Transdisciplinary analysis and Life Cycle Assessment on CO2 Direct Air Capture using membrane technology

Details

Supervisors

Luis Alconero, Patricia

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil en chimie et science des matériaux, à finalité spécialisée

Abstract

Intensive human activity is responsible for global warming, mainly because of CO2 emissions into the atmosphere. The European Commission has launched The European Green Deal, under which the European Union aims to emit zero greenhouse gases by 2050. Carbon capture technologies have a role to play in achieving this goal. In this work, the direct air capture technology based on the use of membranes (m-DAC) is studied. This technology has a relatively low maturity, but would have certain advantages over the most advanced DAC technologies. It would be more energy efficient and would have a lower environmental footprint. A life cycle analysis is carried out on this technology to determine whether it has a place as a future option for reducing CO2 emissions. The results show that the technology implemented in this work has a carbon removal efficiency of 83.7% when the source of electricity used is decarbonised, i.e. wind energy in this case, and when the membrane used has sufficient CO2 permeance. Under less favourable conditions, the technology emits more CO2 than it captures, making it inefficient. This process captures a flow of CO2 whose concentration is only around 50%. At this concentration, the possible ways of using and storing CO2 are limited, although some do exist. Sufficient purity for any application can be achieved by increasing the number of membranes in series used in the process. LCA has its limitations and weaknesses, principally the fact that it only considers the environmental situation of the product, service or process analysed, thus failing to take account of issues in other areas, for example economic and social, and the fact that it is based on a model of reality, so that certain sources of impact may not be taken into account even though they would have significant environmental impacts, making the LCA results optimistic compared with the real situation. A discussion based on interviews with experts working in various fields is conducted, raising awareness of the complexity of implementing solutions to reduce greenhouse gas emissions in society, particularly with regard to the rebound effect of certain solutions and the risk that their implementation could lead to an increase in social inequalities and poverty in the world.