Development Of Second-generation Biofuels Research Articles

Impacts of Palm Oil-based Biofuel Utilization Promotion Policy in the Thai Transport Sector

This paper aims to provide an analysis of the impacts of the promotion policy of palm oil-based biofuel utilization in the Thai transport sector for the period 2020–2037. For this purpose, three scenarios are developed to represent different proportions of palm oil-based biofuel blending implemented in Thailand and their impacts are analyzed through the application of the Low Emissions Analysis Platform (LEAP) model. The analysis reveals that an increase in the proportion of palm oil-based biofuel in a diesel mix would provide several noticeable benefits, for example, help reducing diesel consumption, decreasing crude oil requirement, and mitigating emissions of CO2 and PM2.5 – a major source of current environmental health problems. In addition, increased proportion of palm oil-based biofuel in the diesel mix would contribute to a growing demand for oil palm production and a plantation area to meet an increase in palm oil-based biofuel production. A high demand for oil palm production and plantation land requirement could, however, be emerging challenges. In order to address these challenges, the effective strategies could include a plan for agricultural crop zoning, crop breeding, the efficiency enhancement of biofuel conversion technology, the reduction of chemical fertilizers and pesticides, and the support from the government for research and development of second-generation biofuels. The analysis will be useful for Thai planners and policy makers to design policies to overcome the issues of energy and food security as well as climate change problems.

Nitrogen Use Efficiency for Sugarcane-Biofuel Production: What Is Next?

Land area devoted to sugarcane (Saccharum spp.) production in Brazil has increased from 2 million to 10 million ha over the past four decades. Studies have shown that, from an environmental perspective, the transformation of nitrogen (N) fertilizers into N2O gases can offset the advantages gained by replacing fossil fuels with biofuels. Our objectives here were to review recent developments in N management for sugarcane-biofuel production and assess estimates of N use efficiency (NUE) and N losses based on future scenarios, as well as for life-cycle assessments of bioenergy production. Approximately 60 % of N-based fertilizer applied to sugarcane fields in Brazil is recovered by plants and soils, whereas N losses to leaching and N2O emissions can average 5.6 and 1.84 % of the total applied N, respectively. Maintenance of trash, rotation with N-fixing legume species, and optimization of byproducts usage have potential for reducing the N requirements of sugarcane cultivation in Brazil. Moreover, the development of sugarcane genotypes with higher NUEs, along with management systems that consider soil capacity of mineralization, is required for improving the NUE of sugarcane. Strategies to maintain N as NH4 + in sugarcane-cropped soils also have the potential to reduce N losses and enhance NUE. The development of second-generation biofuels is important for increasing biofuel production while simultaneously maintaining N rates and improving NUE, and sugarcane systems in Brazil show potential for sustainable biofuel production with low N rates and limited N2O losses. Reducing N rates in sugarcane fields is thus necessary for improving sugarcane-based biofuel production and reducing its environmental impacts.

Combining and Comparing Coalescent, Distance and Character-Based Approaches for Barcoding Microalgaes: A Test with Chlorella-Like Species (Chlorophyta).

Several different barcoding methods of distinguishing species have been advanced, but which method is the best is still controversial. Chlorella is becoming particularly promising in the development of second-generation biofuels. However, the taxonomy of Chlorella–like organisms is easily confused. Here we report a comprehensive barcoding analysis of Chlorella-like species from Chlorella, Chloroidium, Dictyosphaerium and Actinastrum based on rbcL, ITS, tufA and 16S sequences to test the efficiency of traditional barcoding, GMYC, ABGD, PTP, P ID and character-based barcoding methods. First of all, the barcoding results gave new insights into the taxonomic assessment of Chlorella-like organisms studied, including the clear species discrimination and resolution of potentially cryptic species complexes in C. sorokiniana, D. ehrenbergianum and C. Vulgaris. The tufA proved to be the most efficient barcoding locus, which thus could be as potential “specific barcode” for Chlorella-like species. The 16S failed in discriminating most closely related species. The resolution of GMYC, PTP, P ID, ABGD and character-based barcoding methods were variable among rbcL, ITS and tufA genes. The best resolution for species differentiation appeared in tufA analysis where GMYC, PTP, ABGD and character-based approaches produced consistent groups while the PTP method over-split the taxa. The character analysis of rbcL, ITS and tufA sequences could clearly distinguish all taxonomic groups respectively, including the potentially cryptic lineages, with many character attributes. Thus, the character-based barcoding provides an attractive complement to coalescent and distance-based barcoding. Our study represents the test that proves the efficiency of multiple DNA barcoding in species discrimination of microalgaes.

