Rahul P.B. Ashok: Industrial production of colloidal lignin particles and biomass-based platform chemicals

Abstract:

The main goal of this doctoral research is the development of economically, technically feasible, sustainable, and profitable processes to produce valuable products from biomass. The lignin fraction is used to produce lignin-based adhesives and coatings which are more sustainable and eco-friendlier in comparison to the currently used phenol-formaldehyde based adhesives in the market. On the other hand, multiple valuable platform chemicals are produced using the cellulose and hemicellulose fractions for use in applications such as biofuels and solvents. Sustainable synthesis routes were identified, and techno-economic process models were developed to carry out process conceptualization, process simulation and modelling, process optimization and feasibility assessment. Discounted cash flow rate of return (DCFROR) analysis was performed to determine the cost of production/minimum selling prices of the biomass derived products. The process profitability was ascertained by using different criteria such as net present value (NPV), internal rate of return (IRR), payback period and return on investment. Sensitivity studies helped in understanding the impact of key process and economic parameters on the process and the risk involved in the project was gauged by carrying out uncertainty analysis using Monte Carlo simulations.

The key findings of the dissertation are as follows: (1) A novel and sustainable approach for the economical industrial-scale production of colloidal lignin particles was conceptualized and developed. The CLPs produced could compete with petrochemical feedstock and ensure efficient way to utilize lignin in value-added applications capable of generating revenue; (2) A novel tubular reactor containing static mixing elements was designed and developed for the continuous processing of colloidal lignin particles. The tubular reactor produced CLPs with uniform particle diameter, high stability and enabled easy scalability for industrial use; (3) The techno-economics of furfural production from birch hydolysate liquor was investigated and biomass derived furfural could be manufactured at a competitive market price (4) An integrated biorefinery concept was conceptualized and developed to produce multiple platform chemicals such as GVL, 2-MTHF and 5-HMF from lignocellulosic biomass (spruce). The lignin and humins generated during the process were used for meeting the heating and electricity demands for the process, thereby making it self-sustaining, energy efficient and environmentally sustainable.

Follow the remote defence: TBC

Opponents: Professor Riita Keiski, University of Oulu, Finland, and Professor Christian Hulteberg, Lund University, Sweden

Supervisor: Professor Pekka Oinas, Aalto University, School of Chemical Engineering, Department  of Chemical and Metallurgical Engineering

Link to electronic thesis: Industrial production of colloidal lignin particles and biomass-based platform chemicals