A current PhD student in Molecular Plant Genetics who has a masters in Agrobiotechnology
Highly innovative, yet simplistic solution to global energy crisis - let's get the ball rolling
Ever since the climate agreement has been reached unanimously in Paris in 2015, countries all over the world have agreed upon to cut emission of CO2 and other greenhouse gases. This summit was a timely wake up call for everybody in order to minimize global warming and keep world temperature rise below 2 degrees Celsius by the end of this century. Dependence on fossil fuels and over use of such materials over the past few centuries has put the earth on edge. As a result of that a shift in global focus towards alternative source of energy production is at its peak than ever before. The idea of making fuel from food crops such as wheat, corn, soybean, sugarcane etc. is around for quite sometime, and so is from algae.
Now, let us have a look at the basic aspects related to production of algal biofuel. The lipid or oily part of algae is extracted to generate biodiesel whereas the carbohydrate portion is exploited for manufacturing bioethanol. In addition to light and water, nitrogen and phosphorus are the two most crucial nutrients that is needed for algal growth. Upon initial anaerobic digestion by bacteria, waste-water could be used for algal growth as it is enriched with such nutrients. Marginal lands that are almost futile for farming are useful sites for cultivating algae. Some of the algal species such as Schizochytrium could produce oil amounting to nearly 77% of its dry weight compared to 2-3% of that in soybean.
However, the most striking feature of using algae is that it produces almost 300 times more oil per acre than the aforementioned crops. Besides, they have a life cycle of 1-10 days, which means much faster and less tedious outcome compared to the annual crops. In addition, algal growth eliminates the necessity of using herbicides and pesticides, thereby limiting pollution. Moreover, persistent use of food grains to produce biofuel would have huge impact on global food security which could be avoided by using algae for the same purpose.
In conclusion, significantly less afford for maintenance and high output makes algae as the top choice for production of biofuel and we would probably see more established companies as well as new entrepreneurs moving towards the direction of algal biofuel in future.
Abstract: Modern society is fueled by fossil energy produced millions of years ago by photosynthetic organisms. Cultivating contemporary photosynthetic producers to generate energy and capture carbon from the atmosphere is one potential approach to sustaining society without disrupting the climate. Algae, photosynthetic aquatic microorganisms, are the fastest growing primary producers in the world and can therefore produce more energy with less land, water, and nutrients than terrestrial plant crops. We review recent progress and challenges in developing bioenergy technology based on algae. A variety of high-value products in addition to biofuels can be harvested from algal biomass, and these may be key to developing algal biotechnology and realizing the commercial potential of these organisms. Aspects of algal biology that differentiate them from plants demand an integrative approach based on genetics, cell biology, ecology, and evolution. We call for a systems approach to research on algal biotechnology rooted in understanding their biology, from the level of genes to ecosystems, and integrating perspectives from physical, chemical, and social sciences to solve one of the most critical outstanding technological problems.
Pub.: 04 Oct '16, Pinned: 23 Apr '17
Abstract: Interest in algae as a feedstock for biofuel production has risen in recent years, due to projections that algae can produce lipids (oil) at a rate significantly higher than agriculture-based feedstocks. Current research and development of enclosed photobioreactors for commercial-scale algal oil production is directed towards pushing the upper limit of productivity beyond that of open ponds. So far, most of this development is in a prototype stage, so working production metrics for a commercial-scale algal biofuel system are still unknown, and projections are largely based on small-scale experimental data. Given this research climate, a methodical analysis of a maximum algal oil production rate from a theoretical perspective will be useful to the emerging industry for understanding the upper limits that will bound the production capabilities of new designs. This paper presents a theoretical approach to calculating an absolute upper limit to algal production based on physical laws and assumptions of perfect efficiencies. In addition, it presents a best case approach that represents an optimistic target for production based on realistic efficiencies and is calculated for six global sites. The theoretical maximum was found to be 354,000 L·ha−1·year−1 (38,000 gal·ac−1·year−1) of unrefined oil, while the best cases examined in this report range from 40,700–53,200 L·ha−1·year−1 (4,350–5,700 gal·ac−1·year−1) of unrefined oil.
