(6ma) Utilizing bioenergy for production of energy and mitigation of climate change

Research Interests: Bioenergy with carbon capture and storage; Thermochemical conversion processes; Chemical looping; Heterogeneous catalysis; Waste management; Process modeling, integration, and optimization

Post-doctoral Projects

1) Gasification and pyrolysis of garden waste and agro residue for thermal applications Funded by: Tata Centre for Technology and Design (TCTD) IIT Bombay in collaboration with TCTD MIT; Supervisor: Prof. Sanjay Mahajani, Department of Chemical Engineering, IITB

2) Developing low-cost biomass to power systems using engine for tar reduction

Department of Mechanical Engineering, MIT; Prof. John Heywood’s research group with Dr. Leslie Bromberg (Funded by: Yanmar, Japan)

3) Current project: Decentralized biomass torrefaction systems for biochar production

Department of Mechanical Engineering, MIT (Funded by: J-WAFS) Supervisor: Prof. Ahmed Ghoniem

Research Experience

During PhD, I worked on an alternative chemical looping based process to produce feedstock for ammonia and nitric acid plants. The project was sponsored by Orica Mining Services, Australia, and the work primarily involved studying reaction of ammonia with different metal oxides, thermodynamic analysis, investigating reaction mechanism, and Aspen simulations. Later, in postdoc at TCTD, we developed an improved pelletization and gasification process, and patented a new fixed bed downdraft gasifier design for high ash feedstock. I worked on TGA, bench-top reactor, and pilot gasifier (40 kg batch capacity) primarily to investigate gasification performance, effect of operating parameters, and the role of ash on char reactivity. I also studied co-gasification of high ash coal and high ash biomass in the designed gasifier analyzing the effect of inorganic content on the synergistic performance. At MIT, my first project involved optimizing the induced downdraft gasifier and connecting it to the internal combustion engine that was investigated for its ability to crack tar in the producer gas. Presently, I am working on torrefaction of different biomass (e.g. pine shavings, hay, rice husk, wood chips, coconut shells) to produce biochar for improving crop yield and enhancing soil quality. We developed an auger- based moving bed torrefaction reactor where the reaction temperature is governed by controlling air-biomass ratio and the residence time is governed by controlling the speed of the motor operated auger. We defined an index of torrefaction to measure the severity of the process and proposed it as a parameter to guide the operation protocol of the reactor for a specific biomass based on application requirement. I am currently working on developing a control system for the reactor and carrying out a comparative life cycle analysis for non-oxidative and oxidative torrefaction.

Teaching Experience

1. Teaching Assistant in Department of Energy Science and Engineering, IIT Bombay (1 course each semester during PhD): a) Energy management; b) Process Integration; c) Non-conventional energy sources; d) Electrochemistry; e) Thermodynamics
2. Demonstrator for Mass Transfer (Separation) lab for undergraduate students at Department of Chemical Engineering, Monash University, Australia.
3. Lab instructor for Process Control at Department of Chemical Engineering, BITS Pilani.
4. Completed KTCP Summer Teachers’ Training Program at MIT (2019), and Professional Practice courses at BITS Pilani (2010-11).

As a post-doctoral fellow at Tata Centre, I took several sessions on different topics such as stakeholder analysis, business plan preparation, waste management, to name a few. These sessions used to be organized once a month for about 25 Masters students. I prefer teaching the courses such as Introduction to Chemical Engineering, Thermodynamics, Chemical Process Safety, Thermodynamics, Reaction Engineering, and other courses related to energy and environment.

Future Direction

I want to contribute to resolve the issues of energy security, environmental emissions, and waste management using chemical engineering knowledge through experimental and theoretical research in the areas of bioenergy, alternative fuels, and sustainability.

1) Bioenergy with Carbon Capture and Storage (BECCS)

BECCS is viewed as a promising negative emissions technology because the carbon dioxide released after conversion of biomass is captured and stored, and the new growing biomass consumes CO2 already in the atmosphere. However, there is no successful BECCS plant at commercial scale with rare exceptions, which means there are still several challenges that need to be addressed. A single large sized (500 MW) coal-fired or biomass co-fired power station typically emits 2 to 3 million tons of CO2 per year. I will work on mapping biomass resource availability at regional and global level; investigating supply demand chain of biomass & BECCS technology scenarios; evaluating the environmental and economic impacts of BECCS; and identifying the potential challenges & opportunities of large scale deployment of BECCS. Recently, U.S. Department of Energy (DOE) announced over $79 million in funding for bioenergy research and development including biofuels, bio-products, and biopower.

