问题 问答题 简答题

叙述二氧化碳精馏塔的物料流程及精馏原理

答案

参考答案:来自净化系统的CO2进入塔釜,控制塔釜的温度使CO2气化并上升到精馏塔。气态的CO2与塔顶回流的液态CO2逆流接触发生热量、质量传递。气相的CO2浓度沿塔高向上逐渐提高并从塔顶进入冷凝器冷凝成液体后进入回流罐,通过回流泵把一部分液体CO2送回精馏塔作为回流液,一部分作为产品送到储存系统。液相的重组分浓度沿塔高向下逐渐提高、CO2浓度逐渐降低,重组分进入塔釜并在塔釜积累(CO2中的重组分是微量的,可能看不到塔釜的液位上涨)、排放;更低沸点的组分(如氢气、氮气、甲烷等)在冷凝器不能冷凝,以不凝气的形式从冷凝器放空。沸点与CO2相接近的组分不能得到分离。

阅读理解

Once there was a huge apple tree. A little boy loved to come and play around it every day. He loved the tree and the tree loved to play with him.

Time went by …The little boy had grown up and he no longer played around the tree every day. One day, the boy came back to the tree and he looked sad , " Come and play with me," the tree asked the boy. "I'm no longer a kid. I wouldn't play around the tree any more. " The boy replied.  "I want toys. I need money to buy them. " " Sorry, I don't have money. But you can pick all my apples and sell them. So you will have money. " The boy picked all the apples on the tree and left happily. The boy never came back after he picked the apples.

One day, the boy returned and the tree was so excited. "Come and play with me, " the tree said.  "I don't have time to play. I have to work for my family. We need a house for shelter. Can you help?" " Sorry ,  I don't have a house. But you can cut off my branches(树枝)to build your house. " So the boy cut all the branches off the tree and left happily. The tree was glad to see him happy but the boy never came back since then. The tree was again lonely and sad.

One hot summer day, the boy returned and the tree was pleased. " Come and play with me ! " the tree said. "I am sad and getting old. I want to go sailing to relax myself. Can you give me boat?" " Use my trunk(树干)to build your boat. You can sail far away and be happy. " So the boy cut the tree trunk to make a boat. He went sailing and never showed up for a long time.

Finally, the boy returned after he left for so many years. " Sorry, my boy. But I don't have anything for you any more. The only thing left is my dying root(树根).” The tree said with tears. “I don't need much now, just a place to rest. I'm tired after all these years," the boy replied.

"Good! Old tree root is the best place to lean on and rest. Come and sit down with me and rest. " The boy sat down and the tree was glad and smiled with tears.

小题1:-When did the boy come back to the apple tree?

-He came back___________.

A.whenever he was happy

B.if he missed the apple tree

C.when he was in times of difficulty

D.as soon as he was free小题2:-What did the boy want at last?

-He wanted ___________.        .

A.to have a house to live in

B.nothing except a place to rest

C.the root of the apple tree

D.anything that the apple tree had小题3:-What can we learn from the story?

-We should ___________.

A.plant more apple trees

B.learn from the boy

C.always stay at home

D.be thankful to our parents小题4:According to the passage , which of the following statements is NOT true?

A.The phrase " with tears① " means that the apple tree was sad because the boy asked for too much.

B.The phrase " with tears② " means that the apple tree was still happy because she could help the boy for the last time.

C.Each time the boy asked the apple tree for help, the tree tried her best to satisfy him.

D.After reading the passage, we can easily think of the old Chinese saying “ Parents love is universal !”

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