Purification Technology Q&A [019]

Make comprehensive use of process energy, enhance waste heat recovery, and optimize plant operations to achieve reduction at the source. Further optimize the steam power system and establish a steam data collection and simulation monitoring system

Optimize operations and improve processes. Reduce direct steam emission and leaks. Eliminate outdated energy-consuming equipment.

Answer: 1. Use a low-temperature, high-activity catalyst to reduce the vapor-to-gas ratio. 2. Increase the temperature and saturation of the gas exiting the saturated tower. 3. Ensure proper temperature regulation and heat recovery between the different sections. 4. Strengthen the insulation of equipment and pipelines to reduce heat loss.

1) Use a low-temperature, high-activity catalyst to reduce the steam-to-gas ratio. 2) Increase the temperature and saturation of the gas exiting the saturated tower. 3) Ensure proper temperature regulation and heat recovery between the transition sections. 4) Strengthen the insulation of equipment pipelines to reduce heat loss.

Mainly through improving processes, using low-temperature sulfur-resistant catalysts, and controlling operations under optimal conditions

1. It is necessary to reduce leaks in the steam system. 2. Improve insulation of steam pipelines to reduce heat loss. 2. Increase the recovery of condensate.

Moderator, what kind of process system do you use? From my perspective, the first step is to ensure proper insulation of the steam pipes in order to reduce losses during transportation. Secondly, if possible, it’s advisable to modify the process system, such by using a negative-pressure ammonia vaporization system.

1. Final conversion rate: An excessively high or low final conversion rate can have adverse effects. If it is set too high, excessive catalyst will be required, or steam consumption will increase as a result of the need to raise the vapor-to-gas ratio ； If it is too low, the consumption of semi-water gas will increase, placing greater strain on the copper washing unit and wasting energy used for gas compression. Since a process with low variability is employed in the design, and copper washing is used in subsequent stages to remove residual carbon monoxide, it is possible to allow a slightly higher level of residual carbon monoxide in the syngas leaving the conversion system; therefore, a final conversion rate of 95% can be chosen, corresponding to a CO content of around 1%. 2. Converter inlet temperature: To make full use of the catalyst’s low-temperature activity, the inlet temperature should be determined based on the catalyst selected; generally, it is sufficient to set it 20°C above the catalyst’s onset activity temperature. 3. The outlet temperature of the hot water tower is the criterion for determining energy recovery in the conversion process. It can be explained from the following two points: (1) In a saturated hot water tower, the recovery of the waste heat from the reformate gas and its transfer to semi-water gas is accomplished through water as a medium. The amount of water circulating in the saturated hot water tower must meet the following basic conditions: a The water volume must ensure maximum heat transfer. b must meet the requirements for spray density. For example, in a packed tower, the water volume must be ensured to keep the entire tower operating at an appropriate wetting rate. (2) Generally, at the beginning of use, a new catalyst has high activity and requires a relatively low steam pressure; this temperature is then quite low. As the catalyst’s activity gradually decreases, this temperature rises as well. When it becomes unacceptably high, the catalyst must be replaced, otherwise the load on the soft water heater and condenser increases, and the steam consumption becomes unmanageable.