Biochar: Production, Applications, and Impact

Since the technology of BECCS has been considered to achieve CO2 emissions target set by Paris Agreement, understanding the role of biochar in reducing carbon emissions and providing energy has become an important area. Primary processes for production of biochar includes pyrolysis, gasification, and torrefaction. I will do the experimental studies on producing different grades of biochar using each of these processes at different scales starting with TGA and bench- top reactor. I also plan to investigate the synthesis of different magnetic biochars (Ca/Mg/Fe loaded) and their effectiveness in removing different contaminants from waste water. On application side, I will investigate carbon accounting and sustainability assessment of biochar chain using Life Cycle Assessment. On implementation and commercialization side, I will work with end-users (e.g. farmers) to acquire and use biochar, create demonstration plots, and develop training methods and materials to teach growers to implement biochar strategy effectively.

2) Chemical looping

Chemical looping is an innovative approach assisting CCS as it enables an almost pure CO2 gas to be produced, which can then be relatively easily stored without any further major processing. The process uses an oxygen carrier that is cycled between a fuel and an air reactor to provide oxygen for partial (Chemical looping gasification (CLG)) or complete (Chemical looping combustion (CLC)) conversion of the feedstock such as biomass, avoiding requirement of air separation unit. The relatively high quantity of volatile matter, and low sulfur and ash content of biomass makes it better feedstock over coal in chemical looping process. Two main reasons for the technology not being commercialized are oxygen carrier (OC) issues (e.g. inadequate reactivity, recyclability, strength, attrition resistance, oxygen-carrying capacity) and plant complexity especially the solids-circulating systems and heat transfer. I will start with work on developing efficient oxygen carriers from cheaper metal oxides, ilmenite, industrial waste, and bimetallic oxides; and then would investigate them for their gasification and combustion performance.

Publications

1. Thengane, S.K., Hoadley, A., Bhattacharya, S., Mitra, S., Bandyopadhyay, S. (2014). Cost- benefit analysis of different hydrogen production technologies using AHP and Fuzzy AHP. International Journal of Hydrogen Energy, 39
2. Thengane, S.K., Hoadley, A., Bhattacharya, S., Mitra, S., Bandyopadhyay, S. (2016). Exergy efficiency improvement in hydrogen production process by recovery of chemical versus thermal energy. Clean Technologies and Environmental Policy, 18 (5)
3. Thengane, S.K., Hoadley, A., Bhattacharya, S., Mitra, S., Bandyopadhyay, S. (2016). An alternative process for nitric oxide and hydrogen production using metal oxides. Chemical Engineering Research and Design, 112
4. Thengane, S.K., Hoadley, A., Bhattacharya, S., Mitra, S., Bandyopadhyay, S. (2017). Thermodynamic evaluation of chemical looping based nitric oxide and hydrogen production. Chemical Engineering Research and Design, 132
5. Siddiqui, H., Thengane, S.K., Sharma, S., Mahajani, S.M. (2018). Revamping downdraft gasifier to minimize clinker formation for high-ash garden waste as feedstock. Bioresource Technology 266 (Equal first author)
6. Gupta, A., Thengane, S.K., Mahajani, S.M. (2018). CO2 gasification of char from lignocellulosic garden waste: Experimental and kinetic study. Bioresource Technology, 263
7. Thengane, S.K. (2018). Assessment of different technologies for managing yard waste using analytic hierarchy process. Process Integ. and Opti. for Sustainability, 3(2)
8. Thengane, S.K., Tan, R.R., Foo, D.C.Y., Bandyopadhyay, S. (2019). A pinch-based approach for targeting of carbon capture, utilization, and storage (CCUS) systems. Industrial & Engineering Chemistry Research 58 (8)
9. Thengane, S.K., Gupta, A., Mahajani, S.M. (2019). Co-gasification of high ash biomass and high ash coal in downdraft gasifier. Bioresource Technology, 273
10. Kung, K., Thengane, S.K., Shanbhogue, S., Ghoniem, A. (2019). Parametric analysis of torrefaction reactor operating under oxygen-lean conditions. Energy, 181
11. Gupta, A., Thengane, S.K., Mahajani, S.M. (2019). Kinetics of pyrolysis and gasification of cotton stalk in the Central parts of India. Fuel (accepted)
12. Kung, K., Thengane, S.K., Ghoniem, A. (2019). Functional mapping of torrefied product characteristics for biofuel and chemical production. Journal of Cleaner Production (revised)
13. Thengane, S.K., Bandyopadhyay, S. (2019). Biochar Mines: Panacea to Climate Change and Energy Crisis? Clean Technologies and Environmental Policy (under review)