Aston works with Asian partners to tackle rice crop emissions

Rice farming accounts for around eight per cent of agricultural greenhouse gas emissions around the world. The flooded fields in which it is grown produce large quantities of methane, as organic waste decays in the absence of oxygen. When rice is harvested, its straw then becomes a source of waste, 300 million tonnes of which is burned across Asia each year.

The RICE (Renewable, Inclusive Carbon-negative Energy) project will see Aston working with UK company Straw Innovations and Indian SME Takachar to cut rice emissions. Takachar’s biochar technology converts agricultural waste into higher value products such as fertilizer blends, chemicals and biofuels.

The Indian firm is now developing a larger scale version that is suitable for rice mills, with the potential for the heat created by the biochar process to be harnessed for drying rice. This machinery will be deployed by Straw Innovations in the Philippines and by Takachar in India, with farmers exploring a variety of business models.

Aston University researchers will help assess the sustainability of the project, calculating the greenhouse gas emissions savings of the new systems in both countries. Sustainability expert Dr Mirjam Röder, from  Aston University’s Energy & Bioproducts Research Institute (EBRI), will engage with the local farming communities to quantify how the systems impact incomes, equality of opportunity, food security and decarbonisation.

“Environmentally, rice produces 48 per cent of all global crop emissions, due to methane from flooded fields,” Dr Röder said in a statement.

“This is halved when the straw is removed and reduced further when its carbon is stored in biochar. We are aiming for carbon negative, which means removing carbon dioxide (CO2) from the atmosphere or sequestering more CO2 than is emitted.”

In January, Dr Röder published a paper related to the project alongside colleagues Professor Patricia Thornley, director of Aston’s EBRI, and Craig Jamieson from Straw Innovations. Appearing in the journal Biomass and Bioenergy,  the paper is titled ‘The greenhouse gas performance and climate change mitigation potential from rice straw biogas as a pathway to the UN sustainable development goals’.

"We’ve been pioneering rice straw work with the team at Aston University for the past seven years,” said Jamieson. “We're delighted to continue that strong partnership and widen it to include Takachar in this new project.

“Takachar is a leader in making biochar from crop residues and our partnership with them is very strategic. We look forward to combining our new improved straw harvesting technology with their scaled-up biochar production. It will be a step change, creating a new, more efficient system for carbon negative energy and soil improvement for rural communities across Asia."