Decarbonisation of the Dutch PVC manufacturing industry through hydrogen and biomass configurations

Abstract

In line with the Paris Agreement goals that were signed in 2015 by a total of 195 countries,among which the Netherlands, governments worldwide are formulating plans to reducetheir CO₂ emissions. In the Netherlands the Dutch industry accounts for 40% of the total CO₂ emissions and therefore decarbonisation of this sector is highly relevant. The Port of Rotterdam is home to a large variety of power plants and chemical companies producing all sorts of essential products, such as fuels, platform chemicals and polymers. Polyvinylchloride (PVC) is one of the polymers produced in the Port and on average 100 ktonne of CO₂ is emitted every year during the manufacturing. PVC manufacturing companies have a significant responsibility to reduce their CO₂ emissions and explore more environmental-friendly production methods. This research aims to aid in the transition by exploring decarbonisation pathways through which PVC manufacturers in the Netherlands can reduce their direct CO₂ emissions. 
This study will answer the main research question: How can selected hydrogen and biomass decarbonisation configurations reduce direct CO2emissions in the Dutch PVC industry and how do these perform in a grey-box techno-economicanalysis?
To answer the main research question, secondary research questions were formulated, which are systematically answered throughout this study:• What are the main steps of the production of PVC in the Netherlands and which step is the primary source of CO₂ emissions?• Which three selected hydrogen and biomass decarbonisation configurations are promising for decarbonisation of the Dutch PVC industry and where do they fit in the PVC production process?• How do the selected hydrogen an biomass decarbonisation configurations compare in a grey-box techno-economic analysis? 
This was done by carrying out a literature study on the current PVC production process ofShin-Etsu in the Port of Rotterdam, followed by a Mass Flow (MFA) and Energy Flow Analysis (EFA) which identified the thermal cracking of ethylene dichloride (EDC) to vinylchloride monomer (VCM) as the main source of CO₂ emissions in the production process. Next, three decarbonisation configurations were proposed that make use of several renewable energy technologies, such as solid oxide fuel cells (SOFC), solid oxide electrolyser cells (SOEC), electric furnaces (EF) and hydrogen furnaces (HF):• Configuration A: A hydrogen-fed SOFC system with an electric furnace.• Configuration B: A biomass-fed SOFC system with an electric furnace.• Configuration C: A electricity-fed SOEC system with a hydrogen furnace.

These configurations were modelled using grey-box modelling and compared in a techno-economic analysis using the following parameters: Net Present Value (NPV), Payback Period (PBP), Technology Readiness Level (TRL) and Energy Efficiency (EE). The main results and conclusions of the study are as follows:
• PVC production in the Netherlands can be split in two main production steps: VCM production and PVC polymerisation. It was found that thermal cracking of EDC to VCM during VCM production is the main source of CO₂ emissions.• Under the assumption that indirect heating technology will continue to be developedand pilot tested, electric furnaces with a supporting SOFC system could see implementation in the future. The energy efficiency of this configuration was estimated at 51%. This setup has the potential to negate direct CO₂ emissions from the traditional cracking furnaces. However, the economic viability of hydrogen fed SOFC systems will be highly dependent on lower hydrogen market prices. In order to avoid shifting CO₂ emissions from inside the gate to outside the gate an infrastructure where affordable, green hydrogen is available is key. Close collaboration between all the stakeholders in this supply chain will be important.• Biomass-fed SOFC systems combined with an electric furnace showed a positive NPV due to the lower price of biomass compared to hydrogen. The energy efficiency of this configuration was estimated at 45%. Sufficient availability of biomass in the Netherlands would benefit the potential of biomass-fed SOFC systems in the future, but this is not certain. Furthermore, the debate whether or not the use of biomass is carbon neutral continues as scientists call for caution since burning biomass is instant, while depending on the type of biomass it might take decades before the same amount of CO₂ is drawn from the air. Biomass should therefore be used carefully. The future price of electric furnaces are subject to uncertainty and the economic viability of configurations using this technology should be reaccessed once the technology is closer to maturity.• A SOEC system supporting a hydrogen cracking furnace showed the highest NPV and the shortest pay back period of all three configurations. The energy efficiency was estimated at 61% which is the highest of all three configurations. SOEC is reaching high TRL and it is expected that by 2030 1+ MW systems are commercially available. If hydrogen cracking furnaces will also continue to strongly develop in the future, this configuration could be successful. Availability of renewable electricity and storage methods to deal with the intermittent nature of wind and solar are important enablers that could help SOEC systems gain momentum. Access to renewable electricity will also avoid displacement of direct CO₂ emissions from the PVC industry to indirect CO₂ emissions sources.