No, but you can hide one or more projects in your list of projects. As the number of projects you create grows over time, with older projects perhaps not being relevant anymore, it is convenient to be able to hide them on-screen.
This is achieved using the "Hide Project" icon:
Clicking on this icon shows the list of projects, each prefixed by an open check-box.
By checking each box for those projects no longer required to be visible, the user can hide or unhide each project. For example, hiding "Accounts clerk" and "HR Manager" and then clicking on the 
button:
The operation can be undone by clicking on the Hide Project icon 
and 'unchecking' the relevant check-boxes.