I want to energize a solenoid based on a temperature without arduino?
You could build a comparator circuit around an LM339 (or similar), a voltage reference, and your LM35. However, this is such a common application that there are temperature sensors with built in alert outputs such as the LTC2996 that have it all in one package. http://www.linear.com/product/LTC2996. It's a linear temperature sensor with a built in comparator. You set the thresholds by resistor selection.