A pipe carrying heat from 2,500 meters underground is a good place to start a story about future energy. So is a liquid that can chemically bind hydrogen and release it later. Sharp Eagle has worked on equipment for both: a Heat Exchanger Skid for a geothermal heating project in Zhengzhou, China, and a Hydrogen Skid for testing a liquid organic hydrogen carrier.

These geothermal and hydrogen skid systems show how modular process equipment can support two very different approaches to future energy. One transfers underground heat, while the other helps researchers study hydrogen storage and release.

For anyone who has paused a sci-fi film to work out how the machinery is supposed to function, these projects offer something worth exploring. The interesting questions begin with how heat and materials move through the equipment.

How the Geothermal Heat Exchanger Skid Works

The Zhengzhou project, commissioned by China Huaneng, uses supercritical carbon dioxide to collect underground heat. The CO₂ circulates through a closed loop extending into a geothermal well approximately 2,500 meters deep, then returns to the surface.

“Supercritical” means the fluid is above its critical temperature and pressure. Keeping the system within its intended operating conditions requires temperature, pressure, and flow to be managed together.

At the surface, the returning CO₂ passes through heat exchange equipment that transfers energy to a separate heating-water circuit. The two fluids remain separate. The water carries the recovered heat onward for residential heating.

This arrangement collects underground heat without extracting groundwater.

The Heat Exchanger Skid and Hydrogen Skid demonstrate how skid-mounted equipment can adapt to very different energy applications. Each system requires careful engineering around pressure, temperature, piping, instrumentation, access, and testing.

It also keeps the high-pressure CO₂ circuit separate from the water circuit serving buildings. The surface heat exchanger is where those two systems meet without mixing their contents.

Sharp Eagle supplied the complete heat exchange skid. A skid is a process assembly mounted on a structural frame, with equipment, piping, valves, and instruments arranged as a module.

The project called for 20 MPa-class design conditions, equivalent to roughly 200 bar. Its module envelope measured 10.2 meters long, 4 meters wide, and 4.4 meters high.

That sounds spacious until the equipment goes in.

High-pressure piping takes up room. So do its supports, valve assemblies, instrument connections, and the spaces people need for maintenance. A component that fits in a computer model may still be awkward to reach with a tool.

Sharp Eagle’s detailed engineering brought the equipment, piping, structural, electrical, and instrumentation work together. The heat exchanger’s position had to work with the pipe routes, while the overall arrangement had to accommodate lifting, transport, and site connections.

Manufacturing included thick-wall welding controls, inspection of key welds by radiographic or phased-array methods as required, and pressure and sealing checks before delivery. Material and inspection records were retained for acceptance and traceability, giving the customer a documented basis for later checks.

How the Hydrogen Skid Supports LOHC Storage

The hydrogen project starts with a familiar renewable-energy problem: electricity may be available when there is limited demand or grid capacity to absorb it.

Using that electricity to split water produces hydrogen. The next question is where to put it and how to move it.

This project investigates dibenzyltoluene, a liquid organic hydrogen carrier, usually shortened to LOHC. During hydrogenation, hydrogen chemically bonds with the carrier. During dehydrogenation, it is released for subsequent use.

It is easy to picture this incorrectly. The liquid is not a container full of tiny hydrogen bubbles. The storage mechanism involves a reversible chemical reaction.

The process therefore needs equipment at both ends. Hydrogen must be added under controlled conditions, and recovering it requires another reaction stage. Between those stages, the hydrogen-bearing material can be handled as a liquid.

Sharp Eagle built a pilot skid around the customer’s process package, integrating reaction equipment, circulation piping, valves, instruments, and control interfaces.

The distinction between a pilot and a commercial installation matters. This unit was built to support engineering validation: examining catalyst behavior, checking process parameters, and learning how the connected system operates.

It gives the customer a place to investigate the questions that remain after the process has been worked out on paper.

Making the Test Results Useful

Imagine the hydrogen output changes during a trial. The team needs to determine what caused it.

Did the catalyst respond differently? Did the feed flow drift? Was the temperature stable? Could an instrument reading be misleading?

A pilot unit needs to make those questions answerable. Its layout must allow observation, sampling, adjustment, and maintenance. Its instruments need to report the conditions the team is trying to study.

On the LOHC skid, Sharp Eagle’s work included individual checks of temperature, pressure, flow, and control signals. Manufacturing controls also covered the fit-up and welding of small-diameter piping, followed by cleaning and purging.

Small pipes leave little room for careless assembly. They also sit among reactor connections, valves, cables, and instruments, so access has to be considered early.

Hydrogen sealing received specific attention, with checks at valves, flanges, welds, and instrument interfaces. Factory testing covered pressure, sealing, electrical, and functional checks, with records prepared for delivery.

The customer supplied the process package; Sharp Eagle handled the detailed engineering and fabrication needed to turn it into an assembled test unit. That division lets the process team concentrate on the chemistry while the equipment team works through how to build and inspect the system.

From the Workshop to the Site

For both projects, much of Sharp Eagle’s work happened before shipment: resolving pipe routes, leaving maintenance access, checking welds and seals, and verifying instrument connections. Completing these tasks in the factory reduces the number of unresolved issues carried into site installation.

There is still work after delivery. Each skid needs to be positioned, connected, and commissioned. The geothermal system must work with the site’s heating circuit, while the hydrogen pilot must support the customer’s planned trials. Factory testing provides a checked starting point for that work.

These geothermal and hydrogen skid systems serve very different purposes. In Zhengzhou, the heat exchange skid transfers energy brought up from a deep well into water used for residential heating. In the LOHC project, the pilot skid gives researchers an integrated unit for studying hydrogen storage and release. Sharp Eagle’s role in both was to work through the physical details—equipment layout, piping, fabrication, and testing—so the customer could put the process to use.