Patent DE-102010010091-A1 (DE)
Title: Method and device to treat biogenic raw material for fractionated use as solid fuel during producing liquid substrate for anaerobic production of energy-carrier methane, by attaining high energetic overall yield per treated substrate unit
Inventor: LEHMANN THILO
IPC: C05F11/00
Filed: 2010-03-04
Abstract: The method and device for treating biogenic raw materials for the fractionated use as an one-side confectioned solid fuel during simultaneous production of a highly-energetic liquid substrate for the anaerobic production of energy-carrier methane, comprise attaining a high energetic overall yield per treated substrate unit in a manner by coupling to known process steps and technological components. The raw materials are fibrous lignocellulose-containing raw materials, whose conventional handling storing of energetic use is ineffective. The method and device for treating biogenic raw materials for the fractionated use as an one-side confectioned solid fuel during simultaneous production of a highly-energetic liquid substrate for the anaerobic production of energy-carrier methane, comprise attaining a high energetic overall yield per treated substrate unit in a manner by coupling to known process steps and technological components. The raw materials are fibrous lignocellulose-containing raw materials, whose conventional handling storing of energetic use is ineffective. The foreign material pollutants are divided into a compacted solid fuel fraction with optimized transport-, storage and combustion characteristics and a liquid fraction with dissolved and fine-suspended carbon compounds and nutrients for an efficient fermentation and biogas production. The raw substrate is subjected into an input batch feeder of a washing- and foreign material selection process. The raw substrate is subjected to a longitudinal transport using a paddle stirrer and is decomposed to deposit the sediment foreign materials supported by air injection pressing and ultrasound for a discharge at the end of the input batch feeder using a scraper chain conveyor. The washing water heated with combined heat and power system-waste heat causes a fiber swelling and pre-percolation for the further material treatment. The sediment-loaded substrate suspension is delivered to the next process step over transport screws, where the excess water is passed-off by condensation and is fed back into the input batch feeder during the fibrous substrate portion is adjusted to 22-25% of dry substance. The fibrous substrate cakes are fed to an extruder over a compression- and feeding screw, where the fibrous substrate cake is controllably dehydrated and is pre-crushed to long-fiber material before the compatibly running extruder screw thermo-mechanically or hydrothermally defibrate and decompose the input material by alternating pressure- and relaxation zones. The process-optimized pressure- and temperature ratios are attained by modified coefficient and slope along the extrusion path. The extruded material is fed over a conveyor unit with switchable hot air dosage of a continuous intensive decomposition, in which it is percolated by heated process water displaced with selective urea- and enzyme addition from the upstream and downstream steps. The extruded material is heated further by simultaneously running aerobic exothermic processes, which are initiated by controlled ventilation. The heated material finds at 60-80?0C instead of an intense acid catalysis, which includes the heavy enzymatically vulnerable lignocellulose. The substrate-specific retention time of the intensive decomposition is controllable over the passage. The material falls into a hydrolysis basin, is moved into the heated process water and further acidifies and swells. The soluble components are washed out and the fibrous constituents are decomposed to soluble compounds in increased dimensions. The soluble organics and the inorganic nutrients pass into the liquid phase. The improved combustion properties of the remaining residual fibers, the fermentability of the liquid substrate and the residence time of the hydrolysis is controllable over the passage. The intensively decomposed and hydrolyzed material is fed to a separation press under further washing of the soluble substances. In the separation press, the residual fiber is pressed to a filter cake of material-dependent 40-60% of tensile strength to obtain the desired phase separation in the residual solid and liquid substrate. The filter cake is adjusted to a dry substance content of greater than 60% in a mixer with dry mixing product and is pressed into a compactor over matrices in the desired dimensions. A post-drying is possible at a drying base to 90% of tensile strength independent of the desired solid fuel properties or compost qualities. The resulting liquid phases are fed to a percolate-/process water tank and are collected for their further use in the entire process, where the excess percolate stream loaded with the energy-rich organic compounds and nutrients is fed to the fermenter of the biogas plant for the further anaerobic treatment and biogas production.