Combined fermentation of sewage sludge and bio waste

Sludge Load

Experience92' on the combined fermentation of sewage sludge and bio waste has been obtained in a plant in Germany Figure 5.1 .93' The daily throughputs per inhabitant of processed waste water and bio waste are listed in Table 5.1. The bio waste from different origins is collected separately and dumped together into a flat hopper from where a wheel loader transports it to a screw mill, from where it is then transported to the liquid preparation stage, consisting of two steps dissolving the...

Reinforced concrete tanks

How Will Field Concrete Tanks

The reinforced concrete must be free of cracks and resistant under the special conditions during fermentation over the entire period of utilization. With reinforced concrete, the acidic substrate can penetrate to the reinforcement and corrode it if carbon dioxide-containing air also permeates to the Figure 1.1 Reinforced concrete in Europe top left , Heating and agitation devices inside a vertical bioreactor top right , Construction of a basin middle left , Uncovered basin middle right , Thoeni...

Low pressure biogasholder

Biogasholder

Most i.e. 80 of the installed biogasholders are of the low-pressure type. Many consist of a biogas bag of plastic foil. Others are constructed of steel. Biogas from Waste and Renewable Resources. An Introduction. Dieter Deublein and Angelika Steinhauser Copyright 2008 WILEY-VCH Verlag GmbH amp Co. KGaA, Weinheim ISBN 978-3-527-31841-4 Bioreactor cover or biogas bag of foil The plastic foils used are manufactured from plastics resistant to UV, weather, fungus, microbes, and biogas, e.g.,...

Landfill for residual waste

Until the 1990s, residual waste i.e. household waste was discarded on landfills, by default. Biological components of the waste were degraded quite slowly and the fermentation process took about 20-40 years. The landfill gas produced during the process was gathered by using horizontal drainages and gas pits for disposal. About 12-300m3 oflandfill gas was produced in total per Mg ofresidual waste, but it contained quite a high level of toxic and corrosive organic components, so that damage to...

Utilization of biogas for the generation of electric power and heat

Biogas can be used either for the production of heat only or for the generation of electric power. When current is obtained, normally heat is produced in parallel. Such power generators are called combined heat and power generation plants CHP and are normally furnished with a four-stroke engine or a Diesel engine. A Stirling engine or gas turbine, a micro gas turbine, high- and low-temperature fuel cells, or a combination of a high-temperature fuel cell with a gas turbine are alternatives....

Process engineering and equipment construction

Flowsheet Biogas

Figure 4.41 shows the flow sheet ofa biogas plant for bio waste. The biomass is continuously dehydrated by centrifuges applied during the hydrolysis stage. In this process the liquid phase is transferred into the methane reactor while the solid phase is recirculated for continuous hydrolysis. A series arrangement of several tanks allows the use of cultures of special bacteria and optimization of the degradation of organic substances. Usually about 40-50 of the organic substances dissolve easily...

Bio waste plants

In Germany, 70 of the biogas plants for bio waste, operate based on wet fermentation with suspension of the wastes, while in 30 of the plants, stacked waste is leached by means of percolation. Most plants work in batch mode Table 5.2 . In all current processes, the bio waste is first accepted and then pretreated and subjected to a single-phase or multi-stage bioreactor plant. The biogas is utilized for power generation and the fermentation residue aerobically decomposed, while waste water is...

Parameter pH

Ammoniak Ammonium Buffer System

The equation below gives the relationship between pH and hydrogen ion concentration in mol mL-1 Water with a hydrogen ion concentration of 10-6molL-1 or 10-4gL-1 has, for instance, a pH value of 6. Because of the hydrogen transportation by NAD, different products of fermentation are developed the H ions isolated from the substrate are carried over to the uncharged NAD. The NAD molecules so charged NADH H regenerate oxidize , by forming H2 molecules NADH H H2 NAD AG 18.07kJmol-1 This reaction...

Generation of electricity in a micro gas turbine

Biogas Gas Turbine

Micro gas turbines are small high-speed gas turbines with low combustion chamber pressures and temperatures. They are designed to deliver up to ca. 200 kWei electrical power. Nearly all micro gas turbine manufacturers offer turbines of radial design with combustion air compressor, combustion chamber, generator, and heat exchanger Figure 5.13 . Micro gas turbines are characterized by a single shaft on which the compressor, the turbine, and the generator are fixed. The turbine propels the...

Ammonium NH and ammonia NH

Www Anastrip Net

Ammonia and ammonium result from the anaerobic biological degradation of nitrogen compounds. Ammonia forms ammonium ions in the substrate, the extent of this depending on the pH value. Ammonia has an inhibiting effect, and with larger concentrations can even be toxic, while ammonium is innocuous. It can only have an inhibiting effect at concentrations NH4 -N gt 1500 mgMg-1, where its inhibiting effect is predominantly due to the species whose concentration depends on the pH value. Ammonium...

