Since today’s infrastructure for transport is based on liquid fuels, the introduction of gaseous fuels into the transport sector is slow and challenging for future transport strategies. Nevertheless, there exists already a market for vehicles which use gaseous fuels in place of liquid fuels. Today, most of them run on natural gas. Many automotive manufacturers already offer pure or bivalent natural gas vehicl es as standard models. One
of the promising future options for sustainable transport fuels is the subsidization of natural gas by biomethane
Biomethane is the most efficient and clean burning biofuel which is available today. It can be produced from nearly all types of biomass including wet biomass which is not usable for most other biofuels. Another motivation for using gaseous biofuels for transport applications is the opportunity of diversifying feedstock sources. The raw material for the production of biomethane is biogas, which can be processed from various feedstock sources. For biogas production much more different feedstock sources can be used than for common liquid biofuels. For instance biodiesel can be only made from plant materials containing certain amounts of oil. In contra st, biogas is produced from nearly all types of organic materials including vegetable and animal feedstocks. The origin of the feedstock can vary, rangi ng from livestock waste, manure, harvest
surplus, to vegetable oil residues. Dedicated energy crops are becoming more and more practice as feedstock source for biogas pr oduction. Recently, wastewater sludge, municipal solid wastes and organic wastes from house holds have been introduced as feedstock. Another feedstock source is the collection of biogas from landfill sites. In Germany biogas is produced in agricultural facilities, main ly by the fermentation of manure and maize
One main advantage of methane production is the ability to use so-called “wet biomass” as feedstock source. Wet biomass can not be used for the production of ot her biofuels such as PPO, biodiesel or biomethane. Examples for wet biomass are sewage sludge, manure from dairy and swine farms as well as residues from food processing. They all are characterized by moisture contents of more than 60–70 %. The use of waste materials is not only excellent suitability for biogas production it also creates some additional benefits. Thus, it cont ributes to reduce animal wastes and odors. Digestion effectively eliminates environmental hazards, such as overproduction of liquid manure. Therefore biogas production is an excellent way for livestock farmers to comply with increasing governmental regulations of animal wastes. In addition it destroys disease-causing pathogens existing in waste materials. Nevertheless, using animal feedstock can be
critical as well. For instance anaerobic degradation of poultry excrements with high contents of organic nitrogen produce high concentrations of undesirable ammonium. Furthermore, new economical and ecological solutions for the treatment of animal by products are required due to the BSE-crisis (PRECHTL & F AULSTICH 2004). However, it is often the combination of environmental, ec onomical and legal reasons that motivates farmers to use digester t echnology for waste treatment. Apart from waste materials wet biomass also includes dedicated energy crops or any other vegetable materials with high moisture contents. Even grass can be used as feedstock. The suitability of energy crops for biogas production was received through improvements in the fermentation process. The main disadvantage of energy crops when compared to waste materials is their need for additional agricultural land as it is needed also for PPO,
biodiesel and bioethanol production. Nevertheless, energy crops for biogas production have several advantages which make them very promising for the future. One main advantage is the production of considerably high yields of energy crops, even when they are cultivated extensively. Chemical fertilizers and pesticides are not required or only in small amounts. Damaged and uneatable harvests resulting from unfavorable growing and weather conditions, as well as from pest contaminations are suitable for biogas production, too. In addition, cultivations do not have to become fully ripe, since the whole plant can be
used for biogas production. Harvests do not have to be dried. The quality and yield of bi ogas heavily depends on the feedstock type. According to (BENSMANN 2005) the average yield of biogas is 4 100 liters per hectare. This is equivalent to approximately 127 GJ/ha, being nearly three times as high as for RME and one and half times higher than for ethanol. Much higher yields can be expected from energy crop
optimization (ARNOLD et al. 2005).
of the promising future options for sustainable transport fuels is the subsidization of natural gas by biomethane
Biomethane is the most efficient and clean burning biofuel which is available today. It can be produced from nearly all types of biomass including wet biomass which is not usable for most other biofuels. Another motivation for using gaseous biofuels for transport applications is the opportunity of diversifying feedstock sources. The raw material for the production of biomethane is biogas, which can be processed from various feedstock sources. For biogas production much more different feedstock sources can be used than for common liquid biofuels. For instance biodiesel can be only made from plant materials containing certain amounts of oil. In contra st, biogas is produced from nearly all types of organic materials including vegetable and animal feedstocks. The origin of the feedstock can vary, rangi ng from livestock waste, manure, harvest
surplus, to vegetable oil residues. Dedicated energy crops are becoming more and more practice as feedstock source for biogas pr oduction. Recently, wastewater sludge, municipal solid wastes and organic wastes from house holds have been introduced as feedstock. Another feedstock source is the collection of biogas from landfill sites. In Germany biogas is produced in agricultural facilities, main ly by the fermentation of manure and maize
One main advantage of methane production is the ability to use so-called “wet biomass” as feedstock source. Wet biomass can not be used for the production of ot her biofuels such as PPO, biodiesel or biomethane. Examples for wet biomass are sewage sludge, manure from dairy and swine farms as well as residues from food processing. They all are characterized by moisture contents of more than 60–70 %. The use of waste materials is not only excellent suitability for biogas production it also creates some additional benefits. Thus, it cont ributes to reduce animal wastes and odors. Digestion effectively eliminates environmental hazards, such as overproduction of liquid manure. Therefore biogas production is an excellent way for livestock farmers to comply with increasing governmental regulations of animal wastes. In addition it destroys disease-causing pathogens existing in waste materials. Nevertheless, using animal feedstock can be
critical as well. For instance anaerobic degradation of poultry excrements with high contents of organic nitrogen produce high concentrations of undesirable ammonium. Furthermore, new economical and ecological solutions for the treatment of animal by products are required due to the BSE-crisis (PRECHTL & F AULSTICH 2004). However, it is often the combination of environmental, ec onomical and legal reasons that motivates farmers to use digester t echnology for waste treatment. Apart from waste materials wet biomass also includes dedicated energy crops or any other vegetable materials with high moisture contents. Even grass can be used as feedstock. The suitability of energy crops for biogas production was received through improvements in the fermentation process. The main disadvantage of energy crops when compared to waste materials is their need for additional agricultural land as it is needed also for PPO,
biodiesel and bioethanol production. Nevertheless, energy crops for biogas production have several advantages which make them very promising for the future. One main advantage is the production of considerably high yields of energy crops, even when they are cultivated extensively. Chemical fertilizers and pesticides are not required or only in small amounts. Damaged and uneatable harvests resulting from unfavorable growing and weather conditions, as well as from pest contaminations are suitable for biogas production, too. In addition, cultivations do not have to become fully ripe, since the whole plant can be
used for biogas production. Harvests do not have to be dried. The quality and yield of bi ogas heavily depends on the feedstock type. According to (BENSMANN 2005) the average yield of biogas is 4 100 liters per hectare. This is equivalent to approximately 127 GJ/ha, being nearly three times as high as for RME and one and half times higher than for ethanol. Much higher yields can be expected from energy crop
optimization (ARNOLD et al. 2005).
