Pyrolysis and Gasification Characteristics of High Ash Indian and Turkish Coals

Abstract

Pyrolysis and gasification studies of Indian and Turkish high ash coal samples have been performed using coupled TGA-MS method. Coal samples were heated in the TGA apparatus in an argon, steam, CO 2 and blended mixtures of CO2 and steam in a temperature range from 25-1250°C with heating rates from 35 to 1000 K/min. Gas evolution measurements is performed using the mass spectrometry system. During the devolatilisation stage (350-700°C), the maximum mass loss has observed in which O 2 , CO 2 , CO, H 2 and small amount of hydrocarbon compounds are released. Char gasification is mainly influenced by operating conditions such as heating rate and reaction temperature and also the char production method, its physical structure and size and chemical composition of the char. The steam and CO 2 gasification rates of the chars are carried out at the temperatures of 850, 900, 950, and 1000°C. Three kinetic models are applied to describe the char conversion rates: volumetric model, grain model, and random pore model. The activation energy of Indian coal-char is varying from 122 to 177 kJ mol-1 under steam gasification and from 130 to 214 kJ mol-1 for CO 2 gasification. The activation energy for char-steam gasification is 156-173 kJ/ mol, whereas in the steam blended with CO 2 gasification, it ranges between 162 and 196 kJ/ mol for 3 mm particles. Similar trends are observed for the Arrhenius constant values for both sized particles.

CO2 Gasification Reactivity and Syngas Production of Greek Lignite Coal and Ex-Situ Produced Chars under Non-Isothermal and Isothermal Conditions: Structure-Performance Relationships

“…850 o C until fuel depletion. The production of CO is enhanced with temperature due to the high endothermic nature of the Boudouard reaction [17,32,33,[65][66][67]. The LG300 sample exhibited a similar RCO value with raw lignite LG (0.009 min −1 ), whereas the chars at 500 o C (LG500) and 800 o C (LG800) showed increased instant CO production rates equal to 0.011 and 0.013 min −1 , respectively.…”

Utilization of Low-Rank Coals for Producing Syngas to Meet the Future Energy Needs: Technical and Economic Analysis

“…Many of the developing and developed countries, including China, Turkey, India, South Africa, Romania, etc., still rely heavily on coals to meet their power generation needs [2]. To meet the energy demand and supply gap, low-rank coals can be an attractive option due to the availability of huge reserves for at least the next few decades [3,4]. Coal has the greatest capacity compared to any non-renewable fuel, accounting for 56% of global reserves and 89% of global capital [5].…”