Emerging Biofuel Industry Research Articles

Perennial cover crop influences on soil C and N and maize productivity

New management systems are needed that enhance the sustainability of crop residue harvesting for use as feedstock in the emerging biofuel industry. We investigated whether a novel perennial cover crop management system, designed to overcome yield drag, would enhance sustainability of maize (Zea mays L.) residue harvesting. Overall the perennial cover crop treatments [Kentucky bluegrass (Poa pratensis L.) (BG) and creeping red fescue (Festuca rubra L.) (RF)] increased the soil potential mineralizable N (8.5%), decreased the loss of total soil organic C (10.1%) and N (6.5%) relative to the no-cover crop controls [with (RR) and without (RS) removal of crop residues]. Respired CO2, measured during 28 day incubations, decreased in the following order: RF > RS ≈ BG > RR for both in-row and in-between-row samples implying high microbial activity under cover crop treatments. SPAD readings, growth stage, and end of season maize-stalk nitrate test results varied by site-year but were consistent with soil NH4+/NO3− dynamics. Results indicate that competition between the maize and perennial cover crops for water and N resources was weather dependent. Although previous research documented that the management system employed was able to overcome the yield drag associated with perennial cover crops, in our study maize yields for the perennial cover crop treatments were only one-third the yields for the controls. Overall, we conclude that the perennial cover crop system is capable of enhancing the sustainability of maize residue harvesting, but more work is needed to overcome the yield drag which may be caused by perennial cover crops under some conditions.

Bioeconomy Survey Results Regarding Barriers to the United States Advanced Biofuel Industry

Although the 2005 Environmental Protection Act (EPAct) was enacted to bolster the emerging biofuel industry, 52% of advanced biofuel (AB) projects ended by 2015. However, there are no complete lists of internal and external barriers that can help to explain why these projects are failing. The goal of this study was to develop a list of barriers impeding advanced biofuel projects by conducting a survey of biofuel stakeholders. Based on a literature review and previous research, a list of 23 hypothesized internal and external barriers was elaborated. A survey was conducted to have industry stakeholders provide their perception on the list of hypothesized barriers. The perceptions of industry stakeholders were analyzed by dividing the sample in three different stakeholder groups: advanced biofuel industry members, government representatives, and a third category called others that included publishers, journalists, suppliers, and other related stakeholders to the industry. In addition, nonparametric statistical techniques were used to compare the perceptions of the groups. The most significant results indicated that Technology issues was considered as an internal barrier for the three groups while Funding and Renewable Fuel Standards were perceived as external barriers by the three groups too. In addition, the rating of barriers was further analyzed only by AB industry stakeholders in order to uncover more details on the perception of barriers that might be preventing the AB industry to prosper.

Quantifying the Impact of Feedstock Quality on the Design of Bioenergy Supply Chain Networks

Logging residues, which refer to the unused portions of trees cut during logging, are important sources of biomass for the emerging biofuel industry and are critical feedstocks for the first-type biofuel facilities (e.g., corn-ethanol facilities). Logging residues are under-utilized sources of biomass for energetic purposes. To support the scaling-up of the bioenergy industry, it is essential to design cost-effective biofuel supply chains that not only minimize costs, but also consider the biomass quality characteristics. The biomass quality is heavily dependent upon the moisture and the ash contents. Ignoring the biomass quality characteristics and its intrinsic costs may yield substantial economic losses that will only be discovered after operations at a biorefinery have begun. This paper proposes a novel bioenergy supply chain network design model that minimizes operational costs and includes the biomass quality-related costs. The proposed model is unique in the sense that it supports decisions where quality is not unrealistically assumed to be perfect. The effectiveness of the proposed methodology is proven by assessing a case study in the state of Tennessee, USA. The results demonstrate that the ash and moisture contents of logging residues affect the performance of the supply chain (in monetary terms). Higher-than-target moisture and ash contents incur in additional quality-related costs. The quality-related costs in the optimal solution (with final ash content of 1% and final moisture of 50%) account for 27% of overall supply chain cost. Based on the numeral experimentation, the total supply chain cost increased 7%, on average, for each additional percent in the final ash content.

