Advanced tar processing
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Dear sea friends, let’s share the common problems that arise in tar processing and production, as well as the suggestions and experiences for dealing with them, so that we can learn from each other.
This is just a preliminary attempt to stimulate further discussion. In current coking production, the main focus is on producing metallurgical coke, with no consideration given to the rational utilization of coal resources. There are few liquid products: most of the coal tar fractions pass through high-temperature zones, where they are either cracked into gas or polymerized into asphalt or coke. As a result, the coal tar yield is low, at 4%, of which the pitch accounts for 55%-60%. The energy utilization in the production process is inefficient, resulting in high energy consumption and severe pollution. Mixed solvents such as methanol-water can be used to reduce solvent evaporation; by combining supercritical extraction with pyrolysis under milder conditions, it is possible to extract coal tar more effectively while minimizing solvent loss. The main objective of this process is to perform supercritical extraction of the volatile components in coal in order to obtain light coal tar. To simplify the process, complex steps such as methylation reactions, ash removal, and the use of alkalis for coal acid washing are omitted, thereby making industrial implementation easier. Distillation can be utilized to recover solvents and separate coal tar, avoiding the difficulties associated with solid-liquid separation, which also facilitates industrial application.
I have been involved in tar processing for 30 years, and there have been too many problems, just to mention the major accidents that have occurred. Two people died in a fire at an oil depot. A squad leader was killed by fire caused by an open flame used to seal the oil in the secondary evaporator. A fire broke out in the welding area due to a leak in an industrial naphthalene pipeline. The lid of the crystallization heating tank in the three-tank mixing system flew more than two miles away without causing any injuries.
Vague questions really leave me speechless; I hope the original poster will ask more meaningful questions next time.
Most of the coal tar fractions pass through the high-temperature zone, where they are either cracked into gas or polymerized into asphalt or coke ? ? Is there a theoretical basis for this? The tar here, after further processing, has an asphalt content of 70%. Should we consider the type of coal used, or should we focus on the issue of excessively high temperature in the furnace top, as you mentioned?
How many advanced processing techniques are there for coal tar nowadays? I know it’s a kind of separation. There is also a new process nowadays: coal tar hydrogenation.
I hope to discuss specific issues