Artificial Intelligence Enabling Future Optimal Flexible Biogas Production for Net-Zero

Lead Research Organisation: University of Surrey
Department Name: Chemical Engineering

Abstract

Anaerobic digestion (AD) is a technology where microorganisms break down organic matter to produce biogas, thereby generating renewable energy from waste. Biogas can be combusted to produce electricity or purified and used as a substitute for natural gas (NG). Because it provides a carbon-neutral substitute for fossil fuels, while also preventing methane emissions at landfills by processing organic waste, AD is noted as an important part of the UK Net Zero Strategy: Build Back Greener.
This project aims to develop artificial intelligence (AI) tools to enable radical efficiency improvements in AD biogas production. Currently, there are about 650 operational AD sites in the UK, which reduce UK greenhouse gas emissions by an estimated 1%. This contribution is meaningful, but modest in comparison to AD's potential. The fundamental roadblock at present is a lack of flexibility. Due to the complexities of predicting how different waste feedstocks and different microbial communities will interact under varying operating conditions, AD biogas producers must minimise risk by purchasing only the highest-quality, consistent feedstock, which may also be seasonal; any errors could result in long and costly downtimes. Thus, available waste streams are vastly under-utilised; feedstock prices are driven up, weakening the economic viability of AD biogas production; and limited feedstocks may need to be transported longer distances, increasing carbon emissions.
AI holds crucial promise for the optimisation and future expansion of AD biogas production. As an industry that does not have the central research capabilities of other large energy sectors, it furthermore presents exceptional challenges due to the complexities and inherent uncertainties across interacting chemical, biological, and - if reductions in total life-cycle emissions are to be achieved - environmental systems. The project team therefore unites expertise in AI, process optimisation, systems microbiology, and life-cycle assessment to develop whole-systems decision-making tools informed by detailed sub-system modelling.
The outputs will include decision-making tools, specifically: A) a hybrid machine-learning digital twin of the biodigesters, based on novel mechanistic modelling approaches combined with process data from industrial partners and new experimental data from the project; and B) optimisation-based system models of other components of a site, to perform site-wide real-time optimisation through a multi-layer digital twin that includes economic and environmental indicators. By linking the digital twin of the biodigester to feedstock procurement and downstream processes, it will be possible to quickly determine the impact of different feedstocks, their combinations, and their prices on biogas quality, while also tracking quantified environmental impacts across AD value chains in real-time and assessing negative emissions potential in future.
Increasing the flexibility of UK AD industry will expand waste markets and lower prices to grow the sector with more capacity, boost profits and productivity, and enhance the overall attractiveness of AD as an investment. Increasing biogas output will help lower UK dependence on foreign NG sources and lower overall emissions from the energy system. The project is supported by partners from across the UK to ensure the aims and objectives can be met, to result in a step-change in the AD industry and position the UK as a global AD leader. The knowledge, tools, and methods developed will be applicable in wastewater treatment, where AD is also used. Beyond that, our AI approaches to systems biology will have potential for widespread application in bioprocessing sectors more generally, such as biopharmaceuticals, biofuels, food, and fermentation. With our network of partners, we will explore potential commercialisation and licencing of our digital techniques to maximise impact and work across sectors toward the common goal of Net Zero.

Publications

10 25 50
 
Description Life Cycle Assessment for the EBNet Industrial Community: Goal and Scope Definition
Geographic Reach National 
Policy Influence Type Influenced training of practitioners or researchers
Impact With the worldwide concerns of the living environment, it is highly important to investigate and understand the environmental impacts of each technology and feedstock, for decision-makers to develop the future energy management plan. This understanding is crucial for decision-makers in formulating strategies for managing these organic materials using circular economy principles. AD is assisted by hydrothermal treatment and nutrient recovery, with this framework seen as a promising circular economy concept for food waste valorization, while reducing the carbon footprint. Developing an LCI and gathering data stand as a pivotal phase in any LCA investigation. Our novel standard anaerobic digestion (AD) / biogas / biomethane / bio-electricity GWP calculation equation follows the format for GWP measurements, regulations, and reporting of the EU directive, consisting of GWP from individual life cycle stages, i.e., resource acquisition or cultivation, transportation including feedstock and digestate, AD plant operation, CHP systems, and digestate application. Further, avoided GWP includes GWP from natural gas production (displaced by cradle-to-gate AD systems), or GWP from grid electricity and heat, and conventional fossil-based fertilizer (displaced by cradle-to-grave AD systems). The net GWP saving by AD systems is the difference between avoided GWP and GWP impacts. Commendably, our novel model provides the formulation in a format similar to the EU Directive of the European Parliament and of the Council by establishing a minimum threshold for greenhouse gas emissions savings.
 
