During lockdown, we have been speaking to various partners and teams within ABC-Salt. Balaji Sridharan is a research student. We asked him about the work he and his team have been doing during lockdown.
ABC- salt research in Groningen
The ABC-salt team in Groningen is quite diverse and packs a good strength in numbers. We currently have three staff members, a postdoctoral researcher, two PhD students, and six master students who are busy with ABC-salt experiments. The team here contributes towards all the technical work packages WP3 (Primary Liquefaction) through WP6 (demonstration of integrated concept). We have in total 6 dedicated experimental setups running parallelly: a liquefaction setup, a gram scale pyrolysis setup, a slightly bigger scale batch hydropyrolysis setup, a continuous hydrodeoxygenation setup, and two integrated units capable of combining both hydropyrolysis and liquefaction.
At the end of month 24 of the project, we were finally able to reach our desired targets for the work package on liquefaction (WP3) of lignin in molten salts with a lignin recovery of at least 90wt% post liquefaction. Our focus since then has shifted strongly towards the next work package, hydropyrolysis of biomass (WP4). Two main experimental setups are used in the hydropyrolysis of biomass. One of these is the setup I use for the fast hydropyrolysis of lignin in molten salts, schematically shown in Figure 1. By injecting a mixture of cresol and lignin into a hot pressurized reactor with molten salts, lignin is hydropyrolysed to produce liquids.
Another interesting experimental setup used for hydropyrolysis is the integrated unit that was built in house in RUG. The setup is used for the semi-continuous hydropyrolysis of wood in molten salts. Biomass and molten salts added in a metal or quartz tube is dropped into the setup, where it passes through different heating zones (liquefaction and pyrolysis). The biomass is thereby depolymerized to volatile gases that are collected in three condensation steps.
The work environment
The research environment in Groningen is very diverse and international which is also representative of the team of contributors in this project as well. Even though pyrolysis of wood or even lignin is not a new concept, experiments are usually complicated when salts enter the picture. Such challenges make a typical experimental day very dynamic with new things to learn every day. Experiential days are often long, but I have seen in myself, the increase in motivation with every successful experiment. Our experimental results have grown increasingly positive over the last year with liquid yield of lignin hydropyrolysis increasing from just 4wt% to over 30wt% of the mass of input lignin. This learning curve has helped us successfully deliver a number of deliverables over the last 12 months.
It is hard to talk about the last 12 months without mentioning Covid-19 and its effect on both personal and professional life. Similar to how Adriana had mentioned well in her article in the previous newsletter, the lockdowns and restrictions did have a significant delay in research in the Netherlands as well. For a period of over three months, the labs were closed which caused significant delay in submitting our deliverables. As a very small hint of a silver lining of these restrictions, flexibility at work increased dramatically, with all meetings done mostly virtually. Work from home has become the new norm (which I am a huge fan of) possibly increasing work efficiency by forcing me to plan my experiments better. Even though the experimental time during the day is reduced significantly, we remain measurably optimistic towards overcoming the current delay to ensure the completion of a very successful project!