The Lemon Fool

Spet0789 wrote:I’m not sure that coal gas (which I was aware of) is what most people have in mind when they think of the modern hydrogen economy. As I said, the problems with leaks arise when hydrogen is at higher pressures. Because of its low specific energy, most of the modern applications do require these pressures.

You might like to read https://funscience.in/calorific-value-o ... industries.

This will tell you that hydrogen has by far the highest calorific value of any gas.

Table of calorific value of fuels
Serial No.                          Fuel            Calorific value
                              1.    Hydrogen        150 KJ/g       
                              2.    Methane         55 KJ/g        
                              3.    LPG             50 KJ/g        
                              4.    Kerosene oil    48 KJ/g        
                              5.    Charcoal        33 KJ/g        
                              6.    Wood            17 KJ/g

It also has the lowest density, which means that the calorific value of a Nm3 is lower. So 22.4Nm3 of Hydrogen contains just over 2kg, whereas the value for Methane is about 16kg.

TJH

tjh290633 wrote:

Spet0789 wrote:I’m not sure that coal gas (which I was aware of) is what most people have in mind when they think of the modern hydrogen economy. As I said, the problems with leaks arise when hydrogen is at higher pressures. Because of its low specific energy, most of the modern applications do require these pressures.

You might like to read https://funscience.in/calorific-value-o ... industries.

This will tell you that hydrogen has by far the highest calorific value of any gas.

Table of calorific value of fuels
Serial No.                          Fuel            Calorific value
                              1.    Hydrogen        150 KJ/g       
                              2.    Methane         55 KJ/g        
                              3.    LPG             50 KJ/g        
                              4.    Kerosene oil    48 KJ/g        
                              5.    Charcoal        33 KJ/g        
                              6.    Wood            17 KJ/g

It also has the lowest density, which means that the calorific value of a Nm3 is lower. So 22.4Nm3 of Hydrogen contains just over 2kg, whereas the value for Methane is about 16kg.

TJH

That’s exactly the point. From the figures above, you need almost three times the volume of hydrogen as methane for a given amount of energy, hence the need to compress it. Compared with other energy sources, even worse.

I haven’t checked how good your website source is, but I did read it (perhaps you didn’t?) and note it says that:

“The storage and transportation of hydrogen gas from one place to another is very difficult.”

Which is precisely what I am saying and you are disputing.

Spet0789 wrote:]

That’s exactly the point. From the figures above, you need almost three times the volume of hydrogen as methane for a given amount of energy, hence the need to compress it.

Off the top of my head here, but I think it’d be between five and a half to six times the volume of hydrogen cf methane.

GrahamPlatt wrote:

Spet0789 wrote:]

That’s exactly the point. From the figures above, you need almost three times the volume of hydrogen as methane for a given amount of energy, hence the need to compress it.

Off the top of my head here, but I think it’d be between five and a half to six times the volume of hydrogen cf methane.

Not as much as that. You have to multiply the weight by the CV to make the comparison.

Hydrogen 2*150=300
Methane 16*55= 880

So on a volume basis about 3 times.

TJH

Spet0789 wrote:I haven’t checked how good your website source is, but I did read it (perhaps you didn’t?) and note it says that:

“The storage and transportation of hydrogen gas from one place to another is very difficult.”

Which is precisely what I am saying and you are disputing.

Of course I read it. I was merely correcting your false assertion.

TJH

tjh290633 wrote:

GrahamPlatt wrote:

Spet0789 wrote:]

That’s exactly the point. From the figures above, you need almost three times the volume of hydrogen as methane for a given amount of energy, hence the need to compress it.

Off the top of my head here, but I think it’d be between five and a half to six times the volume of hydrogen cf methane.

Not as much as that. You have to multiply the weight by the CV to make the comparison.

Hydrogen 2*150=300
Methane 16*55= 880

So on a volume basis about 3 times.

TJH

I was speaking of volumes. Methane has a MW of 16, H is 1. So a cubic meter of methane weighs 16 times that of a cubic meter of Hydrogen. Ah, hang on, it’s H2 in its gaseous state... 8 times then. Then you divide by the relative CVs, ~3:1. So yes, Spet was right.

The basic problem with State aid is that the people who ultimately make the decisions are not qualified to do so.
Which is rather our fault, as we elect them, and we give them our money, and they put it into ...... a defunct satellite company.

V8

88V8 wrote:The basic problem with State aid is that the people who ultimately make the decisions are not qualified to do so.
Which is rather our fault, as we elect them, and we give them our money, and they put it into ...... a defunct satellite company.

V8

And.. was it snow ploughs or water cannon?

88V8 wrote:The basic problem with State aid is that the people who ultimately make the decisions are not qualified to do so.
Which is rather our fault, as we elect them, and we give them our money, and they put it into ...... a defunct satellite company.

V8

Hmm...

I have to say that I'm neither a politician or a bank manager. But re. State Aid surely a set of policies and procedures is all that's needed? I don't imagine that either BJ or DC were ever really going to hand pick the individual companies, but rather enable the creation of the necessary administrative framework.

I'm at a loss as to why State Aid for firms in need of capital is any different than getting a business loan from a bank or £££ from VC, except that maybe the State Aid capital, would be

1. more generous
2. lower interest
3. be less short termist than VC

Matt

TheMotorcycleBoy wrote: But re. State Aid surely a set of policies and procedures is all that's needed? I don't imagine that either BJ or DC were ever really going to hand pick the individual companies, but rather enable the creation of the necessary administrative framework.

I'm at a loss as to why State Aid for firms in need of capital is any different than getting a business loan from a bank or £££ from VC, except that maybe the State Aid capital, would be

1. more generous
2. lower interest
3. be less short termist than VC

There are two ways for the state to assist businesses. One is through the effective taxation system and to have things like R&D tax credits. In that situation the state is not picking winners and losers.

The other is for someone to decide which companies to assist out of a budget of assistance. I first met this on Birmingham City Council where the Committee of Councillors approved or rejected reports prepared by Council Employees.

That is where the state (in that case the local authority) decides which companies to support.

Big transactions will have political approval by ministers or other elected officials (strictly ministers do not have to be elected or even members of parliament, but that is another issue).