Утилизация водорода от электролиза - как?

[SupFanat]

Желательно превратить водород в другое вещество - тоже восстановитель.

Но при этом более компактный - жидкий или твёрдый. Что можно придумать?

 

Лучше всего наверное превратить углекислый газ в жидкое топливо, желательно при не очень жёстких условиях.

Например 2CO₂+6H₂→C₂H₅OH+3H₂O.

 

А то при получении хлората/бромата/иодата электролизом водород всё равно получается как побочный продукт.

[ssch]

Пинены, составная часть скипидара, легко при комнатной температуре на платиновом катализаторе гидрируются до пинанов. Один раз перегнать в вакууме и у вас отличное топливо для ДВС.

[SupFanat]

Возможно ли разработать гидрирование углекислого газа до жидких при нормальных условиях органических соединений?

Например того же этанола. Условия реакции - чем мягче чем лучше.

[ssch]

Уже разработано.

 

Chi, Dinghui; Yang, Hengpan; Du, Yanfang; Lv, Ting; Sui, Guojiao; Wang, Huan; Lu, Jiaxing
RSC Advances, 2014 ,  vol. 4,  # 70  p. 37329 - 37332,4

 

Yu, Shi-Rui; Wang, Xiao-Dong; Huang, Wei
Turkish Journal of Chemistry, 2014 ,  vol. 38,  # 3  p. 381 - 387

 

Murata, Akira; Hori, Yoshio
Bulletin of the Chemical Society of Japan, 1991 ,  vol. 64,  # 1  p. 123 - 127

 

Baussart, Herve; Delobel, Rene; Bras, Michel Le; Leroy, Jean-Marie
Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1987 ,  vol. 83, p. 1711 - 1718

 

Campbell, Gregory A.
Patent:   US2007/282021 A1, 2007 ;
Location in patent: Page/Page column 3; 5-6 ;

 

EXAMPLE 1A water saturated stack gas/air is fed into an Amine absorber column. In the absorber, Diethanolamine (DEA) at a strength of 30percent in water is used as the absorbent. The number of stages and the operating condition of the amine absorber are listed in the tables below. Sweet gas escapes from the top of the column. Rich amine leaves the absorber and moves through a turbo-expander for stepping down its high pressure and getting work out of it. Low pressure rich amine is flashed off in a flash vessel to release off a part of the absorbed CO₂. Rich amine from the bottom of the flash vessel goes to the regenerator via a lean amine/rich amine heat exchanger where it is heated to about 90° C. The number of stages, heat load at the reboiler and the operating condition in the regenerator are changed depending upon the amount of amine flowing and its CO₂ loading. Desorbed CO₂ comes out of the condenser and is sent to the Ethanol synthesis plant. Bottom of the regenerator goes back to the absorber via a cooler. The operating conditions are as follows: Stream Name: Air CO₂ content: 400 ppm Flow rate: 60000 Kgmole/hr Lean amine flow rate: 1874 Kgmole/hr Lean amine temperature: 35° C. Lean amine composition: Net CO₂ Flow from Regenerator: 986 kg/hrHydrogen gas, H₂ is produced using greenhouse gas free based electrical power. Solar energy is used in this example to produce the electrical power. The power system comprises several units comprising a parabolic solar collector, a Stirling engine and an electric generator. Water electrolysis is used to split water into hydrogen and oxygen. An electrolyser is the device used for electrolysis. Water is subjected to electrical power in alkaline electrolysers and the result is hydrogen and oxygen. In the alkaline electrolyser a liquid electrolyte is used-typically a 25percent potassium hydroxide solution.The mixture of CO₂ and H₂ is passed through a heat exchanger and heated to the reaction temperature of up to about 240-260° C. The reaction mixture is passed through a series of 4 reactors with intermediate cooling by generating steam in the process. The catalyst in the reactors is composed of a mixture of Fe-Cu-Zn-AL-K, in a ratio of 1.0:0.53:0.5:2.5:0.75, respectively. The conversion of CO₂ per single pass is 28.5percent. The product contains measurable quantities of alcohols with carbons from 1 to 6. The product stream is 52percent ethanol and the ratio of ethanol to methanol is about 2:1. The product and unconverted reactant mixture then enters the stripper. Unconverted reactants are compressed and recycled back before reactor 5. The stripped-off ethanol goes to a distillation column and is then separated into product ethanol. A small amount of vent gas, about 1 kgmole/hr is released from the condenser of the distillation column. The final ethanol produced in this process is 87percent pure with a flow of 245 kg/hr. The details of the stripper column are: EXAMPLE 4 A water saturated stack gas/air is fed into the amine absorber column. In the absorber, diethanolamine (DEA) at a strength of 30percent in water is used as the absorbent. The number of stages and the operating condition of the amine absorber are listed in the tables below. Sweet gas escapes from the top of the column. Rich amine leaves the absorber and moves through a turbo-expander for stepping down its high pressure and getting work out of it. Low pressure rich amine is flashed off in a flash vessel to release off a part of the absorbed CO₂. Rich amine from the bottom of the flash vessel goes to the regenerator via a lean amine/rich amine heat exchanger where it is heated to about 90° C. The number of stages, heat load at the reboiler and the operating condition in the regenerator are changed depending upon the amount of amine flowing and its CO₂ loading. Desorbed CO₂ comes out from the condenser and is sent to the ethanol synthesis plant. Bottom of the regenerator goes back to the absorber via a cooler. The operating conditions are as follows: Stream Name: Air C0₂ content: 400 ppm Flow rate: 60000 Kgmole/hr Lean amine flow rate: 1874 Kgmole/hr Lean amine temperature: 35° C. Lean amine composition: Net CO₂ Flow from Regenerator: 986 kg/hrHydrogen gas, H₂ is produced using greenhouse gas free process utilizing the reaction of a metal with water. Water is reacted in this case with zinc to split water into hydrogen and zinc oxide. The process is operated at 525° C.The mixture of CO₂ and H₂ is passed through a heat exchanger and heated to the reaction temperature of 240-260° C. The reaction mixture is passed through a series of 4 reactors with intermediate cooling by generating steam in the process. The catalyst in the reactors is composed of a mixture of Fe-Cu-Zn-AL-K, in a ratio of 1.0:0.53:0.5:2.5:0.75, respectively. The conversion of CO₂ per single pass is 28.5percent. The product contains measurable quantities of alcohols with carbons from 1 to 6. The product and unconverted reactant mixture then enters the stripper. Unconverted reactants are compressed and recycled back before reactor-1. The stripped-off ethanol goes to a distillation column and is then separated into product ethanol. A small amount of vent gas, about 1 kgmole/hr is released from the condenser of the distillation column. The final ethanol produced in this process is 87percent pure with a flow of 245 kg/hr.

[SupFanat]

Вроде бы комплекс рутения позволяет гидрировать углекислый газ до метанола в растворе.  

[SupFanat]

На этом тема окончена?

Больше вариантов особо не имеется?

А то без решения вопроса использования водорода электролизёры малополезны. (Закачать в баллон - тоже "использование", но разве это для простых установок?)

Изменено 3 Февраля, 2015 в 02:43 пользователем SupFanat