What is the difference between the semi-boilerless process and the full-boilerless process in coal gasification?

I looked around, but there were no half-defective or fully defective ones

The methods used to cool the crude syngas produced in the gasifier are quenching, waste heat recovery, and semi-waste heat recovery. The quenching process is relatively easy to understand – it involves directly cooling the gas with water. In the waste heat recovery process, cooling is achieved entirely through waste heat recovery. The semi-waste heat recovery process involves cooling with waste heat recovery (at around 700°C) followed by additional quenching for further cooling.

What category does the Shell process belong to? In addition to the waste heat exchanger, Shell syngas also needs to be cooled using the returned low-temperature syngas; does this constitute a semi-waste heat exchanger process?

I’m sorry; the previous reply wasn’t perfect enough. In fact, continuous efforts are being made to explore ways for cooling and making use of the heat in coal gasification crude syngas, Of course this also needs to take into account the conditions in subsequent processes ； The concept of the semi-waste-heat boiler process emerged as part of the continuous improvements to Texaco’s water-coal slurry vaporizers (I’m sorry; I couldn’t find out who first proposed it). It is defined as including the quenching, semi-waste-heat boiler, and full-waste-heat boiler processes. The difference between the semi-waste-heat boiler process and the full-waste-heat boiler process lies in whether there is a boiler with a convection section; if there is such a boiler, it is considered a full-waste-heat boiler process, while if there is no convection section, water must be used for quenching, in which case it is a semi-waste-heat boiler process ； Later, its concept was applied to pulverized coal gasification. What category does the Shell process belong to? Some scholars consider it a semi-waste-heat boiler process; I personally believe it should be classified as a waste-heat boiler process. Although quenched gas flows back to the gas pipeline for cooling, this only provides partial cooling, and ultimately the syngas is cooled by a syngas cooler that contains evaporation surfaces and superheating surfaces, which are part of the convective section of the boiler.

The earliest waste heat boilers were not designed to incorporate a convective section; Shell and GE initially used both radiation and convection for heat transfer. However, the problem of slag buildup in the convective section was extremely serious, especially in GE’s waste heat boilers, where buildup was severe. Shell also spent many years experimenting before making improvements by recovering the residual heat from the high-temperature area, eliminating the convective section, and using rapid cooling to avoid the condensation temperature range. Unlike the original radiation + convection, this radiation + quenching is a semi-waste boiler. As for Shell’s recirculation of chilled air, it has little impact on the overall process characteristics; the entire boiler still needs to be discarded.