How can I convert an integer to a character in MIPS?

I want to convert an integer value into a character, and then want to print that character as a 'character'.

# convert an word into bye and print it
.data
    integer: .word 1

.text
    la $a0, integer # load the address of 'integer' into $a0
    lw $t0, ($a0) # load the value stored in address
    addi $t0, $t0, 31 # convert digit to a character

    # print the character
    move $a0, $t0 # prepare the value for printing
    li $v0, 4 # syscall value for a character
    syscall

    # exit program
    li $v0, 10
    syscall

Output:

Assemble: assembling number_to_character.asm

Assemble: operation completed successfully.

Go: running number_to_character.asm

Error in number_to_character.asm line 13: Runtime exception at 0x00400018: 
address out of range 0x00000020

Go: execution terminated with errors.

The programs seems to be not working. Probably, because of the size difference between an integer (word) and a character (byte).