bacteria. The nitrogen fixation carried out by it is called autogenous nitrogen fixation, symbiotic nitrogen fixation or combined nitrogen fixation. In addition, there are organisms such as soybeans, which also have a nitrogen fixation effect.

Nitrogen fixation is the process by which molecular nitrogen is reduced to ammonia and other nitrogen-containing compounds. There are two ways to fix nitrogen (N2) in nature: one is abiotic nitrogen fixation, that is, nitrogen fixation through lightning, high-temperature discharge, etc., so that little nitride is formed; The second is biological nitrogen fixation, that is, the process of reducing molecular nitrogen to ammonia in living organisms.

More than 90% of the molecular nitrogen in the atmosphere is reduced to ammonia by the action of nitrogen-fixing microorganisms.

The process of turning nitrogen in the free state (elemental N2) into a chemical state.

It is to turn the nitrogen in the air into a compound and fix it.

Compounds that turn N2 into nitrogen are called nitrogen fixation.

The three pathways and equations for nitrogen fixation are as follows:

1. Natural nitrogen fixation: nitrogen and oxygen in the atmosphere will be synthesized into NO at high temperature or lightning discharge, and the equation is 2NO+O2==2NO2.

2. Artificial nitrogen fixation: industrially use N2 and Chenchai H2 as raw materials to produce ammonia, equation: N2+3H2==2NH3 (high temperature and high pressure, catalyst).

3. Biological nitrogen fixation: The rhizobia in the roots of some leguminous plants can convert the free N2 in the atmosphere into NH4+, which is absorbed by plants.

Nitrogen fixation:

The process of converting free nitrogen from air aging into synthetic nitrogen is called nitrogen fixation. Artificial nitrogen fixationFor a long time, there was an expectation that food crops in farmland would have the same nitrogen fixation capacity as legumes, in order to reduce dependence on chemical fertilizers.

In the 70s, nitrogen fixation between bacteria was first realized, mainly in the synthesis of ammonia artificial nitrogen fixation (in industry, H2 and N2 are usually used to synthesize ammonia under catalyst, high temperature and high pressure, chemical equation: N2 + 3H2 = (high temperature and high pressure catalyst) 2NH3). All nitrogenous chemical fertilizers are also mainly made from ammonia processing.

It is called this pietrophic method of synthetic ammonia"Haber-Bosch"This is a major achievement of artificial nitrogen fixation technology of world significance. It is the first milestone in chemical production to achieve high temperature, high pressure and catalytic reaction. Ammonia is made from air, coal and water, making it the most economical method of artificial nitrogen fixation, thus ending the history of mankind relying exclusively on natural nitrogen fertilizers.

1. Artificial nitrogen fixation is mainly for biological nitrogen fixation, through chemical methods, the preparation of substances similar to biological "nitrogen-fixing bacteria", so that the nitrogen in the air reacts with water and carbon dioxide at room temperature and pressure, and is converted into ammonia nitrogen or ammonium nitrogen, and then realizes the artificial synthesis of a large number of proteins, etc., and finally realizes the factory production of protein food.

2. Since the beginning of this century, the global crop yield per unit area has been increasing, and to a certain extent, it depends on the continuous increase in the application of nitrogen fertilizers. The increase in crop yields achieved by relying on nitrogen fertilizers actually comes at the cost of consuming energy and polluting the environment. The nitrogen content in the atmosphere is close to 80%, but this nitrogen is not directly absorbed and utilized by higher plants.

It has been 112 years since the discovery of the symbiotic formation of leguminous plants and rhizobia and the phenomenon of nitrogen fixation in tumors, and the first scientist to try to synthesize ammonia has been 131 years. The prospects for artificial nitrogen fixation are endless. This will significantly increase the grain production of the developing countries that send friends.

This will be a blessing to mankind. However, the ecological problems caused by artificial nitrogen fixation are also becoming more and more prominent. The greenhouse benefits due to the increase in N2O (laughing gas) should not be underestimated.

It absorbs long waves 200 times more than carbon dioxide. Promoting organic agriculture to reduce nitrogen fertilizer consumption is more in line with our sustainable development path.

The term nitrogen fixation is defined as the conversion of nitrogen in the air into ammonia or other nitrogen-containing organic matter that plants can absorb and utilize through the action of microorganisms.

The term nitrogen fixation is defined as the conversion of nitrogen in the air into ammonia or other nitrogen-containing organic matter that plants can absorb and utilize through the action of microorganisms. The structure is:

Solid (fully enclosed structure) nitrogen (semi-enclosed structure). The part of speech is: noun.

The phonetic pronunciation is: 晌纳 Pinyin is: gùdàn.

The specific explanation of nitrogen fixation is blind, we will introduce it to you through the following aspects:

1. Online explanation [click here to view the details of the plan].

Nitrogen fixation is the process by which free nitrogen in the air is converted into synthetic nitrogen, which is called nitrogen fixation

Idioms about nitrogen fixation.

The deep ditch is solid, the foundation is solid, the root is solid, the wall is solid, the name of the clear field is solid, I am solid, if it is solid, it is not clear, if it is solid, it is deep, and the key will be solidified.

Words about nitrogen fixation.

It is indeed unstoppable, and the key is solid, because it is certainly incomprehensible, and the wall is clear, and the fortress and stubbornness are firmly entrenched.

The process of converting free nitrogen into synthetic nitrogen, that is, the process of converting free nitrogen in the air into synthetic nitrogen, is called nitrogen fixation.

Nitrogen fixation can be divided into artificial nitrogen fixation and biological nitrogen fixation.

The first is the loss of artificial nitrogen fixation, which has long been expected to have the same nitrogen fixation capacity as legumes in the field to reduce dependence on chemical fertilizers. Nitrogen fixation among bacteria was first achieved in the 70sArtificial nitrogen fixation is mainly achieved in the synthesis of ammonia (H2 and N2 are usually used in industry to synthesize ammonia under catalyst, high temperature and high pressure, chemical equation:

N2 + 3H2 = (HPHT catalyst) 2NH3). All nitrogen-containing chemical fertilizers are also mainly made from ammonia processing.

Flow diagram of artificial nitrogen fixation.

The second is natural imitation nitrogen fixation, lightning can convert nitrogen in the air into nitric oxide, and a lightning can produce 80 1500kg of nitric oxide. It is also a natural nitrogen fixation. However, natural nitrogen fixation is far from meeting the needs of agricultural production.

The lightning on the right is natural nitrogen fixation.