I am a PhD student in Curtis group (joined October 2010). My B.S. in Chemical Engineering was from Bangladesh University of Engineering and Technology, Dhaka, Bangladesh in 2006 and M.S. (also in ChE) from North Carolina A&T State University in Greensboro, NC in 2010.
My project is about developing an alternative biofuel production platform. Specifically, using a genetically engineered organism (Rhodobacter capsulatus) to produce C30 hydrocarbons from H2, O2 and CO2. The research funding is from ARPA-E and the project is part of an Electrofuels program. The idea is to convert renewable electricity (solar photovoltaics, wind etc.) into H2 and O2 by splitting water. Use these together with CO2 from a point source, such as power plants, to feed to R. capsulatus that can produce the fuel.
So far we have successfully genetically engineer R. capsulatus to produce C30 hydrocarbons, botryococcene and squalene. We have been able to use metabolic engineering strategies to improve production of these molecules in R. capsulatus. Then used autotrophic bioreactor culturing to attain higher culture densities and production levels > 100 mg/L and continuous specific titers of 23 mg/gDW. We have also compared the production levels in the various trophic modes (heterotrophic, photoheterotrophic and autotrophic) that R. capsulatus can grow in and found surprisingly similar levels of production in all. A manuscript of this work is currently in preparation.
A separate aim of this project was also to assess the economic viability of the scaled-up process. To that end, we have developed a process model integrating biological yield and maintenance parameters, reactor residence time, gas-liquid mass-transfer coefficients and specific fuel productivity to obtain capital and operating costs. We have found that the cost of electricity (both capital and operating) is the largest fraction of the fuel cost by an order of magnitude, followed by cost of reactor and mass transfer. As a convenient benchmark, we have calculated that a levelized cost of electricity (LCOE) of about 2 cents/kWh would make this process economically competitive with current crude oil prices if the fuel productivity of 0.5 g-fuel/(gDW.hr) was achieved. This work has recently been accepted for publication Bioresource Technology.
We are currently working on improving the productivity of the fuel in R. capsulatus by engineering the heterologous mevalonate (MVA) pathway.
from Penn State work
Nymul Khan, John Myers, Amalie Tuerk, Wayne Curtis, A process economic assessment of hydrocarbon biofuels production using chemoautotrophic organisms, Bioresource Technology, 2014 (accepted).
N.E. Khan. Rhodobacter as a platform for autotrophic fuel production, AIChE National Conference, Pittsburgh PA, Oct. 29 2012.
Nymul Khan, John Myers, Ryan Johnson, Alex Rajangam, Eric Nybo, Joe Chappell and Wayne Curtis. Progress and economic considerations for the biological production of triterpene biofuels from gases. AIChE annual meeting, San Francisco, 2013.
N. E. Khan. Autotrophic biofuel production via Transgenic Rhodobacter capsulatus, Biomass 2012: Confronting Challenges, Creating Opportunities, Washington, DC, July 10-11, 2012.
from prior research
Y. G. Adewuyi and N. E. Khan. Modeling the Ultrasonic Cavitation-Enhanced Removal of Nitrogen Oxide in a Bubble Column Reactor. AIChE J, Online, 2011.
N. E. Khan and Y. G. Adewuyi. A new method of analysis of peroxydisulfate using ion chromatography and its application to the simultaneous determination of peroxydisulfate and other common inorganic ions in a peroxydisulfate matrix. J. Chroma. A, 1218, 392-397 (2011).
N. E. Khan and Y. G. Adewuyi. Absorption and Oxidation of Nitric Oxide (NO) by Aqueous Solutions of Sodium Persulfate in a Bubble Column Reactor. Ind. Eng. Chem. Res., 49, 8749-8760 (2010).
M. A. Rahman and N. E. Khan. Study of an Evaporation System for Sodium Hydroxide Solution. J. Chem. Eng. Inst. Engineers, Bangladesh, 24, 1, 35 (2006).
226 Fenske Laboratory,
Pennsylvania State University
University Park, PA 16802
Phone: (336) 790 8954