My fascination with the concept of sustainability is an old one. I was introduced to sustainability during middle school days when my notion about it was, “Wise use of resources so that they can be sustained for the future generations”. Although I could perceive very little about the nuances of sustainability, I was definite about two things – fossil fuels are running out due to our overdependence on them for energy and we are releasing a lot of CO2 into the air while burning them, causing climate change. From the miniscule knowledge of science I had, I wondered, “If fossil fuels burn and break into CO2, can’t we take all the unwanted CO2 and fix them up together to form fuels again?”. This idea seemed more and more childish as I kept advancing through my career and had eventually forgotten about it.
Was the idea really forgotten?
Years passed by and my inclination towards sustainability drove me to pursue a career in process engineering with focus on sustainable energy. More than a decade after I declared the idea as childish, I got an opportunity to work at the German Aerospace Centre on Power-to-X technology which, simply speaking, involves CO2 capture and its conversion into energy carriers. To work among a team of professionals involved with research and development of sustainable energy systems was once an unachievable dream, which turned into reality. But what really feels surreal now, is the realization that the “childish idea” I had once disregarded, is the idea behind this sustainable technology of the future. My work did involve developing a process that captures excess CO2 from the air and converting it into a fuel.
How “matured” is the idea today?
The concept of carbon capture and utilization (CCU) is a fairly old one. Processes such as CO2 capture and its injection into oil wells for enhanced oil recovery, CO2 mineralization have been in practice for decades. However, the Power-to-X concept involving CO2 conversion into fuels made its impression in the mainstream consequent to the steep fall of renewable electricity prices during the last decade. The Power-to-X concept was first commercially realized in 2012 by the George Olah CO2 to methanol plant in Iceland. Currently, many research and development projects are being carried out in this area to produce green substitutes of conventional fuels from CO2, especially in Europe.
What was my contribution in this field?
My work at the German Aerospace Centre focused on production of conventional LNG substitute through CO2 capture and its conversion to synthetic natural gas (SNG). I designed and simulated different production routes using Aspen plus, performed feasibility analyses and heat integration to come up with an optimized, energy efficient production process. A thorough economic analysis was carried out to calculate the net production cost of the plant using detailed engineering and cost indices and factors to calculate CAPEX and OPEX. My designed process is able to capture 30 t/h of CO2 from the atmosphere, perform >99% conversion into SNG and produce 11 t/h of LNG with a methane content of >98%. The high energy density of the product makes it an efficient energy carrier and finds usefulness in transportation and maritime sectors.
I am fortunate to have been able to shape my work in this field into my Master thesis. I believe, it led to a nice culmination of my Master’s degree that I had so passionately pursued. In the video below I have presented a summary of my work that I had put in for my thesis. If you were intrigued by the technology that addresses two of the most major global concerns (energy and climate change), please go through the video and leave your thoughts and comments!