Unless you are able to restart your iPad to a running state - and successfully enter your Passcode - you'll not be able to erase the iPad - or recover any data from it. If you intend to dispose of your non-functional iPad, you shouldn't be concerned...
iPadOS uses an encrypted filesystem. Successful entry of your iPad Passcode unlocks the Secure Enclave (this being your iPad's security chip) within which the only copy of the encryption keys - that are required to access and decrypt your data - are stored. If the iPad is ever restored to a running state, in absence of the correct passcode (known only to you) all data remains beyond reach.
There are a limited number of opportunities to enter the correct Passcode before the iPad will be automatically disabled - at which point the Secure Enclave erases all the encryption keys.
As for recycling, simply return your iPad to the Genius Bar at any official Apple Store or Apple Authorised Service Provider (AASP) - who will arrange for the iPad to responsibly recycled at no cost to you.