Biogas upgrading to biomethane by pressure swing adsorption

Anaerobic digestion is a proven technology to treat farm and food industry wastes. Due to microbiological activities, macromolecules such as lipids, proteins and carbohydrates are converted into small chain acids and ultimately into a gaseous mixture (biogas) comprising mainly methane and carbon dioxide. Farm originated biogas presents a CH4 mole fraction close to 60% while CO2 largely accounts for the remainder. The biogas produced during this process can be used in a variety of ways. Most frequently, it is converted into electricity and heat in a combined heat and power plant. Alternatively, biogas can be upgraded to biomethane for injection to the gas network for use in domestic, commercial and industrial heating or used as fuel in road transport. Since CO2 is removed in the separation process biomethane allows for carbon negative emissions in the heating and transport sectors.

Different gas separation technologies can be used purify the CH4-rich stream such as absorption (both physical and chemical), pressure swing adsorption, membrane separation and cryogenic treatment. After absorption processes, pressure swing adsorption (PSA) is the second most employed technique for biogas upgrading with several commercial small-to-medium scale plants worldwide.

In PSA processes, biogas is compressed to a pressure between 4-10 bar and is fed to a vessel (column) where it is put in contact with a material (adsorbent) that will selectively retain CO2. The adsorbent is a porous solid, normally with high surface area. Recent research and experimental demonstrations have shown that adsorption technology paves the way for scaling up the biogas upgrading process with high energy efficiencies. Moreover, PSA systems can be deployed in any part of the world since they do not depend on the availability of cold or hot sources. In this project, you will design and simulate an industrial vacuum PSA unit applied to the upgrading process of biogas to biomethane. A parametric techno-economic analysis will be carried out to assess the feasibility and the impact of this technology on a typical dairy cattle farm in Scotland.

Further Information: 

Closing Date: 

Wednesday, April 1, 2020

Principal Supervisor: 

Assistant Supervisor: 

Eligibility: 

Minimum entry qualification - an Honours degree at 2:1 or above (or International equivalent) in a relevant science or engineering discipline, possibly supported by an MSc Degree. Further information on English language requirements for EU/Overseas applicants.

Funding: 

Further information and other funding options.

Competition (EPSRC) funding may be available for an exceptional candidate but please note you must be a UK student or an EU student who has lived in the UK 3+ years.  This will be allocated around spring 2020.

Applications are welcomed from international students but you must apply for a University Scholarship (due to open around January 2020). 

Applications are also welcomed from self-funded students.

Informal Enquiries: