Conversion Of Water Hyacinth Research Articles

Test operation of microwave-assisted chemical looping gasification for water hyacinth with a lean iron ore as oxygen carrier

Chemical looping gasification has been considered as a promising biomass energy conversion technology for syngas production. In this work, a novel microwave-assisted chemical looping gasification (MACLG) reactor system is applied to water hyacinth with a lean iron ore as the oxygen carrier (OC). This approach is expected to achieve effective gasification performance with fast heating and small temperature fluctuation. MACLG can promote the proportion of syngas to 74.39%, lower heating value to 11.83 MJ/Nm3 and cold gasification efficiency to 80.94%. In addition, the increase of OC has a great effect on the conversion of water hyacinth. Favorable gasification performance, including total gas yield, H2/CO ratio, carbon conversion efficiency, and OC reactivity, can be achieved when the molar ratio of Fe2O3/C is in the range of 0.25–0.50. Furthermore, a moderate temperature is also vital for reaction effect. With a temperature of 900 °C, the highest H2/CO ratio of 1.37 of syngas is obtained.

Evaluating the spatial and temporal variations of aquatic weeds (Biomass) on Lower Volta River using multi-sensor Landsat Images and machine learning

Aquatic invasive weeds affect hydrological, ecological, and socio-economic activities on freshwater ecosystems. On the Lower Volta River (LVR) of Ghana, invasive aquatic weeds have been known to be nuisance to fishing, navigation, aquaculture, hydropower production and other agricultural practices in the area. While information on the spatial and temporal distribution of aquatic weeds would be beneficial in improving weed management and control measures on the river, such information is very scanty. Also, these aquatic weeds are also biomass resources, that can be transformed to bioenergy. Thus, this study evaluated the spatial and temporal variations of aquatic weeds on the Lower Volta River, and assessed their potential biomass for bioenergy production.Random Forest (RF) algorithm and Landsat images were used to map the distribution of the weeds in 1975, 2003, and 2020, respectively. Accuracy assessment results showed mean Overall Accuracy (OA) of 83.44% and mean User Accuracy (UA) of 79.24%. The results indicated that as of 1975, aquatic weeds covered only 1495 ha and appeared in some specific locations such as Kpong and Ada. However, by 2003, the weeds had spread to most parts of the river covering 5600 ha, which was an increase of approximately 4-fold within a period of 28 years. The area covered by the weeds, however declined by 1505 ha between 2003 and 2020. Thus, in 2020, water hyacinth covered about 36% of the aquatic weeds relative to 28% in 2003. The results showed that, the quantity of the water hyacinth biomass per unit area was 21.5 kg/m2. This result can also be used as the basis for resource assessment as well as determination of its viability for bioenergy production and strategies for its modern utilisation. The conversion of water hyacinth into bioenergy remains one of the best aquatic weed management strategies that must be adopted in LVR.

Investigation of Water Hyacinth as a Feedstock for Bioethanol Production by Simultaneous Saccharification and Fermentation Process

As an abundant biomass of surface water, water hyacinth was used as an input material to produce bioethanol in this study. Steam explosion and alkaline pre-treatment were applied on the material before simultaneous saccharification and fermentation (SSF) process was carried out. Experimental data suggested the optimal enzyme dosage be 1.0 wt% of the dry mass of the biomass, and the mass of the material be up to 8.0 wt% of the whole mixture in a one-step loading procedure to obtain the climax efficiency after 78 h. The process does not need additional nitrogen nutrition, such as corn steep liquor (CSL), as those in other common lignocellulosic bioethanol processes, because water hyacinth itself contains much protein in its chemical composition. Protein content analysis showed that it was 17.2 wt% (on dry basis), similar to what reported in some published studies. The SSF efficiency was positively 72.8 % at the optimal conditions resulted out from the experiments. Such a convenient conversion of water hyacinth to bioethanol is not only meaningful in term of biofuel production but also in term of environmental treatment.

Determination of the activation energy of water hyacinth (Eichornia crassipes) pyrolysis

ABSTRACTThermogravimetric investigation of the thermo-chemical conversion of water hyacinth to bio-fuels was carried out at temperatures between 35 and 915 °C under a nitrogen environment. It envisaged that the operational envelope for bio-oil production from water hyacinth pyrolysis lies between 250 and 550 °C. Kinetic analysis reveals that pyrolytic degradation of water hyacinth to bio-fuels is actually four consecutive reactions of desorption, evaporation, devolatization, and secondary cracking reactions, which takes place at the temperature range of 35 – 95 °C, 95 – 215 °C, 215 – 355 °C, and 355 – 915°C, with activation energies of 34.18, 6.60, 34.48, and 6.92 kJ/mol respectively. The kinetic parameters determined will prove useful in the design of pyrolysis reactors and gasifiers for the biomass.

‘Proceed to your death’: Lakuwa, environmental disaster management, and the culture of oil politics in Nigeria

Since the 1990s, in the riverine areas of Nigeria, the ecological menace of water hyacinth has been turned into an object of politics by various administrations. Among the Ilajes, an oil-rich community in the southwestern part of Nigeria, water hyacinth is considered to be poisonous and an impediment to people’s livelihoods. Drawing on ethnographic fieldwork, the authors explore how an invasive species, known locally as lakuwa – translated as ‘proceed to your death’ – gets inserted into the politics of oil distribution. They argue that, just like oil, water hyacinth presents certain features that enable its conversion from poisonous species to money, and the article particularly explores how the conversion of water hyacinth, an ecological ‘plague’, fits into popular narratives of environmental degradation in Nigeria. The authors argue that the invasive nature of water hyacinth warrants a form of state response that deepens already existing forms of prebendal political interactions between the environment, local political leaders, and their numerous followers.

Efficiency and mechanisms of Cd removal from aqueous solution by biochar derived from water hyacinth (Eichornia crassipes)

This study investigated the efficiency and mechanisms of Cd removal by biochar pyrolyzed from water hyacinth (BC) at 250–550 °C. BC450 out-performed the other BCs at varying Cd concentrations and can remove nearly 100% Cd from aqueous solution within 1 h at initial Cd ≤ 50 mg l−1. The process of Cd sorption by BC450 followed the pseudo-second order kinetics with the equilibrium being achieved after 24 h with initial Cd ranging from 100 to 500 mg l−1. The maximum Cd sorption capacity of BC450 was estimated to be 70.3 mg g−1 based on Langmuir model, which is prominent among a range of low-cost sorbents. Based on the balance analysis between cations released and Cd sorbed onto BC450 in combination with SEM-EDX and XPS data, ion-exchange followed by surface complexation is proposed as the dominant mechanism responsible for Cd immobilization by BC450. In parallel, XRD analysis also suggested the formation of insoluble Cd minerals (CdCO3, Cd3P2, Cd3(PO4)2 and K4CdCl6) from either (co)-precipitation or ion exchange. Results from this study highlighted that the conversion of water hyacinth into biochar is a promising method to achieve effective Cd immobilization and improved management of this highly problematic invasive species.