1.2.2 Introduction

Gasification is a technology commonly used nowadays for extracting energy from biomass. Over the past decade, there has been great progress in the development of gasification technology in China. Many kinds of biomass gasification processes have been developed, treating different materials for various purposes.

1.2.3 Gasification technology development

Dating back to the 19th century, gasification technology now attracts new interests in Europe, because of the end use flexibility of the syngas (Lan et al., 2011).

A charcoal gasifier had been developed in the 1940s and was tried to drive vehicles with the technology, which is the initial exploration in China in gasification of biomass. But the technology did not obtain further development for various reasons.

A fluidized bed reactor for industrial applications had been developed in China in the 1950s, but there were some imperfections in the technology, and the application was suspended. In the 1960s, Chinese researchers began to study the biomass gasification power generation and gained some experiences, and the preliminary prototype had been developed and gained some experiences, but these researches were stopped because of the economic conditions and the small profits.

A fixed bed gasifier (updraft and downdraft) circulating fluidized bed gasifer was developed in China in the 1980s. The product gases were used for power generation, supplying heat and cooking.

An 1 MW BGPG system with a circulating fluidized bed (CFB) gasifier had been developed, and constructed in a rice mill in the Fujian province of China (Wu et al., 2002; Wang et al., 2005; Lu et al., 2004b; Wu et al., 2003). A neural network was focused on for the simulation of gasification process. An artificial neural network model was developed to simulate the gasification processes in order to obtain the gasification profiles (Guo et al., 2001; Tang et al., 2003; Wang et al., 2002).

Gasification and polygeneration technology in the fluidized bed were concentrated on by Tie et al. (2003; 2005). They studied four kinds of biomass (bagasse, pine sawdust, peanut shell, rice husk) in a fluidized bed reactor and found that the temperature was a key parameter due to biomass pyrolysis in a fluidized bed reactor.

Lu etal. (2005; 2007) developed hydrogen production technology by using supercritical water. He and other researchers (Guo et al., 2006; Yan et al., 2006) mixed several kinds of biomass in sodium carboxymethylcellulose, which was gasified successfully at 650°C, 25 MPa in a tubular flow reactor with formation of hydrogen, carbon dioxide, carbon monoxide, methane and a small amount of ethane and ethylene.

Furthermore, the domestic garbage gasification was studied by Yuan et al. (2002). Chen et al. (2003a, b; 2005; 2006; 2008) made progress in cogasification of biomass and glycerin. They studied four kinds of biomass in a two-stage reactor to produce hydrogen-rich gas, and investigated the effect of a catalytic bed on the pyrolysis behavior.