An effluent collection unit for engine washing is formed by a portable trailer having a plurality of sides forming an internal compartment and an effluent collection system positioned within the internal compartment, which effluent collection device captures engine wash water effluent when the trailer is placed in an operational configuration. The outer side surface of the power take-off support portion is shaped to fit a power take-off casing supporting a power take-off shaft in a first direction. Then organohalosilanes can be produced quite efficiently at a high reaction rate while maintaining a low TD ratio and minimizing the deposition of by-products and carbon.