Although there were many books and papers that deal with gasification, there has been only a few practical book explaining the technology in actual application and the market situation in reality. Gasification is a key technology in converting coal, biomass, and wastes to useful high-value products. Until renewable energy can provide affordable energy hopefully by the year 2030, gasification can bridge the transition period by providing the clean liquid fuels, gas, and chemicals from the low grade feedstock....
The energy demand for the endothermic
gasification reaction is met by the combustion of residual char in the fast bed combustor.
The circulating bed materials act as heat carrier between the two fluidized beds and
maintain the required temperature in gasifier. Therefore, the hydrodynamics of such a dual
fluidized beds system needs to be thoroughly understood for successful design and
operation of the system for industrial application.
A dual fluidized beds system essentially comprises of two fluidized bed reactors coupled
together with a provision of gas or materials transfer in between. It may be a combination of
circulating-circulating or bubbling-circulating or bubbling-bubbling type systems. A noble
application is in a gasification process for coal or biomass where nitrogen of air is not
allowed to dilute the product gas.
Hydrogen and synthesis gas (syngas) are indispensable in chemical, oil, and energy industries. They are important building blocks and serve as feedstocks for the production of chemicals such as ammonia and methanol. Hydrogen is used in petroleum refi neries to produce clean transportation fuels, and its consumption is expected to increase dramatically in the near future as refi ners need to process increasingly heavier and sour crudes.
An integrated gasification process was developed for an Ohio-based kraft pulp mill to produce
liquid transportation fuels from biomass and coal. Black liquor byproduct from the pulp mill is
co-gasified with coal to generate high quality syngas for further synthesis to dimethyl ether
(DME) and/or Fischer-Tropsch fuels. A Texaco gasifier was chosen as the focal point for this
design. Whenever possible, energy is recovered throughout to generate heat, steam, and power.
Mass and energy balances were performed for individual process components and the entire