+Policy Fellow Research Highlight: Theo Lim

Theo Lim

Assistant professor, Urban Affairs and Planning in the School of Public and International Affairs. 

+Policy Fellows Project:  Technoeconomic Analysis of Negative Emissions of Bioenergy with Carbon Capture and Storage through Pyrolysis and Bioenergy District Heating Infrastructure

The director of the +Policy Network and Communications Specialist Felicia Spencer sat down with Theo to talk about his project and his research related to policy.

Tell us a bit about your Fellows project.

The project modeled thermochemical processes to estimate most effective ways facilities could reduce or eliminate carbon emissions while generating their electricity.  More concretely, the project was a case study of a Virginia state hospital - Piedmont Geriatric Hospital - that already had switched from burning coal to burning switchgrass to make their energy through a biochar process. The hospital had reduced their costs substantially and also lowered their carbon emissions.  I was interested in what it would take to go further, to eliminate carbon emissions altogether, or even reach net negative emissions.   Though this was primarily a technical question, the policy implications centered around feasibility and benefits for localities.

From a community economic development perspective, I wanted to explore how this type of alternative energy production might help localities own and produce their own energy sources.  Also, growing, harvesting and burning switchgrass might appeal to rural communities more than solar and wind power, for example, which tend to change agrarian landscapes and require different skillsets. 

I remember talking with the hospital boiler operator and him saying, "I'm a boiler guy.  I don’t want to mess around with solar panels - my job is burning [material]!"  With the biochar process, farmers would still grow crops - switchgrass - and operators would still burn it.

We ran a lot of models, testing different scenarios, based on actual energy generation values from the hospital integrated with research literature, to see what we would get if we added a pyrolyzing element into it, adjusting for seasonal energy need fluctuation.  "Pyrolysis" is the burning process that results in biochar.  That charcoal can be stored for later heat generation, like in the winter, or better yet, can be spread on land where because of its stability, the carbon will stay inert or "captured" for hundreds of years.

The upshot is that we showed that - once a pyrolysis process is developed - the facility will achieve net-negative carbon release just by following standard procedure.  This is really encouraging, because it means that this process is feasible at small-scale.   Some infrastructure would need to be developed, but it would be much less costly than building a big plant, for example.

What most excited you about the work?

I am very interested in scale, especially in relation to energy transition and energy policy.  When most people talk about negative emissions, they usually talk about a huge centralized, engineered project…we were trying to show that decarbonized energy production can be distributed at the small-scale, local level for community economic planning.  It fits into the re-localization, community envisioning ethos.

This project fits into my general research interest in how to make scientific and technical information actionable within specific communities. For example, for my recently awarded NSF CAREER grant, I am looking at how computer models are adopted, used, and updated in complex environmental planning and management contexts. I am also involved in participatory action research in the City of Roanoke, Virginia on increasing capacity to deal with heat waves from within the community.  That project combines local and experiential knowledge from residents with scientific and technical information from urban climate science and urban planning.

How did the fellowship help advance your work? What were you able to do that you could not have done without the funding?

The fellowship enabled me to hire two engineers - Kyle Langseth and Amanda Cuellar - as consultants to support the thermochemical modeling and infrastructure design and cost analysis.  We collaborated on the eventual publication, in Environmental Science and Technology.   So in addition to creating a new research team, the +Policy Fellows grant helped me expand my expertise into technoeconomic analysis, and exploring the uncertainty around energy systems operations.

Just this month (July 2023), I was approached by researchers from another university, who want to apply some of what we learned and scaling from the case study to a wider geography.    We are discussing possibilities, so that is pretty cool.

We have a few questions about the policy-science interface we are curious about from all our +Policy Fellows.

How do you see your work influencing policies or policy-related research?

I don’t parachute into communities and say, “You need this.” I work at creating relationships with governmental entities that affect policies. We could not do the work without the collaboration of those entities. They help to define what the problem is. I try to listen to what their needs are. For the applied policy sciences, I rely on partnerships to help me determine what research questions could be useful. This is sometimes called “the co-production of knowledge.”

I am looking at the scale and technology communities could build and use on their own. In the local-scale carbon capture project, that community could be reaching negative carbon conditions because they have a district heating plant there and a lot of land. That would be a different influence in policy because that type of policy is not even on the radar yet.

How have you disseminated your Fellow work to non-academic audiences, including policymakers?

I use listservs, create contacts in local government, and forward studies and publications to state agencies.  For this study, I shared our results with the hospital, biomass producers, and a biochar discussion forum and mailing list.

Do you have any advice for faculty considering applying?

Demonstrating the relevance of my research to a specific community helped.

Did COVID affect your work?

I was able to make a few field trips to the hospital before the shutdowns, luckily.  The rest of the project was mostly me in my basement, Zooming a lot with Kyle and Amanda and running models.

Thank you!