Kraul & Wilkening u. Stelling KG-GmbH & Co., a midsize company resident in Hannover for over 140 years, produces and refines alcohol of the highest quality. KWST provides the entire range of agricultural alcohol products from its own production for use in numerous applications. In addition to the spirits and cosmetic industries, the principal customers are the chemical and pharmaceutical industries as well as manufacturers of paints, films and plastics. With an annual output of over 200,000 hectolitres of ethanol and storage capacity for over 20,000 cubic metres of ethanol, the Lower Saxon company is one of Germany's leading producers of alcohol from renewable raw materials. Quality and customer satisfaction are the paramount concerns of the company: certified according to DIN ES ISO 9002, KWST monitors its high standards of quality within its own laboratory with the aid of state - of - the - art analytical technology. The ethanol specialists set great store by energy conservation and environmental protection, not only in their modern distillery and the plants for the rectification and absolution of alcohol, but also in the field of recycling and waste water treatment, where the company plants are among the most technically advanced in the world. The production processes have been largely developed by the company itself, which has enabled them to be specifically tailored to the high demands of the customers. Even polluted Ethanol must be regarded as highly valued raw-material. It has to undergo a process of recycling treatment and may thus be put to use again. Therefore, we are maintaining a special distillery and processing plant for organic solvents - this being certified according BlmschG Nr. 4 8 regulations.
Contact: Kraul & Wilkening u. Stelling KG - GmbH & Co Lohweg 39, Hannover Miesburg T.: +49 - (05 11) 510 05 - 0; F.: +49 - (0511) 5 10 05 - 24 E-mail: info(at)KWST.com Internet: www.KWST.com
Excursion II: Biogas plant Ronnenberg with methane purification and grid feed-in
The BiogasUpgrader in Ronnenberg ordered by enercity (Stadtwerke Hannover) has successfully been feeding 650 m³/h biomethane in the natural gas net of the Stadtwerke since March 2008. The biogas plant Ronnenberg offer approx. 2.4 million m³ biogas for preparation and feed-in. This is sufficient for supplying about 1,400 households with heat. The order was placed in the frame of a EU tender. Project: Refinement of raw biogas to biomethane (bio natural gas) for the supply into the local natural gas distribution system acc. to the requirements of the DVGW worksheet G260 Customer: enercity (Stadtwerke Hannover); Year of construction 2008 Procedure: HAASE BiogasUpgrader, Organic physical scrubbing at approx. 7 bar (gauge) Continuous regeneration of the organic liquid detergent Capacity 650m3/h of raw biogas Uprading of the methane content acc. to calorific value specification Feed of 2.4 million m3 of biomethane (bio natural gas) per year Hydrogen sulphide < 5mg/m3 Methane slip lower 2% (retrofittable to zero-methane-concept by HAASE VocsiBox®)
Excursion III: WWTP Rheda-Wiedenbrück - combined treatment of municipal and slaughter house wastewater.
The Waste Water Treatment Plant Theda-Wiedenbrück has approximate total capacity of 300,000 PE (94,000 PE from the commune and more than 200,000 PE from slaughterhouse). The daily daily N-load of the partstreams is about 1,4 kg/d. In this Treatment plant a new technology named Panda was applied. Normally the sludge liquor with the high ammonia concentration will be treated in two stages (nitritation and denitritation according to process. The special property of the PANDA technology is the internal recirculation. It supports the recovery alkalinity, maintains sludge flocs structure and regulars the variation of hydraulic and polluting loads. Ammonia from sludge liquor is partly oxidized to nitrite in tanks N1, N2 (Nitritation) and the denitritation will take place in tanks D1, D2. There is an intermediate sedimentation between nitritation and denitritation stages. The process is carried out as a plug-flow procedure. The effluent of PANDA plant will be returned to influent of WWTP. The partial nitrification is controlled by sludge age in the nitritation stage. The first operational results show that the partial nitrification was successfully applied and the nitrogen removal efficiency reached up to 93%. Since November 1997 the Waste water treatment plant Rheda Wiedenbrück utilize flotation tailings and pig stomach content from a slaughterhouse nereby. Flotation tailings (37 m³/d, TS = 5.7%) are pumped directly into the digestion tank (5000 m³), stomach content (50 m³/week, TS = 17%) are pumped through a solids trap and macerator to the digester. These co-substrates increase the input quantity of 18%, so that the retention time decrease from 21 to 18 days. The Loading rate in the reactor increase over 61 % (from 0.78 to 1.26 kg VS/(m³*d) and also the gas quantity over approx. 60 %.
