The calcium looping CO2 capture process using calcium oxide as a regenerable solid sorbent has been under development at the Industrial Technology Research Institute (ITRI) of Taiwan for several years. The 3‐kWth test facility built at ITRI is mainly composed of a fluidized‐bed carbonator and a rotary kiln calciner. The calcination efficiency, the CO2 capture efficiency, and operating stability were investigated. In addition, a cold model test facility has been constructed and a 1.9‐MWth pilot plant designed by ITRI is currently being erected. The combination of calcium looping and cement manufacturing process reduces the cost of adsorbent and calcination energy consumption.

The Industrial Technology Research Institute has developed a 30 kWth moving bed chemical looping system for hydrogen production. Methane is supplied as a fuel to the reducer, and steam is supplied to the oxidizer to produce hydrogen. An iron-based oxygen carrier is used circulating between the reactors. In this study, the mechanical strength, attrition rate, and conversion rate of the oxygen carrier were tested at two Fe2O3 levels of content (40 and 60 wt %) calcined at temperatures of 1100 and 1300 °C. The oxygen carrier with the lower iron content presented the higher conversion rate of 72% at both calcination temperatures. The mechanical strength (170.5 N) and attrition rate (0.3%) of the oxygen carrier with a low Fe2O3 content were higher at the higher calcination temperature. Further, the oxygen carriers were circulated in the 30 kWth moving bed chemical looping system under ambient and high-temperature conditions. The oxygen carrier with two Fe2O3 content levels (40 and 60 wt %) at the calcination temperature of 1200 °C was employed in the attrition rate test conducted in the chemical looping system. Under the ambient temperature conditions, the average attrition rate of the oxygen carrier with a lower Fe2O3 content was lower (0.16%) than that of the oxygen carrier with a higher Fe2O3 content (0.24%). Moreover, the test results show the operating temperature has a lower level of influence on the attrition rate of the oxygen carrier.

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One of the problems frequently encountered in a coal gasifier operation is fuel injector failure. Operating in extreme high pressure and high temperature, the typical fuel injector life span is 6–12 months. Numerical simulations are performed to study the flow and temperature fields in the vicinity of the injector tip and the metal temperature of two different fuel injector designs—one with a conical-nozzle tip and the other with a blunt tip—in a dry-fed, entrained-flow coal gasifier. The complete 3D Navier–Stokes equations are solved. The instantaneous gasification model is employed to simulate three global heterogeneous reactions and three homogeneous reactions, including volatile combustion. The results show that the two different injectors give very different temperature and species distributions inside the gasifier. In the gasifier with the conical injector tip, the highest temperature inside the gasifier occurs at the center of the gasifier, whereas in the gasifier with the blunt-tip injector, the highest temperature occurs near the wall. There is a potential of flash-back combustion in the nozzle at the tip of the conical injector due to its premixing feature of fuel and oxidant in the nozzle. The highest temperatures on both injectors are the same, which is around 1600 K. However, the highest temperature on the conical-tip injector is concentrated at one location with an extended region of 30 mm between 1600 K and 1100 K, whereas on the blunt-tip injector, hot spots are scattered and the hot region (1600–1100 K) only extends about 3 mm. Experimental results support the simulated results and has demonstrated a short life of the conical-tip fuel injector and much extended life for the blunt-tip fuel injector.

A computational fluid dynamics scheme is employed to simulate the effects of potential fuel injection techniques on gasification performance. The objective is to help design the top-loaded fuel injection arrangement for an entrained-flow gasifier using coal water slurry as the input feedstock. Two specific arrangements are investigated: (a) coaxial dual jet impingement with slurry coal in the center and oxygen in the outer jet and (b) four jet impingement with two single slurry coal jets and two single oxygen jets. When the heterogeneous finite-rate solid-gas reaction scheme is implemented, it is discovered that the particle collision model cannot be implemented with the heterogeneous gasification scheme in the present computational model. The instantaneous gasification model is later employed to examine the particle collision phenomenon by implementing the particle collision model, in which the coal (consisting of carbon and volatiles) is injected as gas, and the water is injected as droplets. The result of droplet tracks shows that the droplets are not bounced around, as speculated, at the intersection where the jets meet, and majority of the droplets pass through the jet impingement section and hit the wall as in the finite-rate case. This implies that the results of the finite rate are acceptable even though the particle collision model is not implemented. The finite-rate result actually presents a worst-case scenario for predicting wall erosion. The particle tracks for both the two concentric and four separate injection configurations show that the coal particles hit the wall and can accelerate the deterioration of the refractory bricks. The case employing two concentric injections provides better fuel-oxidant mixing and higher heating values than the case using four separate injections.