Many countries (including the US) will allow you to have PR without a passport or citizenship. (In fact, PRs are the only people who can enter the US without showing a passport - the green card is sufficient.) Many countries (including Singapore) will issue you a travel document (I think it is called a certificate of identity) if you are a PR and for some reason don't have a passport (maybe your country is in a state of war, or in the case of Zimbabwe, dealing with a shortage of paper).taxico wrote: while i understand your intentions, i must comment that i've not encountered any immigration department in the western world that would issue and attach a valid visa/permit/PR to an expired passport.
It is of little use to the OP though, since your Singapore passport expires soon and it is basically impossible to obtain US PR in 2 years (the only ways I can think of are (1) win the green card lottery or (2) marry a US citizen). It does not matter if you have a PRC passport. If your Singapore passport expires, you are unlikely to be approved for a US student visa using your PRC passport because you have basically never lived in the PRC. The criterion for getting a US visa is to show that you have strong ties to a foreign country that you can return to, and neither Singapore nor PRC would qualify if you lost your Singapore citizenship.
Which means your only route is to use your Singapore passport to apply for the US student visa, then once your Singapore passport expires, stay put in the US and maintain your student status, and then switch to a H1-B work visa after you graduate. (The H1-B visa does not require you to prove that you have strong ties to a country you can return to.) This is incredibly risky. H1-B visas are limited by quota, and if the US economy recovers, it can easily go back to the situation where all the visas for the year are taken up on the first day of the year! And that assumes there is a US employer who is willing to go the process of doing the paperwork and paying the fees for you! And that is not all. If you lose your job, you have to leave the US (and again, with a PRC passport and no ties to the PRC you won't be allowed back). Which means you have to apply for PR after you get the H1-B visa. But people born in the PRC are subject to a special waitlist when it comes to PR applications (the US does not want any one country to dominate the PR numbers, a rule which affects people born in countries like China, India, Mexico and the Philippines). That means a long long time on a H1-B visa waiting for a greencard, with the risk of being laid off and forced to return to the PRC.
On the other hand, if you are not looking to immigrate to the US, then you have more options. With a degree (preferably Masters or PhD), you might be able to get a work visa (or even PR) in countries like Canada or the UK that use a point system. But that assumes immigration laws do not change by the time you graduate.
The one thing to remember is this: With a PRC passport you are not stateless and you have a country to return to. But countries like the US that expect you to show strong ties to a foreign country will refuse to let you in, so forget about using the PRC passport to travel to the West.
So think very very hard about the risks!