Description African Agriculture KTP:23-24 Part 2
Amount £241,337 (GBP)
Funding ID 10097617 
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 07/2024 
End 07/2026
 
Description Research and Innovation for Development in ASEAN (RIDA)
Amount £60,000 (GBP)
Organisation Foreign Commonwealth and Development Office (FCDO) 
Sector Public
Country United Kingdom
Start 01/2024 
End 06/2024
 
Description Supergen Bioenergy Impact Hub 2023
Amount £5,295,845 (GBP)
Funding ID EP/Y016300/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 11/2023 
End 10/2027
 
Title Novel Algebraic Equation-based Models for Global Warming Standardization in Anaerobic Digestion Systems with Critical Life Cycle Analyses 
Description There is renewed interest in biogas due to the Green Gas Support Scheme to create Net-Zero UK. It is crucial to develop a universally robust LCA model to conduct structured and reliable evaluations of LCA, ensuring the results remain comparable with those from LCI databases. Thus, our approach results in two sets of algebraic equations for standard GWP estimation, one based on published literature and the other based on the Ecoinvent LCI database. The predictions between the two models are compared, so that the former set of algebraic equations based on published literature can be easily applied in other studies to calculate the GWP of biogas in various contexts (biomethane and bio-electricity). Our approach emphasizes ease of updating and can be used in long-term or short-term scheduling and control optimization models, achieving the same quality of results as the LCI database. In this study, we pursued several objectives: (i) a comprehensive analysis of LCA results for various feedstocks used in AD systems worldwide; (ii) an exploration of the impact of different AD system variabilities on LCA through sensitivity analysis; (iii) the development of LCA-based algebraic formulae to evaluate the environmental footprint of cradle-to-grave (literature-based) and cradle-to-gate (both literature-based and Ecoinvent LCI-based) AD systems across different scenarios, feedstocks, geographic locations, etc.; and (iv) a comparison between the two approaches. It can be noted that Ecoinvent LCI data for cradle-to-grave AD systems are aggregated and indivisible by life cycle stage or activity. Consequently, Ecoinvent LCI-based formulae are limited to cradle-to-gate up to biomethane production systems. In contrast, literature-based formulae cover holistic cradle-to-grave systems with contributions of individual life cycle stages or activities. Furthermore, comparisons of the literature-based model with the Ecoinvent-based predictions are conducted to reveal closely aligned results, affirming their robustness. 
Type Of Material Technology assay or reagent 
Year Produced 2024 
Provided To Others? Yes  
Impact The organic waste processors can easily access this research tool and method to calculate the GWP saving through their waste treatment process. This result will help them to comply with the regulations. Biogas or anaerobic digestion (AD) systems can mitigate global warming potential (GWP), but carbon trading is complex. Successful carbon offsetting requires AD systems to adhere to key carbon crediting or offsetting programs, such as Verra's Verified Carbon Standard (VCS), Gold Standard (GS), Climate Action Reserve (CAR) and American Carbon Registry (ACR) by standardizing life cycle GWP reporting. For example, there are 147 ongoing VCS carbon offsetting projects with biogas estimated to reduce 16.93 Mt (million tonnes) CO2e. There are 322 ongoing GS carbon offsetting projects with biogas estimated to reduce 22.88 Mt (million tonnes) CO2e. This study focuses on creating algebraic equations for calculating the GWP of biogas, crucial for carbon crediting or offsetting programs and net-zero goals, which balance carbon emissions and sequestration. Biogas, derived from carbon-neutral organic waste and used as a substitute for natural gas, contributes to reducing greenhouse gas (GHG) emissions. With increases in carbon markets and the value of selling carbon offsets, it is important to predict GWP savings from replacing fossil fuels, and a comprehensive life cycle assessment (LCA) is thus necessary. The study develops two novel methods for GWP calculation based on published literature and the Ecoinvent life cycle inventory (LCI) database. These methods, which differ in how they group life cycle activities, are compared to assess their predictive accuracy. The methods conduct a rigorous and significant modular synthesis approach, assigning a distinct GWP to the life cycle stages or activities in the system. This study's models are thus essential for an effective and thorough life cycle GWP assessment in AD systems. The tool will be applied by waste processors to calculate the carbon offset or saving or reduction by their system enabling them to apply for the various carbon offsetting schemes as well as qualifying them for the Green Gas Support Scheme. An example is the 50 g CO2e per kWh biomethane production rate requirement by 2030 for gas grid injection of biomethane in the UK's net-zero electricity carbon intensity requirements. 
 
Title Digital whole-site decision-making models for Anaerobic Digestion 
Description We have developed optimisation models for whole-site decision-making (feedstock acquisition, storage, digester performance prediction with co-digestion, and downstream gas cleaning and storage). 
Type Of Material Computer model/algorithm 
Year Produced 2024 
Provided To Others? No  
Impact We are in the early stages of implementing this on partner sites. Hence, no quantified impacts to report as of yet. 
 
