In the heart of our cities, Ginkgo biloba trees stand as resilient, long-lived sentinels, their fan-shaped leaves adding a touch of elegance to urban landscapes. Yet, their annual pruning, necessary to maintain their size and shape and prevent interference with traffic and pedestrians, results in a substantial volume of unutilized biomass. A recent study, published in the journal “Energy Conversion and Management,” has explored the potential of transforming this urban waste into a valuable energy resource through a process known as pyrolysis.
Pyrolysis, a thermochemical process that involves heating biomass in the absence of oxygen, can convert Ginkgo biloba pruning residues into charcoal. The study, conducted by a team of researchers from the University of Science and Technology of China, aimed to optimize the pyrolysis conditions and evaluate the fuel properties of the resulting charcoal.
The researchers conducted their experiments at temperatures ranging from 400 to 600 degrees Celsius, following an oven drying pretreatment. They found that the mass yield of charcoal varied from 27.33 to 32.05 percent, with a volume shrinkage of approximately 41.19 to 49.97 percent. The fuel properties of the charcoal were then evaluated using a series of tests, including moisture absorption, proximate and ultimate analysis, thermogravimetry, calorimetry, and inductively coupled plasma optical emission spectrometry.
The results were promising. The calorific value of the charcoal improved from 20.76 to 34.26 MJ per kg, with an energy yield of up to 46.75 percent. The charcoal also exhibited superior thermal stability and better combustion performance compared to the original biomass. Moreover, the product complied with first-grade standards at 550 and 600 degrees Celsius and second-grade wood charcoal standards at other temperatures.
However, the study also highlighted some challenges. The researchers found higher concentrations of certain heavy metals, such as zinc, in the charcoal. This indicates the need for pretreatment and further research on co-pyrolysis for resource optimization.
The study’s findings have significant implications for the energy sector and urban planning. By converting Ginkgo biloba pruning residues into high-grade charcoal, cities can not only manage their waste more effectively but also generate a renewable energy source. This dual benefit of waste management and renewable energy production could provide valuable insights for urban planning and policymaking.
As the world grapples with the challenges of climate change and the need for sustainable energy sources, studies like this one offer a glimpse into the potential of urban biomass as a valuable resource. By harnessing the power of pyrolysis, cities can transform their green waste into a valuable energy resource, contributing to a more sustainable and resilient urban future.
This research was published on arXiv and can be read in full [here](http://arxiv.org/abs/2507.20683v1).