Situated in southern Taiwan, the water caltrop-growing region accounts for about 70 percent of the country’s annual output of the black hard-shelled fruit. Previously, thousands of metric tons of water caltrop shells were burned or discarded in the area each year, causing significant environmental concerns.
Yen Neng-tung, head of Guantian District Office, said these days nearly all of the shells are collected and reused. With assistance from the academic and private sectors, the office developed a way to transform this leftover material into what locals like to describe as black gold, he added.
Guantian is Taiwan’s primary water caltrop-growing region.
Supported by Lin Hong-ping, a chemistry professor at Tainan-based National Cheng Kung University, Yen’s team developed a 1,000 C-plus incineration system for turning the shells into biochar, a form of charcoal used to enrich soil. The system is set to be further upgraded with assistance from homegrown enterprises such as sheet metal fabricator Chih Kang Material Co. Ltd.
In addition to boosting nutrient content, biochar can limit acidification, Yen said, adding that this makes it a popular soil additive among agricultural enterprises. With an impressive surface area of 250 square meters per gram, the water caltrop-derived product is also effective at absorbing moisture, odors and volatile chemicals, he added.
Touting these attributes, social enterprise Guantian Black Gold Community Cooperative markets the biochar to the public, selling it in variously sized cloth pouches for use in cars, closets, drawers, refrigerators and toilets.
Guantian District Office head Yen Neng-tung (left) and chemistry professor Lin Hong-ping display biochar at a drying stand.
“Our project addressed a community environmental issue and tapped a commercial opportunity,” Yen said. “By seeking a scientific answer to our waste problem, we have fashioned a long-term economic benefit.”
While many other agricultural sectors in Taiwan are characterized by the widespread dispersion of farmers, Guantian’s biochar venture was enabled by the centralization of the water caltrop-growing industry, making it possible to achieve economy of scale in implementing circular solutions.
Next on the agenda for the Guantian cooperative is competing directly against more established products, such as Japanese bamboo-based biochar. “With further equipment upgrades and investment in R&D, we will be able to challenge international market leaders in this industry,” Lin said. (E) (By Pat Gao)
Biochar is used to enhance water quality for potted plants.
Write to Taiwan Today at ttonline@mofa.gov.tw
(This article is adapted from Taking Root in the September/October 2019 issue of Taiwan Review. The Taiwan Review archives dating to 1951 are available online.)