Influence of pyrolysis condition and coal type on char gasification reactivity

Abstract

The CO 2 gasification property of char particles was investigated with pressurized and ambient thermal analyzer with four typical Chinese industrial coals as samples. The influence of pyrolysis pressure and final temperature was analyzed and a new index (specific maximum gasification rate) of char CO 2 gasification reactivity was approached. The process of char gasification can be divided into two steps: the thermal cracking and CO 2 shifting of volatile hydrocarbon residues and the CO 2 shifting of carbon matrix. Higher pressure did not show positive effect on char gasification enhancing as pyrolysis pressure lower than 1.5 MPa, whereas it was accelerated with pressure increasing further as more volatile hydrocarbon left in char particles. Temperature showed variant influence on char gasification with different pyrolysis pressures. There exist some interaction between pyrolysis temperature and pressure. Furthermore, coal type played vital role on char gasification behavior and the specific maximum gasification rate showed great consistency with char gasification behavior.

Advanced technologies for coal and biomass utilization

“…This special theme can be divided into four research groups, which are described as follows: The first group of papers covers a wide spectrum of coal science and technology, including the gasification reactivity of coal‐char, characterization of coal surface functional group, NOx emission control from coal‐fired power stations by methane reburn, ignition characteristics of coal during oxy‐fuel combustion, and techno‐economic analysis of coal‐fired power plant with post‐combustion CO 2 capture equipments. The second group provides insights into key issues associated with biomass utilization, such as combustion mechanisms of biomass, development of biosorbents for waste water treatment, biodiesel production and the emission of heavy metals during waste incineration. The third group focuses on the solid mixing mechanisms in a bubbling fluidized bed reactor. The fourth group investigates the characterization of activated carbon fiber modified by plasma.…”

“…The effects of the pyrolysis conditions and coal type to the char reactivity during pressurized CO 2 gasification are studied by Wang et al . A new index of char reactivity during CO 2 gasification is also developed. The results indicate that char gasification process can be divided into two steps including thermal cracking and CO 2 shifting of volatile hydrocarbon residues and the CO 2 shifting of carbon matrix.…”

Effect of Steam on the Tar Reforming during Circulating Fluidized Bed Char Gasification

“…The used char can be fully utilized through gasification and combustion processes. 19 Therefore, the research on char as catalysts has received extensive attention in recent years.…”

Characteristics of Tar Thermal Cracking and Catalytic Conversion during Circulating Fluidized Bed Char Gasification

“… , Compared with other common catalysts, the char catalyst has obvious advantages in catalytic removal of tar in coal gasification . The most significant advantage is that the reactivation will not be an obstacle because the used char is also a product that can be fully used by gasification or combustion . Therefore, reports on using char as a catalyst to remove tar have increased in recent years.…”

“…15 The most significant advantage is that the reactivation will not be an obstacle because the used char is also a product that can be fully used by gasification or combustion. 16 Therefore, reports on using char as a catalyst to remove tar have increased in recent years.…”