Given the recent strong change on societal and economical context but also with new recent regulations (the Paris Agreement, CO2 price increasing, Greenhouse House Gases quota), industrials are willing to reduce the environmental impact of their activities by improving and upgrading current asset operation. Thus, the major challenge of our industry in the incoming decades will be to reduce CO2 emissions while remaining profitable and competitive. The sustainable development scenario of IEA puts energy on tracks to meet sustainable energy objectives, with a global temperature increase of less than 2°C by 2100. To reach this target, several options are possible: improve the energy efficiency of existing assets, move to renewables energies, fuel switch or even carbon capture. Several options, but how to select the best option? It depends strongly of climate strategy, existing assets and development plan of each industrial. It is the role of Axens, as consulting team, to support industrials in this challenge by developing a comprehensive roadmap of sustainable process solutions to address this CO2 reduction ambition. Axens has a dedicated multi disciplinary team with long expertise in master planning, which has privileged access to green technology and carbon capture expertise whose competency is to develop short, medium and long-term plans for decarbonization. Through a holistic and proven approach, Axens supports industrials and develop a specific and customized decarbonization program taking into account baseline set in Group Strategy. The approach and methodology is presented in this paper an illustrated through three different decarburization projects studied by Axens applicable to the Refining sector. In this Energy Transition context, an increasing number of refineries in the world are being partially or completely transformed from tradition fossil oil refining activity to bio-refineries treating bio sourced or waste feedstocks. First Case Study presents a grass root project feasibility study where two of the most attractive options for production of renewable fuels are compared: HVO and 2G bio-ethanol. These are two of the main sustainable technologies that can be integrated in existing refining sites taking profit of all the synergies with existing facilities and activities. In Case Study 2 different configurations for sustainable transformation of a multi-site refining system where evaluated for a Client. This case is an example of the very large panel of options that refineries will have to evaluate when defining their strategies to adapt to the Energy Transition and new regulations. Each solution resulting into very different level of investments, different business models and different social and environmental impacts. Case Study 3 presents the pre-feasibility study for an ongoing project of CO2 capture and transformation to methanol for a cement plant. Carbon Capture is also applicable to Refineries, especially in the main refinery emitters such as FCC unit flue gases and SMR unit syngas or flue gases, which are often the best candidates on medium complex refineries to apply Carbon Capture in a cost –effective way.