Can we effectively use solar power for Sulphur-Ammonia Thermocycle?

[Elmansi]

We are required to design a facility to produce hydrogen via Sulfur-ammonia cycle making use of the solar spectrum with long wavelength spectral composition to drive thermal processes and short wavelength composition to drive the hydrogen producing using photolysis. Also, I must use the economic analysis to evaluate the design project
Initial searches of the advantages and challenges for photolytic Sulphur ammonia
Advantages: Separations are simple
Ultra-high temperature not required
Solar thermal spectrum applied to thermochemical steps; solar photolytic spectrum applied to photolysis step.
Low cost of photolytic reactor

Challenges: Solids transport required
Coordinated operation required
Spectral splitting
Photocatalyst cost effectiveness
https://www1.eere.en...r_thermo_h2.pdf
Regarding the reactor design
I lack information that is normally available at the initial stages of a design problem. In particular, the desired production rate but I can assume it, reaction conditions(only Temperature is known), information about the rate of reaction ( all reactions went to completion and that there were no side reactions or unreacted products that carried over to the next step) and catalyst state(homogenous, slurry, packed bed powder, etc), and cost data for equipment and utilities.

To efficiently use solar power one has to split intercepted solar radiation into these components and direct the split beams to their respective tasks. Since the thermal component will be useless for the photolysis process and the photoactive component will not add materially to thermal processes, can one solve this problem by using the electrical energy stored by the solar collectors to operate radiation sources located along the reactor length but this restricts us from running the process in continuous mode?

 

[trurle]

We are required to design a facility to produce hydrogen via Sulfur-ammonia cycle making use of the solar spectrum with long wavelength spectral composition to drive thermal processes and short wavelength composition to drive the hydrogen producing using photolysis. Also, I must use the economic analysis to evaluate the design project
Initial searches of the advantages and challenges for photolytic Sulphur ammonia
Advantages: Separations are simple
Ultra-high temperature not required
Solar thermal spectrum applied to thermochemical steps; solar photolytic spectrum applied to photolysis step.
Low cost of photolytic reactor

Challenges: Solids transport required
Coordinated operation required
Spectral splitting
Photocatalyst cost effectiveness
https://www1.eere.en...r_thermo_h2.pdf
Regarding the reactor design
I lack information that is normally available at the initial stages of a design problem. In particular, the desired production rate but I can assume it, reaction conditions(only Temperature is known), information about the rate of reaction ( all reactions went to completion and that there were no side reactions or unreacted products that carried over to the next step) and catalyst state(homogenous, slurry, packed bed powder, etc), and cost data for equipment and utilities.

To efficiently use solar power one has to split intercepted solar radiation into these components and direct the split beams to their respective tasks. Since the thermal component will be useless for the photolysis process and the photoactive component will not add materially to thermal processes, can one solve this problem by using the electrical energy stored by the solar collectors to operate radiation sources located along the reactor length but this restricts us from running the process in continuous mode?

I think the assumption of no side reactions here is incorrect. The photolitic stage may may emit NO and SO2 as byproduct, according Wikipedia page on ammonia sulfite says. Also, ammonia cooling step will decompose about 1-3% of ammonia back to N2 and H2, similar to yield of Haber process.

Also, high temperature part may have material compatibility problems. At 1000C, most ceramics will react with SO2 (alumina absorbs SO2 even at room temperature), and resulting mixed sulfates flux may erode reactor walls pretty rapidly.

Regarding radiation split technique, it do not work at radiation flux required for 1000C if first concentrated and then split. Even most robust glass-embedded diffraction gratings will likely become unstable at 500-800C. Splitting and then concentrating radiation may be a solution, although it will require industrial-scale installation of panels with gratings - something nobody have tried yet.