1. Consider the flow demand of hydrogen gas
High flow application scenario: If the usage scenario of hydrogen is large-scale hydrogen transportation or chemical production that requires a large amount of hydrogen to participate in reactions, such as hydrocracking units in large refineries, centrifugal Hydrogen Compressors are a more suitable choice. Due to the large flow rate of centrifugal compressors, they can efficiently process large amounts of hydrogen gas. For example, in a hydrocracking unit that produces thousands of tons of oil per day, tens of thousands of cubic meters of hydrogen gas need to be transported per hour, and centrifugal compressors can meet such high flow demands.
Small flow application scenarios: For small experimental devices, hydrogen filling stations, or fuel cell vehicle refueling stations with low flow rates, reciprocating compressors or diaphragm compressors are more suitable. For example, in a fuel cell vehicle refueling station, when refueling a single vehicle, the hydrogen flow rate is relatively small. The diaphragm compressor can work stably at low flow rates and ensure the purity of hydrogen, avoiding pollution of the fuel cell.
2. Pay attention to the required pressure range
Low to medium pressure range (generally less than 10MPa): Adsorption compressors, liquid driven compressors, etc. have certain advantages in the low to medium pressure range. For example, in some hydrogen storage systems or small hydrogen recycling devices that do not require high pressure, adsorption compressors can utilize their simple structure and low operating costs to compress hydrogen to a lower pressure range for storage or circulation.
Medium to high pressure range (10-100MPa): When hydrogen needs to be compressed to medium to high pressure for high-pressure storage or long-distance transportation, reciprocating compressors, diaphragm compressors, and ionic liquid compressors can be used. For example, in a hydrogen refueling station that compresses hydrogen gas to around 70MPa for filling on-board hydrogen storage tanks, a diaphragm compressor can achieve a larger compression ratio, lift hydrogen gas from lower pressure to higher pressure, and ensure the purity of hydrogen gas.
Ultra high pressure range (greater than 100MPa): For some special research applications or situations that require extremely high pressure storage of hydrogen gas, such as metal hydride compressors or electrochemical hydrogen compressors, they may be more suitable. Metal hydride compressors can generate ultra-high pressure hydrogen gas through the hydrogen absorption and desorption reactions of metal hydrides, and have potential applications in some ultra-high pressure hydrogen storage research experiments.
3. Consider the purity requirements for hydrogen gas
High purity requirement scenario: In the field of fuel cell applications, hydrogen purity is extremely high because impurities may poison the electrodes of the fuel cell. Diaphragm compressors are a great choice as they can completely isolate hydrogen gas from impurities such as lubricating oil through membranes, ensuring the purity of hydrogen gas. For example, in the hydrogen supply system of proton exchange membrane fuel cells (PEMFC), a diaphragm compressor can provide pure hydrogen gas, extending the service life of the fuel cell.
Scenarios with relatively low purity requirements: If hydrogen is used in some chemical synthesis reactions that are not very sensitive to purity, such as some rough processing processes that use hydrogen as a reducing agent, reciprocating compressors or centrifugal compressors can also be used after taking appropriate purification measures. These compressors can meet the flow and pressure requirements while removing most impurities through the front-end gas purification device to meet the requirements of chemical production.
4. Combining cost and operational maintenance factors
In terms of cost:
Initial investment cost: Generally speaking, centrifugal compressors and ionic liquid compressors have higher initial investment costs due to their high technological content and complex equipment. However, reciprocating compressors and adsorption compressors have relatively simple structures and lower initial investment costs. For example, in a small-scale hydrogen experimental setup with limited budget, choosing a reciprocating compressor can reduce equipment procurement costs.
Operating costs: The operating costs of liquid driven compressors may be higher as they may require the consumption of more consumables such as hydraulic oil. The operating cost of adsorption compressors is relatively low because they do not have complex mechanical moving parts and have lower energy consumption. In long-term hydrogen compression systems, operating costs are a key factor to consider. For example, in hydrogen energy storage systems, choosing adsorption compressors can reduce long-term operating costs.
In terms of maintenance:
Vulnerable parts and maintenance difficulty: reciprocating compressors have vulnerable parts such as piston rings that need to be replaced regularly, and maintenance requires certain skills and tools. If the impeller and other key components of the centrifugal compressor are damaged, it is difficult to repair and the cost is also high. In contrast, adsorption compressors do not have complex vulnerable parts and maintenance is relatively simple. For example, in some remote hydrogen application scenarios where equipment maintenance technology is not required, choosing an adsorption compressor can reduce maintenance difficulty.
Maintenance cycle: The diaphragm of the diaphragm compressor has a certain service life and needs to be regularly inspected and replaced. The maintenance cycle is relatively short. If the material properties of the metal hydride compressor are stable, the maintenance cycle can be longer because it does not have the problem of frequent wear of complex mechanical moving parts. When choosing a compressor, it is necessary to consider the impact of maintenance cycles on production or application based on the actual situation.
