Hydrogen is one of the energy carriers proposed by global governments such as the UK and companies globally to play a role in reducing the carbon emissions from energy production and utilisation. Blue hydrogen, which is produced from natural gas with the associated CO2 emissions stored permanently in geological reservoirs, has received notable support from industry and government alike, this support has been demonstrated through investment decisions, policy support and technology support.
As a direct product of fossil fuel, there is a significant concern about the rationale in prioritising blue hydrogen as one of the energy transition mechanisms over others such as wind, hydroelectricity, solar and more due to the potential cost, low technological readiness and environmental impact.
At the National Subsea Centre, the Integrated Energy team is working on understanding the impact of the production and utilisation of blue hydrogen. The aim of this environmental impact assessment study is focused on the environmental, human health and resource-use impacts. To do this, a life-cycle assessment approach is used to quantify the role of blue hydrogen in the decarbonisation effort, which will help support future policy directions and industry investments.
Lifecycle Assessment of Blue Hydrogen Utilisation
Lifecycle assessment (LCA) is one of the processes used in evaluating the impact of a product or service across its lifecycle. Previously, Alexander Oburoh has carried out LCA studies to understand the environmental impact of producing blue hydrogen using case studies from four planned blue hydrogen facilities in the UK, results show that the environmental impact from the production of blue hydrogen can meet the UK low carbon hydrogen standard of 20g CO2e/MJLHV if key parameters such as methane leakages, carbon capture rates and steam utilisation are strictly controlled.
Furthermore, it is also vital to understand the environmental impact of the utilisation of blue hydrogen when compared to other renewable energy sources. With the amount of investment in blue hydrogen from an economic, technology research and human resources perspective, it is important to understand the scale of environmental benefits for the utilisation of blue hydrogen for industrial purposes. The following use cases are being analysed for the LCA of blue hydrogen: refinery, natural gas blending, gas turbines, steel and ammonia production.
In this article, the refinery use case will be analysed to understand the impact of using blue hydrogen.
The Approach & Methodology
The goal is to evaluate the environmental, human health and resource use impact of the utilisation of blue hydrogen in a refinery operation. The scope is as shown in Figure 1 below:
Figure 1: Boundary and Scope for the LCA. Figure generated by Integrated Energy PhD Student, Alexander Oburoh.
The scope covers the transportation of crude oil through the crude oil distillation to the final products using a gate-to-gate boundary condition. Unlike the conventional refinery that uses natural gas as feedstock for electricity, heating and power requirements as well as to produce hydrogen, this model replaces natural gas with the direct use of blue hydrogen. The functional unit for this analysis will be referenced to the input of the crude oil based on the case study that would be used (i.e. 50,000 barrels of crude oil per day).
Conclusions & Impact
With this analysis, the LCA results from using blue hydrogen as a primary fuel for energy use in a refinery (replacing it with natural gas) will be compared with the LCA results using the conventional natural gas that is currently being used. Using the primary indicators of environmental impacts (mainly CO2 emissions), human health impacts (SO2, NOx emissions etc.) and resource utilisation and depletion (water, critical raw materials etc.), the team have the potential to discover the degree and scope of the benefits derived from this fuel switching. These benefits derived from fuel switching will help inform policy and industry planning and prioritise investment strategies and policy support mechanisms.