Supplementing with Non-Glycoside Hydrolase Proteins Enhances Enzymatic Deconstruction of Plant Biomass

The glycoside hydrolases (GH) of Caldicellulosiruptor bescii are thermophilic enzymes, and therefore they can hydrolyze plant cell wall polysaccharides at high temperatures. Analyses of two C. bescii glycoside hydrolases, CbCelA-TM1 and CbXyn10A with cellulase and endoxylanase activity, respectively, demonstrated that each enzyme is highly thermostable under static incubation at 70°C. Both enzymes, however, rapidly lost their enzymatic activities when incubated at 70°C with end-over-end shaking. Since crowding conditions, even at low protein concentrations, seem to influence enzymatic properties, three non-glycoside hydrolase proteins were tested for their capacity to stabilize the thermophilic proteins at high temperatures. The three proteins investigated were a small heat shock protein CbHsp18 from C. bescii, a histone MkHistone1 from Methanopyrus kandleri, and bovine RNase A, from a commercial source. Fascinatingly, each of these proteins increased the thermostability of the glycoside hydrolases at 70°C during end-over-end shaking incubation, and this property translated into increases in hydrolysis of several substrates including the bioenergy feedstock Miscanthus. Furthermore, MkHistone1 and RNase A also altered the initial products released from the cello-oligosaccharide cellopentaose during hydrolysis with the cellodextrinase CbCdx1A, which further demonstrated the capacity of the three non-GH proteins to influence hydrolysis of substrates by the thermophilic glycoside hydrolases. The non-GH proteins used in the present report were small proteins derived from each of the three lineages of life, and therefore expand the space from which different polypeptides can be tested for their influence on plant cell wall hydrolysis, a critical step in the emerging biofuel industry.

DbCAN: a web resource for automated carbohydrate-active enzyme annotation

Carbohydrate-active enzymes (CAZymes) are very important to the biotech industry, particularly the emerging biofuel industry because CAZymes are responsible for the synthesis, degradation and modification of all the carbohydrates on Earth. We have developed a web resource, dbCAN (http://csbl.bmb.uga.edu/dbCAN/annotate.php), to provide a capability for automated CAZyme signature domain-based annotation for any given protein data set (e.g. proteins from a newly sequenced genome) submitted to our server. To accomplish this, we have explicitly defined a signature domain for every CAZyme family, derived based on the CDD (conserved domain database) search and literature curation. We have also constructed a hidden Markov model to represent the signature domain of each CAZyme family. These CAZyme family-specific HMMs are our key contribution and the foundation for the automated CAZyme annotation.

Economic and socioeconomics impact of biofuel production in the Arab Region

The growing global demand for energy with expected fossil fuel shortages accompanied with high fossil energy consumption and its adverse impact of environment and climate change stresses the search for alternative energy resources. However, biofuel energy offers many opportunities but poses a number of risks and tradeoffs that result in the shortage of food supply to the poor and increase, at the same time, food prices and food insecurity. The diversion of land by food staples to fuel increases food prices and reduced food availability worldwide. The main objective of this study is to assess the status of liquid biofuel production and processing in the Arab Region, to identify multiple effects of biofuel production and to identify the opportunities and challenges stemming from emerging biofuel industry for smallholder producers in the Arab Region countries. Primary information has been collected from stakeholders through questionnaires, rapid appraisal and field visits. Several Arab countries are using biomass from farms, processing residues and livestock manure. The other group is trying to grow fuel plants like Jatropha, such Saudi Arabia, Egypt and Jordan. The positive and negative impacts, in general, were briefly discussed, which in turn reflected the impact of biofuel production on economic and socio-economic. In conclusion, biofuels bring challenges and risks, including potential land-use conflicts, environmental risks, and heightened concerns about food security. These challenges and risks can be effectively dealt with through governmental policies. Key words: Biofuel, socioeconomic, food security, environmental impact.

Technological evolution and interdependence in China's emerging biofuel industry

This study uses the European Patent Office worldwide patent database and applies two-stage interactive data collection methods to reveal the evolving technological interdependence for China's emerging biofuel industry. Three findings are excerpted from our empirical results. First, due to dominant patterns of business ownership, China's biofuel technology is seen as largely based on the evolutionary strength of the foodstuff and chemical fields. Second, China's biofuel technology development has evolved in the mode of ‘forward engineering’, led by Chinese universities rather than initiated by the public research institutes as in the experience of other East Asian latecomers. Third, our patent map and technology trajectory analyses illustrate that China's biofuel technology tends to be application-oriented and highly intertwined with the pharmaceutical industry since the 2000s, which evidences the development of biofuel industry as reciprocally reinforcing China's innovation capability deriving from its prominent chemical sector. By examining endogenous technology capability embedded in the national innovation capacity, this study uncovers public implications for other technology latecomers attempting to build an emerging industry while facing technology uncertainty in a transitional society.

