Modular, portable processes and apparatus for the production of tight gas (including shale gas) and tight oil (including shale oil) and for the conversion of tight oil into a plurality of marketable fuels are described which enable easy deployment and start-up and are specifically useful in remote areas. Furthermore, these modular processes and apparatus are configured to use co-produced tight gas as a source of processing energy. Another feature of the modular processes is to substantially reduce the use of fracking water and process water. In some embodiments modular processes include (A) Purified Salt Production; (B) Modular Hydrochloric Acid (HCl) Production; (C) Hydrogen Production by Autothermal Reformer; (D) Optimized Hydraulic Fracturing; (E) Desalting with Bi-Electric Configuration with an Interchanger; (F) Desalter Water Recovery and Recyclling; (G) Precut Column with a Gas-Fired Heater; (H) Crude Distillation with a Gas-Fired Heater; (I) Hydrodesulfurization using Reactive Distillation; and (J) Vacuum Distillation.