Enzyme recovery and fouling mitigation by ultrasound-enhanced ultrafiltration

The development of second-generation biofuels from cellulosic/lignocellulosic biomass has advantages from energy and environmental aspects, but the overall cost of the process is mainly dependent on the cost of the enzymes. Enzyme recovery and recycling is one of the most important and effective means of increasing the efficiency of enzymatic hydrolysis processes by lowering the enzyme costs. The primary objective of this study was to investigate the possibilities of enzyme recovery by membrane separation. Ultrafiltration (UF) membranes with various cut-off values and materials were used to recycle cellulase and cellobiase in model solutions and cellulosic hydrolysates. The membrane separation process was followed by determination of the flux, and its efficiency of it was measured via sugar and protein retention, and the resistances were also calculated. A polyether–sulfone membrane with a cut-off value of 5 kDa, (PES5) operated at 26.8 L m-2 h-1 with 87.3% protein rejection while a thin-film membrane with a cut-off value of 4 kDa (TF4) operated at 26.3 L m-2 h-1 with 92.4% of protein rejection, allowing the free transmission of glucose. Large differences were measured between the distrubutions of various kinds of resistances for the PES5 and TF4 membranes; 65% of the total resistance was due to the fouling mechanism in the case of the PES5 membrane, whereas the fouling resistance amounted to only 41% for TF4 membrane. Ultrasound (US) treatment during the UF of a hydrolysate increased the flux and changed the proportions of fouling resistance and the gel resistance.

Impact of biofuel production and other supply and demand factors on food price increases in 2008

The prices of some grain commodities more than doubled from March 2007 to March 2008. Increased food prices coincided with increasing global biofuel production, leading to speculation that biofuel production was responsible for the increased food prices. However, over the six-month period after March 2008, grain prices declined by 50% while biofuel production continued to increase. It is not possible to reconcile claims that biofuel production was the major factor driving food price increases in 2007–2008 with the decrease in food prices and increase in biofuel production since mid-2008. The available data suggests that record grain prices in 2008 were not caused by increased biofuel production, but were actually the result of a speculative bubble related to high petroleum prices, a weak US dollar, and increased volatility due to commodity index fund investments. Many factors converged in 2007–2008 to increase food and related commodity prices including increased demand, decreased supply, and increased production costs driven by higher energy and fertilizer costs. Disentangling these factors and providing a precise quantification of their contributions is a difficult, perhaps impossible, task. In 2008, several reports were published by governmental and international agencies that speculated on the cause of increased food prices worldwide. Taken together, the available analyses suggest that biofuel production had a modest (3–30%) contribution to the increase in commodity food prices observed up to mid-2008. The development of second-generation biofuels (e.g., cellulosic ethanol) which use non-food residual biomass or non-food crops should mitigate any future impact of biofuel production on food prices.

A roadmap for biofuels…

Biofuels have been in the eye of the storm, in particular since 2008, when the food crisis was considered by many to be caused by the increased production of biofuels. Heavy criticism in public media made various governments, including the European Commission, reconsider their targets and ambitions for biofuels. A year after the climax of the food (and biofuels) crisis, the debate around biofuels has calmed down to quite an extent. The fierce debate has in the meantime translated into strong policy action: sustainability schemes for biomass and biofuel production are developed and implemented around the globe. Dozens of systems are developed by governments, NGOs and stakeholder initiatives, such as the various Roundtables. The Renewable Energy Directive of the European Commission contains one of the most comprehensive proposals to date and is backed by strong legislation: for biofuels, meeting sustainability criteria will be a prerequisite to be counting towards the obligatory targets. In addition, there is a heavy emphasis in Europe, the United States, but also key countries like China on the rapid development of second generation biofuels in order to further develop a sustainable biofuels industry that can cover a significant share of the worlds transport fuel needs. Such modified policies are also backed by the International Energy Agency’s Energy Technology Perspectives report, that projects a dominant role for 2nd generation biofuels in the medium (2030) term.

Biofuels Policies in Asian Countries: Impact of the Expanded Biofuels Programs on World Agricultural Markets

The governments of Asian countries are promoting biofuels programs to deal with energy security and environmental problems, and to increase farm income. However, securing raw materials for biofuels is a crucial problem, because these raw materials comprise various agricultural products which are used as food sources in Asian countries. Increasing biofuel consumption is exacerbating this problem. To address it, the governments of Asian countries are working on biofuel programs which will not compete with food security. Most of the Asian countries are food-importing countries. Increasing food prices, due to competition, could lead to social unrest. It is expected that the introduction and development of second-generation biofuels can mitigate the competition between food and energy. As various countries develop second-generation biofuels, international cooperation is needed to maximize such development in Asia and other regions. Establishing international cooperation to develop second-generation biofuels is urgently needed in Asian countries.