Rice husks provide clean electricity

Press release /

Rice is the most important staple food worldwide. However, its production is associated with high energy consumption and the associated negative environmental impact. Researchers at Fraunhofer UMSICHT are developing a promising sustainable alternative by using previously unused biomass for decentralized electricity production.

View into a rice mill in Indonesia: Rice husks as a valuable supplier of energy.
© Fraunhofer UMSICHT
View into a rice mill in Indonesia: Rice husks as a valuable supplier of energy.

Worldwide, vast amounts of biomass are produced as a waste product in the production of food. However, many of these products could be recycled by an intelligent recycling management. This requires know-how of economically viable processes and new methods in the agricultural and food industry. The international project CARE (Towards Circular Indonesian AgricultuRE) addresses agricultural recycling in Indonesia with the aim of making local electrification more sustainable. Currently, electricity is often generated by diesel generators in the rural areas of the island state. "This is due to the geographical conditions – widespread power grids are the exception. On the other hand, diesel generators can be put into operation at short notice and as needed," explains Dr. Esther Stahl from the Process Engineering Department at Fraunhofer UMSICHT. However, there are the high fuel costs and about 4.6 million tons of CO2 per year that are released in Indonesia alone by this type of power generation.

Enormous quantities of unused biomass

At the same time, Indonesia is one of the largest rice producers in the world, producing over 70 million tons per year. And experts estimate that this alone generates up to 12 million tons of organic waste with a high calorific value and low moisture content – ideal sources of energy that have not yet been used. This is where the researchers at Fraunhofer UMSICHT come in by developing sustainable recycling paths for rice husks. More precisely, they want to make the power supply of rice mills more climate-friendly.

The rice husks are to be pelletized on site and used as fuel in special biomass gasifiers. The gas produced can then replace large parts of the diesel used up to now as an energy supplier for electricity generation. By compacting and adding suitable additives to increase the ash melting point and mechanical stability, the rice husks become a valuable raw material. "We assume that a quarter of all diesel generators in the country can be supplemented with this technology," says Esther Stahl.

But Indonesia is not the only country to benefit from the CARE project: In addition to other rice-growing regions, for example in Italy, Spain or France, the technology could also be transferred to biomass streams such as leaves or bedding materials. CARE thus makes an important contribution to reducing greenhouse gases and supports the UN sustainability goals.

Sustainable business models

The development of the technical process is one part of the project. In parallel, the project consortium, consisting of Institut Teknologi Sepuluh Nopember (Surabaya, Indonesia), MicroEnergy International GmbH (Berlin), Fraunhofer Center for International Management and Knowledge Economy IMW (Leipzig) and Fraunhofer UMSICHT (Oberhausen), is developing suitable business models and is taking into account the acceptance of the technology in politics, industry and society. Esther Stahl: "We take a detailed look at the respective framework conditions, from the potential of the raw material rice husk to regional regulations and infrastructure to financing. This enables us to ensure the long-term profitability of the process".


Funding information

The project CARE (Towards Circular Indonesian AgricultuRE) is funded by the German Federal Ministry of Education and Research within the Bioeconomy International Programme (FKZ 031B0912A).