Trends and future of sustainable development
Microalgae as a biofuel feedstock:
risks and challenges
Presentation By: Liandong Zhu
Contents
Introduction
Purpose and perspective
Potential risks and challenges
Conclusions
Recommendations
Introduction
• Energy crisis
Based 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 changes
The 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
Introduction
Microalgae have overwhelmingly received a lot of
attention as a new biomass source for the production
High 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.
Introduction
Where can we get algae?
Introduction
Where can we get algae?
Introduction
Products: biodiesel, bioethanol, biohydrogen, biogas
Purpose and perspective
Microalgae-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 challengesEnvironmental
Water
Water resource abuse;
• Without feasible water usage planning (recycling)
Damage to waterways;
• Systems discharge (toxicants): chemical additives,
flocculants, solvents, and catalysts
Groundwater may not be recharged effectively
• Waterproof surface
Potential risks and challengesEnvironmental
Land
Land use overexpansion;
• Amount of space is required; Over-pursue
commercial profits cause an indirect land use
Earth 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 challengesEnvironmental
Biodiversity
Eutrophication;
• Downstream discharge leads to nutrient imbalance
Algal blooms and fish kills;
• Caused by eutrophication
Biological invasion
• Downstream carries non-harvested microalgae cells
Potential risks and challengesEnvironmental
Greenhouse gas
Greenhouse 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 challengesEconomic
Start-up is expensive (overwhelming investments);
• Capital costs occupy about 50% of the total costs
Loss of jobs
• Development of increased automation
Potential risks and challengesSocial
Jeopardize the health of local wildlife and people;
• Pollution
Diseases (e.g. yellow fever, malaria) spread
• Microalgae may provide some habitats for laying
and hatching of mosquito eggs and larvae
Potential risks and challengesCultural
–Difficult for people to adapt to
• Traditionally used to produce cosmetics and food;
• Microalgae biomass is a very new biofuel type
Conclusions
Recommendations
Efficient government policies
e.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 activities……
Proactive company behaviors
e.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 participation
Public perception, sense and participation