[chiralSPO]

Look, it's clear that you need to do a lot more learning before tackling this subject. Many of the questions here indicate that you still don't grasp some very basic principles of chemistry and circuits--there's no shame in not knowing something, that's what learning is for. You appear to have the motivation and the time to dedicate to study. I highly encourage you to find an educational medium that suits you (formal classes, online courses, self-lead, etc.), but I don't think you can expect forum participants to provide this education: most of us are happy to chat and entertain new ideas and share some of our knowledge, but none of us has signed up to be your personal tutor.

[Bored chemist]

Look, it's clear that you need to do a lot more learning before tackling this subject. Many of the questions here indicate that you still don't grasp some very basic principles of chemistry and circuits--there's no shame in not knowing something, that's what learning is for. You appear to have the motivation and the time to dedicate to study. I highly encourage you to find an educational medium that suits you (formal classes, online courses, self-lead, etc.), but I don't think you can expect forum participants to provide this education: most of us are happy to chat and entertain new ideas and share some of our knowledge, but none of us has signed up to be your personal tutor.

The problem is that he wants us to post a book worth of material here rather than doing the sensible thing and going to somewhere like this
https://www.khanacademy.org/

[scientizscht (OP)]

OK I had a look but not everything is explained on youtube.

If you have a homogeneous solution of many different ions, like Na+, Cl, H+, SO4- etc, can you put two different selective electrodes and separate the electrodes with a semipermeable membrane and generate electricity?

So in theory, if you have an electrode that oxidises one ion and reduces another ion, then you can generate electricity right? And you don't need a gradient.

[Bored chemist]

if you have an electrode that oxidises one ion and reduces another ion,

Then the ions would react.

https://www.khanacademy.org/

[scientizscht (OP)]

A pH=1 equals to +342mV and a pH=5 equals to +114mV. So you cannot produce energy from that?

[chiralSPO]

A pH=1 equals to +342mV and a pH=5 equals to +114mV. So you cannot produce energy from that?

No where in this thread is anybody claiming that energy cannot be harvested from a pH gradient (obviously it can!)

The general thrust of the answer is yeah, but not enough to be useful.

It is technically possible for me to heat my house by burning the lint that accumulates in my belly button each day. It just won't be able to heat my house very much.

[acsinuk]

Trying to make a liquid flow battery is something the US is looking into.  They are looking into ferrocene, metallcene and other electrolytes but nothing that can compete with a lead acid battery has as yet been developed as far as I know.

[scientizscht (OP)]

A pH=1 equals to +342mV and a pH=5 equals to +114mV. So you cannot produce energy from that?

No where in this thread is anybody claiming that energy cannot be harvested from a pH gradient (obviously it can!)

The general thrust of the answer is yeah, but not enough to be useful.

It is technically possible for me to heat my house by burning the lint that accumulates in my belly button each day. It just won't be able to heat my house very much.

OK but how exactly? What are the available methods?

It doesn't matter if it's not very efficient as it can be used to power something small like a pH sensor.

[chiralSPO]

It doesn't matter if it's not very efficient as it can be used to power something small like a pH sensor.

It doesn't power the pH sensor (my electronic pH meters require batteries or a power cord). The sensor works by "feeling" the difference in potential.

OK but how exactly? What are the available methods?

We already said that you need to learn more of the fundamentals before you can understand how this can work. And there is no way you're going to get people to provide a list of available methods.

[acsinuk]

If you have a homogeneous solution of many different ions, like Na+, Cl, H+, SO4- etc, can you put two different selective electrodes and separate the electrodes with a semipermeable membrane and generate electricity?
OP's quote above is interesting as you can produce chlorine gas on the positive and hydrogen gas on the negative electrode if you apply a 12 volt battery to a salt NaCl cell.  The membrane in my case was an unglazed flower pot which stopped the chlorine from getting at the water and making NaOH alkaline solution which is not useful to chlorinate swimming pools.  But whether you can reverse the process to make a battery  I am not sure?

[scientizscht (OP)]

It seems like this violates the second thermodynamics law.

[Bored chemist]

It seems like this violates the second thermodynamics law.

And yet it works, so it's clearly not a breach of the laws of thermodynamics.