Biogas Generation from Maize and Cocksfoot Growing in Degraded Soil Enriched with New Zeolite Substrate

Degraded lands are potential areas for obtaining biomass which can serve as an energy source after its conversion into biogas. Thus, the studies on biogas production from maize and cocksfoot biomasses obtained from degraded soil supplemented with additions of new zeolite substrate (Z-ion as the nutrient carrier) and on arable soil (reference soil) were carried out during batch digestion tests. It was found that the biogas and biomethane potentials and specific energy of the test species growing in degraded soil enriched with Z-ion additions (1% and 5% v/v in the cases of cocksfoot and maize, respectively) did not differ significantly from the values of these parameters that were found for the plants growing in arable soil. The application of Z-ion to the degraded soil (especially in a dose of 5% v/v) resulted in an increase in the nitrogen content and decrease (below the lower optimum value) in the C/N ratio in the plant biomass. However, these changes did not negatively influence the final values of the biogas or methane potentials or the specific energy found for the maize biomass. Therefore, the study results indicated the usefulness of Z-ion substrate for improving the growth conditions for energy crops in degraded soils and, as a consequence, obtaining a plant feedstock suitable for the digestion process.

Hope or hype: A critical assessment of Jatropha curcas for domestic biofuel production in Senegal

<p>This thesis was designed to critically test the suitability of Jatropha curcas as a plant feedstock for liquid biofuel production in Senegal. Many countries around the globe have attempted to incorporate bioenergy into their broader energy supply mix, and liquid biofuels are a key component of a low-carbon economy to replace fossil fuels for transport and electrical generation. The Senegalese government instituted a national biofuel plan between 2007 and 2012 to achieve energy independence through biofuels with an annual production target of more than a billion liters of oil. The plan was intended to reduce problems with energy scarcity and price fluctuations, contribute to local economic growth, and expand agricultural production to degraded or otherwise fallow land. The project was largely unsuccessful, and to date there has been no significant oil production from Jatropha curcas for the national energy supply. This research study was developed to understand the key barriers to the success of this program and mitigate the mistakes of future project developers and policymakers. Preliminary literature reviews and examples from similar endeavors in other countries suggested three main barriers that would be primary determinants of success or failure: the agronomic suitability, and therefore production and yield capacity, of Jatropha curcas to the Senegalese climate; the socio-economic challenges of integrating a broad national plan with smallholder farmers and assuring that the economics are fair for both growers and buyers; and the policy framework developed by government agencies, development organizations, and commercial interests to support an emergent biofuel industry. A mixed-method research design including document reviews, interviews and surveys, and case studies was employed to answer the key questions of why and how the Senegalese biofuel program has failed to achieve its intended goals. Results from this study indicate that Jatropha curcas is unsuitable as a plant feedstock for liquid biofuels in Senegal at this time, due to significant shortcomings in all three key categories examined. The plant is vastly underproductive and requires considerable investment in scientific improvement of yield, pest tolerance and seed oil content; the economic gain is neither adequate to justify smallholder farmers to adopt it as an alternative to existing crops nor for project developers to generate income from fuel on the open market; and supporting policy has not been consistent or favorable enough to carry this emergent industry from nascence to maturity. There are, however, encouraging signs of resilience in two particular case studies that provide insight into how future programs could be structured, most notably in the Sine-Saloum Delta region. Further research should be devoted to specific economic schemes and innovative financing options for community focused biofuel programs.</p>

Hope or hype: A critical assessment of Jatropha curcas for domestic biofuel production in Senegal

<p>This thesis was designed to critically test the suitability of Jatropha curcas as a plant feedstock for liquid biofuel production in Senegal. Many countries around the globe have attempted to incorporate bioenergy into their broader energy supply mix, and liquid biofuels are a key component of a low-carbon economy to replace fossil fuels for transport and electrical generation. The Senegalese government instituted a national biofuel plan between 2007 and 2012 to achieve energy independence through biofuels with an annual production target of more than a billion liters of oil. The plan was intended to reduce problems with energy scarcity and price fluctuations, contribute to local economic growth, and expand agricultural production to degraded or otherwise fallow land. The project was largely unsuccessful, and to date there has been no significant oil production from Jatropha curcas for the national energy supply. This research study was developed to understand the key barriers to the success of this program and mitigate the mistakes of future project developers and policymakers. Preliminary literature reviews and examples from similar endeavors in other countries suggested three main barriers that would be primary determinants of success or failure: the agronomic suitability, and therefore production and yield capacity, of Jatropha curcas to the Senegalese climate; the socio-economic challenges of integrating a broad national plan with smallholder farmers and assuring that the economics are fair for both growers and buyers; and the policy framework developed by government agencies, development organizations, and commercial interests to support an emergent biofuel industry. A mixed-method research design including document reviews, interviews and surveys, and case studies was employed to answer the key questions of why and how the Senegalese biofuel program has failed to achieve its intended goals. Results from this study indicate that Jatropha curcas is unsuitable as a plant feedstock for liquid biofuels in Senegal at this time, due to significant shortcomings in all three key categories examined. The plant is vastly underproductive and requires considerable investment in scientific improvement of yield, pest tolerance and seed oil content; the economic gain is neither adequate to justify smallholder farmers to adopt it as an alternative to existing crops nor for project developers to generate income from fuel on the open market; and supporting policy has not been consistent or favorable enough to carry this emergent industry from nascence to maturity. There are, however, encouraging signs of resilience in two particular case studies that provide insight into how future programs could be structured, most notably in the Sine-Saloum Delta region. Further research should be devoted to specific economic schemes and innovative financing options for community focused biofuel programs.</p>