Bioenergy II: Bio-Ethanol from Municipal Solid Waste (MSW): The Role of Biomass Properties and Structures During the Ethanol Conversion Process

The emerging biofuel industry demands large amount of biomass feedstock. Although commercial ethanol has been produced from primary biomass sources such as corns, the global food crisis caused by the use of primary biomass has been raised. Thus, lignocellulosic biomass, known as second generation of biomass, has become a promising source for ethanol production. However, the more complex structure requires more advance technology. MSW with more than 60% of biodegradable composition, as one of the promising biomass sources has the potential benefits of replacing primary biomass and preventing environment from MSW pollution.In this paper, three major biodegradable municipal solid waste (BMSW) components: kitchen organic waste (KOW), green organic waste (GOW) and paper and card waste (PCW), are classified and characterised according to substrate composition, cellulose crystallinity, bulk density and particle size. The substrate composition indicates how much cellulose, lignin, hermicellulose each model waste has. The cellulose content shows the potential glucose/ethanol product yield. Other chemical composition such as lignin and hemicellulose indicates how easy of each model waste can be converted. These contents are also important information when selecting pretreatment methods and conversion process conditions in the following steps.Based on the comprehensive understanding of biomass structures and compositions, studies look into the effects of substrate properties (such crystallinity, presence of lignin and cellulose content on process performances during enzymatic hydrolysis adsorption. Results indicated how the adsorption process is affected by the substrate properties. This provides understanding of the role of substrate properties during enzyme-cellulose adsorption.

Conserving and Enhancing Maize Genetic Resources as Global Public Goods–A Perspective from CIMMYT

ABSTRACTThe growing demands for food, feed, and bioenergy worldwide will require a 2% per annum increase in global maize (Zea mays L.) production. Maize is one of the most important staple food crops across the developing world as well as being an important feed crop for global livestock production and the emerging biofuel industry. Maize genotypes can range from 0.5 to 5 m standing height at flowering, mature in 60 to 330 d from planting, produce 1 to 4 ears per plant, 10 to 1800 kernels per ear and yield from 0.5 to 23.5 Mg of grain per hectare. Even greater genetic diversity is present in related species yet surprisingly little of the maize‐related biodiversity is present in the current elite breeding pools. Improved methods and tools for germplasm conservation, characterization, and data sharing, as well as for population improvement, gene pool enhancement, and genomics‐aided breeding are urgently needed if increases in maize productivity, particularly in the developing world, are to keep pace with predicted increases in demand. Progress in the private sector, particularly with the development of temperate maize cultivars, is far beyond that of the public sector, particularly regarding tropical maize cultivar development. This article provides an overview of progress at the International Maize and Wheat Improvement Center (CIMMYT) with national partners across the developing world. Particular emphasis is given to issues related to the continued development of elite maize breeding material as global public goods, especially regarding the introgression of new variations from genetic resources and the legal and phytosanitary issues related to international exchange of maize germplasm.

Enzymatic deconstruction of xylan for biofuel production.

The combustion of fossil-derived fuels has a significant impact on atmospheric carbon dioxide (CO(2)) levels and correspondingly is an important contributor to anthropogenic global climate change. Plants have evolved photosynthetic mechanisms in which solar energy is used to fix CO(2) into carbohydrates. Thus, combustion of biofuels, derived from plant biomass, can be considered a potentially carbon neutral process. One of the major limitations for efficient conversion of plant biomass to biofuels is the recalcitrant nature of the plant cell wall, which is composed mostly of lignocellulosic materials (lignin, cellulose, and hemicellulose). The heteropolymer xylan represents the most abundant hemicellulosic polysaccharide and is composed primarily of xylose, arabinose, and glucuronic acid. Microbes have evolved a plethora of enzymatic strategies for hydrolyzing xylan into its constituent sugars for subsequent fermentation to biofuels. Therefore, microorganisms are considered an important source of biocatalysts in the emerging biofuel industry. To produce an optimized enzymatic cocktail for xylan deconstruction, it will be valuable to gain insight at the molecular level of the chemical linkages and the mechanisms by which these enzymes recognize their substrates and catalyze their reactions. Recent advances in genomics, proteomics, and structural biology have revolutionized our understanding of the microbial xylanolytic enzymes. This review focuses on current understanding of the molecular basis for substrate specificity and catalysis by enzymes involved in xylan deconstruction.

Intentions of UK Farmers toward Biofuel Crop Production: Implications for Policy Targets and Land Use Change

The United States and the European Union have set targets for biofuel production to decrease reliance on fossil fuels and to reduce fossil carbon emissions. Attainment of biofuel targets depends upon policy and infrastructure development but also on production of suitable raw materials. Production of relevant crops relies on the decisions that farmers make in their economic and political environment. We need to identify any farmer-related barriers to biofuel production and to determine whether novel policy and technology are required to meet targets. These aspects of the emerging biofuel industry are relevant across international barriers and have not yet been addressed quantitatively. We describe a case study from the UK of farmers' intentions toward producing two biofuel crops for which refining capacity either exists or is under construction. Given farmers' intentions, current land use, and conversion efficiency, we estimate potential biofuel production. These estimates indicate that EU targets are not achievable using domestically grown raw materials without policy intervention, use of alternative feedstocks, and either significant improvements in processing efficiency or large-scale changes in land use.