Excursion IV: ProEn BiogasPlant Fallingbostel, Exhaust Heat Recovery through Industry
Daily approx. 150 to 200 t of raw materials delivered which become before deposition on the vehicle scale balanced. The vegetarian raw materials are stored in the acceptance hall and are given after view control and quality control into the dosage tank. By means of push grounds and augers the material gets in the raw material processing. There the biomass is unlocked mechanically and mixed together with the fermenting substrate by the effluent of the mixing tank. From here the fermenter are charged with the mixed biomass. Microorganisms ferment the substrate to biogas, rich in energy, which consists abou 53 % of methane gas. For an optimum process the reactors must be held permanently homogeneous. Therefore ProEn has an innovative process for pressing the gas. In this case no aqitators are in the reactors and also the temperature inside of the reactors are setting outside via heat exchangers. The produced biogas is collected in 2,000 m³ fermentation gas accumulators to be supplied afterwards to combined heat and power plant. In three CHP electric and thermal energy is produced. The electric energy (max 4.2 MW) is fed into the public electricity network. The thermal energy of max. 5.6 MW is uncoupled and forwarded tot he drying plant. The digestate is storage for a while into a digestate substrate tank and afterwards is supplied to the agricultural utilization.
Contact: Protein und Energie Soltau GmbH Beim Schäferkreuz 6, D-29614 Soltau, Germany T.: +49 (0)40 44 11 4-0, F.: +49 (0)40 44114-127 Email: info(at)proen.de Internet: http://www.proen.de/
Excursion Va: Municipal Solid Waste Treatment Plant Hannover (MBT ) aha Zweckverband Abfallwirtschaft Region Hannover
The MBT plant serves the city of Hannover and the surrounding municipalities, which are named as "Friendly Partnership Solid Waste Management Hannover Region (Zweckverband Abfallwirtschaft Hannover (AHA))". The landfill ban was the driving force for the development of this plant. In 1997, to prepare for the ban in june 2005, the municipality decided to build a MBT adjacent to the 140ha Lahe landfill site. The total area of the plant is about 20 to 25 ha. The investment was about 60 billion Euro. More than 1,400 staff are employed for collecting and treating the waste for more than 500,000 private properties and 40,000 commercial clients. The technical details of the plant are as follows: Waste types: private households and trade wastes Throughput: around 55% of the total waste generated in the region (i.e. 200,000 tons per year) Process: 14 unloading bays, 3 processing lines performing mechanical, aerobic and anerobic biological treatment
Mechanical Waste Processing Plant: Wastes are shredded, sorted (60mm sieve) and processed. Metals are separated and brought to utilization. High heat value coarse waste (e.g. paper, plastics and wood) is sorted, packed into containers and sent as refuse derived fuel to the adjacent incineration plant at a cost of roughly 100 Euro/t. Fine waste is treated in the biological waste treatment plant to reduce the organic content.
Biological Waste Compost Plant (BAK): The plant converts about 160 tonnes per day of separately collected organic and green wastes to high-quality compost in an enclosed structure over a 6-week process. Emission from the composting plant is treated by a bio-filter.
Biological Waste Treatment Plant (BA): Fine waste from the mechanical waste processing plant goes through dry fermentation (i.e. anaerobic digestion) and stabilization for meeting the legal requirements. Dry fermentation is a batch-wise process conducted in a series of small tanks simulating the process inside a cow's stomach. It turns biomass into biogas (methane) under anaerobic condition for 3 weeks, but requires less water, piping, storage capacity and process energy. The biogas is compressed and piped to the treatment centre's CHP plant to generate electricity for the national grid. The residues is re-oxygenated with aerobic fermentation for a further six weeks and sent to the landfill. The air extracted from the complex is thermally purified and released through a 35 metre chimney.
