This collaborative research into sustainable biogas recovery was led by researchers at Queen’s University Belfast. The project resulted in the construction of a pilot anaerobic digestion plant, the dissemination of findings through workshops and policy briefings, and the integration of case studies into a new undergraduate module at Queen’s Business School.

Dr Thomas Hastings from Queen’s Business School, in collaboration with Dr Beatrice Smyth from the School of Mechanical and Aerospace Engineering,  led an interdisciplinary and international project that aimed to address the environmental and economic challenges associated with the burning of rice straw residues in developing countries. The project involved King Monghut’s University of Technology North Bangkok and was funded by the Global Challenges Research Fund. The focus of the research was to examine the environmental impacts and socio-economic factors influencing biogas transitions in Thailand using sustainable biogas recovery from rice straw residues.

Understanding the science

It is a common practice in Thailand to burn rice straw in the fields after harvest. This results in the release of greenhouse gases and toxic pollutants. Burning rice straw significantly contributes to air pollution, which particularly affects the most impoverished within the population. To mitigate the environmental and economic issues associated with rice straw burning, Dr Smyth and Dr Hastings devised a plan centred around the process of anaerobic digestion. Anaerobic digestion provides an environmentally friendly method to manage organic waste by reducing landfill waste, capturing harmful gases, producing renewable energy, and creating valuable fertiliser.

Using rice straw for biogas production could alleviate environmental and health burdens, displace fossil fertilisers, and provide sustainable clean-burning energy, benefiting socio- economically farmers and their communities. In particular, the production of renewable energy (i.e., heat, electricity) and nutrient rich biofertiliser has clear use value as a digestate which is pasteurised before use. Biogas may also be converted into bio methane fuel after purification, which can be used as car fuel.

Primary research outcomes

The primary outcome of the research project involved the construction of a pilot anaerobic digestion plant in Valaya Alongkorn Rajabhat University, which is regularly used for demonstrations and open days attended by students, public workers, local industry representatives, and rice farmers. The project concluded with an online rice straw workshop, to disseminate the project's findings to stakeholders in Thailand.

Stakeholder review

In a review that was presented to stakeholders, Dr Hastings found that rural Thailand has undergone economic diversification and administrative integration, resulting in the emergence of a powerful political force among the poorest. While rural living standards have significantly improved, there is a new form of economic disparity, with slower rural income growth compared to other sectors.

The burning of rice straw is convenient but lacks economic incentives for farmers. Air pollution caused by burning has led to social unrest, with calls for unified approaches and the promotion of anaerobic digestion facilities as a possible solution. Economic incentives and suitable conversion technologies are necessary for promoting biomass energy from rice straw.

• Anaerobic digestion presents opportunities for both private and community wealth building projects: Opportunities may be integrated as part of a circular economy and ‘multi-functionality’ approach to farming.
• Opportunities exist to commercialise/capture community benefits relating to gas/energy production from anaerobic digestion (methane related energy is a renewable alternative to fossil fuels). Of these, power and heat produced from biogas can support local facilities, allowing digesters to effectively pay for themselves.
• Anaerobic digestion offers various business opportunities for other products, including organic fertiliser which is cheaper than chemical fertilisers.
• Nutrient recycling may also lead to cooperation between farms, trading excess nutrients to those in need. Digestate used as fertilizer also enables organic farming. This digestate is also less odorous than manure and may be spread closer to residential buildings which allows for savings on transportation costs.
• Some developing countries, including China, have already had success with anaerobic digestion as a source of energy for remote, off-grid rural areas.
• Production of traffic fuel, including bio methane (purified biogas). The use of this fuel has increased substantially in many countries such as Finland.

Comparison with Great Britain and Northern Ireland

Dr Hasting conducted research interviews with Thai stakeholders from Chiang Mai Rajabhat University, the Thai government’s Rice Department and with Northern Irish anaerobic digestion stakeholders. He combined these interviews with an in-depth examination of policies in Northern Ireland and other locations. The outcomes of this research provided valuable insights to both the Thai partners and collaborators from Queen's University Belfast regarding effective and ineffective practices within the anaerobic digestion sector.

Dr Hastings found that in Great Britain and Northern Ireland, anaerobic digestion support has been incentivized through various different schemes, including the Renewable Obligation, the Feed-in Tariff, and the Smart Export Guarantee. Northern Ireland had its own modified version of the Renewable Obligation, known as the NIRO, providing improved incentives for renewable energy.

NIRO has played a significant role in promoting the growth of anaerobic digestion facilities in the region. The scheme offered higher subsidy rates compared to Great Britain, leading to a rapid increase in anaerobic digestion sites by the end of 2017.

Emerging impact

• The pilot plant in Valaya Alongkorn Rajabhat University regularly used for demonstrations and open days at which there is attendance from students, public workers, local industry and local rice farmers and enabled novel research to be conducted on the fungal pre-treatment of rice straw before fermentation.
• The knowledge sharing from a workshop held at Queen’s University Belfast and a socio-economic working paper have provided valuable insights on policies and supports and what is required for a successful biogas industry.
• The socio-economic research findings are informing the design of a new module in Queen's Business School, integrating case studies from the project into the final year undergraduate course on Contemporary and Emerging Issues in Business (MGT3034), which will enhance discussions on green transitions and rural development challenges posed by anaerobic digestion.
• The project laid the foundation for a follow-on study titled "DfE Biogas Technoeconomics," led by Dr Tom Hastings with his colleague Dr Jelena Vlajic.

 

Dr Thomas Hastings

Senior Lecturer - Queen's Business School (QBS)

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