SBASSE Talk: Valorisation of Lignocellulosic Residues in the Arid Regions Using a Bio-refinery Concept

Friday, December 8, 2017 - 11:15am to 12:15pm
Room 10-201, SBASSE

The Department of Chemistry and Chemical Engineering cordially invites you to a talk on

Valorisation of Lignocellulosic Residues in the Arid Regions Using a Bio-refinery Concept

Date: December 8, 2017
Time: 11:15 am -12:15 pm
Venue: Room 10-201, SBASSE

Speaker: Muhammad Tahir Ashraf, PhD

Abstract

Mitigating the ever-increasing greenhouse gases (GHG) emissions requires alternative sources of energy and chemicals that today are mostly coming from fossil fuels. Utilisation of lignocellulosic residues in a bio-refinery can be a potential way to achieve that. Lignocellulosic residues are non-food biomass and can be obtained from trees, grasses and agricultural crops. Polymeric carbohydrates in the lignocellulose, e.g. cellulose and hemicellulose, can be hydrolysed to monomeric sugars (C6+C5) using a pre-treatment process.

In a bio-refinery setup, these monomers can be converted to a range of biofuels and biochemicals. Envisioning a bio-refinery for an arid region starts with the challenge of a sustainable supply of biomass feedstock. Bio-refinery based on multi-feedstock lignocellulosic can be viable and can deal with the issues related to the limited supply of a single feedstock. In this talk, pre-treatment options for the multi-feedstock lignocellulose will be discussed.

An economic evaluation will be presented afterwards to highlight the best processing approach for the multi-feedstock lignocellulosic to produce the monomeric sugars. This modular approach of focusing on sugar platform makes the results applicable for fuel (ethanol) and non-fuel applications. At the end, a game theory based framework will be presented for the process design of bio-refinery networks.

A bio-refinery is analogous to an oil refinery, such that it decomposes feedstock to intermediate platform chemicals, and then these chemicals are upgraded to marketable products. Bioprocessing of lignocellulosic feedstock to produce marketable products constitutes a series of processing steps. There are several technological options available for each of the processing steps. Finding the best series of technologies and marketable products is a structural optimisation or process network synthesis (PNS) problem. Due to processing complexity, geologically disperse feedstock and product market; it might be feasible to distribute the bio-refining process into different sections that could be operated by independent companies.

A bio-refinery can be naturally decomposed on the basis of intermediate platform chemicals, where independent companies produce the intermediate platform chemicals and separate companies utilise the intermediates to produce marketable products. In such a scenario most of the intermediate chemicals will be new entrants to the market, and establishing their market price is imperative for a feasibility of the overall bio-refinery.

The conventional PNS solution approaches do not take into account this feature that each technology or processing step is operated as a separate company. However, for the described distributed manufacturing scenario, a framework is needed that takes into account the competing economies of the interacting actors and assigns a feasible price to the new entrant intermediate chemicals. The game theory based framework was developed to solve this PNS problem and to evaluate the price of intermediate products, where the bio-refinery process is carried out by independent multiple companies with competing economics.

Biography

Dr. Muhammad Tahir Ashraf is a chemical engineer by profession and a PhD graduate from Masdar Institute, part of the Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates. His area of research is modelling, simulation, and process design.

His PhD research was focused on the process design of bio-refineries for arid regions. This research was part of a bio-refinery collaborative project between Masdar Institute and MIT. In 2015, Dr. Ashraf was awarded an Advanced Study Programme at MIT by Masdar Institute. There, he worked on process simulation and structural optimisation of bio-refinery networks. Dr. Ashraf did his Masters of Science in Chemical Engineering from the American University of Sharjah in 2013 and an undergraduate in Chemical Engineering from UET Lahore, FSD Campus in 2010. He has industrial experience of working as a process engineer at Lotte Chemicals Pvt. Ltd., Karachi during 2010-11. Dr. Ashraf is currently a candidate to be a faculty member.