Acidogenic phase

Isovaleric Degradation

The monomers formed in the hydrolytic phase are taken up by different facultative and obligatorily anaerobic bacteria and are degraded in the second, the acidogenic phase, to short-chain organic acids, C1-C5 molecules e.g., butyric acid, propionic acid, acetate, acetic acid , alcohols, hydrogen, and carbon dioxide. The concentra- tion of the intermediately formed hydrogen ions affects the kind of the products of fermentation. The higher the partial pressure of the hydrogen, the fewer reduced...

Generation of electricity in a fourstroke gas engine and a Diesel engine

Disgin Engine Piston

Today's four-stroke biogas engines were originally developed for natural gas and are therefore well adapted to the special features of biogas. Their electrical efficiency normally does not exceed 34-40 , as the nitrogen oxide output NOx has to be kept below the prescribed values. There are, for example, four-stroke engines with electrical offi-ciencies above 40 working with a recuperator Figure 5.5 . The capacity of the engines ranges between 100KW and 1MW and the lifetime is given as ca. 60...

Utilized biomass

The German law of bio waste regulates the circulation of bio wastes in agriculture, in forestry, and in horticulturally used ground Table 1.2 . Bio waste recycling includes all plants which ferment biological waste, even if the fermented substances are only partly of biological origin. The residue is called bio waste and is the subject of the bio waste regulations. Bio waste is, for example, the content of the grease removal tank in catering establishments, mash from Table 1.2 Restrictions when...

Generation of electricity in a fuel cell

Solid Waste Generation Flow Chart

Compared to combustion engines, the fuel cell converts the chemical energy of hydrogen and oxygen directly to current and heat. Water is formed as the reaction product Figure 5.8 . In principle, a fuel cell works with a liquid or solid electrolyte held between two porous electrodes - anode and cathode Figure 5.9 . The electrolyte lets pass only ions and no free electrons from the anode to the cathode side. The electrolyte is thus electrically non-conductive. It separates the reaction partners...

Methanotropic species

Methanomicrobium Paynteri

Methanotropic species methane-consuming microorganisms Figure 3.4 are everywhere. They are undesired in biogas plants, but very importend for our climate. Most of them are aerobics. They use oxygen to split methane and to get their energy. The metabolic products are water and carbon dioxide. M. Defluvii M. Oryzae M. Thermoflexum Mbr. Arboriphilus Mbr. Ruminantium dominant type in stomachs of cattle Mbr. Smithii sewage-sludge and mammalian colons j Mbr. Curvatus Mbr. Cuticularis Mbr. Filifomiis...

Biological desulfurization

H2s Biogas

Biological desulfurization is mostly applied for the reduction of the H2S content. The process is effective at concentrations up to 3000 mg Nm-3.14 ,15 In the biological desulfurization process, the hydrogen sulfide is absorbed in water and then decreased biologically. Microorganisms of the species Thiobacillus and Sulfolobus, which are omnipresent and therefore do not have to be inoculated especially, degrade the hydrogen sulfide. Table 3.2 Decision-making aid for the selection of procedures...

Cryogenic biogas purification

Ch4 Co2 Biogas

Cryogenic or low-temperature biogas purification30 is a procedure which has not yet been sufficiently tested. It is expected to deliver methane of a quality suitable for vehicles. After compression to approximately 200 bar and liquefaction of the biogas, the impurities like H2S are adsorbed onto molecular sieves Figure 3.7 . The liquefied gas mixture is than separated by means of low-temperature distillation, often called very low-temperature rectification at approximately 30 bar, because the...

Plant installations

Aerobic Anaerobic Composting

AN Biothane process Figure 4.45 The AN Biothane process was probably the first process to be developed for bio waste fermentation. In this process the substrate is prepared, then carefully piled up in the percolation reactor and sprayed with a little water, which percolates through the biomass and removes all water-soluble substances. The wash water, containing all the dissolved substances, is roughly separated and fermented in an UASB-digester. Prethane Rudad-Biopaq process or ANM process...

Energy supply in the future scenarios

Shell International4' has published a projection for different energy sources for the years 1990 up to 2100 Figure 2.1 . Assuming the Sustainable Growth scenario, energy consumption will increase by 7 times at most during this period. Applying the Dematerialization scenario much lower consumption driven by sustained economic use , the amount of energy will increase by a factor of 3 at least . Both scenarios can be explained and are driven by the assumptions of an increase in population from...