A few random thoughts: 1) When a company hires somebody from another company, it usually pays salary with some raise from the previous salary. It rarely matches with existing employees. This makes perfect sense. it's likely the offer is higher than your current salary.Did you just get an offer? or you already joined this company? 2) Two signs are not pretty about this company. Your friend left and the company is still laying off people. If you haven't taken this offer, you might consider to reject it.
sorry, I don't know much "process engineer" in this particular company. Your friends from that company should have the best answer for you. Will the technology and dev tools be similar to what you use now? If it's not outdated technology and tools, you will still be marketable if this company doesn't work out, especially from a big name company. If the salary is the concern, you can bargain with them and ask why you would be paid $20K less than your friend, and ask them what you need to improve to get $20K raise. You got nothing to lose by negotiating.