英语翻译The second stage is the key to the process.The direct re

英语翻译
The second stage is the key to the process.The direct reaction between sulphur dioxide and oxygen to give sulphur trioxide is slw and requires a catalyst.In the ole lead chamber process nitrogen dioxide (NO2)was used for the oxidation though in practice mixture of nitrogen oxides were used.This process has now been completely superseded by the contact process,which speeds the direct reaction via a solid-state catalyst of vanadium pentoxide(v2o5).The catalyst is normally absorbed on an inert silicate support and lasts for about 20 years.
The reaction between oxygen and sulphur dioxide is exothermic so the equilibrium favors the product at lower temperatures.So much heat is produced by the reaction that it is difficult to achieve good yields in a single-bed reactor:the reactor warms up so much that the reaction goes into reverse.Most plants therefore used several reactor stages(with coolers between the reactors) so that the heat produces does not drive the reaction backwards.The first reactor chamber converts the mixture of oxygen and sulohur dioxide into a stream about 60%-65% converted to products at about 600度.it is then cooled to about 400度 and passed into the next layer of catalyst,and so on.After three layers 95%-96% of the starting materials have been converted to products(this is near the maximum possible conversion unless sulphue trioxide is removed).

第二舞台是过程的关键.在给出三氧化硫二氧化硫和氧之间直接反作用是slw和要求一催化剂.在叫好声铅房间中虽然氮氧化物的在朝派练习混合物被使用,过程二氧化氮((NO2)被用于氧化的.现在这过程已经被接触过程,其加快经由一固态物理学的催化剂的五氧化二钒((v2o5)直接反作用的完全取代.催化剂有关一无自动力的硅酸盐支持在一般情况下被吸引和维持大约20年.在氧和二氧化硫之间反作用是exothermic,所以平衡在更低温温度方面favors产品.被反作用那它存在困难产生这么多的热量取得在一个单人床-起反应的人身上丰收:起反应的人以至于反作用进入挫折热身.绝大部分植物(用在起反应的人)之间冷却器因此使用几起反应的人舞台,因此热农产品不往后驱动反作用.第一起反应的人房间兑换氧的混合物和向products在大约600度.it兑换存在那时sulohur二氧化物变为一溪流大约60%-65%等等使向在附近400度冷下来和变成下一个的层催化剂.在三层开始95%-96%以后材料已经被向产品兑换((除非sulphue三氧化物是远离的),这个是靠近最大可能转换.