Pub.: 08 Oct '09, Pinned: 23 Apr '17
Abstract: The composition of crude algal oil was analyzed and determined by several methods. Oil was converted to polyols by ozonolysis, epoxidation, and hydroformylation. Ozonolysis gave a polyol with lighter color but a low OH number and was unsuitable for polyurethane applications. Epoxidation also improved the color and gave a polyol with an OH number around 150 mg KOH/g, which with diphenylmethane diisocyanate gave a homogeneous, rubbery, transparent sheet. Desirable rigid foams were prepared with the addition of water to the formulation. Hydroformylation was carried out successfully giving an OH number of about 150 mg KOH/g, but the polyol was black. Casting the polyurethane sheet was difficult due to the very high reactivity of the polyol. Polyurethane foam of lower quality than from epoxidation polyol was obtained. More work on optimization of the foaming system would improve the foam. Crude algal oil is a viable starting material for the production of polyols. Better results would be obtained from refined algal oils.
Pub.: 18 Apr '13, Pinned: 25 Apr '17
Abstract: The potential of microalgae as a source of renewable energy has received considerable interest, but if microalgal biofuel production is to be economically viable and sustainable, further optimization of mass culture conditions are needed. Wastewaters derived from municipal, agricultural and industrial activities potentially provide cost-effective and sustainable means of algal growth for biofuels. In addition, there is also potential for combining wastewater treatment by algae, such as nutrient removal, with biofuel production. Here we will review the current research on this topic and discuss the potential benefits and limitations of using wastewaters as resources for cost-effective microalgal biofuel production.
Pub.: 03 Jul '10, Pinned: 25 Apr '17
Abstract: Microalgae are gaining popularity as a source of biodiesel. Recycling fertilizer nutrients is critical to sustain large-scale biodiesel production because the global supply of surplus fertilizer is limited. This study demonstrates that anaerobic digestion of residual algal biomass from biodiesel production can provide additional nutrients and energy. Anaerobic digestion of Chlorella sorokiniana 1412 whole cell algae (WCA), sonicated algae (SA), and SA subjected to lipid extraction (LEA) in bench-scale batch reactors operated at 30 ± 2 °C for 42 days released a considerable amount of the nitrogen and phosphorus in the algal cells. Digestion of WCA, SA, LEA released 48.1, 77.4, and 61.5% of the total algal nitrogen as NH4+-N, and 87.7, 99.4, and 93.6% of the total algal P as soluble P, respectively. The energy recovery from algae biomass was quantified through the methane yield. The biochemical methane potential of WCA, SA and LEA was 0.298, 0.388 and 0.253 L methane per gram algal volatile solids, respectively. The conversion of LEA and WCA biomass to methane was very similar (38 and 41% on a COD basis, respectively), indicating that the energy yield was not significantly lowered by extraction of the lipid fraction (which accounted for 9% of algal dry weight). Sonication improved the access of hydrolytic enzymes to algal biopolymers (compensating in part for the energy lost due to lipid extraction). The results taken as a whole indicate that anaerobic digestion of LEA can provide considerable yields of methane and soluble nutrients.
Pub.: 28 Feb '17, Pinned: 25 Apr '17
Abstract: Considerable research and development is underway to produce fuels from microalgae, one of several options being explored for increasing transportation fuel supplies and mitigating greenhouse gas emissions (GHG). This work models life-cycle GHG and on-site freshwater consumption for algal biofuels over a wide technology space, spanning both near- and long-term options. The environmental performance of algal biofuel production can vary considerably and is influenced by engineering, biological, siting, and land-use considerations. We have examined these considerations for open pond systems, to identify variables that have a strong influence on GHG and freshwater consumption. We conclude that algal biofuels can yield GHG reductions relative to fossil and other biobased fuels with the use of appropriate technology options. Further, freshwater consumption for algal biofuels produced using saline pond systems can be comparable to that of petroleum-derived fuels.
Pub.: 14 Feb '12, Pinned: 23 Apr '17
Abstract: The objective of this work is to establish whether algal bio-crude production is environmentally, economically and socially sustainable. To this end, an economic multi-regional input-output model of Australia was complemented with engineering process data on algal bio-crude production. This model was used to undertake hybrid life-cycle assessment for measuring the direct, as well as indirect impacts of producing bio-crude. Overall, the supply chain of bio-crude is more sustainable than that of conventional crude oil. The results indicate that producing 1 million tonnes of bio-crude will generate almost 13,000 new jobs and 4 billion dollars' worth of economic stimulus. Furthermore, bio-crude production will offer carbon sequestration opportunities as the production process is net carbon-negative.