Title Life cycle global warming potential of biogas, biomethane and bio-electricity 
Description Amidst rising interest in biogas as a sustainable alternative to traditional energy vectors like natural gas, this study focuses on its role in achieving net-zero targets-where carbon emissions are balanced with sequestration. Biogas, derived from carbon-neutral organic waste, offers significant greenhouse gas (GHG) emission reductions. Life cycle assessments (LCA) are crucial for evaluating the global warming potential (GWP) of biogas, ensuring its effectiveness in offsetting fossil fuel equivalents. However, current GWP calculations lack transparency and standardization, necessitating new robust easily calculable algebraic equations. Our study introduces two complementary sets of equations, grounded in published literature and LCA databases. Despite their differing structures due to distinctive specific activities across life cycles, both sets yield closely aligned estimations, reinforcing confidence in these models. The GWP is sensitive to the feedstock type, electricity and heat consumption, and fugitive emissions. The statistical distributions show the mean GWP of 0.54 per m3 biogas, 0.09 per kWh biomethane and 0.73 per kWh electricity production rates of cradle-to-grave systems with all plausible technologies available in the database. The lowest GWP meets the UK's 50 g CO2e per kWh biomethane target by 2030 for gas grid injection. The GWP in g CO2e per kg AD feedstock is 93-104 (manure), 16-26 (sludge), and 273 (grass silage), etc. The biowaste AD system reduces at 0.5-0.7 kg CO2e per kWh of electricity generated, requiring 1.5 MWh of minimum threshold electricity generation to reduce 1 tonne of CO2e. 
Type Of Material Computer model/algorithm 
Year Produced 2024 
Provided To Others? Yes  
Impact There has been an upsurge of renewed interest in the comparative LCA of biogas/AD as a mechanism to standardize climate change impact reduction potential. This study offers a fresh perspective on calculating the GWP performance of AD setups utilizing data from literature and the Ecoinvent LCI database. First, based on detailed comprehensive literature review, a GWP prediction model with equations focused on GWP of each activity in the AD system has been developed. Second, Ecoinvent 3.6 LCI data of all AD-related systems are assimilated to create another GWP prediction model. Both models are then tested to see how they compare. They show good agreement, despite some distinguishing characteristics. In the process of detailed exploration of the possibility of open-source models based on literature and the Ecoinvent database, some scopes are identified, e.g., Swiss (or alternatively rest of the world) data availability in Ecoinvent. The published literature-based model shows more inclusivity in terms of global contexts, allowing LCA stage-specific GWP factors updating based on geographic contexts. Both models capture sensitivity of feedstock variations in GWP prediction and energy related GWP variations, demonstrating robust comprehensive GWP calculations. Furthermore, the Ecoinvent 3.6 LCI database allowed analysis of GWP due to variations in biomethane purification or pre-combustion upgrading technologies (amino washing, membrane, and pressure swing adsorption) and CHP technologies (micro gas turbine (MGT), polymer electrolyte membrane fuel cell, solid oxide fuel cell (SOFC) and SOFC-MGT). Our modular synthesis approach demonstrates distinguishable GWP from each feedstock and technology type, allowing a statistical analysis that shows GWP variations, 25th, 50th and 75th percentile values, and mean values in transferable units, per unit volume of biogas and biomethane, and per unit energetic value of biomethane and electricity, for the cradle-to-grave systems. Some key quantitative GWP measures are as follows. The cradle-to-grave AD system's GWP (kg CO2e/m3 biogas) from the literature-based and Ecoinvent data-based models is manure: 1.33 and 0.9-0.97, sludge: 0.5 and 0.42-0.48, food waste or biowaste 0.34 and 0.29-0.35, and grass silage 1.2 and 0.5-0.58. The GWP in g CO2e per kg AD feedstock is 93-104 (manure), 16-26 (sludge), 245-618 (UCO), and 273 (grass silage). The intended recipients of this study encompass governmental agencies, environmental engineers, the scientific community, feedstock community and energy companies, informing emerging policies on net-zero. 
 
