Allweiler Peristaltic Pumps: an ingenious solution for biogas plants
Installations and plants used to process biomass for the production of biofuels must be capable of handling difficult conditions. For example, intermediate products in the production of biodiesel exhibit a high level of chemical aggressiveness. Accordingly, pumps, pipe connections, and fittings must be capable of resisting these demanding conditions. In addition, waste products usually contain a large amount of impurities that can disturb the overall process. Depending on the origin of the material, this may include metal parts, sand, small stones, and crushed rock. Biogenic materials such as bones, sticks, or large pieces of wood add yet another challenge to the production of biofuels. In each of these situations, starting materials as well as intermediate products, residuals, and the final product must be pumped efficiently. Allweiler AG in Germany, a member of the Colfax Corporation, provides pumps that are ready to handle these situations. Allweiler's extensive experience, innovative technologies, and customer-oriented product development ensure that its customers have the appropriate solution for their applications, whether pumping biofuels or organic waste.
Allweiler pumps are proven
Allweiler progressing cavity pumps and peristaltic pumps have proven to be highly efficient for handling materials of various consistencies as well as materials that have been reduced or processed in a variety of ways. Progressing cavity pumps made of specially selected materials are the right choice for handling homogenous materials containing relatively small solids, whereas peristaltic pumps are ideal for materials containing larger impurities. Factory technicians regularly consult on-site with plant operators during start-up and even after installation. Their main objective is to optimize the systems in terms of maintenance and operating costs; in other words, they strive to minimize total cost of ownership (TCO).
Processing household and restaurant waste
Bioenergie Bamberg GmbH & Co.KG near Nuremberg, Germany provides a good example. A peristaltic pump plays a central role in its biogas plant. Since September 2005, the plant has produced electricity and heat from organic material. Feedstock includes organic waste from households, restaurants, silage corn, and gardens. The plant processes an average of 50 metric tons of biomass per day. Although the material is pre-cleaned and large extraneous materials are removed, it still contains about 15% crushed rock and sand with a grain size of up to 40 mm. Pieces of wood, fir cones, bones, and other solids like knives and forks up to 4 x 15 cm in size are also present. Such a varied composition places high demands on the pump.
In the first step of the process, a feed screw moves the feedstock into the fermenter. There a paddle stirrer homogenizes the biomass. After draining, cooling, and filtering, the resulting gas powers two 330 kW motors that feed approximately 15,000 kWh of electricity into the public network every day. A neighboring gardening center uses the generated heat (approximately 800 kW per hour) to heat its greenhouses.
Approximately 80% of the original material remains in the fermenter in the form of digestate containing about 25% to 30% dry material. The Allweiler peristaltic pump moves this substrate into a separator. The material is later used as agricultural fertilizer. The pump runs eight to ten hours per day depending on the fill level of the fermenter. With the exception of maintenance, the plant itself operates 24 hours per day, 365 days per year.