Biomass to hydrogen production detailed design and economics utilizing the Battelle Columbus Laboratory indirectly-heated gasifier

Original publisher: Golden, Colo. : National Renewable Energy Laboratory, [2005] OCLC Number: (OCoLC)62234808 Subject: Biomass gasification -- Economic aspects. Excerpt: ... 7.0 Current Design-Process Design, Modeling, and Costing The following sections describe the detailed process design for the current design as outlined in section 5.0 Current Design Process Overview. 7.1 Feed Handling and Drying - Area 100 The feed handling and drying section are shown in PFD-P700-A101 and PFD-P700-A102. Wood chips are delivered to the plant primarily via trucks. However, it is envisioned that there could be some train transport. Assuming that each truck capacity is about 25 tons ( Mann and Spath, 1997 ), this means that if the wood, at a moisture content of 50 %, was delivered to the plant via truck transport only, then 176 truck deliveries per day would be required. As the trucks enter the plant they are weighed ( M-101 ) and the wood chips are dumped into a storage pile. From the storage pile, the wood chips are conveyed ( C-102 ) through a magnetic separator ( S-101 ) and screened ( S-102 ). Particles larger than 2 inches are sent through a hammer mill ( T-102 / M-102 ) for further size reduction. Front end loaders transfer the wood chips to the dryer feed bins ( T-103 ). Because of the large plant size there are two identical, parallel feed handling and drying trains. The wet wood chips enter each rotary biomass dryer ( M-104 ) through a dryer feed screw conveyor ( C-104 ). After drying the wood to a moisture content of 12 wt % with flue gas from the char combustor ( R-202 ), the gas is sent through a cyclone ( S-103 ) and baghouse filter ( S-104 ) to remove any particulates prior to being emitted to the atmosphere. The stack temperature of the flue gas is set at 250 ° F, which is above the dew point of the gas. The stack temperature is controlled by cooling the hot flue gas ( H­ 101 ) prior to entering the dryer. This heat is used to generate steam ( see section 7.6 ...