Turning the fast-growing problem of water hyacinth into sustainable energy solution
Written by Han-Jun, Zeng
The sprawling presence of water hyacinth in some water bodies, presents a growing challenge to some governments around the world right now, especially those that are situated in places with hotter climate. Water hyacinth multiples rapidly in such climate and it is expected that its rate of growth might increase as the global temperature and rainfall increase.
Already, these plants are suffocating some river bodies with their large foliage, often covering the entire surfaces of rivers thereby disrupting the photosynthetic process that is taking place between the sunlight and the fauna and flora in the river. The growth sprawl decreases the amount of sunlight received by these plants, slows down the oxygen creation process and disturbs the natural ecosystem.
A lot of things are happening at this point. Certain plants wither then die off, and this affects organisms that thrive off these plants. Fishes and other living organisms are also affected due to insufficient oxygen. Water flow slows down significantly because the stalks of the water hyacinths pack so closely together, affecting water movement. The entire water body then slowly becomes a huge mass of stagnant water, giving rise to a huge array of disease vector issues.
This has drastic negative implications on the nearby land ecosystem as well. The land ecosystem, comprising people, animals, insects and plants depend heavily on the adjacent water bodies for their daily needs. Rural people who depend on the water for daily needs such as washing, food sources, etc, might have to seek alternatives if the river system fails. If none are available, they’ll have to migrate to other places. This means that they might have to integrate into other communities thus giving rise to potential social implications.
The same goes for animals and insects. If they are not able to adapt to the new situation, they too might have to migrate elsewhere and therein lies the possibility that their migration will disturb other ecosystems. New animals and insect immigrants have to compete for resources with existing living organisms in those ecosystems. Changes to the food chain could sometimes create unexpected outcomes. For e.g. certain incumbent living organisms may proliferate because its predator population was reduced drastically by the changes. Or it may turn out differently too, in many unpredictable ways.
While the leaves of water hyacinth generally turn brown and die during the winter, many water hyacinth plants survive the winter and grow new leaves in spring. This is not the case for countries that are located in tropical areas where temperature remains warm throughout the year. The warm temperature causes the plants to grow stolons, or spreading stems, from which daughter plants grow. Stolon growth is a key driver of water hyacinth dispersal.
Once it starts to flourish, it will clog up waterway which presents a lot of problems to waterway transportation, hydropower stations, etc and these are often very important topics underpinning sustainable urban development. For e.g., in lieu of cars, trains and trams, some societies are contemplating the use of sustainable waterway transportation to decongest land traffic. Additionally, many countries are turning to hydropower station for their energy needs. These tools can be rendered useless by natural outcomes of climate change, in this case, growth of water hyacinth.
Significant investments have already been poured into such sustainable development initiatives. I predict that more investment will go into these areas as the financial markets, regulators and consumers are starting to emphasize on Environmental, Social and Governance (ESG) topics. Once the fundaments are cemented, we can also expect financial derivatives to sprout off from the vanillas, creating an even larger market.
These extremely fast-growing water hyacinth (and will grow even faster when global temperature increases), can derail water supplies’, waterways’ and hydropower stations’ operations, affecting significant future investments and government’s capability to provide for their people.
Since the 1970s, many methods have been proposed to cull these water hyacinth, but this issue still persists. Unfortunately, I think that this challenge will persist into the short to medium term future.
However, I propose for those that are facing these issues, to reframe their thinking and view these water hyacinth as a resource. Through proper pyrolysis process and manufacturing techniques, these water hyacinth can be harvested and transformed into water hyacinth biomass briquette. This product can then be burnt in electric power plants to generate electricity.
According to different studies, the average heat value of water hyacinth biomass briquette is about 14 MJ/kg to 20MJ/kg, averaging 15MJ/kg. For perspective, the heat value of natural gas is about 42 MJ/kg to 55 MJ/kg and hard black coal is about 25 MJ/kg. Though not generating as much heat as the latter two, water hyacinth biomass briquette could present itself as a sustainable energy solution, provided that we can control the carbon output.
Apart from this, if the water hyacinth biomass briquette is manufactured to be transport-friendly, producers can export these products in larger volumes.
Of course, consultants might have to step in to reconfigure the electric power plants in order to accept water hyacinth biomass briquette as a burning agent. Harvesting contracts too, has to be given out. Factories need to be set up or reconfigured, to produce the biomass briquette. Logistics like land and sea transport are also essential part of the whole equation. Not forgetting about all the required certifications and licenses. All these translate to substantial financial commitment but give and take, the investment might be able to create new jobs, expertise and experience, all of which might contribute to creating positive economic and social values.
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