Pub.: 04 Dec '14, Pinned: 23 Apr '17
Abstract: Social and economic indicators can be used to support design of sustainable energy systems. Indicators representing categories of social well‐being, energy security, external trade, profitability, resource conservation, and social acceptability have not yet been measured in published sustainability assessments for commercial algal biofuel facilities. We review socioeconomic indicators that have been modeled at the commercial scale or measured at the pilot or laboratory scale, as well as factors that affect them, and discuss additional indicators that should be measured during commercialization to form a more complete picture of socioeconomic sustainability of algal biofuels. Indicators estimated in the scientific literature include the profitability indicators, return on investment (ROI) and net present value (NPV), and the resource conservation indicator, fossil energy return on investment (EROI). These modeled indicators have clear sustainability targets and have been used to design sustainable algal biofuel systems. Factors affecting ROI, NPV, and EROI include infrastructure, process choices, and financial assumptions. The food security indicator, percent change in food price volatility, is probably zero where agricultural lands are not used for production of algae‐based biofuels; however, food‐related coproducts from algae could enhance food security. The energy security indicators energy security premium and fuel price volatility and external trade indicators terms of trade and trade volume cannot be projected into the future with accuracy prior to commercialization. Together with environmental sustainability indicators, the use of a suite of socioeconomic sustainability indicators should contribute to progress toward sustainability of algal biofuels.
Pub.: 10 May '16, Pinned: 23 Apr '17
Abstract: In the USA, approximately 6 million tons of nitrogen and 1 million tons of phosphorus are being produced as a waste stream from the dairy operations. The main aim of this research was to estimate the potential of algal biofuel production, using waste nutrients present in the dairy waste, as well as performing a life cycle assessment to estimate the energy requirement of produced algal biofuel. Four different scenarios for algal biofuel production were simulated using different combinations of the following processes (i) algal-biodiesel-production, (ii) anaerobic-digestion (AD), (iii) pyrolysis and (iv) enzymatic-hydrolysis. Scenario 1 consists of AD and algal biodiesel production. Introduction of pyrolysis in the second scenario decreased biofuel production by ∼6% in the initial cycle and gradually increased to 25% in the later cycles. In the third scenario, biomass liquefaction through enzymatic hydrolysis was introduced to recover nutrients and sugars from the sludge generated from the AD process. Recovered nutrients and sugars were used for additional algal biodiesel production. Remaining sludge after the biomass liquefaction was applied on the agricultural land. As compared to the 1st scenario, further processing of the sludge through liquefaction increased the overall bioenergy production marginally. In the fourth scenario, biomass left after liquefaction was further processed through pyrolysis. In the fourth scenario, a 38% increase in the energy production was observed versus the 1st scenario. Additional energy production (compared to 1st scenario) through pyrolysis (Scenario 2) required additional 1.5 GJ of energy per GJ of energy produced and showed little variability. Additional energy production through the 3rd and the 4th scenario is not energetically favorable as compared to the 1st scenario. With respect to the 3rd scenario, energetically favorable additional energy can only be produced by the 4th scenario. Life-cycle energy-demand of the produced biofuel was varied from 0.35 to 0.68 GJ/GJ of energy produced. This study estimated that using dairy waste at a maximum of 3.14 billion GJ bioenergy could be produced.
Pub.: 20 Jul '16, Pinned: 23 Apr '17
Abstract: This study focuses on analyzing nutrient distributions and environmental impacts of nutrient recycling, reusing, and discharging in algal biofuels production. The three biomass conversion pathways compared in this study were: hydrothermal liquefaction technology (HTL), hydrothermal hydrolysis pretreatment +HTL (HTP), and wet lipid extraction (WLE). Carbon, nitrogen, and phosphorous (C, N, P) flows were described in each pathway. A primary cost analysis was conducted to evaluate the economic performance. The LCA results show that the HTP reduced life cycle NOx emissions by 10% from HTL, but increased fossil fuel use, greenhouse gas emissions, and eutrophication potential by 14%, 5%, and 28% respectively. The cost of per gallon biodiesel produced in HTP was less than in HTL. To further reduce emissions, efforts should be focused on improving nutrient uptake rates in algae cultivation, increasing biomass carbon detention in hydrothermal hydrolysis, and/or enhancing biomass conversion rates in the biooil upgrading processes.
Pub.: 06 Feb '17, Pinned: 23 Apr '17
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