Description Carbon credits and life cycle assessment for biogas CHPs 
Organisation Rolls Royce Group Plc
Country United Kingdom 
Sector Private 
PI Contribution We have developed Life Cycle Assessment models for biogas with Rolls-Royce for their internal use. We have also provided them with guidance on carbon credits for increasing plant profitability.
Collaborator Contribution Using their expertise and data, they have helped us to develop LCA models for environmental performance monitoring of AD. Through several meetings jointly held with them, they have helped us to better understand the process for carbon credit verification. They have also attended our workshops.
Impact Internal models of LCA for Rolls-Royce use. We have an output under review.
Start Year 2023
 
Description Increasing Biogas in South Africa 
Organisation Council of Scientific and Industrial Research (CSIR)
Country South Africa 
Sector Academic/University 
PI Contribution After this award, I was invited to give work with South Cape TVET College on a waste-to-energy project in George, South Africa. We are meeting with the Mayors in the area and doing research on feedstocks and carbon financing for these projects.
Collaborator Contribution They have been finding local partners on the ground and liaising between myself and the municipalities and local stakeholders to find interest and funding. They have also been handling questionnaires for local waste collection and landfills.
Impact None
Start Year 2023
 
Description New partnerships in Brazilian biogas 
Organisation Universidade de São Paulo
Country Brazil 
Sector Academic/University 
PI Contribution We hosted research visits at Surrey of undergraduate and Professors working in this space to share ideas and data. We provided modelling insights and techniques for their work in mapping biomass potentials in Brazil.
Collaborator Contribution We hosted an undergraduate research assistant, sponsored by FAPESP, at Surrey. The researcher worked with the Surrey team to develop new models and visualisation tools for mapping biogas potential in the UK. They also invited Dr Short to give a presentation in Sao Paulo to partners, CopaEnergia. This partnership is still developing.
Impact Under review
Start Year 2023
 
Description EBNet Webinar: Unlocking AI and Machine Learning's Potential for Environmental Biotechnology 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Dr Short and Dr Zhang were invited to the webinar as it featured prominent academics discussing the application of AI and machine learning to improve bioremediation, resource recovery, and environmental protection. The audience asked questions after presentations on the use of AI in AD and it sparked discussions and new collaborations.
Year(s) Of Engagement Activity 2024
URL https://ebnet.ac.uk/wgai-ebml-240221/
 
Description Interview on BBC Surrey radio 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Media (as a channel to the public)
Results and Impact 5 minute interview on BBC Surrey radio to discuss the award of the project (15-06-2024). The interview was played as a small snippet throughout the day and then the full interview at around 17h30. We discussed AI and biogas generally
Year(s) Of Engagement Activity 2023
 
Description Invited talks/panel at African Summit on Entrepreneurship and Innovation 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Dr Short invited to attend the African Summit on Entrepreneurship and Innovation by the Department for Business and Trade. Dr Short presented this project to delegates from across Africa in academia, government and industry. The simple explanations on what AI is and how it can be applied, as well as the potential for bioenergy sparked debate and new partnerships in South Africa.
Year(s) Of Engagement Activity 2023
URL https://www.facebook.com/ASENTIKE/
 
Description Life Cycle Assessment (LCA) for the EBNet Industrial AD Community-Goal and Scope Definition 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We co-hosted an industrial workshop, which attracted 25 industrial practitioners from as far as Germany and Chile to interact in a workshop discussing AD life cycle assessment, challenges and future directions.. This sparked a lot of discussion and has also resulted in new partnerships with some of the companies that attended.
Year(s) Of Engagement Activity 2023
URL https://ebnet.ac.uk/wg-lca-231030-scope/
 
Description Media attention related to project announcement 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact We have been the subject of a fair amount of media attention, with the press release picked up by national and international trade media, including EnviroTech Magazine, AzoRobotics, Green Business Journal, and Biofuels Digest.
Year(s) Of Engagement Activity 2023,2024
URL https://envirotecmagazine.com/2023/06/14/ai-plus-microbes-could-unlock-higher-biogas-production-for-...
 
Description Presented at Energy Systems Catapult South Africa Industrial Decarbonisation workshop 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Dr Short invited by Energy Systems Catapult to support the FCDO-funded UK-SA Industrial Decarbonisation project. Dr Short presented this project and resulting discussions for engagement with large South African companies, government and academia in future.
Year(s) Of Engagement Activity 2024
 
Description TV interview on BBC South 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Media (as a channel to the public)
Results and Impact I was interviewed related to an explosion on an anaerobic digester site in Oxfordshire.
Year(s) Of Engagement Activity 2023
 
Description Talk at the ECO-AI Workshop: AI-Driven Solutions for Carbon Capture and Storage 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact As part of building the AI for Net Zero Community, I was invited to deliver a talk at the workshop hosted by another project, ECO-AI.
Year(s) Of Engagement Activity 2024
 
Description Webinar on AD Modelling Demystified: Essential Fundamentals and Hands-on Applications 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact In this webinar, Dr Short was invited by EBNet and Modela PTY to participate in describing the modelling fundamentals and highlight the benefits associated with its practice. The goal was to demonstrate the significant role that modelling should play in the context of climate change, industrial automation and digitalisation for both academia and industrial partners. We had around 50 people live and the Youtube video has been viewed over 100 times. This has led to follow-up work.
Year(s) Of Engagement Activity 2024
URL https://ebnet.ac.uk/ad-modela-ai-240208/