Hello Sergej,
Good to know that you are going to use SAP HANA platform for academic projects.
Here are a few pointers:
Getting twitter feeds:
You can use SAP Event Stream Processor (ESP) to get real-time feeds to SAP HANA from twitter API's. You can find more information in SCN area for ESP
Link: http://scn.sap.com/community/event-stream-processor
Eric Du's blog: http://scn.sap.com/community/developer-center/hana/blog/2015/04/09/text-analysis-in-sap-hana-integrate-with-twitter-api
Sridevi's Post: http://scn.sap.com/docs/DOC-53824
Text processing, NLP etc.,:
There is a course on open.sap.com on Text Analytics with SAP HANA
https://open.sap.com/courses/hsta1
Hope these pointers are of some help to you.
Gopal