Aston University to aid Indonesia with affordable energy drawn from rice straw

Scientists at the Energy and Bioproducts Institute at Aston University are to start a project to convert Indonesia’s unwanted rice straw into low-cost energy on a commercial scale.

Each year the country produces 100 million tonnes of the rice waste, of which 60% is burned in open fields, causing air pollution and has even been linked to lung cancer.

The amount burned is equivalent to approximately 85 Terawatts of electricity, which is enough to power Indonesia’s households 10 times over.

A consortium which includes Aston University aims to develop processes to capture more affordable energy from rice straw than ever before – and demonstrate that it can be done on a commercial scale.

Part of the process involves a biomass conversion technology called pyrolysis. This involves heating organic waste materials to high temperatures of around 500 °C to break them down, producing vapour and solid products. Some of the vapour may be condensed into a liquid product called pyrolysis oil or pyrolysis bio-oil. Both the pyrolysis vapour and liquid bio-oil can be converted to electricity.

Current methods convert just 35% of the thermal energy of rice straw to affordable electricity. However, a newly patented combustion engine designed by consortium member, UK-based Carnot Limited, could see that doubled to 70%.

Energy extracted this way could help low and middle-income countries create their own locally generated energy, contribute to net zero by 2050, create new jobs and improve the health of locals.

The project will help develop a business model which could support companies and local authorities to produce local, cheap energy in Indonesia, and other countries with biomass capacity.

Three academic experts from different disciplines at Aston University are involved in this initial project, which focuses on Indonesia’s Lombok Island.

Dr Jude Onwudili, Dr Muhammad Imran and Dr Mirjam Roeder are based at Aston University’s Energy and Bioproducts Research Institute (EBRI).

Dr Jude Onwudili who is leading the team said: “This project has huge potential – commercialisation of this combined technology will have significant economic benefits for the people of Indonesia through direct and indirect job creation, including the feedstock supply chain and electricity distribution and sales.

“About one million Indonesian homes lack access to energy and Indonesia’s 6,000 inhabited islands make sustainable infrastructure development challenging in areas such as Lombok Island.

“The new techniques being explored could reduce environmental pollution, contribute to net zero and most importantly, provide access to affordable energy from sustainable local agricultural waste.

“Aston University is a global leader in bioenergy and energy systems, and I am delighted we received funding to explore this area.”

Over a power plant’s life, the project team have calculated that biomass produces cheaper electricity (approx. $4.3$/kWh) compared to solar (approx. $6.6/kWh), geothermal (approx. $6.9/kWh), coal (approx.$7.1/kWh), wind (approx. $8/kWh) and subsidised gas (approx.$8.4ckWh).

The project will start in April 2023 with a total of £1.5 million funding for the four partners from Innovate UK.
Alongside Carnot Limited, the Aston University scientists will be working with two other UK-based businesses to deliver the project, PyroGenesys and Straw Innovations.

PyroGenesys specialises in PyroChemy technology which will convert 70% of the rice straw into vapour or bio-oil for electricity production, with the remainder converted into nutrient-rich biochar, which can be sold back for use as fertiliser on the rice farms.

Straw Innovations will contribute their rice straw harvesting and collection expertise, with their many years of similar operations in Asia.