Integrating Waste Heat from Hydrogen Production Into District Heating

Abstract

The aim of this research is to explore the feasibility of the integration of waste heat from electrolyzers within a Combined Heat and Power (CHP) plant and district heating (DH) network and suggest a practical setup for integration. With the escalating emphasis on the development of green hydrogen through electrolysis powered by renewable energy, a substantial amount of waste heat is generated, typically left unused. This study explores the potential of harnessing this waste heat and integrating it into DH networks, thereby enhancing the system's overall efficiency and sustainability. Using advanced simulation software, the research demonstrates that an existing 37 MW CHP plant can feasibly accommodate up to 21 MW of waste heat injection into a DH network with negligible impact on the electrical power output. The incorporation of waste heat significantly increases the heat absorbed by the DH water, thereby improving the quality of heat supplied to connected buildings. The findings from this research contribute to a deeper understanding of waste heat recovery in green hydrogen production and its potential benefits in the context of sustainable heating systems.

Popular Abstract

You're probably familiar with the idea of recycling paper, plastic, or even composting leftover food, but what about recycling heat? It's not a concept that often makes headlines, but it's a crucial part of our efforts to combat climate change and make our energy use more efficient.
Picture this: It's a cold winter day, and you're cozy at home thanks to the heat flowing from your radiators, providing a comfortable indoor environment. That heat didn't just come from nowhere – it's part of an intricate, yet efficient, process involving a network of pipes, a power plant, and, surprisingly, the production of hydrogen, the most abundant element in the universe.
Let's break it down. We're talking about district heating systems (DH), which are becoming increasingly popular, especially in countries like Sweden. These systems work by pumping heated water from a central source – usually a power plant – through a network of insulated pipes to homes and businesses in a given area. It's like a communal heating system, sharing the warmth around.
In our research, we've been focusing on combined heat and power (CHP) plants, which generate electricity and capture the excess heat produced in the process. The heat is typically directed into the DH systems, where it warms up water that is then delivered to heat buildings. The beautiful thing about CHP plants is that they use the energy twice, first to generate electricity, and then to heat water – a level of efficiency that is a significant leap forward in our quest for sustainable energy use.
However, our research takes this efficiency one step further. Ever heard of electrolysis? It's a process used to produce hydrogen from water. Hydrogen is an element gaining attention for its potential as a clean energy source, so we're expecting to see much more of it in the future. But like all processes, electrolysis produces heat – heat that is usually wasted.
So, we had an idea: why not recycle this waste heat and put it to good use? That's precisely what we've done in our research. We've looked at the feasibility of integrating the waste heat produced by an electrolyser into the DH network in combination with a CHP plant.
Now, this isn't as straightforward as it sounds. There's a delicate balance at play between the heat and the power produced. In essence, we're repurposing some of the energy that would have gone into producing electricity and using it to heat water instead.
Our study shows that an already functioning 37MW CHP plant and DH network can easily integrate up to 21 MW of this waste heat. That means less heat wasted and more homes heated with the same amount of water. This might seem like a small change, but when you consider that energy production accounts for over two-thirds of global greenhouse gas emissions, every improvement counts. By making our heating systems more efficient and cutting back on wasted heat, we're taking a crucial step towards reducing our carbon footprint.
But what does this mean for you, sitting at home on that chilly winter day? It means you can stay warm, knowing your heat isn't contributing as much to climate change. You can enjoy the comfort of your heated home while knowing that you're part of a bigger picture – one that's striving for a more sustainable future. Now, isn't that a warming thought?

• author: Kayali, Fawzi
• supervisor: Magnus Genrup
• organization: Department of Energy Sciences
• course: MVKM05 20231
• year: 2023
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Hydrogen, Electrolysis, Waste Heat Recovery, Combined Heat and Power Plant, District Heating, Simulation, Sustainable Heating Systems
• report number: LUTMDN/TMHP-23/5536-SE
• ISSN: 0282-1990
• language: English
• id: 9123887
• date added to LUP: 2023-06-12 16:04:48
• date last changed: 2023-06-12 16:04:48