Interviews with Marianne Nyman and Alex Allen

Interview Preparation

Overall objective of research: Determine the yield of biochar that can be achieved from a given mass of agricultural waste. Create a cost-benefit analysis of biochar vs. charcoal.

Research questions Interview questions for Marianne Nyman and Alex (student)
What are the best materials to contract heat from the sun What are the biggest pitfalls to avoid when designing
To what extent does the atmosphere have to be low or no oxygen Propose the idea of using magnifying glasses in addition to mirrors, to get feedback
How can we maximize throughput of biochar from agricultural waste through solar energy? What is the ideal tube diameter/length to use
What are the benefits (agricultural, economical, etc.) that Ghanaians (or others) might gain from utilizing biochar instead of normal charcoal? Something about water filtration – the efficiency of regular carbon versus solar produced biochar.
Can we shrink the size if we supplement the mirror with other heating techniques what is the optimal angle for the mirror/ tracking system to have it follow the sun
Does proportion between mirror and reactor size matter Would it be useful to make the reactor portable / carryable

Background information on Marianne Nyman (chemistry, biology, environmental)

  • Water quality
  • HOC’s
  • Aquatic chemistry

Link to publications:

Research Activities:

Fate (and transport) of hydrophobic organic compounds (HOCs) in natural and engineered systems, aquatic chemistry, method development for HOCs, sorption/desorption processes, abiotic degradation of HOCs, modeling and mass spectrometry.

Interview Findings

Expert interview with Marianne Nyman at Materials Research Center.

Area of expertise: HOC’s, water filtration, aquatic chemistry.


  • recommends using a pressure cooker to process the biomass
  • a larger number of sides in the (activated) carbon will increase it’s ability to filtrate and clean contaminated water (can ‘absorb’ more)
  • Dr. Nyman does not agree with the fact that it is an environmental benefit to bind the carbon to the ground in the form of biochar.
  • coconut leftovers

Weight of corncobs:

  1. 35.4894 g
  2. 53.4316 g

The purpose of weighing the corncobs is to be able to determine how much biochar we can make from them. We will have to weigh the corncobs again after the pyrolysis. We will also measure the time it takes to process a corncob – an important consideration here is how we know that the corncobs have been fully processed.

Own reflections:

  • cooperation with CASE? (
  • could vacuum be relevant to look into? (in relation to the pressure cooker)
  • Questioning PVC as a good material for the reactor
  • we want to measure the throughput (the capacity) – but how do we know if the biomass has been fully processed and not over-processed?

Conversation with Prof. Eglash:

  • Valuable data: to make mistakes (for instance the prepared questions (assignment 6) that were irrelevant, when we were interviewing Dr. Nyman) and document these.
  • Biggest challenges now: the heliostat and the reflective foil
  • The parabola: we have to figure out the

Interview with Alex (RPI student, was in Ghana during the summer of 2014)

Summary: We talked to Alex for 30 minutes in the studio, before she had to leave for class. Her main focus this summer in Ghana seems to be working on the reflector, and especially how to apply the reflective material to a sheet.