Hydrogen Production – Centralized / Decentralized

Hydrogen is produced either in a centralized or decentralized manner, but transportation is key point.
The cost of hydrogen generation is lower due to economies of scale but transmission and distribution costs are higher in the centralized production.
The T & D costs are lower but production cost is higher in the decentralized production at the refueling station using electrolyzer or reformer.

Transportation of Hydrogen

The selection of transportation depends upon geography of country, volume of transportation, distance of transport and its application.

The long distance and large volume of hydrogen can be transported through shipping route or pipelines whereas local distribution is done either pipeline or through road route via trucks.
The pipelines have high capital expenditure but lower operational and maintenance cost whereas road transport have low capital expenditure but higher operational and maintenance cost.
The transportation of hydrogen is done through pipelines for large distances ( < 1500 km ), for further higher distances, hydrogen carrying in the form of high energy density materials like liquid organic hydrogen carriers ( LOHC ) is preferred choice which involves extra cost for conversion of hydrogen to LOHC and reconversion.
If the infrastructure of pipeline is not available, liquid hydrogen is transported and carried through super insulated, cryogenic tankers and trucks.

The transportation of hydrogen in the form of liquid or gaseous hydrogen is chosen when volumes and distances is lower as compared to pipelines.
Liquid hydrogen is carried through trucks which saves transportation cost considerable.
Gaseous hydrogen can be transported through high pressure tank through tube trailers.
The density of hydrogen at 200 bar pressure is 15.6 kg/m³ and 500 bar pressure is 33 kg/m³.
Pressurized tube trailers operate between pressure of 200 – 500 bar to carry compressed hydrogen over short distances.
The capacity of tube trailer may be in the range of 500 – 1000 kg.

Hydrogen may be transport at ambient temperature and pressure is in the form of liquid organic carriers.
Hydrogen can be carried in the form of hydrocarbon carrier which are high energy density materials having low flammability and toxicity.
Liquid organic carriers can be converted to hydrogen at the point of use.
The small refuel stations can refill 10 -2 -vehicles and having capacity of 50 – 100 kg per day.
Hydrogen CNG is more efficient than CNG in terms of reducing emissions.