Luchi wastewater treatment

The Lurgi gasifier is a fixed-bed gasifier, in which the feed coal reacts with the gasifying agents (steam and oxygen) to produce gas. The production of gas generates corresponding gas water as well. The gas and water, after oil recovery and phenol-amine recovery, are sent to a wastewater treatment plant for processing. The composition of such wastewater is relatively complex, making it difficult to treat ； Some sources say that biochemical treatment can be used; I would like to ask fellow aquarists if there are any other good methods besides biochemical treatment.

There are no successful cases of Luchi furnace wastewater treatment in China; only the Haiyi Gas plant has passed the inspection by the Heilongjiang Provincial Environmental Protection Department. The wastewater from Lurgi furnaces is difficult to treat: it has poor biodegradability, high total phenol concentrations, slow microbial growth, and excessive foam formation – all of which are the main reasons for it not meeting the required standards. To meet the standards, it is necessary to address the issues mentioned above.

Wastewater treatment for Lurgi furnaces is a challenge

The water quality of the effluent from the hydrogenation treatment facility is good; the key lies in the pre-treatment facilities for ammonia evaporation and phenol removal, for which nearly 100 million was invested upfront, as water that does not meet the pre-treatment standards is not discharged into the sewage treatment system. The influent to the wastewater treatment system has also been diluted by almost half due to domestic wastewater, yet the overall treatment efficiency is indeed very good. The Luchi furnace has also been in use in China for many years, and it’s impossible to say that there are no successful cases. The key point is that as **and local emission standards become increasingly stringent, some of the existing treatment facilities are no longer able to meet these standards, or certain existing systems indeed have defects that require modification. Wastewater from Ruchi furnaces is indeed difficult to treat, but it should still be possible to handle it if costs are not a concern. The key lies in the choice of pretreatment and biochemical treatment processes, as well as the advanced treatment methods to be used. The investment and operating costs are certainly relatively high; it depends on whether the investors can accept them.

Luchi wastewater includes dust-containing gas water from pressurized gasification and oil-containing gas water from gas cooling, and a gas water separation unit is used to separate pure tar and oil from it. There are also some acidic gases in the gas water, such as ammonia, and the levels of total phenols and COD are significantly above the allowed limits. It is necessary to use an acid removal tower equipped with a phenol recovery system to remove carbon dioxide and hydrogen sulfide ； Ammonia gas is removed through the deammoniation tower ； It then passes through an extraction tower, where monophenols and polyphenols are extracted using diisopropyl ether ； Then the solvent ether is recovered through water. . . . . .

It remains an academic challenge at present. Although many experts (it is said that there are over 2 million experts in China) have theoretically devised methods for treating such wastewater, none of them are currently in use in practice.