Excursion Vb: Waste Incineration Plant in Hannover - Lahe
Waste is a valuable raw material. The E.ON Energy from Waste plants process the energy potential contained in waste and generate environment-friendly power, district heating and process steam from it. Waste incineration is therefore not only an integral element of a modern and sustainable solid waste management, but at the same time an important component part of a balanced energy mix. E.ON Energy from Waste develops, builds and operates waste incineration plants on a high technical and ecological level. With trendsetting, state-of-the-art technology E.ON Energy from Waste make a significant contribution to the protection of the environment and the climate. The delivery of the residual waste is the first step in the complete process. At the Hannover site about 1000 tons of waste is handled daily - from the adjacent mechanical-biological treatment plant (MBT) and from external sources. The waste bunker takes about 10,000 m3 of residual waste, which ensures six days operation at full capacity. Because the air needed for the incineration is suctioned from the bunker, it is subject to constant negative pressure. This ensures that no odours escape. The waste is also treated and prepared in the bunker for later incineration. With the aid of two crane grippers the delivered waste is mixed into a homogenous fuel in order to achieve a consistent as possible heating value - an indispensable requirement for consistent incineration at very different fractions such as solid waste from the MBT and normal household waste. In the furnace the continuous use of residual waste with a heating value of 8,000 to 18,000 kilojoules per kilogram is possible. A crane gripper grabs up to five tons residual waste, which is fed onto the fire grates of both incineration lines via a feeding hopper.
Contact: E.ON Energy from Waste Hannover GmbH Moorwaldweg 310 30659 Hannover, Germany T +49 5 11-33 63 97-0 F +49 5 11-33 63 97-90 info(at)eon-energyfromwaste.com, Internet: www.eon-energyfromwaste.com
Excursion VIa: Biogas plant Oehmer Feld Leese
Raiffeisen Agil Leese eG bought a huge area of 71 ha (175 acre) of an old military basis in former times and named it Oehmer Feld. Since that time a commercial and industrial park grew up. Over 18 companies are established there.... In 2003 a biogas plant was founded with a financial volume of 3.3 billion Euro by a consortium of 50 financial interests and farmers. The biogas plant produces 1.25 MW of electrical power and could supply approx. 3.800 private households.. That means, that the whole village Landesbergen could supplied by this power plant. The input of the so called co-fermentation plant is in total 35,000 t/a of pig and cow slurry, poultry litter and waste of food industry. The biogas plant feed power into the public grid. But the power could also used directly for the whole commercial and industrial park, so that they could work independent from other energy producer. Also thermal energy are used for heating of 16 buildings and drying of woodchips.
Excursion VIb: Renewable primary products Biogas plant Wolter
Specific data of biogas plant Wolter (Renewable primary products (NaWaRo): - HRT digester: 45 days - Organic load digester: 5,3 kg VS/m³*d - Electricity production: 5.500 - 7.000 kWh/d - Spec. Biogas production: 655 m³/t VS - Biogas production: 3.500 m³/d - Gas achievment: 3,5 m³/m³RV*d - Spec. Energy content: 5,2 kWh/m³ biogas - Approx. Electrical efficiency : 36% - Electricity production: 6,5 kWh/m³ digester*d
Contact: Biogasanlage Carsten Wolters Sudholzer Weg 15, 31621 Pennigsehl T.: +49 5028 1252
Excursion VII: Waste Water Treatment Plant Hannover Herrenhausen
Every day, about 187,000 m³ of waste water from the state capital Hanover and a number of adjacent cities and municipalities arrives in Hanover-Herrenhausen Sewage Work. Of this, about 120,000 m³ is immediately pumped on to the Gümmerwald Sewage Works. The remaining 67,000 m³ is treatetd in the Herrenhausen Sewage Works. The two sewage works thus share waste water treatment. The waste water from approx. 720,000 people and quantities of waste water from industry and commerce are purified by them using the most modern technology and are finally discharged - with a purity of 98% - into the River Leine. After a purification process lasting about 20 h, the waste water treated in this way attains the quality of river water. Because of its historical site and its central location in the district of Herrenhausen, large investments have been made in the past for the treatment of exhaust air and for odour reduction specifically at the Herrenhausen Sewage Works in order to avoid nuisance to the local residents.