Microalgae as a biofuel feedstock: risks and challengesPresentation By: Liandong Zhu
Trends and future of sustainable development
IntroductionEnergy crisisBased on the current consumption of about 11.6 million tons of crude oil per day, it is expected that the entire resources can only suffice for a rather short time period;UK Energy Research Centre even concluded that oil resources will be used up between 2020 and 2030 New oil and gas reserves are always discovered Global warming and global climate changesThe use of oil can cause the risks of the rise of greenhouse effect, which can result in all kinds of disasters to our planet Earth and its inhabitants
IntroductionMicroalgae have overwhelmingly received a lot of attention as a new biomass source for the productionHigh photosynthesis efficiency and can grow very fast; Without occupying farmlands; Can be supplied by saline and brackish water, seawater, wastewater, and other salt water like saline groundwater and CO2 by combustion gas; Can be collected very quickly; Uniform cell structure with no bark, stems, branches or leaves; Physical and fuel properties of biofuel (e.g. density, heating value, etc.) are comparable to those of fuel diesel.
IntroductionWhere can we get algae?
IntroductionWhere can we get algae?
IntroductionProducts: biodiesel, bioethanol, biohydrogen, biogas
Purpose and perspectiveMicroalgae-based biofuel (MBB) industry is booming. But there is limited and fragmented published information available on the environmental, social, cultural and economic dimensions involved with potential sustainable risks.From sustainability perspective, this paper explores the potential risks and challenges connected with the production of MBB, systematically. Afterwards, some corresponding recommendations about government policies, company behaviors and public participation are put forward in order to minimize the potential risks to the permitted levels.
Potential risks and challenges-EnvironmentalWaterWater resource abuse; Without feasible water usage planning (recycling)Damage to waterways; Systems discharge (toxicants): chemical additives, flocculants, solvents, and catalystsGroundwater may not be recharged effectively Waterproof surface
Potential risks and challenges-EnvironmentalLandLand use overexpansion; Amount of space is required; Over-pursue commercial profits cause an indirect land useEarth pollution, and soil erosion Discharge pollution; Heavy rain or flood might lead to high biomass overflow; Pipelines construction involves the removal of plenty of rocks and earth
Potential risks and challenges-EnvironmentalBiodiversityEutrophication; Downstream discharge leads to nutrient imbalanceAlgal blooms and fish kills; Caused by eutrophicationBiological invasion Downstream carries non-harvested microalgae cells
Potential risks and challenges-EnvironmentalGreenhouse gasGreenhouse gases (e.g. NOx, CH4) emissions Appearance of anaerobic zone under water surface and biomass death can bring about the emission of CH4, N2O, etc.
Potential risks and challenges-EconomicStart-up is expensive (overwhelming investments); Capital costs occupy about 50% of the total costsLoss of jobs Development of increased automation
Potential risks and challenges-SocialJeopardize the health of local wildlife and people; PollutionDiseases (e.g. yellow fever, malaria) spread Microalgae may provide some habitats for laying and hatching of mosquito eggs and larvae
Potential risks and challenges-CulturalDifficult for people to adapt to Traditionally used to produce cosmetics and food; Microalgae biomass is a very new biofuel type
RecommendationsEfficient government policiese.g., roles and responsibilities within government agencies must be clarified; contracts of environmental impact statements must be reinforced; regulatory industry roadmap must be developed; propaganda activitiesProactive company behaviorse.g., water and land use planning should be carried out in an environmental friendly manner; assessment of potential risks should be conducted prior to facilities introduction; require transparency of process inputs and outputs..Positive public participationPublic perception, sense and participation