Updraft Gasification

Koss, L.I, Walker, L.P. (1988). An iterative kinetic model for the updraft gasification of wood, The 8 Miami International Conference on Alternative Energy Sources. 

A survey of commercial thermal gasification in the United States shows that few gasifiers have been installed since 1984 (115). Most units in use are retrofitted to small boilers, dryers, and kilns. The majority of existing units operate at 0.14 to 1.0 t/h of wood wastes on updraft moving grates. The results of this survey are summarized in Table 36. Assuming all 35 of these units are operated continuously, extremely unlikely, the maximum amount of LHV gas that can be produced is about 0.003 to 0.006 EJ/yr (222—445 td /d). 

With fixed-bed updraft gasifiers, the air or oxygen passes upward through a hot reactive zone near the bottom of the gasifier in a direction counter-crrrrent to the flow of solid material. Exothermic reactions between air/oxygen and the charcoal in the bed drive the gasification process. Heat in the raw gas is transferred to the bio-... 

Rice Hull Gasification in an Air-Blown Updraft Gasifier... 

The temperature in the sampling line of the product gas of the updraft gasifier is kept at 00 250 C (to be examined) and in downdraft and fluid ised-bed gasification at 250 C. 

In the Guideline, a compound list will be added with Individual organic compounds including chemical abstract service (CAS) registry numbers. This list is compiled from experimental data on the presence of compounds found in biomass producer gases from updraft, downdraft and fluidised bed gasification. 

In the updraft gasifier x essentially equals 1 for gasification by steam and carbon dioxide, but attains only 0.1 -0.6 for the methanation reaction, the exact figure depending on the reactivity of the coke [ U8J. 

Gas composition and tar content in the product gas from different biomass gasification r under different conditions are reported in Tables 1.3 and 1.4. The produced gas must have a certain percentage of burnable gas (>20 % CO and >10 % H2), a minimum amount of tar content (<100 mg Nm ) and be completely free of dust and other poisonous gases (NH3, SO2, etc.). To satisfy the requirement of product gas, a comprehensive research has been done in the last decades. The entire reactor systems can be classified into two categories (1) updraft gasifier and (2) downdraft gasifier. 

Table 1.3 Gas composition and tar content in the product gas from different biomass gasification in updraft gasifier under different conditions [174]... 

Chen W, Annamalai K, Ansley RJ, Mink M (2012) Updraft fixed bed gasification of mes-quite and juniper wood samples. Energy 41 454—461... 

---