H2-Heat: Thermal energy transport for heating and cooling with innovative hydrogen(H2) technologies

In the UK, heat accounts for over a third of the nation's greenhouse gas emissions. Most of the heating and cooling in our industries and buildings are delivered directly or indirectly by fossil fuels. Apart from the greenhouse emissions, the extensive consumption of fossil fuels can also lead to a large depletion of energy resources, waste heat production and pollution to the surrounding environment. To meet the target of Net Zero greenhouse gas emissions by 2050, there is an urgent need for decarbonising heating and cooling by utilising renewable energy and industrial waste heat with advanced technologies. Compared to renewable energy such as solar, the resources from industrial waste heat have clear advantages including greater stabilisation, less cost and larger temperature ranges. Therefore, industrial waste heat recovery for decarbonised heating and cooling is an attractive concept that could simultaneously reduce fossil fuel consumption and CO2 emissions. Evidently, in the UK, based on a recent report, it was identified that around 48 TWh/yr industrial waste heat sources were available of which about 28 TWh/yr could be potentially used to meet the heating and cooling demands. All heat-intensive industrial sectors including iron & steel, refineries, ceramics, glass, cement, chemicals, food and drink, paper and pulp can contribute to this potential. Even so, high efficient energy conversion systems need to be designed and applied so as to maximize the waste heat utilisations for heating and cooling. On the other hand, the locations of industrial waste heat providers such as steel plants are mostly far away from the utilisers for heating and cooling. Conventionally, hot water heated by the industrial waste heat is transported through long distance water pipe to the end user site which can cause huge pump power consumption and heat losses due to significant friction pressure drop for the water flow and large temperature difference between water flow and ambient. There are therefore challenges to the long-distance waste heat transport and high-efficient and innovative energy conversion technologies for the decarbonising heating and cooling.

To address these challenges, in this proposal, strategies for a novel concept of decarbonising district heating and cooling system (H2-heat) will be developed with the integration of metal hydride (MH) heat pump on site, long distance hydrogen and heat transport, and MH heating and cooling for end users. In such a system, low grade heat (~210C) and extra low grade heat (~40C) from TATA Steel plant or a similar industry site will be used as heat sources while building heating and cooling spaces are applied as heat sink and low temperature heat source respectively at end user side. Technologies of MH heat pump, a thermal driven chemical compressor with MH, long distance hydrogen and heat transport, MH space heating and cooling, MH alloys and reactors applied in the systems and processes, controls for space heating and cooling etc. will be identified and investigated. Ultimately, a decarbonising district heating and cooling test system with industrial waste heat from TATA Steel plant or other industrial sites will be constructed in lab with 5 kWth heating or cooling capacity and high heat transport efficiency. Furthermore, a detailed mathematical model will be developed and validated for the established system; this can be used for a system scale-up into actual application in TATA Steel plant or other industrial sites where low grade waste heat is available. As yet, no research activity on such a system can be found either nationally or internationally. Important reasons include the difficulty in choosing a thermal driven long distance hydrogen and heat transport system and associated MH alloys for space heating and cooling and complicated designs of MH reactors in the H2-heat system. These challenges and issues will be addressed and solved by this proposed project.

The impact of the research will be widespread and varied. It is highly relevant to many sectors including: (i) Industry - The success of this project will directly contribute the performance evaluations and improvements of developing technologies such as low grade waste heat recovery with metal hydride (MH) heat pump, thermal driven hydrogen chemical compressor, hydrogen and heat long distance transport, metal hydride heating and cooling circuits, as well as the application and control of the district heating and cooling system. It will have long-term influence on the industry by enabling high efficiency waste heat recovery and district heating and cooling operations. ii) End-users- UK domestic buildings particularly in the areas which are not quite far away from the industrial sites. This proposal will also benefit other end-user types such as schools, out-of-town retail, leisure developments, district heating networks and other commercial buildings where heating/cooling is demanded. Since the project will establish long distance H2 and heat transport, it can also benefit to the users of hydrogen such as hydrogen automotive filling stations, hydrogen heating networks , future hydrogen grid and industrial processes where hydrogen is needed. iii) Academics: This proposal, using an advanced long distance H2 and heat transport with industrial waste heat for district heating and cooling, is a novel research and development area. It has combined challenges in terms of thermal driven MH compressors, long distance H2 and heat transport, MH heat pump with low grade industrial waste heat and MH reactors operating at high temperatures and pressures, MH reactors for heating and cooling and advanced control technologies. As a result, the exploration and understanding of fundamental physical processes and mechanisms resulting from this project will benefit a wide range of academics interested in these areas. iv) Government: Reducing heating and cooling demand and carbon emission from buildings by using industrial waste heat is essential to the UK government's target to reduce the UK CO2 emissions by 80% of 1990 levels by 2050 . The proposed programme will support and enhance the achievements of these targets. Furthermore, the use of a long distance H2 and heat transport will lead to higher efficiency and, therefore, improved cost-effectiveness and increased reduction in CO2 emissions. The growth and diversification of different scale businesses from industrial waste heat for the production of district heating and cooling will help to engender greater fuel independence for the UK. It will also contribute significantly to the government's future scheme of fuel switch with hydrogen.

The industrial, end users' and government impact will be achieved through direct industrial interaction and knowledge transfer. The industrial partners in this project are the potential manufacturers and users of the proposed technology. Residential houses in district heating networks in both rural and urban areas are our potential users of the proposed system and technology. Our outcomes will also be disseminated through various knowledge transfer networks as well as application-oriented magazines to maximize impact. The academic impact will be achieved via article publications and conferences/seminars events. We will keep publishing our findings in a timely manner in top peer-reviewed journals and conferences. We will also report our outcomes to other relevant programmes such as Sustainable Environment Research Centre's (SERC) and Sustainable Energy Use in Food Chains' (CSEF) programmes to attract attention in this new area, with the ultimate goal of establishing a society for industrial waste heat -fuelled district heating and cooling research. In addition we will be involved in two new developed master programs related to Renewable Energy at both University of South Wales and Brunel University.