Towards a Full Circular Economy in Biogas Plants: Sustainable Management of Digestate for Growing Biomass Feedstocks and Use as Biofertilizer

The digestate is a prospective biofertilizer and potential source of income for many biogas plants worldwide. However, its actual impact on the soil properties and biomass yield is still unexploited. The different digestates from eight agricultural biogas plants were researched in terms of their chemical composition and the fertilizing potential. The results obtained from digestate chemical analysis indicate that the digestate biomass had large amount of nitrogen (up to 73 g kg−1 fresh mass) and potassium (up to 25 g kg−1 fresh mass). The value of the digestate was estimated in the range of 2.88–7.89 EUR Mg−1 for liquid digestate and 7.62–13.61 EUR Mg−1 for solid digestate based on the commercial fertilizer market price of nitrogen, potassium phosphorus, organic carbon, Cu, Zn, Fe and Mg. The digestate produced at the 1 MW biogas plant is worth EUR 941–2095 per day in addition to energy sales income. The application of digestate on low-fertility land in areas close to the biogas plant allows the production of up to three-fold more biomass suitable for biogas production. The digestate’s application on semi-natural grass biomass production in the low-fertility soils near the biogas plants could be an alternative strategy for the biogas plant feedstock portfolio diversification.

Cellulose and Nanocellulose Productions from Lignocellulosic Biomass for Biofuel Production

Abstract:: Biofuel is an emerging fuel to replace the conventional fuel used in transportation. With intensive research efforts, a new number of novel technologies having high potential for sustainable development have been developed to extensively utilize the biomass with zero waste. Cellulose and nanocellulose is becoming as one of the most targeted polymers to convert in to biofuel. It is being obtained from different plants parts. However, a concern is that the source of sustainable feedstocks for cellulosic component as desired process under different circumstances to produce biofuel. This study reviews concisely the cellulosic component, nanocellulose, isolation and extraction by different pretreatment technologies envisaging enzy-matic hydrolysis, biochemical conversion process and different plant feedstock as biofuel production. Particular attentions are paid to first generation of biofuel, second generation of biofuel and third generation of biofuel in regards to nanocellulose applications. The most common feedstocks lignocellulosic biomass is extensively discussed in the later part. The review also aims to present different methods of syntheses of nanocellulose, cellulose production from biomass and their applica-tion towards the biofuel production.

Optimization Model for Biogas Power Plant Feedstock Mixture Considering Feedstock and Transportation Costs Using a Differential Evolution Algorithm

In this paper, an optimization model for biogas power plant feedstock mixture with respect to feedstock and transportation costs using a differential evolution algorithm (DEA) is presented. A mathematical model and an optimization problem are presented. The proposed model introduces an optimal mixture of different feedstock combinations in a biogas power plant and informs about the maximal transportation distance for each feedstock before being unprofitable. In the case study, the proposed model is applied to five most commonly used feedstock in biogas power plants in Croatia and Hungary. The research is performed for a situation when the biogas power plant is not owned by the farm owner but by a third party. An optimization procedure is performed for each scenario with a cost of methane production that does not exceed 0.75 EUR/m3 in 1 MWe biogas power plant. The results show the needed yearly amounts and the maximum transportation distance of each feedstock.

THE INFLUENCE OF REACTION TIME ON THE PROPERTIES OF MICROWAVE SYNTHESIZED POLY(LACTIDE)

The consequence of drastic reduction in fossil fuel reserves has forced the scientific community to find and develop new ways to exploit renewable resources and optimize the process of polymer materials production. The aim is to obtain applicable polymer whose complete life cycle is set in ecological framework. Poly(lactide) (PLA) meets these requirements as biodegradable polyester whose monomer is derived from the plant feedstock containing carbohydrates. PLA could be prepared using the different synthesis routes, but from the point of energy saving, as well as environmental protection, the microwave synthesis of PLA is the best solution. In this work, poly(L-lactide) were synthesized in microwave reactor. Reaction time was varied, while the other parameters of the synthesis were constant. The structures of obtained polymers were confirmed by Fourier – transform infrared spectroscopy (FT-IR). For determination of molar masses of poly(L-lactide) samples, the gel permeation chromatography (GPC) was applied. Thermal properties were investigated by differential scanning calorimetry (DSC).