Electrochemical reduction device and method for manufacturing hydride of aromatic compound

Patent metadata

Field	Value
Publication number	US-2016010223-A1
Application number	US-201514864069-A
Country	US
Kind code	A1
Filing date	Sep 24, 2015
Priority date	Mar 29, 2013
Publication date	Jan 14, 2016
Grant date	—

Abstract

An electrochemical reduction device includes an electrode unit, a power control unit, an organic material storage tank, a concentration measurement unit, a water storage tank, a gas-water separation unit, and a control unit. The electrode unit includes an electrolyte membrane, a reduction electrode, and an oxygen evolving electrode. The control unit controls the power control unit so as to satisfy a relation of V HER −V allow ≦V CA ≦V TRR when the potential at a reversible hydrogen electrode, the standard redox potential of the aromatic compound, and the potential of the reduction electrode are expressed as V HER , V TRR , and V CA , respectively. V allow is adjusted according to the concentration of the aromatic compound measured by the concentration measurement unit.

First claim

1 . An electrochemical reduction device comprising:
an electrode unit configured to include an electrolyte membrane having ionic conductivity, a reduction electrode that is provided on one side of the electrolyte membrane and that contains a reduction catalyst for hydrogenating at least one benzene ring of an aromatic compound, and an oxygen evolving electrode that is provided on the other side of the electrolyte membrane; a power control unit that applies a voltage Va between the reduction electrode and the oxygen evolving electrode; a concentration measurement unit that measures a concentration of an aromatic compound to be supplied to the reduction electrode; a control unit that controls the power control unit so as to satisfy a relation of V HER −V allow ≦V CA ≦V TRR when a potential at a reversible hydrogen electrode, a standard redox potential of the aromatic compound, a potential of the reduction electrode, and a potential difference for setting a lower limit potential used for determining a lower limit acceptable potential of the potential V CA are expressed as V HER , V TRR , V CA , and V allow , respectively; and a lower limit potential setting unit that determines a lower limit of the potential V CA by adjusting the potential difference V allow for setting the lower limit potential according to the concentration of the aromatic compound measured by the concentration measurement unit.

2 . The electrochemical reduction device according to claim 1 , wherein the lower limit potential setting unit increases an absolute value of the potential difference V allow for setting the lower limit potential when the concentration of the aromatic compound is decreased.

3 . The electrochemical reduction device according to claim 1 , the electrochemical reduction device further comprising:
a reference electrode that is arranged to be in contact with the electrolyte membrane and to be electrically isolated from the reduction electrode and the oxygen evolving electrode and that is held at a reference electrode potential V Ref ; and a voltage detection unit that detects a potential difference ΔV CA between the reference electrode and the reduction electrode, wherein the control unit acquires the potential V CA of the reduction electrode based on the potential difference ΔV CA and the reference electrode potential V Ref .

4 . The electrochemical reduction device according to claim 3 , wherein the control unit changes a voltage Va, and controls the potential V CA of the reduction electrode to be the potential in a predetermined range.

5 . The electrochemical reduction device according to claim 4 , wherein the control unit controls the power control unit so as to satisfy Va≦(V OER −V CA ) when an oxygen evolving equilibrium potential in an electrolysis of water is expressed as V OER .

6 . The electrochemical reduction device according to claim 3 , wherein the reference electrode is arranged on a side that is provided with the reduction electrode on the electrolyte membrane.

7 . An electrochemical reduction device comprising:
a plurality of electrode units configured to include an electrolyte membrane having ionic conductivity, a reduction electrode that is provided on one side of the electrolyte membrane and that contains a reduction catalyst for hydrogenating at least one benzene ring of an aromatic compound, and an oxygen evolving electrode that is provided on the other side of the electrolyte membrane; a power control unit that applies a voltage Va (i) (here, i is a sign for distinguishing individual electrode units, and the same as the following) between the oxygen evolving electrode and the reduction electrode of each of the electrode units; a raw material supply device that allows the aromatic compound to be passed through the reduction electrodes of the respective electrode units in order; a concentration measurement unit that measures a concentration M (i) of an aromatic compound to be supplied to the reduction electrode of each of the electrode units; a control unit that controls the power control unit so as to satisfy a relation of V HER −V allow (i)≦V CA ≦V TRR when a potential at a reversible hydrogen electrode, a standard redox potential of the aromatic compound, a potential of the reduction electrode, and a potential difference for setting a lower limit potential used for determining a lower limit acceptable potential of the potential V CA are expressed as V HER , V TRR , V CA , and V allow (i), respectively; and a lower limit potential setting unit that determines a lower limit of the potential V CA by adjusting the potential difference V allow (i) for setting the lower limit potential according to the concentration of the aromatic compound measured by the concentration measurement unit, wherein when until the concentration M (i) reaches a concentration lower limit value that is set for each of the electrode units, the hydrogenation of at least one benzene ring of the aromatic compound is proceeded in each of the electrode units to make the concentration M (i) to be the concentration lower limit value that is set for each of the electrode units, the aromatic compound is transferred to the electrode units of the downstream side to be subjected to each of hydrogenations.

8 . The electrochemical reduction device according to claim 7 , wherein the lower limit potential setting unit increases an absolute value of the potential difference V allow (i) for setting the lower limit potential when the concentration of the aromatic compound is decreased.

9 . The electrochemical reduction device according to claim 7 , the electrochemical reduction device further comprising:
a plurality of reference electrodes that are arranged to be in contact with an electrolyte membrane of each of electrolysis layers included in the plural electrode units and to be electrically isolated from the reduction electrode and the oxygen evolving electrode; and a voltage detection unit that detects a potential difference ΔV CA (i) between the reference electrode and the reduction electrode, wherein the control unit acquires the potential V CA (i) of the reduction electrode based on the potential difference ΔV CA (i) and the reference electrode potential V Ref (i).

10 . The electrochemical reduction device according to claim 9 , wherein the control unit changes a voltage Va (i), and controls the potential V CA (i) of the reduction electrode of each of the electrode units to be the potential in a predetermined range.

11 . The electrochemical reduction device according to claim 10 , wherein the control unit controls the power control unit so as to satisfy Va (i)≧(V OER −V CA ) when an oxygen evolving equilibrium potential in an electrolysis of water is expressed as V OER .

12 . The electrochemical reduction device according to claim 9 , wherein the reference electrode is arranged on the side that is provided with the reduction electrode in the electrolysis membrane.

13 . A method for manufacturing a hydride of an aromatic compound, the method comprising:
introducing an aromatic compound to the reduction electrode side of the electrode unit; circulating water or a humidified gas to the oxygen evolving electrode side; and hydrogenating at least one benzene ring of the aromatic compound introduced to the reduction electrode side, by using the electrochemical reduction device according to claim 1 .

14 . The method for manufacturing a hydride of an aromatic compound according to claim 13 , wherein the aromatic compound to be introduced to the reduction electrode side is introduced to the reduction electrode side in a liquid state

Assignees

• Jx Nippon Oil & Energy Corp

Inventors

• Sato Yasushi
• Miyoshi Kota
• Nakagawa Kojiro
• Kobori Yoshihiro

Classifications

• C25B13/04

  characterised by the material · CPC title

• C25B15/02 Primary

  Process control or regulation · CPC title

• C25B11/0415

  Chemistry & Metallurgy · mapped topic

• C25B9/18

  Chemistry & Metallurgy · mapped topic

• C25B11/0478

  Chemistry & Metallurgy · mapped topic