Energy-saving Reforming Projects For50,0000Tons/a Methanol Production Plant

In this paper, the situation of current energy-saving emission reduction of Chinaand the reduction targets in "Twelfth Five-Year Plan" period were analyzed. It is ofgreat importance to carry out energy-saving work in the factory.Based on the process design and the actual operation parameters of theproduction system in our plant, the energy-saving direction was confirmed and thereforming scheme was designed. The reforming projects include: the waste heatrecovery and utilization in transformation process, making full use of the crude gasheat and improving the steam quality of the transform by-product by adding a groupof waste heat boiler of medium pressure steam. At the same time, the sulfur recoverysystem in synthetic area has to be reconstructed. Three additional mixing valves at thetop of the furnace were added and three shares of high-temperature gas wereintroduced into the Claus reactor, which replace the three process heaters. In addition,the tail gas incinerator was added after the Claus reactor. So the tail gas, which can’tmeet the standard requirement, can enter the tail gas incinerator firstly, then enter thethermal emission system after being cooled. Furthermore, a waste heat boiler ofmedium-pressure was added and it can generate2.5MPa steam. Some equipments ofhydrogen recovery system were rectified and overhauled and a new set of separationmembrane was added. So the separation efficiency was improved and the hydrogenrecovery rate was increased. The motor driven circular water blower was replaced bywater turbine, the power consumption can be reduced. Not only the by-productsurplus steam can be recovered but also the power consumption can be decreased byadding a turbine as circulating water pump. The synthesis gas was introduced into theboiler burning, so the emissions were reduced and the energy of purge gas wasrecovered, the coal consumption can be decreased. Slag, coal gasification, coal allwere introduced into the furnace, the energy can be recovered.The running data were collected and the operation situation after thetransformation was discussed. It can be found that the production cost was decreasedeffectively by all the process transformation.