According to studies, plant waste, leftover food, sewage, and other organic waste could be a useful source of “green” hydrogen for transportation and industry.
The team from Fraunhofer IPA in Stuttgart, Germany, discovered that regionally produced green hydrogen might replace up to 30 percent of fossil fuel energy in certain regions within ten years.
Every year, Germany generates around 15 million tons of organic waste, comprising plant waste and rubbish from public parks, agriculture, food production, sewage byproducts, and leftover food. The majority is transported to composting facilities or burnt to generate heat and electricity, resulting in carbon dioxide (CO2) emissions.
“Organic waste is just too precious to be utilized in this manner,” stated Johannes Full, leader of Fraunhofer IPA’s Sustainable Development of Biointelligent Technologies group. “It would make more sense to create hydrogen from the substance. The process’s CO2 emissions might subsequently be isolated, stored, or utilized in industrial applications.”
Currently, the majority of hydrogen is produced from natural gas. According to the Fraunhofer experts, a production process based on plant waste such as wood cuttings would be far more environmentally benign than electrolysis using renewable electricity.
Treatment of plant waste – whether it is used in hydrogen production, composted, or burned – always results in the release of carbon dioxide (CO2). However, according to the researchers, CO2 could be captured during the hydrogen production process and either used in the chemical industry or stored in abandoned natural gas fields.
Full and his colleagues assessed recently developed technologies for converting biomass to hydrogen in their new study.
In a collaboration with a metal industry business, the researchers collected waste from local fruit producers, wineries, cardboard, wood, and canteens. The fruit and leftover food were fermented by bacteria before being transformed to methane at a typical biogas plant through a second fermentation process. The methane was then transformed to CO2 and hydrogen. Using a wood gasifier, the wood and paper fibres were separated into the two gases. Hydrogen was then applied directly to metal processing.
Researchers discovered that purple bacteria is particularly effective at creating hydrogen from fruit and dairy waste. Researchers at the University of Stuttgart tweaked the bacterium such that it needed less light, reducing the amount of energy required for the hydrogen manufacturing process. Together with Fraunhofer IPA, they are studying economically viable methods for creating bigger quantities of hydrogen with purple bacteria.
In a separate analysis, the researchers revealed that green hydrogen might meet a portion of the energy needs of certain industrial sectors and heavy goods transportation. They discovered that decentralized production and usage of green hydrogen is effective if the distribution centres are located as close to users as possible.
Dr. Jürgen Henke, a scientist at Fraunhofer IPA, stated that ideal areas for installing hydrogen filling stations are near busy roadways and truck terminals.
Upon examining the state of Baden-Württemberg, they determined that 30 percent of fossil fuel energy could be replaced within 10 years by green hydrogen utilizing solely hydrogen produced in the region.
