Accelerometer using Kalman filter

Hi, Planning to use accelerometer sensor for measuring the tilt angle. I am looking kalman filter without gyro sensor. I understand that we need gyro sensor for measuring the angular velocity. But in our project we dont need it as of now. still we want to use kalman filter. After browsing , i came to know we give gyro measurement as input (input rate).

my question is how to replace it with only accerleromet measurement to work only with accelermeter sensor.

kindly advise.

Thanks and Regards
Lakshman.